Gastroparesis

The antroduodenal transition time is prolonged in adults with type 1 diabetes

BACKGROUND

The gastroparetic syndrome encompasses antral hypomotility, gastric dysrhythmia, impaired antroduodenal coordination, pyloric dysfunction, and abnormal duodenal motility; the last three collectively referred to as pylorospasms. We hypothesized that antroduodenal motility is diminished and transition time is prolonged in adults with type 1 diabetes (T1D) and polyneuropathy.

METHODS

This cross-sectional study included 124 participants, of which 21 were healthy, 53 had T1D and 50 had T1D with distal symmetrical polyneuropathy (T1D + DSPN). We used the wireless motility capsule to assess antroduodenal transition time, gastric emptying time, gastric and small bowel motility indices (MI), and numbers of alkalic/acidic exposures.

RESULTS

In comparison with controls, patients with T1D had prolonged antroduodenal transition time (1.85±1.5 vs. 6.6±4.8 minutes; p=0.02), which was even more pronounced in patients with T1D+DSPN (1.85±1.5 vs. 17.8±28.5 minutes; p<0.008. T1D+DSPN tended to have diminished gastric MI (11.9±2.4 vs. 12.7±1.0, p=0.07) and small bowel MI (13.1±1.4 vs. 13.6±0.6, p=0.05) and experienced more antral/pyloric alkalic episodes (1.2±1.3 vs. 2.0±2.1, p=0.02) compared with controls.

CONCLUSION

The current method may assess a proxy for severity of pylorospasms in patients with diabetes and other diseases associated with upper gastrointestinal motility disorders, which ultimately may optimize future management.

Role of microRNAs in Disorders of Gut-Brain Interactions: Clinical Insights and Therapeutic Alternatives

Disorders of gut-brain interactions (DGBIs) are heterogeneous in nature and intertwine with diverse pathophysiological mechanisms. Regular functioning of the gut requires complex coordinated interplay between a variety of gastrointestinal (GI) cell types and their functions are regulated by multiple mechanisms at the transcriptional, post-transcriptional, translational, and post-translational levels. MicroRNAs (miRNAs) are small non-coding RNA molecules that post-transcriptionally regulate gene expression by binding to specific mRNA targets to repress their translation and/or promote the target mRNA degradation. Dysregulation of miRNAs might impair gut physiological functions leading to DGBIs and gut motility disorders. Studies have shown miRNAs regulate gut functions such as visceral sensation, gut immune response, GI barrier function, enteric neuronal development, and GI motility. These biological processes are highly relevant to the gut where neuroimmune interactions are key contributors in controlling gut homeostasis and functional defects lead to DGBIs. Although extensive research has explored the pathophysiology of DGBIs, further research is warranted to bolster the molecular mechanisms behind these disorders. The therapeutic targeting of miRNAs represents an attractive approach for the treatment of DGBIs because they offer new insights into disease mechanisms and have great potential to be used in the clinic as diagnostic markers and therapeutic targets. Here, we review recent advances regarding the regulation of miRNAs in GI pacemaking cells, immune cells, and enteric neurons modulating pathophysiological mechanisms of DGBIs. This review aims to assess the impacts of miRNAs on the pathophysiological mechanisms of DGBIs, including GI dysmotility, impaired intestinal barrier function, gut immune dysfunction, and visceral hypersensitivity. We also summarize the therapeutic alternatives for gut microbial dysbiosis in DGBIs, highlighting the clinical insights and areas for further exploration. We further discuss the challenges in miRNA therapeutics and promising emerging approaches.

Preclinical Evaluation of the Effects of Trazpiroben (TAK-906), a Novel, Potent Dopamine D2/D3 Receptor Antagonist for the Management of Gastroparesis

Current therapies for gastroparesis metoclopramide and domperidone carry risks of extrapyramidal symptoms and life-threatening cardiac arrhythmias. Trazpiroben, a novel, potent dopamine D2/D3 receptor antagonist, has low brain permeation and very low affinity for human ether-à-go-go-related gene (hERG) channel inhibition, potentially improving on safety profiles of existing therapies. Trazpiroben demonstrated the following receptor affinities: high for D2 and D3, moderate for D4, and minimal for D1 and D5 It demonstrated moderate affinity for adrenergic α 1B (α 1B) and 5-hydroxytryptamine (5HT) 2A receptors and low potential for off-target adverse events (AEs). Trazpiroben potently inhibited dopamine-activated D2L receptor activation of cognate G-proteins in human embryonic kidney 293 cell membranes and was a neutral D2L receptor antagonist. In vivo, trazpiroben dose-dependently increased prolactin release in orally dosed rat (0.1-1 mg/kg). Additionally, multiple oral doses in the rat (100 mg/kg) and dog (50 mg/kg) for 3 days produced robust plasma exposures and prolactin increases in both species. Trazpiroben inhibited retching/vomiting in the dog with apomorphine-induced emesis with a potency (0.1-1 mg/kg) like that of trazpiroben-mediated prolactin increases in rat. Oral trazpiroben (1, 10, and 30 mg/kg) did not affect rat rotarod performance, suggesting low brain penetration. Trazpiroben concentrations were low in cerebrospinal fluid versus plasma after multiple oral doses for 4 days in rat and dog. Trazpiroben weakly inhibited the hERG channel current (concentration causing half-maximal inhibition of control-specific binding of 15.6 µM), indicating little potential for disrupting cardiac rhythm. Overall, trazpiroben is a potent D2/D3 receptor antagonist designed to avoid the serious potential AEs associated with current gastroparesis therapies. SIGNIFICANCE STATEMENT: Trazpiroben is a novel, potent dopamine D2/D3 selective receptor antagonist designed to avoid adverse effects associated with the current pharmacological therapies metoclopramide and domperidone. Preclinical studies have demonstrated low brain penetration and weak affinity for the hERG channel, indicating that trazpiroben is not expected to be associated with central nervous system or cardiovascular safety issues. With these pharmacological properties, trazpiroben may represent a viable new treatment option for gastroparesis because of a potentially improved safety profile relative to existing therapies.

Evaluation of gastric emptying in patients with gastroparesis by three-dimensional ultrasound

Background

To diagnose gastroparesis, it is necessary to assess gastric emptying accurately. This study aims to investigate the role of three-dimensional ultrasonography (3-D US) on the measurement of gastric volume to evaluate gastric accommodation in healthy patients.

Methods

In this study, 21 volunteers, 46 patients with diabetic gastroparesis (DG), and 22 patients with postsurgical gastroparesis (PSG) underwent 3-D US after oral administration of 250 mL gastrointestinal contrast at 2, 30, 60, and 90 min. The volume of the contrast agent in the stomach was then calculated using the virtual organ computer-aided analysis (VOCAL) (Virtual Organ Computer-aided AnaLysis, General Electric Medical Systems, Kretztechnik, Zipf, Austria).

Results

In the DG group, the gastric residue volumes at postprandial 60 and 90 min were significantly higher than those in the healthy group (P<0.05), and the areas under the receiver operating characteristic (ROC) curve of these parameters were 0.830 and 0.957, respectively. There were significant differences between the PSG and healthy groups at 60 and 90 min; however, the AUC of gastric residue at 90 min (0.955) was higher than the AUC at 60 min (0.697).

Conclusions

Therefore, this study showed that the 3-D US is a powerful tool for assessing gastric emptying and provides a new strategy for diagnosing gastroparesis.

