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Lim AH, Varghese C, Sebaratnam GH, Schamberg G, Calder S, Gharibans AA, Andrews CN, Foong D, Ho V, Ishida S, Imai Y, Wise MR, O'Grady G. Effect of menstrual cycle and menopause on human gastric electrophysiology. Am J Physiol Gastrointest Liver Physiol 2024; 327:G47-G56. [PMID: 38713629 DOI: 10.1152/ajpgi.00216.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/09/2024]
Abstract
Chronic gastroduodenal symptoms disproportionately affect females of childbearing age; however, the effect of menstrual cycling on gastric electrophysiology is poorly defined. To establish the effect of the menstrual cycle on gastric electrophysiology, healthy subjects underwent noninvasive Body Surface Gastric Mapping (BSGM; 8x8 array) with the validated symptom logging App (Gastric Alimetry, New Zealand). Participants included were premenopausal females in follicular (n = 26) and luteal phases (n = 18) and postmenopausal females (n = 30) and males (n = 51) were controls. Principal gastric frequency (PGF), body mass index (BMI) adjusted amplitude, Gastric Alimetry Rhythm Index (GA-RI), Fed:Fasted Amplitude Ratio (ff-AR), meal response curves, and symptom burden were analyzed. Menstrual cycle-related electrophysiological changes were then transferred to an established anatomically accurate computational gastric fluid dynamics model (meal viscosity 0.1 Pas) to predict the impact on gastric mixing and emptying. PGF was significantly higher in the luteal versus follicular phase [mean 3.21 cpm, SD (0.17) vs. 2.94 cpm, SD (0.17), P < 0.001] and versus males [3.01 cpm, SD (0.2), P < 0.001]. In the computational model, this translated to 8.1% higher gastric mixing strength and 5.3% faster gastric emptying for luteal versus follicular phases. Postmenopausal females also exhibited higher PGF than females in the follicular phase [3.10 cpm, SD (0.24) vs. 2.94 cpm, SD (0.17), P = 0.01], and higher BMI-adjusted amplitude [40.7 µV (33.02-52.58) vs. 29.6 µV (26.15-39.65), P < 0.001], GA-RI [0.60 (0.48-0.73) vs. 0.43 (0.30-0.60), P = 0.005], and ff-AR [2.51 (1.79-3.47) vs. 1.48 (1.21-2.17), P = 0.001] than males. There were no differences in symptoms. These results define variations in gastric electrophysiology with regard to human menstrual cycling and menopause.NEW & NOTEWORTHY This study evaluates gastric electrophysiology in relation to the menstrual cycle using a novel noninvasive high-resolution methodology, revealing substantial variations in gastric activity with menstrual cycling and menopause. Gastric slow-wave frequency is significantly higher in the luteal versus follicular menstrual phase. Computational modeling predicts that this difference translates to higher rates of gastric mixing and liquid emptying in the luteal phase, which is consistent with previous experimental data evaluating menstrual cycling effects on gastric emptying.
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Affiliation(s)
- Alexandria H Lim
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Chris Varghese
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | | | - Gabriel Schamberg
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry, Ltd., Auckland, New Zealand
| | - Stefan Calder
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry, Ltd., Auckland, New Zealand
| | - Armen A Gharibans
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry, Ltd., Auckland, New Zealand
| | | | - Daphne Foong
- School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Vincent Ho
- School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Shunichi Ishida
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Yohsuke Imai
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Michelle R Wise
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Greg O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry, Ltd., Auckland, New Zealand
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2
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Liu X, Fletcher DF, Bornhorst GM. A review of the use of numerical analysis in stomach modeling. J Food Sci 2024. [PMID: 38865250 DOI: 10.1111/1750-3841.17157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/14/2024]
Abstract
Food digestion is important for human health. Advances have been made using in vitro models to study food digestion, but there is considerable potential for numerical approaches in stomach modeling, as they can provide a comprehensive understanding of the complex flow and chemistry in the stomach. The focus of this study is to provide a concise review of the developed numerical stomach models over the past two decades. The gastric physiological parameters that are required for a computational model to represent the human gastric digestion process are discussed, including the stomach geometry, gastric motility, gastric emptying, and gastric secretions. Computational methods used to model gastric digestion are introduced and compared, including different computational fluid dynamics as well as solid mechanics methods. The challenges and limitations of current studies are discussed, as well as the areas for future research that need to be addressed. There has been progress in simulating gastric fluid flow with stomach wall motion, but much work remains to be done. The complex food breakdown mechanisms and a comprehensive chemical digestion process have not been implemented in any developed models. Numerical method that was once computationally expensive will be revolutionized as computing power continues to improve. Ultimately, the advancement of modeling of gastric food digestion will allow for additional hypothesis testing to streamline the development of food products that are beneficial to human health.
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Affiliation(s)
- Xinying Liu
- School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales, Australia
| | - David F Fletcher
- School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales, Australia
| | - Gail M Bornhorst
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, California, USA
- Riddet Institute, Palmerston North, New Zealand
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3
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Wakita Y, Takahashi M, Tamiya S, Kobayashi I. Effect of marination in lemon juice on beef tenderization and in vitro gastric digestibility. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:809-817. [PMID: 37743408 DOI: 10.1002/jsfa.13006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/08/2023] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND There is limited knowledge regarding digestion and absorption of nutrients after cooked marinated meat is ingested. Most of the previous studies on food gastric digestion have focused on chemical digestion and did not reflect upon physical digestion driven by peristalsis. In the present study, we examined the effects of marinating beef in lemon juice on gastric digestibility using a human gastric digestion simulator (GDS) that mimics peristaltic motion called antral contraction waves. RESULTS Beef thigh slices were marinated in 100% lemon juice for 1 h and then grilled; an image of a stained tissue sample revealed that muscle tissue contraction (i.e. that usually occurs upon cooking) was suppressed. The measurement of physical properties using a rheometer and texture analyzer showed that the meat marinated in lemon juice had a soft texture. In vitro digestion experiments using the GDS revealed that the extent of both physical digestion driven by peristalsis and chemical digestion catalyzed by digestive enzymes was enhanced by the lemon juice marinade. CONCLUSION The results of the present study suggest that marinating beef in lemon juice affects nutrient digestibility. An integrated evaluation of tissue structure, physical properties and GDS digestion to analyze meat digestion would enhance our understanding of the effects of seasoning and cooking methods on meat. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Yoshihisa Wakita
- Fundamental Technology R&D Institute, Pokka Sapporo Food & Beverage LTD., Yaizu, Japan
| | - Mayumi Takahashi
- Institute of Food Research, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Shinri Tamiya
- Fundamental Technology R&D Institute, Pokka Sapporo Food & Beverage LTD., Yaizu, Japan
| | - Isao Kobayashi
- Institute of Food Research, National Agriculture and Food Research Organization, Tsukuba, Japan
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4
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Kuhar S, Seo JH, Pasricha PJ, Mittal R. In silico modelling of the effect of pyloric intervention procedures on gastric flow and emptying in a stomach with gastroparesis. J R Soc Interface 2024; 21:20230567. [PMID: 38263890 PMCID: PMC10824103 DOI: 10.1098/rsif.2023.0567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/02/2024] [Indexed: 01/25/2024] Open
Abstract
Pyloric interventions are surgical procedures employed to increase the gastric emptying rate in gastroparesis patients. In this study, we use an in silico model to investigate the consequences of pyloric intervention on gastric flow and emptying for two phenotypes of gastroparesis: antral hypomotility and decreased gastric tone. The transpyloric pressure gradient predicted by the in silico model, based on viscous fluid flow equations, is compared against in vivo measurements. Both phenotypes exhibit a similar pre-procedural emptying rate reduction, but after pyloric surgery, antral hypomotility case with preserved gastric tone shows significant improvements in emptying rates, up to 131%, accompanied by bile reflux from the duodenum into the stomach. Conversely, severely reduced gastric tone cases exhibited a post-procedural reduction in the net emptying rate due to the relatively larger bile reflux. In cases with a combination of antral hypomotility and reduced gastric tone, post-procedural improvements were observed only when both conditions were mild. Our findings highlight the pivotal role of the relative increase in pyloric orifice diameter in determining post-operative emptying rates. The study suggests a possible explanation for the selective response of patients toward these procedures and underscores the potential of in silico modelling to generate valuable insights to inform gastric surgery.
