Recipe for IBD: can we use food to control inflammatory bowel disease?

Association between Dietary Inflammatory Index and Ulcerative Colitis: a case-control study

INTRODUCTION

Diet plays a crucial role in the activity and onset of ulcerative colitis (UC). The aim of this study was to comprehensively explore the association between the dietary inflammatory index (DII) and UC.

METHODS

Participants completed the Food Frequency Questionnaire to obtain data on their dietary intake. Individual DII scores were calculated to assess inflammatory potential of each participant's diet. A logistic regression model was used to analyze the correlation between the DII and UC activity, including the active and remission phases.

RESULTS

In this study, 100 controls and 106 patients with UC were enrolled, including 50 patients in remission and 56 patients with active UC. Dietary nutrient intake was generally slightly lower in patients with UC than in the controls, including energy, protein, dietary fiber, vitamin D, vitamin E, vitamin B1, vitamin B2, vitamin C, folic acid, fat, monosaturated fatty acids, and n-3 fatty acids (P < 0.05). Compared with the low pro-inflammatory potential diet, patients with higher DII had a higher correlation with UC before and after adjustment for relevant confounders. In consecutive DII, the correlation with UC increased with each 1 increase in DII. No significant correlation was observed between DII and UC activity.

CONCLUSIONS

Diets with a high inflammatory index are correlated with UC. Therefore, consuming a diet with a low inflammatory index may be beneficial for patients with UC.

Dietary inflammatory potential, genetic predisposition, and incidence of Crohn's disease and ulcerative colitis

BACKGROUND

Evidence for a potential link between dietary inflammatory potential and inflammatory bowel disease is limited, and the moderating role of genetic susceptibility remains to be assessed.

OBJECTIVE

To evaluate energy-adjusted dietary inflammatory index (E-DII) for the associations with incident Crohn's disease (CD) and ulcerative colitis (UC) and the role of genetic susceptibility.

METHODS

A total of 205,706 UK Biobank participants who were aged 39-72 years and had no known CD or UC at baseline (2006-2010) were included. The E-DII score was calculated based on energy-adjusted average intakes of 33 food or nutrient items derived from up to five 24-hour dietary recalls. Multivariable Cox regression models were used estimate hazard ratios (HRs) with 95% confidence interval (CI) for incident CD and UC.

RESULTS

During a median 12.3 years of follow-up, 382 incident CD and 798 incident UC cases were ascertained. A higher E-DII score was not associated with risk of CD (HR Q4 VS. Q1 = 1.28, 95% CI: 0.94-1.74; P-trend = 0.09) or UC (HR Q4 VS. Q1 = 1.10, 95% CI: 0.90-1.36; P-trend = 0.17). There was an interaction between the E-DII and the polygenic risk score (PRS) for CD on incident CD (P-interaction = 0.023), with an association only among participants with a high PRS (HR Q4 VS. Q1 = 1.64, 95% CI: 1.03-2.61) (P-interaction = 0.023). As compared with the participants with a low PRS for CD and a low E-DII score, participants with high levels of both scores had a particularly higher risk of CD (HR = 3.12; 95% CI: 1.74-5.60).

CONCLUSIONS

The association of dietary inflammatory potential with incident CD appears to be amplified by high genetic susceptibility to CD.

Relieving Effect of Artemisia ordosica Krasch Extract on DSS-Induced Colitis by Regulating Immunity, Antioxidant Function, Gut Microbiota, and Bile Acid Metabolism in Mice