Breath Biomarkers in Diagnostic Applications

The detection of chemical compounds in exhaled human breath presents an opportunity to determine physiological state, diagnose disease or assess environmental exposure. Recent advancements in metabolomics research have led to improved capabilities to explore human metabolic profiles in breath. Despite some notable challenges in sampling and analysis, exhaled breath represents a desirable medium for metabolomics applications, foremost due to its non-invasive, convenient and practically limitless availability. Several breath-based tests that target either endogenous or exogenous gas-phase compounds are currently established and are in practical and/or clinical use. This review outlines the concept of breath analysis in the context of these unique tests and their applications. The respective breath biomarkers targeted in each test are discussed in relation to their physiological production in the human body and the development and implementation of the associated tests. The paper concludes with a brief insight into prospective tests and an outlook of the future direction of breath research.

A Systematic Review of the Therapeutic Role of Gastric Pacemakers in Adults With Gastroparesis

Gastroparesis or gastric stasis is the delayed transit of the ingested contents through the stomach in the absence of mechanical obstruction. It can have multiple etiologies, most commonly idiopathic (ID) and diabetic (DM). Gastroparesis can cause significant distress to patients as it leads to symptoms like intractable nausea and vomiting, weight loss, abdominal bloating, early satiety, etc. The pathogenesis is mainly thought to be due to the dysfunction of the gastric pacemaker cells, i.e., interstitial cells of Cajal (ICC), and their interaction with the other gastric motor function regulatory components. There are several proposed treatment options for gastroparesis. Despite that, most patients remain refractory to medical treatment and require additional interventions for symptomatic relief. One such intervention is gastric electrical stimulation or gastric pacemaker, which aids in improving gastric motility. We have searched PubMed, PubMed Central (PMC), Medline, Science Direct, and Google Scholar for articles pertaining to the use of gastric electrical stimulation in gastroparesis published in the last 10 years. The keywords used include "gastroparesis", "gastric stasis", "gastric pacemaker'', "gastric electrical stimulation", "nausea", "vomiting", "abdominal bloating", "gastric neuromodulation". We have finally included twelve studies that were the most relevant to our research question and met the quality assessment criteria. Exclusion criteria consisted of pediatric population studies, studies conducted on animals, books, and grey literature. Overall, these twelve studies helped evaluate the impact of gastric pacemakers on symptoms of gastroparesis like nausea, vomiting, weight loss, abdominal bloating, and quality of life. We found that most studies favored gastric pacemakers, improving the incidence of nausea and vomiting in patients with gastroparesis. There was a marked improvement in the BMI as well. On the other hand, most open-labeled studies showed improved quality of life and Gastroparesis Cardinal Symptom Index (GCSI) scores, while randomized controlled trials and meta-analyses did not reflect the same result. In addition, some other parameters improved with gastric pacemakers, Inflammatory markers, insulin levels (especially in diabetics), and the number of hospitalizations. In conclusion, gastric pacemaker is a potential treatment option for patients with medically refractory gastroparesis. As noted from the results of our study, nausea/vomiting, weight loss, and overall GCSI scores have shown marked improvement with gastric electrical stimulation (GES). Nevertheless, more extensive research is needed to understand better the full extent of this device's use as a viable treatment option for patients suffering from gastroparesis.

Perioperative challenges in management of diabetic patients undergoing non-cardiac surgery

Prediabetes and diabetes are important disease processes which have several perioperative implications. About one third of the United States population is considered to have prediabetes. The prevalence in surgical patients is even higher. This is due to the associated micro and macrovascular complications of diabetes that result in the need for subsequent surgical procedures. A careful preoperative evaluation of diabetic patients and patients at risk for prediabetes is essential to reduce perioperative mortality and morbidity. This preoperative evaluation involves an optimization of preoperative comorbidities. It also includes optimization of antidiabetic medication regimens, as the avoidance of unintentional hypoglycemic and hyperglycemic episodes during the perioperative period is crucial. The focus of the perioperative management is to ensure euglycemia and thus improve postoperative outcomes. Therefore, prolonged preoperative fasting should be avoided and close monitoring of blood glucose should be initiated and continued throughout surgery. This can be accomplished with either analysis in blood gas samples, venous phlebotomy or point-of-care testing. Although capillary and arterial whole blood glucose do not meet standard guidelines for glucose testing, they can still be used to guide insulin dosing in the operating room. Intraoperative glycemic control goals may vary slightly in different protocols but overall the guidelines suggest a glucose range in the operating room should be between 140 mg/dL to 180 mg/dL. When hyperglycemia is detected in the operating room, blood glucose management may be initiated with subcutaneous rapid-acting insulin, with intravenous infusion or boluses of regular insulin. Fluid and electrolyte management are other perioperative challenges. Notably diabetic ketoacidosis and hyperglycemic hyperosmolar nonketotic state are the two most serious acute metabolic complications of diabetes that must be recognized early and treated.

Gastrointestinal manifestations of systemic sclerosis: An updated review

Systemic sclerosis is an autoimmune disease characterized by vascular disease, fibrosis of the skin, and internal organ dysfunction. Gastrointestinal involvement is the most frequent complication of internal organs, impacting up to 90% of patients. Gastrointestinal involvement can affect any region of the gastrointestinal tract from the mouth to the anus, with a predominance of disorders being observed at the level of the upper digestive tract. The gastrointestinal involvement primarily involves the esophagus, small bowel, and rectum. The severity of gastrointestinal involvement affects quality of life and is a marker of worse prognosis and mortality in these patients. In this review, we describe the current findings regarding gastrointestinal involvement by this entity.

Randomised clinical trial: safety, pharmacokinetics and pharmacodynamics of trazpiroben (TAK-906), a dopamine D2 /D3 receptor antagonist, in patients with gastroparesis

BACKGROUND

Gastroparesis is a chronic gastric motility disorder. Dopamine D₂ /D₃ receptor antagonists metoclopramide and domperidone are current treatment options but are associated with central nervous system and cardiovascular safety concerns, respectively, precluding chronic use. Trazpiroben (TAK-906), a dopamine D₂ /D₃ receptor antagonist, is under development for chronic treatment of moderate-to-severe gastroparesis. Nonclinical data suggest trazpiroben will have D₂ /D₃ receptor antagonism comparable with metoclopramide or domperidone.

AIMS

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics (effect on prolactin and gastric function) of twice-daily trazpiroben (5, 25 and 100 mg) in participants with gastroparesis.

METHODS

This phase 2a pilot study evaluated gastric emptying using the gastric emptying breath test, with metoclopramide as an internal control. Gastric accommodation and gastroparesis symptoms were assessed using the nutrient drink test and American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index-Daily Diary, respectively.

RESULTS

Overall, 51 participants were enrolled. Trazpiroben was well tolerated, demonstrating a favourable safety profile without cardiovascular or central nervous system adverse events. All trazpiroben doses were rapidly absorbed and eliminated (t_1/2z 4-5 hours), and D₂ /D₃ receptor target engagement confirmed by increased serum prolactin (peaking at trazpiroben 25 mg). No effect on gastric emptying was demonstrated with trazpiroben or metoclopramide (P > 0.05), although benefits in volume-to-fullness were seen at trazpiroben 5 mg (P > 0.05) and 25 mg (88.5 vs -26.3 mL; P = 0.019), and nonsignificant numerical aggregate symptom score improvements were observed with trazpiroben 25 mg vs placebo (P = 0.182).

CONCLUSIONS

Trazpiroben was well tolerated with a favourable safety profile, supporting its further development for the treatment of gastroparesis. ClinicalTrials.gov identifier: NCT03268941.