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Affiliation(s)
- Sharun Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jung-Hee Seo
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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5
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Hosseini S, Palmada N, Avci R, Suresh V, Cheng LK. MRI Derived Simulations of Flow Patterns in the Stomach. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083297 DOI: 10.1109/embc40787.2023.10340717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
A framework to simulate the flow in the stomach using subject-specific motility patterns and geometries was developed. Dynamic 2D magnetic resonance images (MRIs) were obtained. Motility parameters such as contraction speed and occlusion were quantified, and 3D stomach geometries were reconstructed using a semi-automated approach. Computational fluid dynamics (CFD) simulations were performed, and flow patterns were investigated. The stomach of both subjects had distinct anatomical features with computed volumes of 789 mL and 619 mL. For the one subject, the occlusion (i.e., normalized contraction size) was 12% while it was around 25% for the other subject. Contraction speeds were also different (1.9-2.8 mm/s vs 3.0-5.1 mm/s) for each subject. CFD simulations resulted in unsteady laminar flow for both subjects with average velocities of 2.1 and 3.2 mm/s. While antegrade flow was mainly observed in the simulations, a retropulsive jet was also present in both stomachs. The versatile framework developed within this study would allow the generation of CFD models of gastric motility from dynamic MRIs.Clinical Relevance- Subject-specific models of flow patterns informed by gastric motility features can elucidate the impact of contractions and anatomical variations on digestion. Such models can inform therapies to treat gastric dysfunctions and improve their efficacy.
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6
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Avvari RK. Role of segmental contraction in the small intestinal digestion: A computational approach to study the physics behind the luminal mixing and transport. J Theor Biol 2023; 561:111418. [PMID: 36682409 DOI: 10.1016/j.jtbi.2023.111418] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Segmentation is well known to digest the food rich in proteins, starch, and lipids; however, the mechanism leading to the digestion remains unclear. In this study, a theoretical model for segmental contractions of the small intestine is developed using lubrication method to explore the mechanisms involved. Here, the nonlinear partial differential equations governing the fluid flow were normalized in viscous regime and solved semi-analytically for a power law fluid under long wavelength approximation on a MatlabTM platform. Study indicates that shearing is highest at the 1st and 4th mid-occlusion in comparison to 2nd and 3rd mid-occlusion. Parametric study indicates that the flow is sensitive to - the span of segmentation or wavelength of the wave, occlusion of the wave and frequency of the contraction; with shearing being highest for dilatants. Shearing is more prominent at higher occlusion (>50 %) and frequency (>6Hz). Further, mixing is more prominent at the steep regions of the wave; having intensity of mixing highest for the outer waves in comparison to waves at mid-region of the segmentation. The power demand is found to be greater in segmentation and has the following precedence - frequency, wavelength, flow behavior index, and occlusion (up to 80 %). Further, multiplicity of the wave gives rise to multiple zones of mixing which increases the rate of mixing of the contents. Suggesting that, the segmentation primarily serves the purpose of mixing. The study will be useful to explore novel therapeutic strategies of managing patients suffering from various motility-associated disorders of the small intestine.
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Affiliation(s)
- Ravi Kant Avvari
- Department of Biotechnology and Medical Engineering, NIT Rourkela, Odisha 769008, India.
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7
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Ebara R, Ishida S, Miyagawa T, Imai Y. Effects of peristaltic amplitude and frequency on gastric emptying and mixing: a simulation study. J R Soc Interface 2023; 20:20220780. [PMID: 36596453 PMCID: PMC9810435 DOI: 10.1098/rsif.2022.0780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/05/2022] [Indexed: 01/05/2023] Open
Abstract
The amplitude and frequency of peristaltic contractions are two major parameters for assessing gastric motility. However, it is not fully understood how these parameters affect the important functions of the stomach, such as gastric mixing and emptying. This study aimed to quantify the effects of peristaltic amplitude and frequency on gastric mixing and emptying using computational fluid dynamics simulation of gastric flow with an anatomically realistic model of the stomach. Our results suggest that both the increase and decrease in peristaltic amplitude have a significant impact on mixing strength and emptying rate. For example, when the peristaltic amplitude was 1.2 times higher than normal, the emptying rate was 2.7 times faster, whereas when the amplitude was half, the emptying rate was 4.2 times slower. Moreover, the emptying rate increased more than proportionally with the peristaltic frequency. The nearest contraction wave to the pylorus and the subsequent waves promoted gastric emptying. These results suggest the importance of maintaining parameters within normal ranges to achieve healthy gastric function.
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Affiliation(s)
- Rika Ebara
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Shunichi Ishida
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Taimei Miyagawa
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan
| | - Yohsuke Imai
- Graduate School of Engineering, Kobe University, Kobe, Japan
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8
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Zhang H, Xu F, Zheng Z, Liu X, Yin J, Fan Z, Zhang J. Gastric emptying performance of stomach-partitioning gastrojejunostomy versus conventional gastrojejunostomy for treating gastric outlet obstruction: A retrospective clinical and numerical simulation study. Front Bioeng Biotechnol 2023; 11:1109295. [PMID: 36873355 PMCID: PMC9982392 DOI: 10.3389/fbioe.2023.1109295] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 02/07/2023] [Indexed: 02/19/2023] Open
Abstract
Purpose: This study evaluated the gastric emptying performance of stomach-partitioning gastrojejunostomy (SPGJ) versus conventional gastrojejunostomy (CGJ) for treating gastric outlet obstruction (GOO). Methods: First, 73 patients who underwent SPGJ (n = 48) or CGJ (n = 25) were involved. Surgical outcomes, postoperative recovery of gastrointestinal function, delayed gastric emptying, and nutritional status of both groups were compared. Second, a three-dimensional stomach model was constructed based on the gastric filling CT images from a GOO patient with a standard stature. The present study evaluated SPGJ numerically by comparing it with CGJ in terms of local flow parameters such as flow velocity, pressure, particle retention time, and particle retention velocity. Results: Clinical data found that SPGJ had significant advantages over CGJ in terms of time to pass gas (3 versus 4 days, p < 0.001), time to oral intake (3 versus 4 days, p = 0.001), postoperative hospitalization (7 versus 9 days, p < 0.001), the incidence of delay gastric emptying (DGE) (2.1% versus 36%, p < 0.001), DGE grading (p < 0.001), and complications (p < 0.001) for GOO patients. Moreover, numerical simulation revealed that the SPGJ model would induce contents in stomach discharge to the anastomosis at a higher speed, and only 5% of that flowed to the pylorus. SPGJ model also had a low-pressure drop as the flow from the lower esophagus to the jejunum, reducing the resistance to food discharge. Besides, the average retention time of particles in the CGJ model is 1.5 times longer than that in the SPGJ models, and the average instantaneous velocity in CGJ and SPGJ models are 22 mm/s and 29 mm/s, respectively. Conclusion: Compared with CGJ, patients after SPGJ had better gastric emptying performance and better postoperative clinical efficacy. Therefore, we think that SPGJ may be a better option for treating GOO.
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Affiliation(s)
- Haiqiao Zhang
- Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Fengyan Xu
- School of Mechanical Engineering, Jiangsu University of Technology, Changzhou, Jiangsu, China
| | - Zhi Zheng
- Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xiaoye Liu
- Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jie Yin
- Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zhenmin Fan
- School of Mechanical Engineering, Jiangsu University of Technology, Changzhou, Jiangsu, China
| | - Jun Zhang
- Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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9
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Makwana R, Crawley E, Straface M, Palmer A, Gharibans A, Devalia K, Loy J, O'Grady G, Andrews PLR, Sanger GJ. Synergistic augmentation of rhythmic myogenic contractions of human stomach by arginine vasopressin and adrenaline: Implications for the induction of nausea. Br J Pharmacol 2022; 179:5305-5322. [PMID: 36068676 PMCID: PMC9826163 DOI: 10.1111/bph.15943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE Nausea is associated with the hormonal secretion of vasopressin and adrenaline, although their actions in inducing nausea is poorly understood. Here, we have investigated their actions on human stomach muscle. EXPERIMENTAL APPROACH Muscle strips were suspended in tissue baths and neuronal-/non-neuronally-mediated contractions were measured. Custom software analysed eight motility parameters defining spontaneous phasic non-neuronally mediated contractions. Receptor distributions were assessed by qPCR and immunofluorescence. KEY RESULTS V1A receptors and α1 -adrenoceptors were located on muscle as well as interstitial cells of Cajal (ICCs). Myogenic contractions of human proximal and distal stomach (respectively, 2.6 ± 0.1 and 2.7 ± 0.0 per minute; n = 44) were larger in the distal area (1.1 ± 0.1 and 5.0 ± 0.1 mN), developing relatively slowly (proximal) or rapidly (distal). Vasopressin caused tonic (proximal) or short-lived (distal) increases in muscle tone and increased myogenic contraction amplitude, frequency and rate (acting at V1A receptors; thresholds 10-11 -10-10 M); by contrast, cholinergically mediated contractions were unaffected. Oxytocin acted similarly to vasopressin but less potently, at OT receptors). Adrenaline increased (10-10 -10-5 M; α1 -adrenoceptors) and decreased (≥10-6 M; β-adrenoceptors) muscle tone and enhanced/reduced myogenic contractions. Cholinergically mediated contractions were reduced (α2 -adrenoceptors). Combined, vasopressin (10-9 M) and adrenaline (10-8 M) increased muscle tone and phasic myogenic activity in a synergistic manner. CONCLUSIONS AND IMPLICATIONS Vasopressin and adrenaline increased human gastric tone and myogenic contraction amplitude, rate of contraction and frequency. In combination, their actions were further increased in a synergistic manner. Such activity may promote nausea.