Artemisia ordosica Krasch, a traditional Chinese herbal medicine, possesses antibacterial, antiviral, and anti-inflammatory properties. The aim of this experiment was to investigate the therapeutic effect of Artemisia ordosica Krasch extraction (AOE) in treating colitis induced by dextran sulfate sodium (DSS) in mice. The in vitro antioxidant activity of AOE was evaluated by assessing its iron reduction capacity and scavenging capacity towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (·OH). The protective effect of AOE on colitis in mice was determined by monitoring key indicators such as body weight, colon length, and survival rate in mice, as well as by assessing the expression of colon-related genes and cytokine levels. We evaluated the impact of AOE on intestinal microbiota by measuring the 16s sequencing of cecal contents and bile acid metabolism. The results showed that the iron reduction capacity of AOE was positively correlated with its concentration. The half-maximal inhibitory concentrations (IC50) for scavenging DPPH and hydroxyl radicals were 3.126 mg/mL and 6.139 mg/mL, with a 95% confidence interval of 95%. In vivo studies demonstrated that AOE reduced DSS-induced colitis in mice by increasing the colon length, enhancing antioxidant enzyme activity, inhibiting inflammatory cell infiltration, suppressing the formation of TNF-α and IL-6, and reducing malondialdehyde (MDA) levels. qPCR analysis revealed that AOE reversed the down-regulation of Claudin mRNA expression, and altered the composition of cecal microbiota, thus mitigating DSS-induced colitis. AOE plays a crucial role in alleviating colitis in mice and effectively improves DSS-induced colitis, highlighting its potential as a therapeutic agent for inflammatory bowel diseases.

Pro-Inflammatory Diet Is Correlated with High Veillonella rogosae, Gut Inflammation and Clinical Relapse of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic conditions arising from an intricate interplay of genetics and environmental factors, and are associated with gut dysbiosis, inflammation, and gut permeability. In this study, we investigated whether the inflammatory potential of the diet is associated with the gut microbiota profile, inflammation, and permeability in forty patients with IBD in clinical remission. The dietary inflammatory index (DII) score was used to assess the inflammatory potential of the diet. The fecal microbiota profile was analyzed using 16SrRNA (V3-V4) gene sequencing, while fecal zonulin and calprotectin levels were measured with enzyme-linked immunosorbent assays. We found a positive correlation between the DII score and elevated calprotectin levels (Rho = 0.498; p = 0.001), but not with zonulin levels. Although α- and β-diversity did not significantly differ across DII quartiles, the most pro-inflammatory diet group exhibited a higher fecal abundance of Veillonella rogosae (p = 0.026). In addition, the abundance of some specific bacteria sequences showed an exponential behavior across DII quartiles and a correlation with calprotectin or zonulin levels (p ≤ 0.050). This included a positive correlation between sq702. Veillonella rogosae and fecal calprotectin levels (Rho = 0.419, p = 0.007). DII, calprotectin, and zonulin levels were identified as significant predictors of 6-month disease relapse (p ≤ 0.050). Our findings suggest a potential relationship of a pro-inflammatory diet intake with Veillonella rogosae and calprotectin levels in IBD patients in clinical remission, which may contribute to disease relapse.

Improvement of ulcerative colitis control by searching and restricting of inflammatory trigger factors in daily clinical practice

BACKGROUND/AIMS

Exacerbating factors of ulcerative colitis (UC) are multiple and complex with individual influence. We aimed to evaluate the efficacy of disease control by searching and restricting inflammation trigger factors of UC relapse individually in daily clinical practice.

METHODS

Both patients with UC history or new diagnosis were asked to avoid dairy products at first doctor visit. Individual-reported potential trigger factors were restricted when UC flared up (Mayo endoscopy score ≥1) from remission status. The remission rate, duration to remission and medication were analyzed between the groups of factor restriction complete, incomplete and unknown.

RESULTS

The total remission rate was 91.7% of 108 patients with complete restriction of dairy product. The duration to remission of UC history group was significantly longer than that of new diagnosis group (88.5 days vs. 43.4 days, P=0.006) in patients with initial endoscopic score 2-3, but no difference in patients with score 1. After first remission, the inflammation trigger factors in 161 relapse episodes of 72 patients were multiple and personal. Milk/dairy products, herb medicine/Chinese tonic food and dietary supplement were the common factors, followed by psychological issues, non-dietary factors (smoking cessation, cosmetic products) and discontinuation of medication by patients themselves. Factor unknown accounted for 14.1% of patients. The benefits of factor complete restriction included shorter duration to remission (P<0.001), less steroid and biological agent use (P=0.022) when compared to incomplete restriction or factor unknown group.