Pyloric distensibility in health and disease

Until recently, gastric motility measurements in humans were mostly limited to accommodation (using barostat or 3-dimensional imaging studies of gastric volume) and gastric emptying tests, the latter being the only one performed in routine clinical care. Accurate and easy to use techniques were lacking to assess pyloric function in health and disease. Recently, pyloric distensibility has been developed and validated to assess pyloric opening. Several studies confirmed that pyloric distensibility was decreased in gastroparesis and correlated with gastric emptying as well as gastroparesis symptoms. In addition, pyloric distensibility may predict outcome of endoscopic techniques targeting the pylorus, namely intrapyloric botulinum toxin injection and gastric per-oral pyloromyotomy. Pyloric distensibility appears therefore to be a promising and useful new tool in the workup of gastroparesis patients.

Safety, Pharmacokinetics, and Pharmacodynamics of Trazpiroben (TAK-906), a Novel Selective D2 /D3 Receptor Antagonist: A Phase 1 Randomized, Placebo-Controlled Single- and Multiple-Dose Escalation Study in Healthy Participants

Gastroparesis is a chronic neuromuscular disorder of the upper gastrointestinal tract in which episodic exacerbation can lead to frequent hospitalizations and severe disability. Dopamine D2 /D3 receptor antagonists have been used to treat patients with gastroparesis with some efficacy; however, their chronic use is limited owing to associated central nervous system (CNS) or cardiovascular safety concerns. Trazpiroben (TAK-906) is a dopamine D2 /D3 receptor antagonist under development for the long-term treatment of gastroparesis. Preclinical studies in rat and dog have shown trazpiroben to have minimal brain penetration and low affinity for the human ether-à-go-go-related gene (hERG) potassium channel (IC50 ,  15.6 µM), thereby reducing the risk of the CNS and cardiovascular adverse effects seen with other dopamine D2 /D3 receptor antagonists. This phase 1 trial evaluated the safety, pharmacokinetics, and pharmacodynamics of trazpiroben in healthy participants. Trazpiroben was rapidly absorbed and eliminated (Tmax , ∼1.1 hours; t1/2 , 4-11 hours) after administration of single (5-300 mg) and multiple (50 or 100 mg) doses. Receptor target engagement was confirmed for all doses, as indicated by an increase in serum prolactin levels compared with placebo (mean prolactin Cmax , 134.3 ng/mL after administration of trazpiroben 10 mg vs 16.1 ng/mL with placebo). Therapeutically relevant single and multiple doses of trazpiroben were well tolerated in healthy participants, and no clinically meaningful cardiovascular adverse effects were observed across the whole dose range. These data support the further development of trazpiroben for the treatment of gastroparesis.

Clinical Efficacy of the Preservation of the Hepatic Branch of the Vagus Nerve on Delayed Gastric Emptying After Laparoscopic Pancreaticoduodenectomy

BACKGROUND

Delayed gastric emptying (DGE) is a common complication following laparoscopic pancreaticoduodenectomy (LPD), although it remains incompletely understood, and only few studies have investigated the clinical benefits of hepatic branch of the vagus nerve (HBVN) preservation on DGE after LPD until now. We intended to evaluate the effect of preservation of the HBVN during LPD on the incidence of DGE.

METHODS

A total of 274 consecutive LPDs performed at a single center between July 2014 and December 2019 with available videos were retrospectively reviewed. DGE was defined according to the International Study Group of Pancreatic Surgery (ISGPS) criteria, and HBVN condition during the LPD procedure was evaluated through a video review. Risk factors associated with DGE were assessed by performing univariate and multivariate logistic regression analyses. Postoperative outcomes between the HBVN-preserved and HBVN-injury groups were compared before and after propensity score matching (PSM).

RESULTS

One hundred fifty-six (56.93%) patients underwent LPD with HBVN-preserved and 118 (43.07%) with HBVN injury. DGE occurred in 33.2% of patients (n = 91) with grades B and C occurring at 13.9% (n = 38) and 7.7% (n = 21), respectively. Longer operative time, more EIBL, HBVN injury, POPF (grades B and C), postoperative hemorrhage, intra-abdominal infection, and Clavien-Dindo ≥III were identified as risk factors for DGE in the univariate analysis. Then, in the multivariate analysis, HBVN injury and intra-abdominal infection were found to be independent risk factors affecting the incidence of DGE (any grade) or clinically relevant DGE (grades B and C). Furthermore, the prevalence of DGE was significantly higher in the HBVN-injury group than in the HBVN-preserved group before and after PSM analysis (46.61% vs. 23.08%, P<0.001; 42.59% vs. 23.15%, P=0.013).

CONCLUSIONS

HBVN preservation during LPD might be associated with a reduced incidence of DGE as a framework for prospective quality improvement.

Evaluation of the Pharmacokinetics of Trazpiroben (TAK-906), a Peripherally Selective D2/D3 Dopamine Receptor Antagonist, in the Presence and Absence of Itraconazole, a Potent CYP 3A4 Inhibitor

Purpose

Treatment options for gastroparesis, such as metoclopramide and domperidone, are limited because of safety concerns, which may be exacerbated in the presence of inhibitors of drug metabolism. This study evaluated the effect of itraconazole on the pharmacokinetics, safety, and tolerability of trazpiroben (previously TAK-906), a novel, peripherally selective D₂/D₃ dopamine receptor antagonist.

Methods

This was a phase 1, two-period, crossover trial in healthy participants (NCT03161405). On day 1, period 1 (days 1–3), participants received a single oral dose of trazpiroben 25 mg. During period 2 (days 4–9), participants received oral itraconazole 200 mg once daily (days 1–5) and one oral dose of trazpiroben 25 mg post itraconazole on day 4. Trazpiroben pharmacokinetics were assessed. Safety assessments included triplicate electrocardiograms.

Results

Twelve healthy males (24–45 years old) were studied. Co-administration of itraconazole increased trazpiroben area under the concentration–time curve from time 0 to infinity by 1.28-fold (90% confidence interval: 1.10, 1.49) and maximum plasma concentration (C_max) by 1.98-fold (1.64, 2.39) versus trazpiroben alone. Placebo-corrected, change from baseline in corrected QT interval at the observed geometric mean C_max for trazpiroben alone (9.53 ng/mL) and with itraconazole (18.00 ng/mL) was estimated at 1.31 ms (−0.39, 3.01) and 1.54 ms (−0.15, 3.24), respectively. There were no clinically relevant abnormalities in any safety parameters.

Conclusion

These results indicate that TAK‑906 is relatively insensitive to inhibition of cytochrome P450 3A4, and cardiovascular safety concerns associated with domperidone are unlikely to be elicited by trazpiroben under similar conditions.

Pathogenesis, diagnosis and clinical management of diabetic sensorimotor peripheral neuropathy

Diabetic sensorimotor peripheral neuropathy (DSPN) is a serious complication of diabetes mellitus and is associated with increased mortality, lower-limb amputations and distressing painful neuropathic symptoms (painful DSPN). Our understanding of the pathophysiology of the disease has largely been derived from animal models, which have identified key potential mechanisms. However, effective therapies in preclinical models have not translated into clinical trials and we have no universally accepted disease-modifying treatments. Moreover, the condition is generally diagnosed late when irreversible nerve damage has already taken place. Innovative point-of-care devices have great potential to enable the early diagnosis of DSPN when the condition might be more amenable to treatment. The management of painful DSPN remains less than optimal; however, studies suggest that a mechanism-based approach might offer an enhanced benefit in certain pain phenotypes. The management of patients with DSPN involves the control of individualized cardiometabolic targets, a multidisciplinary approach aimed at the prevention and management of foot complications, and the timely diagnosis and management of neuropathic pain. Here, we discuss the latest advances in the mechanisms of DSPN and painful DSPN, originating both from the periphery and the central nervous system, as well as the emerging diagnostics and treatments.

Disorders of the brain-gut interaction and eating disorders

BACKGROUND

Eating disorders (ED) involve both the nervous system and the gastrointestinal tract. A similar double involvement is also found in disorders of the brain-gut interaction (DGBI) and symptoms are sometimes similar.