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Affiliation(s)
- Raj Makwana
- Blizard Institute, Faculty of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Ellie Crawley
- Blizard Institute, Faculty of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Marilisa Straface
- Blizard Institute, Faculty of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Alexandra Palmer
- Blizard Institute, Faculty of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Armen Gharibans
- Department of Surgery and Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Kalpana Devalia
- Bariatric Surgery DepartmentHomerton University HospitalLondonUK
| | - John Loy
- Bariatric Surgery DepartmentHomerton University HospitalLondonUK
| | - Greg O'Grady
- Department of Surgery and Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | | | - Gareth J. Sanger
- Blizard Institute, Faculty of Medicine and DentistryQueen Mary University of LondonLondonUK
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10
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Digestion of meat proteins in a human-stomach: A CFD simulation study. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2022.103252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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11
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Hashem R, Kazemi S, Stommel M, Cheng LK, Xu W. SoRSS: A Soft Robot for Bio-Mimicking Stomach Anatomy and Motility. Soft Robot 2022. [DOI: 10.1089/soro.2021.0202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ryman Hashem
- Department of Mechanical and Mechatronics Engineering, The University of Auckland, Auckland, New Zealand
| | - Shahab Kazemi
- Department of Mechanical and Mechatronics Engineering, The University of Auckland, Auckland, New Zealand
- Riddet Institute Centre of Research Excellence (CoRE), Palmerston North, New Zealand
| | - Martin Stommel
- Riddet Institute Centre of Research Excellence (CoRE), Palmerston North, New Zealand
- Department of Electrical and Electronic Engineering, Auckland University of Technology, Auckland, New Zealand
| | - Leo K. Cheng
- Riddet Institute Centre of Research Excellence (CoRE), Palmerston North, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Weiliang Xu
- Department of Mechanical and Mechatronics Engineering, The University of Auckland, Auckland, New Zealand
- Riddet Institute Centre of Research Excellence (CoRE), Palmerston North, New Zealand
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12
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Kuhar S, Lee JH, Seo JH, Pasricha PJ, Mittal R. Effect of stomach motility on food hydrolysis and gastric emptying: Insight from computational models. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:111909. [PMID: 36407285 PMCID: PMC9667910 DOI: 10.1063/5.0120933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
The peristaltic motion of stomach walls combines with the secretion of digestive enzymes to initiate the process that breaks down food. In this study, the mixing, breakdown, and emptying of a liquid meal containing protein is simulated in a model of a human stomach. In this model, pepsin, the gastric enzyme responsible for protein hydrolysis, is secreted from the proximal region of the stomach walls and allowed to react with the contents of the stomach. The velocities of the retropulsive jet induced by the peristaltic motion, the emptying rate, and the extent of hydrolysis are quantified for a control case as well as for three other cases with reduced motility of the stomach, which may result from conditions such as diabetes mellitus. This study quantifies the effect of stomach motility on the rate of food breakdown and its emptying into the duodenum and we correlate these observations with the mixing in the stomach induced by the wall motion.
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Affiliation(s)
- Sharun Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | | | | - Pankaj J Pasricha
- Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - Rajat Mittal
- Author to whom correspondence should be addressed:
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13
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Impact of casein-to-whey protein ratio on gastric emptying, proteolysis, and peptidome profile of fermented milk during in vitro dynamic gastrointestinal digestion in preschool children. Food Chem 2022; 405:134840. [DOI: 10.1016/j.foodchem.2022.134840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/30/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
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14
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Development of an in vitro distal gastric simulator to mimic the mechanical action of the human stomach. Food Res Int 2022; 161:111902. [DOI: 10.1016/j.foodres.2022.111902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/20/2022]
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15
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Li Y, Kong F. Simulating human gastrointestinal motility in dynamic in vitro models. Compr Rev Food Sci Food Saf 2022; 21:3804-3833. [PMID: 35880687 DOI: 10.1111/1541-4337.13007] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 03/26/2022] [Accepted: 06/22/2022] [Indexed: 01/28/2023]
Abstract
The application of dynamic in vitro gastrointestinal (GI) models has grown in popularity to understand the impact of food structure and composition on human health. Given that GI motility is integral to digestion and absorption, a predictive in vitro model should faithfully replicate the motility patterns and motor functions in vivo. In this review, typical characteristics of gastric and small intestinal motility in humans as well as the biomechanical and hydrodynamic events pertinent to gut motility are summarized. The simulation of GI motility in the presently existing dynamic in vitro models is discussed from an engineering perspective and categorized into hydraulic, piston/probe-driven, roller-driven, pneumatic, and other systems. Each system and its representative models are evaluated in terms of their motility patterns, the key hydrodynamic characteristics concerning gut motility, their performance in simulating the key physiological events, and their ability to establish in vitro-in vivo correlations. Practical Application: The review paper provided useful information in the design of dynamic GI models and the simulation of human gastric and small intestinal motility which are important for understanding food and health.
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Affiliation(s)
- Yiwen Li
- Department of Food Science and Technology, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia, USA
| | - Fanbin Kong
- Department of Food Science and Technology, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia, USA
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16
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Lee JH, Kuhar S, Seo JH, Pasricha PJ, Mittal R. Computational modeling of drug dissolution in the human stomach: Effects of posture and gastroparesis on drug bioavailability. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:081904. [PMID: 35971381 PMCID: PMC9372820 DOI: 10.1063/5.0096877] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/23/2022] [Indexed: 05/25/2023]
Abstract
The oral route is the most common choice for drug administration because of several advantages, such as convenience, low cost, and high patient compliance, and the demand and investment in research and development for oral drugs continue to grow. The rate of dissolution and gastric emptying of the dissolved active pharmaceutical ingredient (API) into the duodenum is modulated by gastric motility, physical properties of the pill, and the contents of the stomach, but current in vitro procedures for assessing dissolution of oral drugs are limited in their ability to recapitulate this process. This is particularly relevant for disease conditions, such as gastroparesis, that alter the anatomy and/or physiology of the stomach. In silico models of gastric biomechanics offer the potential for overcoming these limitations of existing methods. In the current study, we employ a biomimetic in silico simulator based on the realistic anatomy and morphology of the stomach (referred to as "StomachSim") to investigate and quantify the effect of body posture and stomach motility on drug bioavailability. The simulations show that changes in posture can potentially have a significant (up to 83%) effect on the emptying rate of the API into the duodenum. Similarly, a reduction in antral contractility associated with gastroparesis can also be found to significantly reduce the dissolution of the pill as well as emptying of the API into the duodenum. The simulations show that for an equivalent motility index, the reduction in gastric emptying due to neuropathic gastroparesis is larger by a factor of about five compared to myopathic gastroparesis.