CONCLUSIONS

Restriction of dairy diet first then searching and restricting trigger factors personally if UC relapse can improve the disease control and downgrade the medication usage of UC patients in daily clinical practice.

Extracellular Vesicles: The Next Generation Theranostic Nanomedicine for Inflammatory Bowel Disease

The recent rapid development in the field of extracellular vesicles (EVs) based nanotechnology has provided unprecedented opportunities for nanomedicine platforms. As natural nanocarriers, EVs such as exosomes, exosome-like nanoparticles and outer membrane vesicles (OMVs), have unique structure/composition/morphology characteristics, and show excellent physical and chemical/biochemical properties, making them a new generation of theranostic nanomedicine. Here, we reviewed the characteristics of EVs from the perspective of their formation and biological function in inflammatory bowel disease (IBD). Moreover, EVs can crucially participate in the interaction and communication of intestinal epithelial cells (IECs)-immune cells-gut microbiota to regulate immune response, intestinal inflammation and intestinal homeostasis. Interestingly, based on current representative examples in the field of exosomes and exosome-like nanoparticles for IBD treatment, it is shown that plant, milk, and cells-derived exosomes and exosome-like nanoparticles can exert a therapeutic effect through their components, such as proteins, nucleic acid, and lipids. Moreover, several drug loading methods and target modification of exosomes are used to improve their therapeutic capability. We also discussed the application of exosomes and exosome-like nanoparticles in the treatment of IBD. In this review, we aim to better and more clearly clarify the underlying mechanisms of the EVs in the pathogenesis of IBD, and provide directions of exosomes and exosome-like nanoparticles mediated for IBD treatment.

Probiotic potential of Tetragenococcus halophilus EFEL7002 isolated from Korean soy Meju

BACKGROUND

Probiotic starters can improve the flavor profile, texture, and health-promoting properties of fermented foods. Tetragenococcus halophilus is a halophilic lactic acid bacterium that is a candidate starter for high-salt fermented foods. However, the species is known to produce biogenic amines, which are associated with neurotoxicity. Here, we report a probiotic starter strain of T. halophilus, EFEL7002, that is suitable for use in high-salt fermentation.

RESULTS

EFEL7002 was isolated from Korean meju (fermented soybean) and identified as T. halophilus, with 99.85% similarity. The strain is safe for use in food as it is a non-hemolytic and non-biogenic amine producer. EFEL7002 is tolerant to gastrointestinal conditions and can adhere to Caco-2 cells. This strain showed antioxidant, anti-inflammatory, and protective effects against the human gut epithelial barrier. EFEL7002 grew well in media containing 0-18% NaCl showing maximum cell densities in 6% or 12% NaCl.

CONCLUSIONS

T. halophilus EFEL7002 can be used as a health-promoting probiotic starter culture for various salty fermented foods.

Association between Dietary Inflammatory Index and Sarcopenia in Crohn's Disease Patients

Background: Chronic inflammation is a pathophysiological cause of sarcopenia in Crohn’s disease (CD) patients. However, the potential impact of diet-related inflammation on sarcopenia has not yet been adequately investigated. We examined the associations between Dietary Inflammatory Index (DII) and sarcopenia in CD patients. Methods: A total of 140 CD patients from Ruijin Hospital in Shanghai were included in this cross-sectional study. DII scores were calculated from the dietary data collected using a validated food frequency questionnaire (FFQ). Sarcopenia was determined according to the Asian Working Group for Sarcopenia. Multivariable logistic regression analyses were performed to determine the association between DII and sarcopenia. Results: The mean DII score was 0.81 ± 2.13, ranging from −3.24 to 4.89. The overall prevalence of sarcopenia was 26.4%. The higher DII score significantly increased the risk of sarcopenia in CD patients (OR_Quartile4vs1: 9.59, 95% CI: 1.69, 54.42, p_trend = 0.031) in the multivariable model after adjusting for more potential confounders. Moreover, CD patients with a lower DII had a significantly higher appendicular skeletal muscle mass index (ASMI, OR_Quartile4vs1: 5.48, 95% CI: 1.51, 19.87, p_trend = 0.018) after adjusting for age, gender, BMI, smoking status and drinking status model. Yet, there were no significant differences between DII and ASMI after adjusting for more potential confounders. Additionally, no significant association was observed between DII and handgrip strength in the multivariable-adjusted models. Conclusions: Pro-inflammatory diet was associated with increased risk of sarcopenia in CD patients. CD patients should have a proper intake of energy and protein. These patients could also benefit from supplementation with enteral nutrition due to its anti-inflammatory potential.