AIM

To find out where there is an association and a cause-effect relationship, we looked for the comorbidity of DGBI and ED.

METHODS

A systematic review was undertaken. A literature search was performed. Inclusion criteria for the articles retained for analysis were: Observational cohort population-based or hospital-based and case-control studies, examining the relationship between DGBI and ED. Exclusion criteria were: Studies written in other languages than English, abstracts, conference presentations, letters to the Editor and editorials. Selected papers by two independent investigators were critically evaluated and included in this review.

RESULTS

We found 29 articles analyzing the relation between DGBI and ED comprising 13 articles on gastroparesis, 5 articles on functional dyspepsia, 7 articles about functional constipation and 4 articles on irritable bowel syndrome.

CONCLUSION

There is no evidence for a cause-effect relationship between DGBI and ED. Their common symptomatology requires correct identification and a tailored therapy of each disorder.

Telocytes: An Emerging Component of Stem Cell Niche Microenvironment

Telocytes (TCs) are newly identified interstitial cells characterized by thin and long cytoplasmic processes, called telopodes, which exhibit a distinctive moniliform shape and, often, a sinuous trajectory. Telopodes typically organize in intricate networks within the stromal space of most organs, where they communicate with neighboring cells by means of specialized cell-to-cell junctions or shedding extracellular vesicles. Hence, TCs are generally regarded as supporting cells that help in the maintenance of local tissue homeostasis, with an ever-increasing number of studies trying to explore their functions both in physiological and pathological conditions. Notably, TCs appear to be part of stem cell (SC) niches in different organs, including the intestine, skeletal muscle, heart, lung, and skin. Indeed, growing evidence points toward a possible implication of TCs in the regulation of the activity of tissue-resident SCs and in shaping the SC niche microenvironment, thus contributing to tissue renewal and repair. Here, we review how the introduction of TCs into the scientific literature has deepened our knowledge of the stromal architecture focusing on the intestine and skeletal muscle, two organs in which the recently unveiled unique relationship between TCs and SCs is currently in the spotlight as potential target for tissue regenerative purposes.

Gastroparesis in Parkinson Disease: Pathophysiology, and Clinical Management

Patients with Parkinson disease (PD) experience a range of non-motor symptoms, including gastrointestinal symptoms. These symptoms can be present in the prodromal phase of the disease. Recent advances in pathophysiology reveal that α-synuclein aggregates that form Lewy bodies and neurites, the hallmark of PD, are present in the enteric nervous system and may precede motor symptoms. Gastroparesis is one of the gastrointestinal involvements of PD and is characterized by delayed gastric emptying of solid food in the absence of mechanical obstruction. Gastroparesis has been reported in nearly 45% of PD. The cardinal symptoms include early satiety, postprandial fullness, nausea, and vomiting. The diagnosis requires an appropriate test to confirm delayed gastric emptying, such as gastric scintigraphy, or breath test. Gastroparesis can lead to malnutrition and impairment of quality of life. Moreover, it might interfere with the absorption of antiparkinsonian drugs. The treatment includes dietary modifications, and pharmacologic agents both to accelerate gastric emptying and relieve symptoms. Alternative treatments have been recently developed in the management of gastroparesis, and their use in patients with PD will be reported in this review.

Serotonin Deficiency Is Associated With Delayed Gastric Emptying

BACKGROUND & AIMS

Gastrointestinal (GI) motility is regulated by serotonin (5-hydroxytryptamine [5-HT]), which is primarily produced by enterochromaffin (EC) cells in the GI tract. However, the precise roles of EC cell-derived 5-HT in regulating gastric motility remain a major point of conjecture. Using a novel transgenic mouse line, we investigated the distribution of EC cells and the pathophysiologic roles of 5-HT deficiency in gastric motility in mice and humans.

METHODS

We developed an inducible, EC cell-specific Tph1CreERT2/+ mouse, which was used to generate a reporter mouse line, Tph1-tdTom, and an EC cell-depleted line, Tph1-DTA. We examined EC cell distribution, morphology, and subpopulations in reporter mice. GI motility was measured in vivo and ex vivo in EC cell-depleted mice. Additionally, we evaluated 5-HT content in biopsy and plasma specimens from patients with idiopathic gastroparesis (IG).

RESULTS

Tph1-tdTom mice showed EC cells that were heterogeneously distributed throughout the GI tract with the greatest abundance in the antrum and proximal colon. Two subpopulations of EC cells were identified in the gut: self-renewal cells located at the base of the crypt and mature cells observed in the villi. Tph1-DTA mice displayed delayed gastric emptying, total GI transit, and colonic transit. These gut motility alterations were reversed by exogenous provision of 5-HT. Patients with IG had a significant reduction of antral EC cell numbers and 5-HT content, which negatively correlated with gastric emptying rate.

CONCLUSIONS

The Tph1CreERT2/+ mouse provides a powerful tool to study the functional roles of EC cells in the GI tract. Our findings suggest a new pathophysiologic mechanism of 5-HT deficiency in IG.

The Effect of Continuous Intake of Lactobacillus gasseri OLL2716 on Mild to Moderate Delayed Gastric Emptying: A Randomized Controlled Study

Probiotics have been suggested to be effective for functional dyspepsia, but their effect on gastric motility is not clear. We evaluated the effect of Lactobacillus gasseri OLL2716 (LG21 strain) on mild to moderate delayed gastric emptying by a double-blind, parallel-group, placebo-controlled, randomized trial. Participants (n = 28) were randomly assigned to ingest LG21 strain-containing yogurt (LG21 strain group) or LG21 strain-free yogurt (placebo group) for 12 weeks. The 13C gastric emptying breath test was performed to measure the gastric emptying rate over time following ingestion of a liquid meal, and the time to reach the peak (Tmax) was used as an indicator of gastric emptying. We also measured the salivary amylase concentration, an indicator of autonomic dysfunction under stress. The per-protocol population (n = 27, male n = 4, female n = 23) was evaluated for efficacy. When a ≥30% reduction in the difference between participant's Tmax and the Japanese mean Tmax was defined as an improvement, the odds ratio of improvement in delayed gastric emptying compared to placebo after 12 weeks was 4.1 (95% confidence interval, 0.8 to 20.2). Moreover, salivary amylase concentrations were significantly lower than in the placebo group, indicating an improvement in autonomic function. The present data were not enough to support the beneficial effects of the LG21 strain on delayed gastric emptying. However, if we define the odds ratio in further study investigated with a larger number of participants, LG21 strain might be expected to have some impact on delayed gastric emptying.

Gastric Mucosal Immune Profiling and Dysregulation in Idiopathic Gastroparesis

INTRODUCTION

It is unclear how immune perturbations may influence the pathogenesis of idiopathic gastroparesis, a prevalent functional disorder of the stomach which lacks animal models. Several studies have noted altered immune characteristics in the deep gastric muscle layer associated with gastroparesis, but data are lacking for the mucosal layer, which is endoscopically accessible. We hypothesized that immune dysregulation is present in the gastroduodenal mucosa in idiopathic gastroparesis and that specific immune profiles are associated with gastroparesis clinical parameters.

METHODS

In this cross-sectional prospective case-control study, routine endoscopic biopsies were used for comprehensive immune profiling by flow cytometry, multicytokine array, and gene expression in 3 segments of the stomach and the duodenal bulb. Associations of immune endpoints with clinical parameters of gastroparesis were also explored.

RESULTS

The gastric mucosa displayed large regional variation of distinct immune profiles. Furthermore, several-fold increases in innate and adaptive immune cells were found in gastroparesis. Various immune cell types showed positive correlations with duration of disease, proton pump inhibitor dosing, and delayed gastric emptying.