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Affiliation(s)
| | - S. Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | | - P. J. Pasricha
- Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - R. Mittal
- Author to whom correspondence should be addressed:
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17
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Acharya S, Halder S, Kou W, Kahrilas PJ, Pandolfino JE, Patankar NA. A fully resolved multiphysics model of gastric peristalsis and bolus emptying in the upper gastrointestinal tract. Comput Biol Med 2022; 143:104948. [PMID: 35091365 PMCID: PMC9014465 DOI: 10.1016/j.compbiomed.2021.104948] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/09/2021] [Accepted: 10/13/2021] [Indexed: 11/22/2022]
Abstract
Over the past few decades, in silico modeling of organ systems has significantly furthered our understanding of their physiology and biomechanical function. In spite of the relative importance of the digestive system in normal functioning of the human body, there is a scarcity of high-fidelity models for the upper gastrointestinal tract including the esophagus and the stomach. In this work, we present a detailed numerical model of the upper gastrointestinal tract that not only accounts for the fiber architecture of the muscle walls, but also the multiphasic components they help transport during normal digestive function. Construction details for 3D models of representative stomach geometry are presented along with a simple strategy for assigning circular and longitudinal muscle fiber orientations for each layer. We developed a fully resolved model of the stomach to simulate gastric peristalsis by systematically activating muscle fibers embedded in the stomach. Following this, for the first time, we simulate gravity-driven bolus emptying into the stomach due to density differences between ingested contents and fluid contents of the stomach. Finally, we present a case of retrograde flow of fluid from the stomach into the esophagus, resembling the phenomenon of acid reflux. This detailed computational model of the upper gastrointestinal tract provides a foundation for future models to investigate the biomechanics of acid reflux and probe various strategies for gastric bypass surgeries to address the growing problem of obesity.
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Affiliation(s)
- Shashank Acharya
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Sourav Halder
- Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL, 60208, USA
| | - Wenjun Kou
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Peter J Kahrilas
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - John E Pandolfino
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Neelesh A Patankar
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, 60208, USA; Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL, 60208, USA.
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18
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Tablet Disintegration and Dispersion under In Vivo-like Hydrodynamic Conditions. Pharmaceutics 2022; 14:pharmaceutics14010208. [PMID: 35057103 PMCID: PMC8779444 DOI: 10.3390/pharmaceutics14010208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 02/05/2023] Open
Abstract
Disintegration and dispersion are functional properties of tablets relevant for the desired API release. The standard disintegration test (SDT) described in different pharmacopoeias provides only limited information on these complex processes. It is considered not to be comparable to the biorelevant conditions due to the frequent occurrence of high hydrodynamic forces, among other reasons. In this study, 3D tomographic laser-induced fluorescence imaging (3D Tomo-LIF) is applied to analyse tablet disintegration and dispersion. Disintegration time (DT) and time-resolved particle size distribution in close proximity to the tablet are determined in a continuously operated flow channel, adjustable to very low fluid velocities. A case study on tablets of different porosity, which are composed of pharmaceutical polymers labelled with a fluorescent dye, a filler, and disintegrants, is presented to demonstrate the functionality and precision of the novel method. DT results from 3D Tomo-LIF are compared with results from the SDT, confirming the analytical limitations of the pharmacopoeial disintegration test. Results from the 3D Tomo-LIF method proved a strong impact of fluid velocity on disintegration and dispersion. Generally, shorter DTs were determined when cross-linked sodium carboxymethly cellulose (NaCMCXL) was used as disintegrant compared to polyvinyl polypyrrolidone (PVPP). Tablets containing Kollidon VA64 were found to disintegrate by surface erosion. The novel method provides an in-depth understanding of the functional behaviour of the tablet material, composition and structural properties under in vivo-like hydrodynamic forces regarding disintegration and the temporal progress of dispersion. We consider the 3D Tomo-LIF in vitro method to be of improved biorelevance in terms of hydrodynamic conditions in the human stomach.
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19
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Seo JH, Mittal R. Computational Modeling of Drug Dissolution in the Human Stomach. Front Physiol 2022; 12:755997. [PMID: 35082685 PMCID: PMC8785969 DOI: 10.3389/fphys.2021.755997] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/27/2021] [Indexed: 11/21/2022] Open
Abstract
A computational model of drug dissolution in the human stomach is developed to investigate the interaction between gastric flow and orally administrated drug in the form of a solid tablet. The stomach model is derived from the anatomical imaging data and the motion and dissolution of the drug in the stomach are modeled via fluid-structure interaction combined with mass transport simulations. The effects of gastric motility and the associated fluid dynamics on the dissolution characteristics are investigated. Two different pill densities are considered to study the effects of the gastric flow as well as the gravitational force on the motion of the pill. The average mass transfer coefficient and the spatial distributions of the dissolved drug concentration are analyzed in detail. The results show that the retropulsive jet and recirculating flow in the antrum generated by the antral contraction wave play an important role in the motion of the pill as well as the transport and mixing of the dissolved drug concentration. It is also found that the gastric flow can increase the dissolution mass flux, especially when there is substantial relative motion between the gastric flow and the pill.
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Affiliation(s)
| | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, United States
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20
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Abstract
Oral drug absorption modeling has developed at a rapid pace in the 40 years or so since the first ideas for mathematical approaches to oral absorption were introduced. The success of compartmental approaches accelerated the uptake of absorption modeling, and over the last 20 years, work on absorption modeling has shifted almost exclusively to the compartmental framework. This report describes a new noncompartmental absorption modeling framework, the Lilly Absorption Modeling Platform (LAMP). LAMP connects a well-mixed stomach to a continuous tube model of the small intestine with plug flow. Within the continuous tube framework, the model includes intestinal mixing and a novel highly tunable precipitation model that can describe a combination of rapid nucleation and slow growth. The framework is designed to balance speed, consistency, and ease of use with a minimum of model complexity to capture the essential features of gastrointestinal (GI) physiology and critical elements of the oral absorption process. The model was validated based on predictions of the fraction absorbed and the maximum absorbable dose for a set of Eli Lilly and Company clinical compounds.
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Affiliation(s)
- Stephen D Stamatis
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
| | - John P Rose
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
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21
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Wang R, Mohammadi M, Mahboubi A, Taherzadeh MJ. In-vitro digestion models: a critical review for human and fish and a protocol for in-vitro digestion in fish. Bioengineered 2021; 12:3040-3064. [PMID: 34187302 PMCID: PMC8806420 DOI: 10.1080/21655979.2021.1940769] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/04/2021] [Indexed: 10/28/2022] Open
Abstract
Digestive systems in human, animals, and fish are biological reactors and membranes to digest food and extract nutrients. Therefore, static and dynamic models of in-vitro digestion systems are developed to study e.g. novel food and feed before in-vivo studies. Such models are well developed for human, but not to the same extent for animals and fish. On the other hand, recent advances in aquaculture nutrition have created several potential fish meal replacements, and the assessment of their nutrient digestibility is critical in the application as a fish meal replacement. Using an in-vitro method, the assessment of an ingredient digestibility could be faster and less expensive compared to using an in-vivo experiment. An in-vitro method has been widely used to assess food nutrient digestibility for humans; however, its application for fish is still in the early stages. Both the human and fish as monogastric vertebrates share similar gastrointestinal systems; thus, the concept from the application for humans could be applied for fish. This review aims to improve the in-vitro digestion protocol for fish by adapting the concept from then study for humans, summarizing the current available in-vitro digestion model developed for human and fish in-vitro digestion study, identifying challenges specifically for fish required to be tackled and suggesting an engineering approach to adapt the human in-vitro gastrointestinal model to fish. Protocols to conduct in-vitro digestion study for fish are then proposed.
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Affiliation(s)
- Ricky Wang
- Swedish Centre for Resource Recovery, University of Borås, Borås. Sweden
| | - Mahtab Mohammadi
- Swedish Centre for Resource Recovery, University of Borås, Borås. Sweden
| | - Amir Mahboubi
- Swedish Centre for Resource Recovery, University of Borås, Borås. Sweden
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22
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O'Grady G, Gharibans AA, Du P, Huizinga JD. The gastric conduction system in health and disease: a translational review. Am J Physiol Gastrointest Liver Physiol 2021; 321:G527-G542. [PMID: 34549598 DOI: 10.1152/ajpgi.00065.2021] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastric peristalsis is critically dependent on an underlying electrical conduction system. Recent years have witnessed substantial progress in clarifying the operations of this system, including its pacemaking units, its cellular architecture, and slow-wave propagation patterns. Advanced techniques have been developed for assessing its functions at high spatiotemporal resolutions. This review synthesizes and evaluates this progress, with a focus on human and translational physiology. A current conception of the initiation and conduction of slow-wave activity in the human stomach is provided first, followed by a detailed discussion of its organization at the cellular and tissue level. Particular emphasis is then given to how gastric electrical disorders may contribute to disease states. Gastric dysfunction continues to grow in their prevalence and impact, and while gastric dysrhythmia is established as a clear and pervasive feature in several major gastric disorders, its role in explaining pathophysiology and informing therapy is still emerging. New insights from high-resolution gastric mapping are evaluated, together with historical data from electrogastrography, and the physiological relevance of emerging biomarkers from body surface mapping such as retrograde propagating slow waves. Knowledge gaps requiring further physiological research are highlighted.