Current Advances in Multifunctional Nanocarriers Based on Marine Polysaccharides for Colon Delivery of Food Polyphenols

Inflammatory bowel disease (IBD) has been considered as a chronic disease that is difficult to cure and needs lifelong treatment. Marine polysaccharides with good biocompatibility and biodegradability, mucoadhesion, sensitivity to external stimuli, and targeting ability can be used as wall materials for oral colon-targeted delivery of polyphenols in nutrition intervention of IBD. This manuscript reviewed the latest progress in the design, preparation, and characterization of marine polysaccharides-derived multifunctional nanocarriers for polyphenol colon delivery. Chitosan, sodium alginate, chondroitin sulfate, and hyaluronic acid were discussed in the preparation of polyphenol delivery systems. The design strategy, synthesis methods, and structure characterization of multifunctional polyphenol carriers including stimuli-responsive nanocarriers, mucoadhesive and mucus-penetrating nanocarriers, colon targeted nanocarriers, and bioactive compounds codelivery nanocarriers were reviewed in the alleviation of IBD. The research perspectives in the preparation and characterization of delivery carriers using marine polysaccharide as materials were proposed for their potential application in food bioactive components.

Development of Anti-inflammatory Probiotic Limosilactobacillus reuteri EFEL6901 as Kimchi Starter: in vitro and In vivo Evidence

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. In this study, we developed an anti-inflammatory probiotic starter, Limosilactobacillus reuteri EFEL6901, for use in kimchi fermentation. The EFEL6901 strain was safe for use in foods and was stable under human gastrointestinal conditions. In in vitro experiments, EFEL6901 cells adhered well to colonic epithelial cells and decreased nitric oxide production in lipopolysaccharide-induced macrophages. In in vivo experiments, oral administration of EFEL6901 to DSS-induced colitis mice models significantly alleviated the observed colitis symptoms, prevented body weight loss, lowered the disease activity index score, and prevented colon length shortening. Analysis of these results indicated that EFEL6901 played a probiotic role by preventing the overproduction of pro-inflammatory cytokines, improving gut barrier function, and up-regulating the concentrations of short-chain fatty acids. In addition, EFEL6901 made a fast growth in a simulated kimchi juice and it synthesized similar amounts of metabolites in nabak-kimchi comparable to a commercial kimchi. This study demonstrates that EFEL6901 can be used as a suitable kimchi starter to promote gut health and product quality.

Armillaria luteo-virens Sacc Ameliorates Dextran Sulfate Sodium Induced Colitis through Modulation of Gut Microbiota and Microbiota-Related Bile Acids

Armillaria luteo-virens Sacc (ALS) is a rare wild Chinese medicinal and edible basidiomycete. However, its protective effect on intestinal functions and the underlying mechanism is still unknown. This work explored the improvement of dextran sulfate sodium (DSS)-induced colitis by ALS. ALS supplementation markedly improved colitis symptoms, gut barrier integrity, and goblet loss in DSS-treated mice. In addition, ALS inhibited colonic inflammation through the inhibition/activation of the mitogen-activated protein kinases/NF-κB signaling pathway. The 16S rRNA gene-based microbiota analysis revealed that ALS altered the gut microbiota composition, decreasing the richness of Enterobacteriaceae and increasing the abundance of Lactobacillaceae. The bile-acid-targeted metabolomic analysis showed that ALS recovered the microbial bile acid metabolism in the gut, enabling the activation of the farnesoid X receptor signaling by these acids, thus maintaining the intestinal homeostasis. Importantly, broad-spectrum antibiotic treatment reduced the efficacy of ALS-induced protection from colitis. Overall, our findings suggest that ALS may represent a novel approach in the nutritional intervention to prevent colitis.

