Prebiotics for Induction and Maintenance of Remission in Inflammatory Bowel Disease: Systematic Review and Meta-Analysis.

BACKGROUND: Prebiotics are nondigestible carbohydrates fermented by gut bacteria into metabolites that confer health benefits. However, evidence on their role for inflammatory bowel disease (IBD) is unclear. This study systematically evaluated the research on prebiotics for treatment of IBD. METHODS: A search was performed in PubMed, Embase, Cochrane, and Web of Science. Eligible articles included randomized controlled trials or prospective observational studies that compared a prebiotic with a placebo or lower-dose control in patients with IBD. Meta-analyses were performed using random-effects models for the outcomes of clinical remission, clinical relapse, and adverse events. RESULTS: Seventeen studies were included. For induction of clinical remission in ulcerative colitis (UC), the fructooligosaccharide (FOS) kestose was effective (relative risk, 2.75, 95% confidence interval, 1.05-7.20; n = 40), but oligofructose-enriched inulin (OF-IN) and lactulose were not. For maintenance of remission in UC, germinated barley foodstuff trended toward preventing clinical relapse (relative risk, 0.40; 95% confidence interval, 0.15-1.03; n = 59), but OF-IN, oat bran, and Plantago ovata did not. For Crohn's disease, OF-IN and lactulose were no different than controls for induction of remission, and FOS was no different than controls for maintenance of remission. Flatulence and bloating were more common with OF-IN; reported adverse events were otherwise similar to controls for other prebiotics. CONCLUSION: Prebiotics, particularly FOS and germinated barley foodstuff, show potential as effective and safe dietary supplements for induction and maintenance of remission in UC, respectively. The overall certainty of evidence was very low. There would be benefit in further investigation on the role of prebiotics as treatment adjuncts for IBD.

Prebiotics are nutrients fermented by gut microbes into healthful metabolites. This systematic review and meta-analysis examined the available research on the efficacy and safety of prebiotics for the treatment of inflammatory bowel diseases.

Trends in the Utilization of Herbal and Dietary Supplements in Patients with Chronic Liver Disease During the SARS-CoV2 Pandemic.

Background: We studied the pattern of herbal and dietary supplement (HDS) use in patients with chronic liver disease (CLD) during the first year of the COVID-19 pandemic. Methods: A questionnaire/survey was sent to hepatology patients with CLD under the care of hepatologists at Johns Hopkins University School of Medicine. Results: The 5 most taken dietary supplements during the pandemic included vitamin B12 (27.7%), vitamin C (32.4%), vitamin D (54.6%), zinc (25.4%) and green tea extract (20.8%). Most participants (82.3%) did not discuss their HDS use with their hepatology providers. Conclusions: Healthcare providers should be mindful of potential HDS use in patients with CLD.

Dietary Interventions for the Treatment of Inflammatory Bowel Diseases: An Updated Systematic Review and Meta-analysis.

BACKGROUND & AIMS: This study aimed (1) to systematically review controlled trials of solid food diets for the treatment of inflammatory bowel disease (IBD); and (2) to grade the overall quality of evidence. METHODS: Systematic review of prospective controlled trials of solid food diets for the induction or maintenance of remission in IBD. Two authors independently performed study selection, data extraction, and assessment of certainty of evidence. Meta-analyses were performed on studies with quantitative data on response, remission, and relapse. RESULTS: There were 27 studies for meta-analysis. For induction of remission in Crohn's disease (CD), low refined carbohydrate diet and symptoms-guided diet outperformed controls, but studies had serious imprecision and very low certainty of evidence. The Mediterranean diet was similar to the Specific Carbohydrate Diet (low certainty of evidence), and partial enteral nutrition (PEN) was similar to exclusive enteral nutrition (very low certainty of evidence). PEN reduced risk of relapse (very low certainty of evidence), whereas reduction of red meat or refined carbohydrates did not (low certainty of evidence). For ulcerative colitis, diets were similar to controls (very low and low certainty of evidence). CONCLUSIONS: Among the most robust dietary trials in IBD currently available, certainty of evidence remains very low or low. Nonetheless, emerging data suggest potential benefit with PEN for induction and maintenance of remission in CD. Reduction of red meat and refined carbohydrates might not reduce risk of CD relapse. As more dietary studies become available, the certainty of evidence could improve, thus allowing for more meaningful recommendations for patients.