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Affiliation(s)
- Gregory O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Armen A Gharibans
- Department of Surgery, The University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Jan D Huizinga
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
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23
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Managing motility disorders of the gastrointestinal segment and obesity through electrical stimulation. HEALTH AND TECHNOLOGY 2021. [DOI: 10.1007/s12553-021-00590-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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24
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Bhattarai A, Kowalczyk W, Tran TN. A literature review on large intestinal hyperelastic constitutive modeling. Clin Biomech (Bristol, Avon) 2021; 88:105445. [PMID: 34416632 DOI: 10.1016/j.clinbiomech.2021.105445] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/29/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023]
Abstract
Impacts, traumas and strokes are spontaneously life-threatening, but chronic symptoms strangle patient every day. Colorectal tissue mechanics in such chronic situations not only regulates the physio-psychological well-being of the patient, but also confirms the level of comfort and post-operative clinical outcomes. Numerous uniaxial and multiaxial tensile experiments on healthy and affected samples have evidenced significant differences in tissue mechanical behavior and strong colorectal anisotropy across each layer in thickness direction and along the length. Furthermore, this study reviewed various forms of passive constitutive models for the highly fibrous colorectal tissue ranging from the simplest linearly elastic and the conventional isotropic hyperelastic to the most sophisticated second harmonic generation image based anisotropic mathematical formulation. Under large deformation, the isotropic description of tissue mechanics is unequivocally ineffective which demands a microstructural based tissue definition. Therefore, the information collected in this review paper would present the current state-of-the-art in colorectal biomechanics and profoundly serve as updated computational resources to develop a sophisticated characterization of colorectal tissues.
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Affiliation(s)
- Aroj Bhattarai
- Department of Orthopaedic Surgery, University of Saarland, Germany
| | | | - Thanh Ngoc Tran
- Department of Orthopaedic Surgery, University of Saarland, Germany.
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25
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Peng Z, Wu P, Wang J, Dupont D, Menard O, Jeantet R, Chen XD. Achieving realistic gastric emptying curve in an advanced dynamic in vitro human digestion system: experiences with cheese-a difficult to empty material. Food Funct 2021; 12:3965-3977. [PMID: 33977933 DOI: 10.1039/d0fo03364b] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nowadays, in vitro digestion models have received growing interest in recent years to track the digestive fate of foods in the gastrointestinal tract. A major challenge in the development of more physiologically relevant in vitro gastric models is to simulate realistic gastric emptying. In this study, an advanced dynamic in vitro human gastric system was investigated for its potential in achieving the above. The mechanisms for controlling the gastric emptying rate by modulations of the peristaltic moving distance, the pylorus opening size/frequency, and the stomach tilting angle in relation to time are illustrated. With solid cheese, a difficult food material for emptying, different combinations of the operational parameters of the stomach system were evaluated. The system was steered to attain consistent gastric emptying curve with the theoretical data by optimizing operational parameters. By fitting the gastric retention data with a power-exponential model, which is a common approach for describing gastric emptying, the total meal achieved an average emptying half-time (t1/2) of 84.5 min and a curve shape coefficient (β) of 1.69, similar to the theoretical data reported in the literature, where the values of t1/2 and β were 85 min and 1.8, respectively (p > 0.05). Furthermore, the mean median particle size was significantly decreased from the initial 2.80 mm (cheese cubes) to the final 1.35 mm (p < 0.05). There are few particles greater than 2 mm observed in the emptied cheese digesta throughout the digestion process. These suggest the powerful gastric grinding and sieving capacity exhibited by the in vitro system. The current study demonstrates that a well-considered in vitro system can offer a reasonable approach for tracking the structural and physicochemical changes of foods during digestion in the stomach, which is practically meaningful.
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Affiliation(s)
- Zhen Peng
- Department of Chemical Engineering and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China and School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou 215123, Jiangsu Province, China.
| | - Peng Wu
- School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou 215123, Jiangsu Province, China.
| | - Jingjing Wang
- Xiao Dong Pro-health (Suzhou) Instrumentation Co Ltd, Suzhou, 215152, Jiangsu Province, China
| | - Didier Dupont
- STLO, UMR 1253, INRA, Agrocampus Ouest, 35000 Rennes, France
| | - Oliva Menard
- STLO, UMR 1253, INRA, Agrocampus Ouest, 35000 Rennes, France
| | - Romain Jeantet
- STLO, UMR 1253, INRA, Agrocampus Ouest, 35000 Rennes, France
| | - Xiao Dong Chen
- Department of Chemical Engineering and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China and School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou 215123, Jiangsu Province, China.
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26
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Li C, Jin Y. A CFD model for investigating the dynamics of liquid gastric contents in human-stomach induced by gastric motility. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2020.110461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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27
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Cheng LK, Nagahawatte ND, Avci R, Du P, Liu Z, Paskaranandavadivel N. Strategies to Refine Gastric Stimulation and Pacing Protocols: Experimental and Modeling Approaches. Front Neurosci 2021; 15:645472. [PMID: 33967679 PMCID: PMC8100207 DOI: 10.3389/fnins.2021.645472] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Gastric pacing and stimulation strategies were first proposed in the 1960s to treat motility disorders. However, there has been relatively limited clinical translation of these techniques. Experimental investigations have been critical in advancing our understanding of the control mechanisms that innervate gut function. In this review, we will discuss the use of pacing to modulate the rhythmic slow wave conduction patterns generated by interstitial cells of Cajal in the gastric musculature. In addition, the use of gastric high-frequency stimulation methods that target nerves in the stomach to either inhibit or enhance stomach function will be discussed. Pacing and stimulation protocols to modulate gastric activity, effective parameters and limitations in the existing studies are summarized. Mathematical models are useful to understand complex and dynamic systems. A review of existing mathematical models and techniques that aim to help refine pacing and stimulation protocols are provided. Finally, some future directions and challenges that should be investigated are discussed.
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Affiliation(s)
- Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of General Surgery, Vanderbilt University Medical Center, Nashville, TN, United States.,Riddet Institute, Palmerston North, New Zealand
| | - Nipuni D Nagahawatte
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States.,Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
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28
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Abstract
In this paper, effects of stationary contraction on mixing and transport of a non-Newtonian fluid in the small intestine are analyzed theoretically. A semi-analytical method is developed to solve the governing equations of fluids flow in the intestine using lubrication theory. Results indicate that the stationary contraction helps in conferring two functions – (1) shearing of the contents, and (2) bidirectional transport over a short distance. The flow resulting from contraction is symmetric and occurs in both the directions; however, they do not lead to a net flow rate in one direction. The amount of shearing developed during such flows is reflective of their mixing ability. The effort of such peristalsis is largely determined by the flow behavior index; where energy requirements of developing similar shearing forces are higher for dilatants and lower for pseudoplastics. Flow is sensitive to frequency of contraction, luminal occlusion and wavelength of the contraction.
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Affiliation(s)
- RAVI KANT AVVARI
- Department of Biotechnology and Medical Engineering, NIT Rourkela, Odisha 769008, India
- Department of Electrical & Electronics Engineering, Sasi Institute of Technology and Engineering, Tadepalligudem, West Godavari, Andhra Pradesh 534101, India
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29
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Karthikeyan J, Salvi D, Karwe MV. Modeling of fluid flow, carbohydrate digestion, and glucose absorption in human small intestine. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2020.110339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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30
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Carson DA, O'Grady G, Du P, Gharibans AA, Andrews CN. Body surface mapping of the stomach: New directions for clinically evaluating gastric electrical activity. Neurogastroenterol Motil 2021; 33:e14048. [PMID: 33274564 DOI: 10.1111/nmo.14048] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/11/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Gastric motility disorders, which include both functional and organic etiologies, are highly prevalent. However, there remains a critical lack of objective biomarkers to guide efficient diagnostics and personalized therapies. Bioelectrical activity plays a fundamental role in coordinating gastric function and has been investigated as a contributing mechanism to gastric dysmotility and sensory dysfunction for a century. However, conventional electrogastrography (EGG) has not achieved common clinical adoption due to its perceived limited diagnostic capability and inability to impact clinical care. The last decade has seen the emergence of novel high-resolution methods for invasively mapping human gastric electrical activity in health and disease, providing important new insights into gastric physiology. The limitations of EGG have also now become clearer, including the finding that slow-wave frequency alone is not a reliable discriminator of gastric dysrhythmia, shifting focus instead toward altered spatial patterns. Recently, advances in bioinstrumentation, signal processing, and computational modeling have aligned to allow non-invasive body surface mapping of the stomach to detect spatiotemporal gastric dysrhythmias. The clinical relevance of this emerging strategy to improve diagnostics now awaits determination. PURPOSE This review evaluates these recent advances in clinical gastric electrophysiology, together with promising emerging data suggesting that novel gastric electrical signatures recorded at the body surface (termed "body surface mapping") may correlate with symptoms. Further technological progress and validation data are now awaited to determine whether these advances will deliver on the promise of clinical gastric electrophysiology diagnostics.