Effect of dietary interventions on inflammatory biomarkers of inflammatory bowel diseases: A systematic review of clinical trials

OBJECTIVES

In this review, we systematically assess whether dietary interventions are effective in attenuating inflammatory biomarkers in IBDs based on clinical trials available in the literature.

RESEARCH METHODS & PROCEDURES

This review was conducted in accordance with the guidelines of the PRISMA. We used the PubMed and SciVerse Scopus databases and the Cochrane collaboration tool to assess the risk of bias in clinical trials. The PICO (patient, intervention, comparison, and outcomes) strategy was used, with the descriptors: "Inflammatory bowel disease", "Crohn's disease", "cd", "ibd", "ulcerative colitis", "uc", "Diet", "Diet Habits", "Feeding", "Nutrients", "Food Intake", "Dietary patterns", "Inflammations", "Inflammation", "acute-phase proteins", "C-reactive protein", "interleukins", "tumor necrosis factor-alpha" and "inflammatory response". There is no conflict of interest.

DATA ANALYSIS

Fifteen studies were included, with a total of 627 participants. Of the total studies included, seven showed a reduction in some inflammatory markers in response to dietary interventions. This review was registered with the PROSPERO platform under number: CRD42021235150.

CONCLUSIONS

The results presented in this review reveal that dietary intervention with specific characteristics may be important during the treatment of the inflammatory process in patients with IBDs.

Novel Gut Microbiota Patterns Involved in the Attenuation of Dextran Sodium Sulfate-Induced Mouse Colitis Mediated by Glycerol Monolaurate via Inducing Anti-inflammatory Responses

Inflammatory bowel disease (IBD) is a type of immune-mediated chronic and relapsing inflammatory gastrointestinal symptoms. IBD cannot be completely cured because of the complex pathogenesis. Glycerol monolaurate (GML), naturally found in breast milk and coconut oil, has excellent antimicrobial, anti-inflammatory, and immunoregulatory functions. Here, the protective effect of GML on dextran sodium sulfate (DSS)-induced mouse colitis and the underlying gut microbiota-dependent mechanism were assessed in C57BL/6 mice pretreated or cotreated with GML and in antibiotic-treated mice transplanted with GML-modulated microbiota. Results showed that GML pretreatment has an advantage over GML cotreatment in alleviating weight loss and reducing disease activity index (DAI), colonic histological scores, and proinflammatory responses. Moreover, the amounts of Lactobacillus and Bifidobacterium and fecal propionic acid and butyric acid were elevated only in mice pretreated with GML upon DSS induction. Of note, fecal microbiota transplantation (FMT) from GML-pretreated mice achieved faster and more significant remission of DSS-induced colitis, manifested as reduced DAI, longer colon, decreased histological scores, and enhanced colonic Foxp3+ regulatory T cells (Tregs) and ratio of serum anti-inflammatory/proinflammatory cytokines, as well as the reconstruction of microbial communities, including elevated Helicobacter ganmani and decreased pathogenic microbes. In conclusion, GML-mediated enhancement of Bifidobacterium and fecal short-chain fatty acids (SCFAs) could be responsible for the anticolitis effect. FMT assay confirmed that gut microbiota modulated by GML was more resistant to DSS-induced colitis via elevating beneficial H. ganmani and establishing Treg tolerant phenotype. Importantly, colitis remission induced by GML is associated with novel gut microbiota patterns, even though different microbial contexts were involved. IMPORTANCE The gut microbiota, which can be highly and dynamically affected by dietary components, is closely related to IBD pathogenesis. Here, we demonstrated that food-grade glycerol monolaurate (GML)-mediated enhancement of Bifidobacterium and fecal SCFAs could be responsible for the anticolitis effect. FMT assay confirmed that gut microbiota modulated by GML was more resistant to DSS-induced colitis via elevating beneficial H. ganmani and establishing Treg tolerant phenotype. Collectively, colitis remission induced by GML is associated with novel gut microbiota patterns, even though different microbial contexts were involved, which further provided a perspective to identify specific microbial members and those responsible for the anticolitis effect, such as Bifidobacterium and Helicobacter.