Microbiome-Targeted Therapies as an Adjunct to Traditional Weight Loss Interventions: A Systematic Review and Meta-Analysis.

Objective: This study evaluated the effect of microbiome-targeted therapies (pre-, pro-, and synbiotics) on weight loss and other anthropometric outcomes when delivered as an adjunct to traditional weight loss interventions in overweight and obese adults. Methods: A systematic review of three databases (Medline [PubMed], Embase, and the Cochrane Central Register of Controlled Trials) was performed to identify randomized controlled trials published between January 1, 2010 and December 31, 2020, that evaluated anthropometric outcomes following microbiome-targeted supplements in combination with dietary or dietary and exercise interventions. The pooled mean difference (MD) between treatment and control groups was calculated using a random effects model. Results: Twenty-one trials with 1233 adult participants (76.4% female) with overweight or obesity were included. Separate meta-analyses were conducted for probiotics (n=11 trials) and synbiotics (n=10 trials) on each anthropometric outcome; prebiotics were excluded as only a single study was found. Patient characteristics and methodologies varied widely between studies. All studies incorporated some degree of caloric restriction, while only six studies included recommendations for adjunct exercise. Compared with dietary or dietary and exercise interventions only, probiotics resulted in reductions in body weight (MD: -0.73 kg; 95% confidence interval [CI]: -1.02 to -0.44, p < 0.001), fat mass (MD: -0.61 kg; 95% CI: -0.77 to -0.45; p<0.001) and waist circumference (MD: -0.53 cm; 95% CI: -0.99 to -0.07, p=0.024) while synbiotics resulted in reductions in fat mass (MD: -1.53 kg; 95% CI: -2.95 to -0.12, p=0.034) and waist circumference (MD: -1.31 cm; 95% CI: -2.05 to -0.57, p<0.001). Conclusion: This analysis indicates that microbiome-targeted supplements may enhance weight loss and other obesity outcomes in adults when delivered as an adjunct to dietary or dietary and exercise interventions. Personalized therapy to include microbiome-targeted supplements may help to optimize weight loss in overweight and obese individuals.

Malnutrition Increases Hospital Length of Stay and Mortality among Adult Inpatients with COVID-19.

Background: Malnutrition has been linked to adverse health economic outcomes. There is a paucity of data on malnutrition in patients admitted with COVID-19. Methods: This is a retrospective cohort study consisting of 4311 COVID-19 adult (18 years and older) inpatients at 5 Johns Hopkins-affiliated hospitals between 1 March and 3 December 2020. Malnourishment was identified using the malnutrition universal screening tool (MUST), then confirmed by registered dietitians. Statistics were conducted with SAS v9.4 (Cary, NC, USA) software to examine the effect of malnutrition on mortality and hospital length of stay among COVID-19 inpatient encounters, while accounting for possible covariates in regression analysis predicting mortality or the log-transformed length of stay. Results: COVID-19 patients who were older, male, or had lower BMIs had a higher likelihood of mortality. Patients with malnutrition were 76% more likely to have mortality (p < 0.001) and to have a 105% longer hospital length of stay (p < 0.001). Overall, 12.9% (555/4311) of adult COVID-19 patients were diagnosed with malnutrition and were associated with an 87.9% increase in hospital length of stay (p < 0.001). Conclusions: In a cohort of COVID-19 adult inpatients, malnutrition was associated with a higher likelihood of mortality and increased hospital length of stay.

Adult-Attained Height and Colorectal Cancer Risk: A Cohort Study, Systematic Review, and Meta-Analysis.

BACKGROUND: The influence of anthropometric characteristics on colorectal neoplasia biology is unclear. We conducted a systematic review and meta-analysis to determine if adult-attained height is independently associated with the risk of colorectal cancer or adenoma. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library, and Web of Science from inception to August 2020 for studies on the association between adult-attained height and colorectal cancer or adenoma. The original data from the Johns Hopkins (Baltimore, MD) Colon Biofilm study was also included. The overall HR/OR of colorectal cancer/adenoma with increased height was estimated using random-effects meta-analysis. RESULTS: We included 47 observational studies involving 280,644 colorectal cancer and 14,139 colorectal adenoma cases. Thirty-three studies reported data for colorectal cancer incidence per 10-cm increase in height; 19 yielded an HR of 1.14 [95% confidence interval (CI), 1.11-1.17; P < 0.001), and 14 engendered an OR of 1.09 (95% CI, 1.05-1.13; P < 0.001). Twenty-six studies compared colorectal cancer incidence between individuals within the highest versus the lowest height percentile; 19 indicated an HR of 1.24 (95% CI, 1.19-1.30; P < 0.001), and seven resulting in an OR of 1.07 (95% CI, 0.92-1.25; P = 0.39). Four studies reported data for assessing colorectal adenoma incidence per 10-cm increase in height, showing an overall OR of 1.06 (95% CI, 1.00-1.12; P = 0.03). CONCLUSIONS: Greater adult attained height is associated with an increased risk of colorectal cancer and adenoma. IMPACT: Height should be considered as a risk factor for colorectal cancer screening.