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Affiliation(s)
- Daniel A Carson
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Greg O'Grady
- Department of Surgery, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Armen A Gharibans
- Department of Surgery, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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31
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Ji H, Hu J, Zuo S, Zhang S, Li M, Nie S. In vitro gastrointestinal digestion and fermentation models and their applications in food carbohydrates. Crit Rev Food Sci Nutr 2021; 62:5349-5371. [PMID: 33591236 DOI: 10.1080/10408398.2021.1884841] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Food nutrients plays a crucial role in human health, especially in gastrointestinal (GI) health. The effect of food nutrients on human health mainly depends on the digestion and fermentation process in the GI tract. In vitro GI digestion and fermentation models had the advantages of reproducibility, simplicity, universality, and could integrally simulate the in vivo conditions to mimic oral, gastric, small intestinal and large intestinal digestive processes. They could not only predict the relationship among material composition, structure and digestive characteristics, but also evaluate the bioavailability of material components and the impact of digestive metabolites on GI health. This review systematicly summarized the current state of the in vitro simulation models, and made detailed descriptions for their applications, advantages and disadvantages, and specially their applications in food carbohydrates. In addition, it also provided the suggestions for the improvement of in vitro models and firstly proposed to establish a set of standardized methods of in vitro dynamic digestion and fermentation conditions for food carbohydrates, which were in order to further evaluate more effects of the nutrients on human health in future.
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Affiliation(s)
- Haihua Ji
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
| | - Jielun Hu
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
| | - Sheng Zuo
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
| | - Shanshan Zhang
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
| | - Mingzhi Li
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
| | - Shaoping Nie
- State Key Laboratory of Food Science and Technology, China-Canada Joint Lab of Food Science and Technology (Nanchang), Nanchang University, Nanchang, China
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32
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Mixing and emptying of gastric contents in human-stomach: A numerical study. J Biomech 2021; 118:110293. [PMID: 33588327 DOI: 10.1016/j.jbiomech.2021.110293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 01/17/2021] [Accepted: 01/23/2021] [Indexed: 11/21/2022]
Abstract
Stomach is one of the most important organs in human gastro-track. To better understand the operation of human-stomach, the process of mixing and emptying of gastric contents is simulated using a numerical method. The numerical results confirm that a fast pathway is located close to the lesser curvature of the stomach when water is emptied. However, this fast pathway doesn't exist when the gastric contents are composed of water and food boluses with different properties. The muscle contractions enhance the mixing of light food boluses and water, while they have limited effects on heavy food boluses. As a result, the foods are distributed in layers; heavy food boluses are located in the bottom layer. Besides the gastric motility and high viscosity of foods, the food matrix made of heavy food particles is also important to the formation of the Magenstrasse (stomach road). The food matrix and the zone of wrinkles behave like a porous medium which has higher flow resistance to the light food particles than to the water, leading to faster emptying of water. The water is emptied along the stomach wall since the flow resistance in the stomach wrinkles is smaller than the one in the food matrix. This mechanism is supported by the numerical results, while it might interpret the phenomena observed in the experiments.
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33
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Wang Z, Kozu H, Uemura K, Kobayashi I, Ichikawa S. Effect of hydrogel particle mechanical properties on their disintegration behavior using a gastric digestion simulator. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Measurement of fasted state gastric antral motility before and after a standard bioavailability and bioequivalence 240 mL drink of water: Validation of MRI method against concomitant perfused manometry in healthy participants. PLoS One 2020; 15:e0241441. [PMID: 33175860 PMCID: PMC7657519 DOI: 10.1371/journal.pone.0241441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 10/14/2020] [Indexed: 12/26/2022] Open
Abstract
Objective The gastrointestinal environment in which drug products need to disintegrate before the drug can dissolve and be absorbed has not been studied in detail due to limitations, especially invasiveness of existing techniques. Minimal in vivo data is available on undisturbed gastrointestinal motility to improve relevance of predictive dissolution models and in silico tools such as physiologically-based pharmacokinetic models. Recent advances in magnetic resonance imaging methods could provide novel data and insights that can be used as a reference to validate and, if necessary, optimize these models. The conventional method for measuring gastrointestinal motility is via a manometric technique involving intubation. Nevertheless, it is feasible to measure gastrointestinal motility with magnetic resonance imaging. The aim of this study was is to develop and validate a magnetic resonance imaging method using the most recent semi-automated analysis method against concomitant perfused manometry method. Material and methods Eighteen healthy fasted participants were recruited for this study. The participants were intubated with a water-perfused manometry catheter. Subsequently, stomach motility was assessed by cine-MRI acquired at intervals, of 3.5min sets, at coronal oblique planes through the abdomen and by simultaneous water perfused manometry, before and after administration of a standard bioavailability / bioequivalence 8 ounces (~240mL) drink of water. The magnetic resonance imaging motility images were analysed using Spatio-Temporal Motility analysis STMM techniques. The area under the curve of the gastric motility contractions was calculated for each set and compared between techniques. The study visit was then repeated one week later. Results Data from 15 participants was analysed. There was a good correlation between the MRI antral motility plots area under the curve and corresponding perfused manometry motility area under the curve (r = 0.860) during both antral contractions and quiescence. Conclusion Non-invasive dynamic magnetic resonance imaging of gastric antral motility coupled with recently developed, semi-automated magnetic resonance imaging data processing techniques correlated well with simultaneous, ‘gold standard’ water perfused manometry. This will be particularly helpful for research purposes related to oral absorption where the absorption of a drug is highly depending on the underlying gastrointestinal processes such as gastric emptying, gastrointestinal motility and availability of residual fluid volumes. Clinical trial This trial was registered at ClinicalTrials.gov as NCT03191045.
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Hosseini S, Avci R, Paskaranandavadivel N, Palmada N, Suresh V, Cheng LK. A Novel Method for Time-Dependent Numerical Modeling of Gastric Motility Directly from Magnetic Resonance Imaging .. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2384-2387. [PMID: 33018486 DOI: 10.1109/embc44109.2020.9175607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Gastric motility has a critical role in disintegration and mixing of the ingested food inside the stomach. Several studies have been conducted to quantify and analyze the effect of the contractions of gastric musculature on the stomach contents. Despite the anatomical variation in stomach shape and motility patterns, previous numerical studies employed generalized geometries of the stomach as the computational domain for simulations. To model realistic gastric muscular contractions, the variation in stomach geometries need to be accounted for in numerical simulations. In the current study, a novel method was developed to utilize the recent advances in magnetic resonance imaging (MRI) technology and computational power expansion to build anatomically and physiologically realistic subject specific models of human gastric motility. In this method, MRI scans of the stomach were used to construct two and three dimensional geometry models of gastric motility. MRI was performed on 4 healthy participants. Using the developed method, dynamic numerical geometry models of gastric motility for each participant were constructed and related geometrical calculations were presented. Different combinations of solid and liquid test meals were consumed prior to the scans. The volume of the stomach ranged between 0.36 - 1.10 L in the fed state. The stomach models had an average length of 184 to 226 mm and a maximum diameter of 65 to 102 mm. Contraction propagation speed calculated from the models and MRI data were in good agreement, measuring around 2 mm/s.Clinical relevance- Clinicians can benefit from the proposed method for diagnostic purposes as the method is semi-automatic and can provide dynamic three-dimensional visualization of gastric motility of patients.