Dietary Intake of Total Carbohydrates, Sugar and Sugar-Sweetened Beverages, and Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Objectives: No earlier study has summarized findings from prospective cohort studies on the association of dietary carbohydrates, sugar, and sugar-sweetened beverages (SSBs) consumption and risk of inflammatory bowel disease (IBD). The current study was done to quantitatively summarize earlier information from prospective cohort studies on the link between dietary carbohydrates, sugar, and SSBs intake with risk of IBD.

Methods: Relevant studies published up to June 2021 were searched through PubMed, Medline, SCOPUS, EMBASE, and Google Scholar with the use of relevant keywords. All prospective cohort studies investigating the association of dietary carbohydrates, sugar, and SSBs consumption with risk of IBD were included.

Results: Combining 5 effect sizes from 4 cohort studies, no significant association was found between dietary intake of carbohydrates and risk of ulcerative colitis (UC) (RR: 1.22; 95% CI: 0.70–2.14). The same findings were obtained for risk of Crohn's disease (CD) (RR: 1.06; 95% CI: 0.64–1.75) based on 4 studies with 5 effect sizes. A significant positive association was observed between sugar intake and risk of UC (RR: 1.59; 95% CI: 1.15–2.20), as well as CD (RR: 1.90; 95% CI: 1.06–3.41) when 5 effect sizes from 4 cohort studies were combined. The overall effect size, based on 4 estimates, revealed no significant association between SSBs consumption and risk of UC (RR: 1.02; 95% CI: 0.92–1.12) and CD (RR: 1.22; 95% CI: 0.91–1.64).

Conclusions: Summarizing earlier studies, sugar intake was found to be associated with increased risk of IBD and its subtypes. Any significant association between dietary intake of carbohydrates and SSBs and risk of IBD and its subtypes was not found.

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.

Inflammatory Potential of the Diet and Incidence of Crohn's Disease and Ulcerative Colitis in the EPIC-Spain Cohort

Diet may influence the development of inflammatory bowel disease through the modulation of inflammation. We investigated whether the inflammatory potential of the diet is associated with the risk of Crohn's disease (CD) and ulcerative colitis (UC) in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain). The study included 32,633 participants aged 29-69 years. The inflammatory potential of the diet was measured by using an inflammatory score of the diet (ISD) based on a baseline dietary history questionnaire. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 21 years (674,547 person-years) of follow-up, 32 and 57 participants developed CD and UC, respectively. In multivariable analysis, a one-standard deviation (SD) increment in the ISD (two-unit increase) was associated with a higher risk of CD (HR of 1.71; 95% CI: 1.05-2.80; p = 0.031). By contrast, ISD was not associated with UC (HR for one-SD increment of 0.89; 95% CI: 0.66-1.19; p = 0.436). Our results suggest that consuming a more pro-inflammatory diet may contribute to the risk of CD, supporting that a healthy diet might be beneficial in its prevention. Further, larger studies are needed to verify these findings.

Age-related changes in ocular mucosal tolerance: Lessons learned from gut and respiratory tract immunity

The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation-free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune-based ocular surface disorders, which could be related to an age-related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.

Association Between Inflammatory Potential of the Diet and Ulcerative Colitis: A Case-Control Study