DISCUSSION

This initial observational study showed immune compartmentalization of the human stomach mucosa and significant immune dysregulation at the level of leukocyte infiltration in idiopathic gastroparesis patients that extends to the duodenum. Select immune cells, such as macrophages, may correlate with clinicopathological traits of gastroparesis. This work supports further mucosal studies to advance our understanding of gastroparesis pathophysiology.

The enteric nervous system in gastrointestinal disease etiology

A highly conserved but convoluted network of neurons and glial cells, the enteric nervous system (ENS), is positioned along the wall of the gut to coordinate digestive processes and gastrointestinal homeostasis. Because ENS components are in charge of the autonomous regulation of gut function, it is inevitable that their dysfunction is central to the pathophysiology and symptom generation of gastrointestinal disease. While for neurodevelopmental disorders such as Hirschsprung, ENS pathogenesis appears to be clear-cut, the role for impaired ENS activity in the etiology of other gastrointestinal disorders is less established and is often deemed secondary to other insults like intestinal inflammation. However, mounting experimental evidence in recent years indicates that gastrointestinal homeostasis hinges on multifaceted connections between the ENS, and other cellular networks such as the intestinal epithelium, the immune system, and the intestinal microbiome. Derangement of these interactions could underlie gastrointestinal disease onset and elicit variable degrees of abnormal gut function, pinpointing, perhaps unexpectedly, the ENS as a diligent participant in idiopathic but also in inflammatory and cancerous diseases of the gut. In this review, we discuss the latest evidence on the role of the ENS in the pathogenesis of enteric neuropathies, disorders of gut-brain interaction, inflammatory bowel diseases, and colorectal cancer.

Preoperative physiological esophageal assessment for anti-reflux surgery: A guide for surgeons on high-resolution manometry and pH testing

Gastroesophageal reflux disease (GERD) is one of the most commonly encountered digestive diseases in the world, with the prevalence continuing to increase. Many patients are successfully treated with lifestyle modifications and proton pump inhibitor therapy, but a subset of patients require more aggressive intervention for control of their symptoms. Surgical treatment with fundoplication is a viable option for patients with GERD, as it attempts to improve the integrity of the lower esophageal sphincter (LES). While surgery can be as effective as medical treatment, it can also be associated with side effects such as dysphagia, bloating, and abdominal pain. Therefore, a thorough pre-operative assessment is crucial to select appropriate surgical candidates. Newer technologies are becoming increasingly available to help clinicians identify patients with true LES dysfunction, such as pH-impedance studies and high-resolution manometry (HRM). Pre-operative evaluation should be aimed at confirming the diagnosis of GERD, ruling out any major motility disorders, and selecting appropriate surgical candidates. HRM and pH testing are key tests to consider for patients with GERD like symptoms, and the addition of provocative measures such as straight leg raises and multiple rapid swallows to HRM protocol can assess the presence of underlying hiatal hernias and to test a patient’s peristaltic reserve prior to surgery.

Personalization of Endoscopic Bariatric and Metabolic Therapies Based on Physiology: a Prospective Feasibility Study with a Single Fluid-Filled Intragastric Balloon

BACKGROUND

The intragastric balloon (IGB) is commonly used for weight loss. Identifying patients who are most likely to tolerate and benefit from IGB therapy will optimize outcomes. Our aims were to prospectively utilize a gastric emptying study to predict intolerance and treatment response with a single fluid-filled IGB and to develop a physiologic prediction model with a treatment algorithm.

MATERIALS AND METHODS

A total of 32 patients had a gastric emptying study before and 2-3 months after placement of an IGB. Multiple logistic regression analyses were performed to calculate likelihood ratios and to develop a physiologic prediction model.

RESULTS

Patients in the higher gastric retention quartile at baseline had a 6.2-time higher likelihood ratio for early balloon removal secondary to intolerance (p = 0.013). Utilizing baseline gastric emptying to predict intolerance to the IGB may have prevented 75% of early removal cases. Decreased gastric emptying at 3 months after balloon placement was significantly correlated with percent total body weight loss (%TWBL) at 6 and 12 months (p = 0.01 and p = 0.014, respectively). At 6 months after IGB, patients with no change in their gastric emptying at 3 months lost significantly less weight compared with those with increased gastric retention (median %TBWL = 9.0% [4.5-14.7] versus 17.3% [12.2-24.4], p = 0.016).

CONCLUSION

Utilizing gastric emptying as a physiologic predictor of intolerance and response to the single fluid-filled IGB can improve outcomes. This pilot feasibility trial ushers in the era of personalized endoscopic bariatric therapies to maximize patients' tolerance, cost-effectiveness, and meaningful weight loss.

Epidemiology and outcomes of gastroparesis, as documented in general practice records, in the United Kingdom

OBJECTIVE

To generate real-world evidence for the epidemiology of gastroparesis in the UK, we evaluated the prevalence, incidence, patient characteristics and outcomes of gastroparesis in the Clinical Practice Research Datalink (CPRD) database.

DESIGN

This was a retrospective, cross-sectional study. Prevalence and incidence of gastroparesis were evaluated in the CPRD database, with linkage to Hospital Episodes Statistics Admitted Patient Care and Office for National Statistics mortality data. Prevalence and incidence were age and sex standardised to mid-2017 UK population estimates. Descriptive analyses of demographics, aetiologies, pharmacological therapies and mortality were conducted.

RESULTS

Standardised prevalence of gastroparesis, as documented in general practice records, was 13.8 (95% CI 12.6 to 15.1) per 100 000 persons in 2016, and standardised incidence of gastroparesis rose from 1.5 (95% CI 1.1 to 1.8) per 100 000 person-years in 2004 to 1.9 (95% CI 1.4 to 2.3) per 100 000 person-years in 2016. The most common disease aetiologies were idiopathic (39.4%) and diabetic gastroparesis (37.5%), with a similar distribution of type 1 and type 2 diabetes among the 90% who had type of diabetes documented. Patients with diabetic gastroparesis had a significantly higher risk of mortality than those with idiopathic gastroparesis after diagnosis (adjusted HR 1.9, 95% CI 1.2 to 3.0). Of those with gastroparesis, 31.6% were not offered any recognised pharmacological therapy after diagnosis.

CONCLUSION

This is, to our knowledge, the first population-based study providing data on epidemiology and outcomes of gastroparesis in Europe. Further research is required to fully understand the factors influencing outcomes and survival of patients with gastroparesis.

miR-10b-5p Rescues Diabetes and Gastrointestinal Dysmotility

BACKGROUND & AIMS

Interstitial cells of Cajal (ICCs) and pancreatic β cells require receptor tyrosine kinase (KIT) to develop and function properly. Degeneration of ICCs is linked to diabetic gastroparesis. The mechanisms linking diabetes and gastroparesis are unclear, but may involve microRNA (miRNA)-mediated post-transcriptional gene silencing in KIT+ cells.

METHODS

We performed miRNA-sequencing analysis from isolated ICCs in diabetic mice and plasma from patients with idiopathic and diabetic gastroparesis. miR-10b-5p target genes were identified and validated in mouse and human cell lines. For loss-of-function studies, we used KIT+ cell-restricted mir-10b knockout mice and KIT+ cell depletion mice. For gain-of-function studies, a synthetic miR-10b-5p mimic was injected in multiple diabetic mouse models. We compared the efficacy of miR-10b-5p mimic treatment vs antidiabetic and prokinetic medicines.