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A comparison of different physical stomach models and an analysis of shear stresses and strains in these system. Food Res Int 2020; 135:109296. [DOI: 10.1016/j.foodres.2020.109296] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 05/04/2020] [Indexed: 01/28/2023]
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Palmada N, Cater JE, Cheng LK, Suresh V. Modelling Flow and Mixing in the Proximal Small Intestine. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2496-2499. [PMID: 33018513 DOI: 10.1109/embc44109.2020.9176688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The small intestine is the primary site of enzymatic digestion and nutrient absorption in humans. Intestinal contractions facilitate digesta mixing, transport and contact with the absorptive surfaces. These motility patterns are regulated by an underlying electrical activity, termed slow waves. In this study, we use computational fluid dynamics simulation of flow and mixing of intestinal contents in the human duodenum with anatomically realistic geometry and contraction patterns. Parameters including the amplitude of contraction (10-50% reduction of radius) and the rheology of the digesta (Newtonian vs Non-Newtonian power law fluid) were altered in-order to study their effects on mixing. Interesting flow features such as stagnation points and reversed flow were observed with digesta. Increases in the amplitude of contraction lead to increased propulsion of digesta along the intestine and increased mixing.
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Dang Y, Liu Y, Hashem R, Bhattacharya D, Allen J, Stommel M, Cheng LK, Xu W. SoGut: A Soft Robotic Gastric Simulator. Soft Robot 2020; 8:273-283. [PMID: 32559391 DOI: 10.1089/soro.2019.0136] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The human stomach breaks down and transports food by coordinated radial contractions of the gastric walls. The radial contractions periodically propagate through the stomach and constitute the peristaltic contractions, also called the gastric motility. The force, amplitude, and frequency of peristaltic contractions are relevant to massaging and transporting the food contents in the gastric lumen. However, existing gastric simulators have not faithfully replicated gastric motility. Herein, we report a soft robotic gastric simulator (SoGut) that emulates peristaltic contractions in an anatomically realistic way. SoGut incorporates an array of circular air chambers that generate radial contractions. The design and fabrication of SoGut leverages principles from the soft robotics field, which features compliance and adaptability. We studied the force and amplitude of the contractions when the lumen of SoGut was empty or filled with contents of different viscosity. We examined the contracting force using manometry. SoGut exhibited a similar range of contracting force as the human stomach reported in the literature. Besides, we investigated the amplitude of the contractions through videofluoroscopy where the contraction ratio was derived. The contraction ratio as a function of inflation pressure is found to match the observations of in vivo situations. We demonstrated that SoGut can achieve in vitro peristaltic contractions by coordinating the inflation sequence of multiple air chambers. It exhibited the functions to massage and transport the food contents. SoGut can simulate the physiological motions of the human stomach to advance research of digestion.
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Affiliation(s)
- Yu Dang
- Department of Mechanical Engineering, The University of Auckland, Auckland, New Zealand.,The Medical Technologies Centre of Research Excellence, Auckland, New Zealand
| | - Yuanxiang Liu
- Department of Mechanical Engineering, The University of Auckland, Auckland, New Zealand.,School of Mechanical and Electrical Technology, Wuxi Vocational Institute of Commerce, Jiangsu, China
| | - Ryman Hashem
- Department of Mechanical Engineering, The University of Auckland, Auckland, New Zealand.,The Medical Technologies Centre of Research Excellence, Auckland, New Zealand
| | - Dipankar Bhattacharya
- Department of Mechanical Engineering, The University of Auckland, Auckland, New Zealand.,The Riddet Institute, Palmerston North, New Zealand
| | - Jacqueline Allen
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Martin Stommel
- The Medical Technologies Centre of Research Excellence, Auckland, New Zealand.,Department of Electrical and Electronic Engineering, Auckland University of Technology, Auckland, New Zealand
| | - Leo K Cheng
- The Medical Technologies Centre of Research Excellence, Auckland, New Zealand.,The Riddet Institute, Palmerston North, New Zealand.,Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Weiliang Xu
- Department of Mechanical Engineering, The University of Auckland, Auckland, New Zealand.,The Medical Technologies Centre of Research Excellence, Auckland, New Zealand.,The Riddet Institute, Palmerston North, New Zealand
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39
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Klemm L, Seydewitz R, Borsdorf M, Siebert T, Böl M. On a coupled electro-chemomechanical model of gastric smooth muscle contraction. Acta Biomater 2020; 109:163-181. [PMID: 32294551 DOI: 10.1016/j.actbio.2020.04.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
The stomach is a central organ in the gastrointestinal tract that performs a variety of functions, in which the spatio-temporal organisation of active smooth muscle contraction in the stomach wall (SW) is highly regulated. In the present study, a three-dimensional model of the gastric smooth muscle contraction is presented, including the mechanical contribution of the mucosal and muscular layer of the SW. Layer-specific and direction-dependent model parameters for the active and passive stress-stretch characteristics of the SW were determined experimentally using porcine smooth muscle strips. The electrical activation of the smooth muscle cells (SMC) due to the pacemaker activity of the interstitial cells of Cajal (ICC) is modelled by using FitzHugh-Nagumo-type equations, which simulate the typical ICC and SMC slow wave behaviour. The calcium dynamic in the SMC depends on the SMC membrane potential via a gaussian function, while the chemo-mechanical coupling in the SMC is modelled via an extended Hai-Murphy model. This cascade is coupled with an additional mechano-electrical feedback-mechanism, taking into account the mechanical response of the ICC and SMC due to stretch of the SW. In this way the relaxation responses of the fundus to accommodate incoming food, as well as the typical peristaltic contraction waves in the antrum for mixing and transport of the chyme, have been well replicated in simulations performed at the whole organ level. STATEMENT OF SIGNIFICANCE: In this article, a novel three-dimensional electro-chemomechanical model of the gastric smooth muscle contraction is presented. The propagating waves of electrical membrane potential in the network ofinterstitial cells of Cajal (ICC) and smooth muscle cells (SMC) lead to a global pattern of change in the calciumdynamics inside the SMC. Taking additionally into account the mechanical response of the ICC and SMC due to stretch of the stomach wall, also referred to as mechanical feedback-mechanism, the result is a complex spatio-temporal regulation of the active contraction and relaxation of the gastric smooth muscle tissue. Being a firstapproach, in future view such a three-dimensional model can give an insight into the complexload transferring system of the stomach wall, as well as into the electro-chemomechanicalcoupling process underlying smooth muscle contraction in health and disease.
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Affiliation(s)
- Lisa Klemm
- Institute of Solid Mechanics, Technische Universität Braunschweig, Braunschweig D-38106, Germany
| | - Robert Seydewitz
- Institute of Solid Mechanics, Technische Universität Braunschweig, Braunschweig D-38106, Germany
| | - Mischa Borsdorf
- Institute of Sport and Motion Science, University of Stuttgart, Stuttgart D-70569, Germany
| | - Tobias Siebert
- Institute of Sport and Motion Science, University of Stuttgart, Stuttgart D-70569, Germany
| | - Markus Böl
- Institute of Solid Mechanics, Technische Universität Braunschweig, Braunschweig D-38106, Germany.
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Martinez AF, Sinha K, Nere N, Slade R, Castleberry S. Characterization of the Hydrodynamics in the USP Basket Apparatus Using Computational Fluid Dynamics. J Pharm Sci 2020; 109:1231-1241. [DOI: 10.1016/j.xphs.2019.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/14/2019] [Accepted: 11/07/2019] [Indexed: 10/25/2022]
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41
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Keppler S, O'Meara S, Bakalis S, Fryer P, Bornhorst G. Characterization of individual particle movement during in vitro gastric digestion in the Human Gastric Simulator (HGS). J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2019.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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42
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Pompa M, Capocelli M, Piemonte V. A new gastro-intestinal mathematical model to study drug bioavailability. Med Eng Phys 2019; 74:106-114. [DOI: 10.1016/j.medengphy.2019.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/27/2019] [Accepted: 09/13/2019] [Indexed: 02/09/2023]
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43
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Ishida S, Miyagawa T, O'Grady G, Cheng LK, Imai Y. Quantification of gastric emptying caused by impaired coordination of pyloric closure with antral contraction: a simulation study. J R Soc Interface 2019; 16:20190266. [PMID: 31387481 PMCID: PMC6731493 DOI: 10.1098/rsif.2019.0266] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/04/2019] [Indexed: 12/18/2022] Open
Abstract
Proper coordination of gastric motor functions is required for healthy gastric emptying. However, pyloric function may be impaired by functional disorders or surgical procedures. Here, we show how coordination between pyloric closure and antral contraction affects the emptying of liquid contents. We numerically simulated fluid dynamics using an anatomically realistic gastrointestinal geometry. Peristaltic contractions in the proximal stomach resulted in gastric emptying at a rate of 3-8 ml min-1. When the pylorus was unable to close, the emptying rate increased to 10-30 ml min-1, and instantaneous retrograde flow from the duodenum to the antrum occurred during antral relaxation. Rapid emptying occurred if the pylorus began to open during the terminal antral contraction, and the emptying rate was negative if the pylorus only opened during the antral relaxation phase. Our results showed that impaired coordination between antral contraction and pyloric closure can result in delayed gastric emptying, rapid gastric emptying and bile reflux.