Dietary Supplements for COVID-19.

Coronavirus disease 2019 (COVID-19) is a highly contagious infectious disease that can rapidly escalate to respiratory failure and death. It has infected millions of people worldwide. The trajectory of this disease continues to progress in some areas of the United States and worldwide. The Institute for Health Metrics now predicts a resurgence of infections in the fall of 2020. The pathogenesis of COVID-19 includes an inflammatory phase with either resolution or the potential to accelerate to a cytokine storm, characterized by high interleukin (IL)-6 and other inflammatory markers. COVID-19 is a condition without a gold-standard treatment. The US Federal Drug Administration (FDA) issued an emergency use authorization for remdesivir in severe cases of COVID-19, which shortened the recovery time in hospitalized patients with lower respiratory tract infection in one study. Although several vaccine trials are underway, no vaccines are available for primary prevention of COVID-19 at this time. Dietary supplement sales have dramatically risen during the COVID-19 pandemic despite depressed economic conditions. Commonly used immune-modulating dietary supplements, including vitamin D, ascorbic acid, zinc, and melatonin, are reviewed in this manuscript highlighting biological plausibility for salutary benefit against COVID-19. Ongoing clinical trials recruiting subjects at the time of this writing are provided for each dietary supplement.

Fish Oil for Inflammatory Bowel Disease: Panacea or Placebo?

Dietary supplements have increasingly gained popularity over the years not only to replete micronutrient deficiencies but for their use in treatment of disease. The popularity of dietary supplements for inflammatory bowel diseases (IBD) arises from their perceived ease of use, potential disease-modifying benefits, and perceived safety. Overall, randomized controlled trials have not consistently shown a benefit of fish oil for the maintenance of remission with Crohn's disease. The inconsistency of these findings highlights the need for more studies that are powered to clarify the context in which omega-3 fatty acids might have a role in the treatment algorithm of IBD.

Correction to: Anatomical Configuration of the Stomach Post-Endoscopic Sleeve Gastroplasty (ESG)-What Are the Sutures Doing?

The name of author Vivek Kumbhari was misspelled in the original article.

Yogurt consumption and colorectal polyps.

Diet modifies the risk of colorectal cancer (CRC), and inconclusive evidence suggests that yogurt may protect against CRC. We analysed the data collected from two separate colonoscopy-based case-control studies. The Tennessee Colorectal Polyp Study (TCPS) and Johns Hopkins Biofilm Study included 5446 and 1061 participants, respectively, diagnosed with hyperplastic polyp (HP), sessile serrated polyp, adenomatous polyp (AP) or without any polyps. Multinomial logistic regression models were used to derive OR and 95 % CI to evaluate comparisons between cases and polyp-free controls and case-case comparisons between different polyp types. We evaluated the association between frequency of yogurt intake and probiotic use with the diagnosis of colorectal polyps. In the TCPS, daily yogurt intake v. no/rare intake was associated with decreased odds of HP (OR 0·54; 95 % CI 0·31, 0·95) and weekly yogurt intake was associated with decreased odds of AP among women (OR 0·73; 95 % CI 0·55, 0·98). In the Biofilm Study, both weekly yogurt intake and probiotic use were associated with a non-significant reduction in odds of overall AP (OR 0·75; 95 % CI 0·54, 1·04) and (OR 0·72; 95 % CI 0·49, 1·06) in comparison with no use, respectively. In summary, yogurt intake may be associated with decreased odds of HP and AP and probiotic use may be associated with decreased odds of AP. Further prospective studies are needed to verify these associations.

Anatomical Configuration of the Stomach Post-Endoscopic Sleeve Gastroplasty (ESG)-What Are the Sutures Doing?