RESULTS

miR-10b-5p is highly expressed in ICCs from healthy mice, but drastically depleted in ICCs from diabetic mice. A conditional knockout of mir-10b in KIT+ cells or depletion of KIT+ cells in mice leads to degeneration of β cells and ICCs, resulting in diabetes and gastroparesis. miR-10b-5p targets the transcription factor Krüppel-like factor 11 (KLF11), which negatively regulates KIT expression. The miR-10b-5p mimic or Klf11 small interfering RNAs injected into mir-10b knockout mice, diet-induced diabetic mice, and TALLYHO polygenic diabetic mice rescue the diabetes and gastroparesis phenotype for an extended period of time. Furthermore, the miR-10b-5p mimic is more effective in improving glucose homoeostasis and gastrointestinal motility compared with common antidiabetic and prokinetic medications.

CONCLUSIONS

miR-10b-5p is a key regulator in diabetes and gastrointestinal dysmotility via the KLF11-KIT pathway. Restoration of miR-10b-5p may provide therapeutic benefits for these disorders.

Meal-Induced Symptoms in Children with Dyspepsia-Relationships to Sex and the Presence of Gastroparesis

OBJECTIVES

To test the hypothesis that in children with dyspepsia, prospective symptom severity following ingestion of a meal would correlate with percent gastric retention, and those ultimately diagnosed with gastroparesis would report worse symptoms.

STUDY DESIGN

Prospective, single-center study with 104 children with dyspepsia completing a prospective dyspepsia symptom questionnaire before and after eating a standardized Tougas meal during gastric emptying scintigraphy. Main outcomes included correlation between gastric retention and symptoms and comparison of symptom severity between those with and without gastroparesis.

RESULTS

Fifty-two children (50%) had gastroparesis (gastroparesis: 12.5 ± 2.9 years, 65% female; nongastroparesis: 13.0 ± 2.9 years, 60% female; all P > .05). Bloating was the only symptom significantly worse in youth with gastroparesis. For the entire cohort, bloating and fullness correlated with percent retention. However, in those with gastroparesis, only nausea correlated with retention (4 hours.; r_s = 0.275, P < .05). Girls with gastroparesis had significantly worse symptoms (except satiety) when compared with boys with gastroparesis (P < .05).

CONCLUSIONS

Overall in children, there is little difference in symptom severity between children with gastroparesis vs normal emptying based on current standards. However, girls with gastroparesis have worse symptoms vs boys with gastroparesis, underscoring a need for further studies into the role of sex in gastroparesis symptoms. In all children, both bloating and fullness correlated modestly with gastric retention, and nausea correlated in those with gastroparesis.

Relationship of motor mechanisms to gastroparesis symptoms: toward individualized treatment

Following a classical paper by Dr. Keith A. Kelly published in this journal, and over the past 40 years, there has been increased understanding of the functions of different regions of the stomach, specifically the fundus, antrum, and pylorus. Several of the important physiological principles were based on in vivo animal studies that led to the appreciation of regional function and control mechanisms. These include the roles of the extrinsic parasympathetic vagal innervation, the gastric enteric nervous system and electrical syncytium consisting of pacemaker cells and smooth muscle cells, and duodenogastric reflexes providing feedback regulation following the arrival of food and hydrogen ions stimulating the release of hormones and vagal afferent mechanisms that inhibit gastric motility and stimulate pyloric contractility. Further insights on the role of regional motor functions in gastric emptying were obtained from observations in patients following diverse gastric surgeries or bariatric procedures, including fundoplication, Billroth I and sleeve gastrectomy, and sleeve gastroplasty. Antropyloroduodenal manometry and measurements of pyloric diameter and distensibility index provided important assessments of the role of antral hypomotility and pylorospasm, and these constitute specific targets for individualized treatment of patients with gastroparesis. Moreover, in patients with upper gastrointestinal symptoms suggestive of gastroparesis, the availability of measurements of gastric accommodation and pharmacological agents to reduce gastric sensitivity or enhance gastric accommodation provide additional specific targets for individualized treatment. It is anticipated that, in the future, such physiological measurements will be applied in patients to optimize choice of therapy, possibly including identifying the best candidate for pyloric interventions.

Mechanisms of Food-Induced Symptom Induction and Dietary Management in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, characterised by upper gastrointestinal symptom profiles that differentiate FD from the irritable bowel syndrome (IBS), although the two conditions often co-exist. Despite food and eating being implicated in FD symptom induction, evidence-based guidance for dietetic management of FD is limited. The aim of this narrative review is to collate the possible mechanisms for eating-induced and food-related symptoms of FD for stratification of dietetic management. Specific carbohydrates, proteins and fats, or foods high in these macronutrients have all been reported as influencing FD symptom induction, with removal of 'trigger' foods or nutrients shown to alleviate symptoms. Food additives and natural food chemicals have also been implicated, but there is a lack of convincing evidence. Emerging evidence suggests the gastrointestinal microbiota is the primary interface between food and symptom induction in FD, and is therefore a research direction that warrants substantial attention. Objective markers of FD, along with more sensitive and specific dietary assessment tools will contribute to progressing towards evidence-based dietetic management of FD.

Point-of-Care Ultrasound (POCUS) in the Field of Diabetology

Ultrasound is increasingly used in daily clinical practice to improve the efficiency of the clinical examination. In this article, we reviewed its various possible uses in the field of diabetology. The ultrasonic evaluation of the carotid arteries (plaques and intima media thickness) allows improving the assessment of the cardiovascular risk. Steatosis can be detected relatively easily on liver ultrasound. Ultrasound also allows a more sensitive detection of lipohypertrophy resulting in glycemic fluctuations and thus increasing the risk of hypoglycemia than the clinical examination. Finally, muscle ultrasound appears to be a promising tool to assess the nutritional status and its consequences (e.g., falls).

Diabetic and Non-Diabetic Gastroparesis: A Retrospective Comparative Outcome Study From the Nationwide Inpatient Sample

Background

Gastroparesis (GP), meaning “gastric palsy”, is a chronic medical condition characterized by delayed or absent gastric emptying in the absence of mechanical obstruction. The primary objective of this study was to determine the patient-specific outcomes and the burden of GP on the US healthcare system.

Methods

This was a population-based, retrospective study designed to analyze data available from the Nationwide Inpatient Sample (NIS) for 2016 and 2017. Using the International Classification of Diseases, Tenth Revision (ICD-10) codes, we identified adult (18 years or older) hospitalizations with a principal diagnosis of GP. The study sample was further classified into two distinct groups based on the presence or absence of GP, namely diabetic GP (DGP) and non-diabetic GP (NDGP). The primary outcome of our study was inpatient mortality secondary to GP while the secondary outcomes included the odds of system-based complications and the burden of the disease on the United States healthcare system.

Results

We identified 99,695 adult (≥ 18 years) hospitalizations with a principal discharge diagnosis of GP in 2016 and 2017. Of these patients, 78.1% (77,885) had DGP and 21.9% (21,810) were classified in the NDGP group. We noted a higher proportion of women (79.3% vs. 63.4%, P < 0.001), patients with a history of smoking (35.8% vs. 31.7%, P < 0.001) and chronic obstructive pulmonary disease (10.7% vs. 7.6%, P < 0.001) in the NDGP group. After adjusting for common confounders excluding age, the inpatient mortality for GP was found to be 0.25%. Furthermore, after adjustments were made for the Charlson comorbidity index (CCI), we noted higher odds of mortality in the NDGP group (0.30% vs. 0.23%, adjusted odds ratio (aOR): 3.18, 95% confidence interval (CI): 1.75 - 5.79, P < 0.001) compared to the DGP group. Additionally, patients with NDGP had a higher mean length of stay (5 vs. 4.1 days, P < 0.001) and higher mean total hospital charge ($44,100 vs. $35,500, P < 0.001) compared to those with DGP. The NDGP group also had higher odds of sepsis, deep vein thrombosis (DVT) and pulmonary embolism (PE); however, the odds of developing acute kidney injury (AKI) were lower than that of the DGP group.