Background/Aim: Despite the inflammatory nature of inflammatory bowel disease (IBD), limited data are available on the association of inflammatory potential of the diet and risk of ulcerative colitis (UC). We aimed to investigate the association of inflammatory potential of the diet (IPD) score and odds of UC in a case-control study. Methods: Patients with UC were enrolled from Iranian IBD registry, whose disease was confirmed by a gastroenterologist. Controls were selected randomly from the Study of the Epidemiology of Psycho Alimentary Health and Nutrition (SEPAHAN) study, a large population-based study on more than 8,000 apparently healthy individuals. Dietary intakes of 28 food items obtained from a validated dish-based food frequency questionnaire (FFQ), were used to compute IPD score. Results: This case-control study was carried out among 109 cases and 218 randomly chosen controls. Mean age of cases and controls was 39.5 ± 10.0 and 41.5 ± 11.8 y, respectively. Totally, 52% of study participants were female and 48% were male. After controlling for age, sex, and body mass index (BMI), we found that the patients with UC were more likely to be in the highest quartile of IPD score compared with controls (OR: 2.83; 95% CI: 1.41-5.69, P-trend < 0.001). This association strengthened after additional adjustment for education, smoking, medical history, and physical activity (OR: 3.48; 95% CI: 1.32-9.10, P-trend = 0.003). When we took dietary habits into account, the association was slightly attenuated (OR: 3.33; 95% CI: 1.20-9.20, P-trend = 0.005). Conclusions: We found that adherence to a pro-inflammatory diet was positively associated with greater odds of UC. Further studies are required to confirm these findings.

Nutrition Regulates Innate Immunity in Health and Disease

Nutrient content and nutrient timing are considered key regulators of human health and a variety of diseases and involve complex interactions with the mucosal immune system. In particular, the innate immune system is emerging as an important signaling hub that modulates the response to nutritional signals, in part via signaling through the gut microbiota. In this review we elucidate emerging evidence that interactions between innate immunity and diet affect human metabolic health and disease, including cardiometabolic disorders, allergic diseases, autoimmune disorders, infections, and cancers. Furthermore, we discuss the potential modulatory effects of the gut microbiota on interactions between the immune system and nutrition in health and disease, namely how it relays nutritional signals to the innate immune system under specific physiological contexts. Finally, we identify key open questions and challenges to comprehensively understanding the intersection between nutrition and innate immunity and how potential nutritional, immune, and microbial therapeutics may be developed into promising future avenues of precision treatment.

Soluble CD83 suppresses experimental food allergy via regulating aberrant T helper 2 responses

Aberrant T helper-2 (Th2) responses play a critical role in the pathogenesis of allergic diseases. The underlying mechanism is to be further investigated. It is reported that soluble CD83 (sCD83) has immune-regulatory effects. This study aims to investigate the role of sCD83 in the regulation of Th2 polarization. Blood samples were collected from pediatric patients with food allergy (FA). The Th2 response was analyzed by pertinent immunological approaches. An FA murine model was developed to test the role of sCD83 in the regulation of FA response. We found that the serum sCD83 levels were lower in FA patients. A negative correlation was detected between serum sCD83 levels and serum Th2 cytokine levels. The presence of sCD83 suppressed Th2 cell differentiation and antigen-specific Th2 cell activation. sCD83 upregulated the T-bet expression and suppressed the GATA3 expression in CD4+ T cells. Administration of sCD83 suppressed experimental FA. Pediatric FA patients have low serum sCD83 levels. Administration of sCD83 can alleviate experimental FA via suppression of aberrant Th2 polarization.

A new target for the treatment of inflammatory bowel disease: Interleukin-37

Interleukin (IL)-37 belongs to the IL-1 cytokine family. It has anti-inflammatory effects on numerous autoimmune diseases such as asthma, psoriasis, inflammatory bowel disease (IBD), systemic lupus erythematosus (SLE), multiple sclerosis (MS) and rheumatoid arthritis (RA). Mechanistically, IL-37 plays an anti-inflammatory role by regulating the expression of inflammatory factors in two ways: binding extracellular receptors IL-18R or transferring into the nucleus with Smad3. IBD is a kind of idiopathic intestinal inflammatory disease with unknown etiology and pathogenesis. Recent researches had proved that IL-37 is negatively involved in the pathogenesis and development of IBD. Among various inflammatory diseases, IL-37 has been shown to regulate inflammatory development by acting on various immune cells such as neutrophils, macrophages (Mϕ), dendritic cells (DCs), T cells and intestinal epithelial cells. This review summarizes the biological role of IL-37, and its immunoregulatory effects on the immune cells, especially anti-inflammatory function in both human and experimental models of IBD.