INTRODUCTION AND AIM: Endoscopic sleeve gastroplasty (ESG) is a procedure in which endoscopically placed sutures involute the stomach and promote weight loss. There is limited data on the durability of these sutures. PATIENTS AND METHODS: This was a single center series of 5 patients who underwent ESG performed by a single endoscopist. Patients underwent repeat endoscopy for different clinical indications. RESULTS: ESGs were successfully reversed at 3 weeks and 1 month following index ESG without significant fibrosis or scaring. At 8 and 14 months, a few sutures had dehisced though there were extensive areas of fibrosis. By 2 years, most of the sutures had dehisced; however, the gastric volume remained reduced. CONCLUSION: This case series offers an intriguing evaluation of the anatomical changes induced by ESG.

Gut Microbial Dysbiosis in the Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies.

BACKGROUND: Irritable bowel syndrome (IBS) is the most common functional digestive condition in the industrialized world. The gut microbiota plays a key role in disease pathogenesis. OBJECTIVE: A systematic review and meta-analysis on case-control studies was conducted to determine whether there is gut microbial dysbiosis in participants with IBS in comparison with healthy controls and, if so, whether the dysbiosis pattern differs among IBS subtypes and geographic regions. METHODS: This review was conducted and reported according to the MOOSE (Meta-Analysis of Observational Studies in Epidemiology) 2000 and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2009 guidelines. Research articles published up to May 9, 2018 were identified through MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (Cochrane Library), ClinicalTrials.gov, EMBASE, and Web of Science. Study quality was assessed using the Newcastle-Ottawa Scale. Case-control studies of participants with IBS who had undergone quantitative gut microbial stool analysis were included. The primary exposure measure of interest is log10 bacterial counts per gram of stool. Meta-analyses were performed to estimate the mean difference (MD) in gut microbiota between participants with IBS and healthy controls using the random-effects model with inverse variance in Revman 5.3 and R 3.5.1. Publication bias was assessed with funnel plots and Egger's test. Between-study heterogeneity was analyzed using Higgins I2 statistic with 95% CIs. RESULTS: There were 6,333 unique articles identified; 52 qualified for full-text screening. Of these, 23 studies were included for analysis (n=1,340 participants from North America, Europe, and Asia). Overall, the studies were moderate in quality. Comparing participants with IBS to healthy controls, lower fecal Lactobacillus (MD= -0.57 log10 colony-forming unit [CFU]/g; P<0.01) and Bifidobacterium (MD= -1.04 log10CFU/g; P<0.01), higher Escherichia coli (MD=0.60 log10CFU/g; P<0.01), and marginally higher Enterobacter (MD=0.74 log10CFU/g; P=0.05). No difference was found between participants with IBS and healthy controls in fecal Bacteroides and Enterococcus (P=0.18 and 0.68, respectively). Publication bias was not observed except in Bifidobacterium (P=0.015). Subgroup analyses on participants with diarrhea-predominant and constipation-predominant IBS showed consistent results with the primary results. A subgroup analysis of Chinese studies was consistent with the primary results, except for fecal Bacteroides, which was increased in participants with IBS vs healthy controls (MD=0.29; 95% CI 0.13 to 0.46; P<0.01). Although substantial heterogeneity was detected (I2>75%) in most comparisons, the direction of the effect estimates is relatively consistent across studies. CONCLUSIONS: IBS is characterized by gut microbial dysbiosis. Prospective, large-scale studies are needed to delineate how gut microbial profiles can be used to guide targeted therapies in this challenging patient population.

The Association between Oral Nutritional Supplements and 30-Day Hospital Readmissions of Malnourished Patients at a US Academic Medical Center.