Conclusions

The inpatient mortality for GP was found to be 0.25%. After adjusting for CCI, patients with NDGP had higher odds of inpatient mortality compared to the DGP group. Additionally, patients with NDGP were associated with a longer length of hospital stay, mean total healthcare cost and higher odds of complications such as sepsis, DVT and PE during the hospitalization.

Significant changes in impedance planimetry (EndoFLIP™) measurements after peroral pyloromyotomy for delayed gastric emptying

BACKGROUND

The endoluminal functional lumen imaging probe (FLIP) can be used to obtain real-time measurements of the diameter (D_min), cross-sectional area (CSA), and distensibility of the pylorus before and after peroral pyloromyotomy (POP), an emerging endoscopic treatment for delayed gastric emptying. Our study aims to report our single-center experience in performing POP with FLIP measurements before and after pyloromyotomy.

METHODS

A retrospective review of a prospectively maintained gastroesophageal database was performed. Demographic and perioperative data, including intraoperative FLIP measurements of the pylorus before and after POP, were analyzed. Measurements were compared using paired t tests.

RESULTS

Thirty-four patients underwent POP between February 2017 and July 2020. Twenty-three (67.7%) patients were male and the average age was 59 years. The etiology of delayed gastric emptying was post-vagotomy in 22 patients, idiopathic gastroparesis in 7 patients, and diabetic gastroparesis in 5 patients. There were no significant differences in pre-myotomy or post-myotomy FLIP measurements when comparing the post-vagotomy versus the gastroparesis groups. There were significant increases in D_min, CSA, and distensibility index when comparing pre-myotomy and post-myotomy readings for all patients (all p < 0.001). At follow-up, 64.7% of patients reported resolution of all symptoms.

CONCLUSION

POP is an effective intervention in patients with delayed gastric emptying. Significant changes in FLIP measurements before and after POP suggest that FLIP may be a useful adjunct in guiding the management of delayed gastric emptying.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

Gastrointestinal motility disorders in neurologic disease

The extrinsic and autonomic nervous system intricately controls the major functions of the gastrointestinal tract through the enteric nervous system; these include motor, secretory, sensory, storage, and excretory functions. Disorders of the nervous system affecting gastrointestinal tract function manifest primarily as abnormalities in motor (rather than secretory) functions. Common gastrointestinal symptoms in neurologic disorders include sialorrhea, dysphagia, gastroparesis, intestinal pseudo-obstruction, constipation, diarrhea, and fecal incontinence. Diseases of the entire neural axis ranging from the cerebral hemispheres to the peripheral autonomic nerves can result in gastrointestinal motility disorders. The most common neurologic diseases affecting gastrointestinal function are stroke, parkinsonism, multiple sclerosis, and diabetic neuropathy. Diagnosis involves identification of the neurologic disease and its distribution, and documentation of segmental gut dysfunction, typically using noninvasive imaging, transit measurements, or intraluminal measurements of pressure activity and coordination of motility. Apart from treatment of the underlying neurologic disease, management focuses on restoration of normal hydration and nutrition and pharmacologic treatment of the gut neuromuscular disorder.

Management of Chronic Abdominal Distension and Bloating

Abdominal bloating and distension are 2 of the most commonly reported gastrointestinal symptoms. Abdominal bloating is characterized by symptoms of trapped gas, abdominal pressure, and fullness. Abdominal distension is defined as a measurable increase in abdominal girth. These symptoms frequently co-exist, although they can occur separately. Defined by Rome IV criteria, functional abdominal bloating and distension commonly coincide with other functional gastrointestinal disorders, such as functional dyspepsia, irritable bowel syndrome, and functional constipation. Abdominal bloating and distension can develop for multiple reasons, including food intolerances, a previous infection that perturbed the intestinal microbiota, disordered visceral sensation, delayed intestinal transit, or an abnormal viscero-somatic reflux. Treatment can be challenging to patients and providers-no regimen has been consistently successful. Successful treatment involves identifying the etiology, assessing severity, educating and reassuring patients, and setting expectations. Therapeutic options include dietary changes, probiotics, antibiotics, prokinetic agents, antispasmodics, neuromodulators, and biofeedback. We review the epidemiology and effects of chronic bloating and distension and pathophysiology, discuss appropriate diagnostic strategies, and assess available treatment options.

Gastric peroral endoscopic pyloromyotomy for decompensated gastroparesis: comprehensive motility analysis in relation to treatment outcomes

Background and study aims  There are no reliable data to predict which patients with gastroparesis (GP) would benefit the most from gastric peroral endoscopic pyloromyotomy (G-POEM). The aim of the present study was to assess whether antro-duodenal motility patterns and pyloric distensibility can predict the outcome of G-POEM in patients with decompensated GP. Patients and methods  In an open-label study, patients with GP and refractory symptoms were eligible for treatment with G-POEM if treatment attempts according to a standardized stepwise protocol had failed. Baseline assessment included Gastroparesis Cardinal Symptom Index (GCSI), C13-octanoic gastric emptying breath test and high-resolution antro-duodenal manometry. Pyloric distensibility using EndoFlip measurements was assessed at baseline and 3 months after the procedure. Explorative analyses were performed on potential predictors of response using logistic regression analyses. Results  Twenty-four patients with decompensated GP underwent G-POEM. At baseline, 78.3 % and 61.9 % of patients showed antral hypomotility and neuropathic motor patterns, respectively. The technical success rate was 100 % (24/24). Mean GCSI improved significantly at 3, 6, and 12 months after G-POEM ( P  = 0.01). Median distensibility index (DI) improved significantly as compared with baseline (7.5 [6.9;11.7] vs. 5.3[3.1;8.1], P  = 0.004). A significant correlation was found between clinical response at 6 months and pyloric DI improvement ( P  = 0.003). No potential predictors of clinical response after G-POEM could be identified in an explorative analysis. Conclusions  G-POEM improved pyloric distensibility patterns in patients with decompensated GP. Clinical response at 6 months after G-POEM was associated with pyloric distensibility improvement. However, no potential predictors of response could be identified from either antro-duodenal motility patterns or pyloric distensibility.

Erythromycin stimulates phasic gastric contractility as assessed with an isovolumetric intragastric balloon pressure measurement

BACKGROUND

A novel technique to assess gastric motility by measuring the pressure in a low-volume intragastric balloon was developed to monitor (disordered) motility. We previously showed that this technique allows measuring pharmacologically induced inhibition of motility. In this study, we assessed whether it is possible to measure pharmacologically induced stimulation of gastric motility using 200 mg erythromycin. Erythromycin is a highly effective stimulator of gastric emptying and contractility.

METHODS

After an overnight fast, a nasogastric balloon catheter was introduced in healthy subjects. After inflation with 120 ml of air, the catheter was connected to a pressure sensor. Intraballoon pressure was continuously recorded for 4 h. After a baseline recording of 2 h, 200 mg erythromycin was infused intravenously over 20 min while the recording continued for 2 h. Epigastric symptoms were surveyed on 100-mm visual analogue scales. Motility was quantified from the pressure recording as a gastric balloon motility index. Wilcoxon signed-rank tests were performed. Data are shown as median (interquartile range).

KEY RESULTS

Six subjects were enrolled and five completed the procedures (age: 28 (25-29) years, body mass index: 24.0 (23.8-24.5) kg m^-2 ). One subject could not tolerate tube placement. Bloating, nausea, and epigastric sensation scores were 0 (0-3), 0 (0-1), and 1 (0-1) mm, respectively. Erythromycin significantly increased the motility index from 0.48 (0.41-0.51) to 0.79 (0.70-0.82) (p = 0.03).

