Administration of dietary antioxidants for patients with inflammatory bowel disease: A systematic review and meta-analysis of randomized controlled clinical trials

A systematic review and meta-analysis of clinical trials on the effects of glutamine supplementation on gut permeability in adults

The gastrointestinal tract's epithelial barrier plays a crucial role in maintaining health. This study aims to investigate the impact of glutamine supplementation on intestinal permeability, considering its importance for immune function and nutrient absorption. The study adhered to the PRISMA protocol for systematic reviews and meta-analyses. A systematic search was performed in four databases (PubMed, Scopus, Web of Science, and Google Scholar) until April 2023 to identify clinical trials on glutamine supplementation and gastrointestinal permeability. Eligibility criteria included randomized placebo-controlled trials measuring gut permeability post-glutamine supplementation. Studies were included regardless of language or publication date. Data extraction involved study characteristics, intervention details, and outcomes. Quality assessment was performed using the Cochrane tool, and statistical analysis utilized mean differences and standard deviations with a random effects model. Subgroup analysis was conducted to explore heterogeneity. The systematic review and meta-analysis included 10 studies from 1998 to 2014 with 352 participants. A total of 216 patients were enrolled in the intervention group, and 212 in the control group. The mean participant age was 46.52 years. The participants had different types of diseases in terms of their health status. Overall, glutamine supplementation did not significantly affect intestinal permeability (WMD: -0.00, 95% CI -0.04, 0.03). Subgroup analysis showed a significant reduction in intestinal permeability with doses over 30g/day (WMD: -0.01, 95% CI -0.10, -0.08). The glutamine supplements were administered orally in all included studies. The meta-analysis demonstrated a significant reduction in intestinal permeability with glutamine supplementation exceeding 30 mg/day for durations of less than 2 weeks. Further investigations with varying dosages and patient populations are warranted to enhance understanding and recommendations regarding glutamine supplementation's effects on gut permeability.

The Role of the Gut Microbiome in Inflammatory Bowel Disease: The Middle East Perspective

The gut microbiome is of paramount importance in preserving internal balance in the gastrointestinal tract; therefore, disruptions in its regulation have been linked to the development of inflammatory bowel disease (IBD). This article explores the intricate details of the gastrointestinal microbiome as it pertains to inflammatory bowel disease (IBD), with an emphasis on the Middle East. The study reviews the typical gut microbiome, modifications in inflammatory bowel disease (IBD), determinants impacting the gut microbiome of the Middle East, and prospective therapeutic interventions.

Diet, Food, and Nutritional Exposures and Inflammatory Bowel Disease or Progression of Disease: an Umbrella Review

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), contributes to substantial morbidity. Understanding the intricate interplay between dietary factors and the incidence and progression of IBD is essential for developing effective preventative and therapeutic strategies. This umbrella review comprehensively synthesizes evidence from systematic reviews and meta-analyses to evaluate these complex associations. Dietary factors associated with an increased incidence and/or progression of IBD include a high intake of red and processed meat, other processed foods, and refined sugars, together with a low intake of vegetables, fruits, and fiber. For most other food groups, the results are mixed or indicate no clear associations with IBD, CD, and UC. Some differences seem to exist between UC and CD and their risk factors, with increased intake of dietary fiber being inversely associated with CD incidence but not clearly associated with UC. Dietary fiber may contribute to maintaining the gut epithelial barrier and reduce inflammation, often through interactions with the gut microbiota. This seems to play an important role in inflammatory mechanisms in the gut and in IBD incidence and progression. Diets low in fermentable saccharides and polyols can alleviate symptom burden, but there are concerns regarding their impact on the gut microbiota and their nutritional adequacy. Mediterranean diets, vegetarian diets, and a diet low in grains, sugars, and lactose (specific carbohydrate diet) are also associated with lower incidence and/or progression of IBD. The associations of dietary patterns are mirrored by inflammatory biomarkers. IBD is typically treated pharmaceutically; however, many patients have a suboptimal response to medical treatments. The findings from this umbrella review could provide evidence for nutritional counseling and be a valuable addition to traditional treatment plans for IBD. This systematic review was registered at PROSPERO as CRD440252.

To Fiber or Not to Fiber: The Swinging Pendulum of Fiber Supplementation in Patients with Inflammatory Bowel Disease

Evidence-based dietary guidance around dietary fiber in inflammatory bowel disease (IBD) has been limited owing to insufficient reproducibility in intervention trials. However, the pendulum has swung because of our increased understanding of the importance of fibers in maintaining a health-associated microbiome. Preliminary evidence suggests that dietary fiber can alter the gut microbiome, improve IBD symptoms, balance inflammation, and enhance health-related quality of life. Therefore, it is now more vital than ever to examine how fiber could be used as a therapeutic strategy to manage and prevent disease relapse. At present, there is limited knowledge about which fibers are optimal and in what form and quantity they should be consumed to benefit patients with IBD. Additionally, individual microbiomes play a strong role in determining the outcomes and necessitate a more personalized nutritional approach to implementing dietary changes, as dietary fiber may not be as benign as once thought in a dysbiotic microbiome. This review describes dietary fibers and their mechanism of action within the microbiome, details novel fiber sources, including resistant starches and polyphenols, and concludes with potential future directions in fiber research, including the move toward precision nutrition.