BACKGROUND: Malnutrition affects up to 50% of hospitalized patients and contributes to adverse health and economic outcomes, but often remains unrecognized or undertreated. OBJECTIVE: This study assessed the utilization of oral nutritional supplements (ONS) and its association with the number of 30-day unplanned hospital readmissions of adult malnourished patients in comparison with the readmissions rates of their malnourished counterparts who did not receive ONS. DESIGN: This was a retrospective cohort study. PARTICIPANTS/SETTING: Of 153,161 inpatient encounters analyzed, a total of 8,713 (5.7%) malnourished adults admitted to an academic medical center hospital in the United States between October 1, 2016, and September 30, 2017 were included in the analyses. The study utilized records of patients at risk of malnutrition on admission and subsequently diagnosed as malnourished by a registered dietitian following established criteria. MAIN OUTCOMES MEASURES: ONS utilization rate, hospital length of stay (LOS), and 30-day unplanned hospital readmissions data were obtained from electronic medical records. STATISTICAL ANALYSES PERFORMED: The associations between the number of 30-day unplanned hospital readmissions and ONS use were analyzed using mixed-effects negative binomial regression models, with coefficients and 95% CIs reported. Important covariates such as age, sex, and the severity of illness index were included in the regression models. RESULTS: Only 3.1% of malnourished patients received ONS. ONS users had 38.8% fewer readmissions compared with non-ONS counterparts (P=0.017). The reduction in hospital readmissions by ONS was even greater for oncology patients (46.1%, P<0.001). A 50% reduction in time from hospital admission to ONS provision was associated with a 10.2% (P<0.01), 10.2% (P=0.014), and 16.6% (P<0.01) decrease in LOS for overall, oncology, and intensive care unit encounters, respectively. CONCLUSIONS: In a large cohort of malnourished adult inpatient encounters, ONS provision rate was low, but when used, ONS intervention was associated with 38.8% fewer 30-day readmissions. This association was more pronounced for oncology encounters. Shorter LOS was observed when the interval between admission and ONS initiation was shorter. Reduced LOS and readmissions rates could result in financial benefits for health care systems prioritizing hospital nutrition care, in addition to informing significant medical benefits for their patients.