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Affiliation(s)
- Shunichi Ishida
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Taimei Miyagawa
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan
| | - Gregory O'Grady
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Leo K. Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Riddet Institute, Palmerston North, New Zealand
| | - Yohsuke Imai
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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44
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Li Y, Fortner L, Kong F. Development of a Gastric Simulation Model (GSM) incorporating gastric geometry and peristalsis for food digestion study. Food Res Int 2019; 125:108598. [PMID: 31554041 DOI: 10.1016/j.foodres.2019.108598] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/23/2019] [Accepted: 07/30/2019] [Indexed: 01/14/2023]
Abstract
There has been growing interest in developing in vitro gastrointestinal models as alternatives to in vivo tests, which is challenging ethically and financially. An in vitro Gastric Simulation Model (GSM) was developed to reproduce the geometry and motility of human stomach. The peristalsis was generated by a series of syringes squeezing a latex chamber pneumatically. In particular, the distribution, amplitude and frequency of contractions demonstrated similar patterns as in human gastric conditions. The breakdown kinetics and size distribution of sausage particles during the digestion were investigated in GSM to demonstrate the effect of the contraction force. Furthermore, the gastric emptying of water-soluble nutrient (methylene blue) and nondigestible solids (amberlite beads) was investigated. The results indicated that the viscosity of the gastric digesta significantly affected the local flow and emptying behavior of nutrients and solids. This study illustrated the capability of GSM to recreate the transient physiological conditions and dynamic flow of gastric contents due to its specificity of geometry and contraction patterns. The new model can be used to investigate the influence of food matrix and physiological conditions, including gastric secretion and contraction forces on transit and digestion of foods in the stomach.
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Affiliation(s)
- Yiwen Li
- Department of Food Science and Technology, The University of Georgia, Athens, GA 30602, USA
| | - Lewis Fortner
- Instrument Design & Fabrication Shop, the University of Georgia, Athens, GA 30605, USA
| | - Fanbin Kong
- Department of Food Science and Technology, The University of Georgia, Athens, GA 30602, USA.
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45
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46
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D’Arcy DM, Persoons T. Understanding the Potential for Dissolution Simulation to Explore the Effects of Medium Viscosity on Particulate Dissolution. AAPS PharmSciTech 2019; 20:47. [PMID: 30617668 DOI: 10.1208/s12249-018-1260-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/24/2018] [Indexed: 02/06/2023] Open
Abstract
Viscosity, influenced by medium composition, will affect the hydrodynamics of a dissolution system. Dissolution simulation methods are valuable tools to explore mechanistic dissolution effects, with an understanding of limitations of any simulation method essential to its appropriate use. The aims of this paper were a) to explore, using dissolution simulation, the effects of slightly viscous media on particulate dissolution and b) to illustrate approaches to, and limitations of, the dissolution simulations. A lumped parameter fluid dynamics dissolution simulation model (SIMDISSO™) was used to simulate particulate (20 and 200 μm diameter) dissolution in media with viscosity at 37 °C of water (0.7 mPa.s), milk (1.4 mPa.s) and a nutrient drink (12.3 mPa.s). Effects of flow rate, modality (constant vs pulsing), viscosity and gravitational and particle motion/sedimentation effects on simulated dissolution were explored, in the flow through and paddle apparatuses as appropriate. Shadowgraph imaging (SGI) was used to visualise particle suspension behaviour. Flow rate, hydrodynamic viscous effects and disabling particle motion and gravitational effects affected simulated dissolution of larger particles. SGI imaging revealed retention of particles in suspension in 1.4 mPa.s medium, which sedimented in water. The effect of diffusion adjusted for viscosity was significant for both particle sizes. The limitations of this 1D simulation approach would be greater for larger particles in low velocity regions of the paddle apparatus. Even slightly viscous media can affect dissolution of larger particles with dissolution simulation affording insight into the mechanisms involved, provided the assumptions and limitations of the simulation approach are clarified and understood.
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47
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Kobayashi I, Kozu H, Wang Z, Ichikawa S. Visualization and Evaluation of Disintegration of Food Particles Using a Human Gastric Digestion Simulator. J JPN SOC FOOD SCI 2018. [DOI: 10.3136/nskkk.65.543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Isao Kobayashi
- Food Research Institute, National Agriculture and Food Research Organization
| | - Hiroyuki Kozu
- Faculty of Life and Environmental Sciences, University of Tsukuba
| | - Zheng Wang
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization
| | - Sosaku Ichikawa
- Faculty of Life and Environmental Sciences, University of Tsukuba
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48
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Lentle RG. Deconstructing the physical processes of digestion: reductionist approaches may provide greater understanding. Food Funct 2018; 9:4069-4084. [PMID: 30011345 DOI: 10.1039/c8fo00722e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
I provide a broad overview of the physical factors that govern intestinal digestion i.e. the admixture of food particles in digesta with secreted enzymes and the subsequent mass transfer of liberated nutrients from the surfaces of particles to the gut wall, with a view to outlining the quantitative work that is required to determine the relative importance of these factors in the digestion of particular foods. I first discuss what is known of the mechanical forces generated by contraction of the walls of the various segments of the gut and the level of diffusive, and advective mixing that it generates within the lumen. I then discuss the particular physical effects that may limit the digestion of solid, physically and/or chemically homogenous and heterogeneous food particles, notably capillarity, porosity, poro-elastic flow and compaction and their likely effects on diffusive and convective mass transfer at particulate surfaces. Similarly, I discuss mucins and morphology on mass transfer of nutrients to the gut wall i.e. the mucosa.
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Affiliation(s)
- R G Lentle
- Digestive Biomechanics Group, College of Health, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
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49
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Li C, Xiao J, Zhang Y, Chen XD. Mixing in a soft-elastic reactor (SER): A simulation study. CAN J CHEM ENG 2018. [DOI: 10.1002/cjce.23351] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Changyong Li
- Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering; Xiamen University; Xiamen Fujian, 361005 P. R. China
| | - Jie Xiao
- China-Australia Joint Research Center in Future Dairy Manufacturing; School of Chemical and Environmental Engineering; College of Chemistry, Chemical Engineering and Materials Science; Soochow University; Suzhou City Jiangsu, 215123 P. R. China
| | - Yu Zhang
- School of Medicine; Tsinghua University; Beijing 100084 P. R. China
| | - Xiao Dong Chen
- Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering; Xiamen University; Xiamen Fujian, 361005 P. R. China
- China-Australia Joint Research Center in Future Dairy Manufacturing; School of Chemical and Environmental Engineering; College of Chemistry, Chemical Engineering and Materials Science; Soochow University; Suzhou City Jiangsu, 215123 P. R. China
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50
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Zhao J, McMahon B, Fox M, Gregersen H. The esophagiome: integrated anatomical, mechanical, and physiological analysis of the esophago-gastric segment. Ann N Y Acad Sci 2018; 1434:5-20. [DOI: 10.1111/nyas.13869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/27/2018] [Accepted: 05/04/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Jingbo Zhao
- GIOME Academy, Department of Clinical Medicine; Aarhus University; Aarhus Denmark
| | - Barry McMahon
- Trinity Academic Gastroenterology Group; Tallaght Hospital and Trinity College; Dublin Ireland
| | - Mark Fox
- Abdominal Center: Gastroenterology; St. Claraspital Basel Switzerland
- Neurogastroenterology and Motility Research Group; University Hospital Zürich; Zürich Switzerland
| | - Hans Gregersen
- GIOME, Department of Surgery; Prince of Wales Hospital and Chinese University of Hong Kong; Shatin Hong Kong SAR
- California Medical Innovations Institute; San Diego California
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