CONCLUSIONS AND INFERENCES

Gastric motility assessed via pressure measurement in a low-volume intragastric balloon is able to detect pharmacologically stimulated motility in healthy subjects, which further validates this technique.

Knowledge, Attitude, and Practice Survey of Gastroparesis in Asia by Asian Neurogastroenterology and Motility Association

BACKGROUND/AIMS

Gastroparesis is identified as a subject that is understudied in Asia. The scientific committee of the Asian Neurogastroenterology and Motility Association performed a Knowledge, Attitude, and Practices survey on gastroparesis among doctors in Asia.

METHODS

The questionnaire was created and developed through a literature review of current gastroparesis works of literature by the scientific committee of Asian Neurogastroenterology and Motility Association.

RESULTS

A total of 490 doctors from across Asia (including Bangladesh, China, Hong Kong, Indonesia, Japan, Malaysia, Myanmar, the Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam) participated in the survey. Gastroparesis is a significant gastrointestinal condition. However, a substantial proportion of respondents was unable to give the correct definition and accurate diagnostic test. The main reason for lack of interest in diagnosing gastroparesis was "the lack of reliable diagnostic tests" (46.8%) or "a lack of effective treatment" (41.5%). Only 41.7% of respondents had access to gastric emptying scintigraphy. Most doctors had never diagnosed gastroparesis at all (25.2%) or diagnosed fewer than 5 patients a year (52.1%).

CONCLUSIONS

Gastroparesis can be challenging to diagnose due to the lack of instrument, standardized method, and paucity of research data on normative value, risk factors, and treatment studies in Asian patients. Future strategies should concentrate on how to disseminate the latest knowledge of gastroparesis in Asia. In particular, there is an urgent need to estimate the magnitude of the problems in high risk and idiopathic patients as well as a standardized diagnostic procedure in Asia.

Gut Microbial Dysbiosis in the Pathogenesis of Gastrointestinal Dysmotility and Metabolic Disorders

Of all microorganisms in the human body, the largest and most complex population resides in the gastrointestinal (GI) tract. The gut microbiota continuously adapts to the host environment and serves multiple critical functions for their hosts, including regulating host immunity, procuring energy from food, and preventing the colonization of pathogens. Mounting evidence has suggested gut microbial imbalance (dysbiosis) as a core pathophysiology in the development of GI motility and metabolic disorders, such as irritable bowel syndrome and diabetes. Current research has focused on discovering associations between these disorders and gut microbial dysbiosis; however, whether these associations are a consequence or cause is still mostly unexplored. State-of-the-art studies have investigated how gut microbes communicate with our body systems through microbiota-derived metabolites and how they are able to modulate host physiology. There is now mounting evidence that alterations in the composition of small intestinal microbes have an association with GI dysmotility and metabolic disorders. Although treatment options for gut microbial dysbiosis are currently limited, antibiotics, fecal microbiota transplantation, probiotics, and dietary interventions are currently the best options. However, treatment with broad-spectrum antibiotics has been viewed with skepticism due to the risk of developing antibiotic resistant bacteria. Studies are warranted to elucidate the cellular and molecular pathways underlying gut microbiota-host crosstalk and for the development of a powerful platform for future therapeutic approaches. Here, we review recent literature on gut microbial alterations and/or interactions involved in the pathophysiology of GI dysmotility and metabolic disorders.

Gastric Electrical Stimulation for Treatment of Refractory Gastroparesis: the Current Approach to Management

Purpose of Review

Gastroparesis is one of the more challenging entities in the landscape of gastroenterology, posing difficulties for both patients and physicians with regard to effective management and therapies. In this article, we reviewed various gastroparesis treatment options, with an emphasis on gastric electrical stimulation (GES).

Recent Findings

GES has demonstrated a significant reduction of cardinal symptoms in refractory gastroparetic patients, particularly nausea and vomiting, across multiple studies. However, GES has not been shown to conclusively decrease gastric emptying time in these patients. Such finding has led the investigators to analyze the impact of combining GES with pyloroplasty. While this treatment pathway is nascent, its results thus far reveal an amplified improvement of gastroparesis symptomatology in addition to significant reduction of gastric transit, compared to GES by itself.

Summary

Limited treatment choices are available for refractory gastroparesis. Combining GES with pyloroplasty holds promise but requires further assessment in large-scale trials to fully evaluate the risks and benefits.

Delayed Gastric Emptying Is Not Associated with a Microbiological Diagnosis of Small Intestinal Bacterial Overgrowth

BACKGROUND

Clinical symptoms of patients with small intestinal bacterial overgrowth (SIBO) may overlap with symptoms of gastroparesis. Prior studies suggest delayed small intestinal transit is associated with SIBO, but have not shown an association between delayed gastric emptying and SIBO. However, these studies have generally relied on the indirect method of breath testing to diagnose SIBO.

AIMS

The aim of this study was to examine the association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy.

METHODS

In a single-center retrospective study of previous research participants who presented for small bowel enteroscopy for diagnostic evaluation of SIBO, we identified 73 participants who underwent gastric emptying study by scintigraphy. A microbiological diagnosis of SIBO was made in patients based on culture results of jejunal aspirates. Clinical symptoms were assessed using the total gastroparesis cardinal symptom index (GCSI) score. We compared delayed gastric emptying, 2- and 4-h gastric retention, and gastroparesis symptoms between patients with and without a microbiological diagnosis of SIBO.

KEY RESULTS

Among 29 participants with SIBO and 44 without SIBO, 33 (45%) had evidence of delayed gastric emptying. There was no significant association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. Percent retained at 2 and 4 h, and total GCSI scores did not differ significantly between those with and without SIBO.

CONCLUSIONS

Although delayed gastric emptying is common in patients with suspected SIBO, gastric emptying is not associated with a microbiological diagnosis of SIBO.

Gastrointestinal symptoms and cardiac vagal tone in type 1 diabetes correlates with gut transit times and motility index

BACKGROUND

Although gastrointestinal (GI) symptoms are common in diabetes, they frequently do not correlate with measurable sensorimotor abnormalities. The wireless motility capsule (WMC) measures pressure, temperature, and pH as it traverses the GI tract wherefrom transit times and motility indices are derived. The aim was to investigate whether GI symptoms correlate with changes in (a) segmental transit times, (b) segmental motility index, (c) cardiac vagal tone, or (d) presence/absence of peripheral neuropathy in type 1 diabetes.

METHODS

Gastrointestinal symptoms in 104 participants with type 1 diabetes were measured using Gastroparesis Cardinal Symptoms Index and Gastrointestinal Symptom Rating Scale. All underwent standardized WMC investigation measuring segmental transit time and motility. Cardiac vagal tone and presence of peripheral neuropathy were measured using electrocardiographic and nerve conduction velocity testing.

KEY RESULTS

Colonic transit time was correlated with postprandial fullness (P = .01) and constipation (P = .03), while decreased colonic motility index was correlated with diarrhea (P = .01) and decreased bloating (P < .05). Symptoms were not correlated with gastric or small bowel transit time or motility index. In participants with low cardiac vagal tone, gastric motility index (P < .01) and colonic transit time (P < .05) were increased, but not in those with peripheral neuropathy. Abdominal pain was decreased with both peripheral neuropathy (P = .04) and decreased cardiac vagal tone (P = .02).

CONCLUSIONS AND INFERENCES

This study supports the rationale for whole gut investigation, using not only transit times but incorporating contractility indices as well. Furthermore, a decreased parasympathetic modulation and an increased hyposensate state appear to be present in type 1 diabetes.