Does the inflammatory potential of diet affect disease activity in patients with inflammatory bowel disease?

Background

Diet is an important modulator of inflammation, which is associated with inflammatory bowel disease (IBD). In this study, we examined whether the inflammatory properties of diets are associated with disease activity in patients with IBD.

Methods

A cross-sectional study was conducted on 143 IBD patients, including 32 patients with Crohn’s disease (CD) and 111 patients with ulcerative colitis (UC). Dietary intakes were assessed by a valid 168-item food frequency questionnaire (FFQ). The inflammatory potential of the diet was assessed by calculating the two scores of Dietary Inflammatory Index (DII®), and the Empirical Dietary Inflammatory Pattern (EDIP), and CD and UC disease activity were determined by the Crohn’s disease activity index (CDAI) and the Mayo score, respectively. Associations of the inflammatory indices as median and as tertiles with disease activity were analyzed using logistic regression in a univariate model and after adjusting for total energy intake (continuous), type of disease (CD and UC) and drug consumption (no drugs, single drug, and multiple drugs).

Results

Sixty-four IBD patients (44.8%) in this study had active disease.The DII® score and the EDIP did not differ significantly between active and inactive patients (− 1.45 ± 1.04 vs.− 1.20 ± 1.24; 0.56 ± 0.22 vs. 0.53 ± 0.28, respectively). After adjusting for energy intake, drug use, and IBD type, the odds (95%CIs) of active disease among patients in tertile 3 compared to those in tertile 1 were 0.84 (0.32–2.17) for DII and 1.50 (0.61–3.72) for EDIP; neither of which were statistically significantly different from the rates in tertile 1.

Conclusions

Although point estimates were in the expected direction of increased risk, the inflammatory potential of diet, assessed using DII or EDIP, was not associated with severity of disease in IBD patients. Whether diet-related inflammation affects disease activity in patients with IBD deserves further investigations.

Gut bioengineering promotes gut repair and pharmaceutical research: a review

The gastrointestinal (GI) tract has a diverse set of physiological functions, including peristalsis, immune defense, and nutrient absorptions. These functions are mediated by various intestinal cells such as epithelial cells, interstitial cells, smooth muscle cells, and neurocytes. The loss or dysfunction of specific cells directly results in GI disease, while supplementation of normal cells promotes gut healing. Gut bioengineering has been developing for this purpose to reconstruct the damaged tissues. Moreover, GI tract provides an accessible route for drug delivery, but the collateral damages induced by side effects cannot be ignored. Bioengineered intestinal tissues provide three-dimensional platforms that mimic the in vivo environment to study drug functions. Given the importance of gut bioengineering in current research, in this review, we summarize the advances in the technologies of gut bioengineering and their applications. We were able to identify several ground-breaking discoveries in our review, while more work is needed to promote the clinical translation of gut bioengineering.

Stress Triggers Flare of Inflammatory Bowel Disease in Children and Adults

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease characterized by chronic and relapsing manifestations. It is noteworthy that the prevalence of IBD is gradually increasing in both children and adults. Currently, the pathogenesis of IBD remains to be completely elucidated. IBD is believed to occur through interactions among genetics, environmental factors, and the gut microbiota. However, the relapsing and remitting course of IBD underlines the importance of other modifiers, such as psychological stress. Growing evidence from clinical and experimental studies suggests that stress acts as a promoting or relapsing factor for IBD. Importantly, recent studies have reported an increasing incidence of anxiety or depression in both children and adults with IBD. In this article, we review the mechanisms by which stress affects IBD, such as via impaired intestinal barrier function, disturbance of the gut microbiota, intestinal dysmotility, and immune and neuroendocrine dysfunction. With regard to both children and adults, we provide recent evidence to describe how stress can affect IBD at various stages. Furthermore, we emphasize the importance of mental healing and discuss the value of approaches targeting stress in clinical management to develop enhanced strategies for the prevention and treatment of IBD.