Dietary interventions for induction and maintenance of remission in inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD), comprised of Crohn's disease (CD) and ulcerative colitis (UC), is characterized by chronic mucosal inflammation, frequent hospitalizations, adverse health economics, and compromised quality of life. Diet has been hypothesised to influence IBD activity. OBJECTIVES: To evaluate the efficacy and safety of dietary interventions on IBD outcomes. SEARCH METHODS: We searched the Cochrane IBD Group Specialized Register, CENTRAL, MEDLINE, Embase, Web of Science, Clinicaltrials.gov and the WHO ICTRP from inception to 31 January 2019. We also scanned reference lists of included studies, relevant reviews and guidelines. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared the effects of dietary manipulations to other diets in participants with IBD. Studies that exclusively focused on enteral nutrition, oral nutrient supplementation, medical foods, probiotics, and parenteral nutrition were excluded. DATA COLLECTION AND ANALYSIS: Two review authors independently performed study selection, extracted data and assessed bias using the risk of bias tool. We conducted meta-analyses where possible using a random-effects model and calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. We assessed the certainty of evidence using GRADE. MAIN RESULTS: The review included 18 RCTs with 1878 participants. The studies assessed different dietary interventions for active CD (six studies), inactive CD (seven studies), active UC (one study) and inactive UC (four studies). Dietary interventions involved either the consumption of low amounts or complete exclusion of one or more food groups known to trigger IBD symptoms. There was limited scope for data pooling as the interventions and control diets were diverse. The studies were mostly inadequately powered. Fourteen studies were rated as high risk of bias. The other studies were rated as unclear risk of bias.The effect of high fiber, low refined carbohydrates, low microparticle diet, low calcium diet, symptoms-guided diet and highly restricted organic diet on clinical remission in active CD is uncertain. At 4 weeks, remission was induced in: 100% (4/4) of participants in the low refined carbohydrates diet group compared to 0% (0/3) of participants in the control group (RR 7.20, 95% CI 0.53 to 97.83; 7 participants; 1 study; very low certainty evidence). At 16 weeks, 44% (23/52) of participants in the low microparticle diet achieved clinical remission compared to 25% (13/51) of control-group participants (RR 3.13, 95% CI 0.22 to 43.84; 103 participants; 2 studies; I² = 73%; very low certainty evidence). Fifty per cent (16/32) of participants in the symptoms-guided diet group achieved clinical remission compared to 0% (0/19) of control group participants (RR 20.00, 95% CI 1.27 to 315.40; 51 participants ; 1 study; very low certainty evidence) (follow-up unclear). At 24 weeks, 50% (4/8) of participants in the highly restricted organic diet achieved clinical remission compared to 50% (5/10) of participants in the control group (RR 1.00, 95% CI 0.39 to 2.53; 18 participants; 1 study; very low certainty evidence). At 16 weeks, 37% (16/43) participants following a low calcium diet achieved clinical remission compared to 30% (12/40) in the control group (RR 1.24, 95% CI 0.67 to 2.29; 83 participants; 1 study; very low certainty evidence).The effect of low refined carbohydrate diets, symptoms-guided diets and low red processed meat diets on relapse in inactive CD is uncertain. At 12 to 24 months, 67% (176/264) of participants in low refined carbohydrate diet relapsed compared to 64% (193/303) in the control group (RR 1.04, 95% CI 0.87 to 1.25; 567 participants; 3 studies; I² = 35%; low certainty evidence). At 6 to 24 months, 48% (24/50) of participants in the symptoms-guided diet group relapsed compared to 83% (40/48) participants in the control diet (RR 0.53, 95% CI 0.28 to 1.01; 98 participants ; 2 studies; I² = 54%; low certainty evidence). At 48 weeks, 66% (63/96) of participants in the low red and processed meat diet group relapsed compared to 63% (75/118) of the control group (RR 1.03, 95% CI 0.85 to 1.26; 214 participants; 1 study; low certainty evidence). At 12 months, 0% (0/16) of participants on an exclusion diet comprised of low disaccharides / grains / saturated fats / red and processed meat experienced clinical relapse compared to 26% (10/38) of participants on a control group (RR 0.11, 95% CI 0.01 to 1.76; 54 participants; 1 study; very low certainty evidence).The effect of a symptoms-guided diet on clinical remission in active UC is uncertain. At six weeks, 36% (4/11) of symptoms-guided diet participants achieved remission compared to 0% (0/10) of usual diet participants (RR 8.25, 95% CI 0.50 to 136.33; 21 participants; 1 study; very low certainty evidence).The effect of the Alberta-based anti-inflammatory diet, the Carrageenan-free diet or milk-free diet on relapse rates in inactive UC is uncertain. At 6 months, 36% (5/14) of participants in the Alberta-based anti-inflammatory diet group relapsed compared to 29% (4/14) of participants in the control group (RR 1.25, 95% CI 0.42 to 3.70; 28 participants; 1 study; very low certainty evidence). Thirty per cent (3/10) of participants following the carrageenan-free diet for 12 months relapsed compared to 60% (3/5) of the participants in the control group (RR 0.50, 95% CI 0.15 to 1.64; 15 participants; 1 study; very low certainty evidence). At 12 months, 59% (23/39) of milk free diet participants relapsed compared to 68% (26/38) of control diet participants (RR 0.83, 95% CI 0.60 to 1.15; 77 participants; 2 studies; I² = 0%; low certainty evidence).None of the included studies reported on diet-related adverse events. AUTHORS' CONCLUSIONS: The effects of dietary interventions on CD and UC are uncertain. Thus no firm conclusions regarding the benefits and harms of dietary interventions in CD and UC can be drawn. There is need for consensus on the composition of dietary interventions in IBD and more RCTs are required to evaluate these interventions. Currently, there are at least five ongoing studies (estimated enrollment of 498 participants). This review will be updated when the results of these studies are available.

The gut microbiome and irritable bowel syndrome: State of art review.

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract, the physiology of which is not very well understood. There are multiple factors and pathways involved in pathogenesis of this entity. Among all, dysmotility, dysregulation of the brain-gut axis, altered intestinal microbiota and visceral hypersensitivity play a major role. Over the last years, research has shown that the type of gut microbiome present in an individual plays a significant role in the pathophysiology of IBS. Multiple studies have consistently shown that subjects diagnosed with IBS have disruption in gut microbiota balance. It has been established that host immune system and its interaction with metabolic products of gut microbiota play an important role in the gastrointestinal tract. Therefore, probiotics, prebiotics and antibiotics have shown some promising results in managing IBS symptoms via modulating the interaction between the above. This paper discusses the various factors involved in pathophysiology of IBS, especially gut microbiota.

Vitamin D levels do not predict the stage of hepatic fibrosis in patients with non-alcoholic fatty liver disease: A PRISMA compliant systematic review and meta-analysis of pooled data.

AIM: To investigate the relationship between 25-hydroxyvitamin D [25(OH)D] levels and fibrosis stage in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: Two individual reviewers identified relevant studies using the PubMed, EMBASE, Cochrane, and Scopus databases. Inclusion criteria were as follows: (1) Studies that evaluated adults with NAFLD and serum or plasma 25(OH)D levels; and (2) assessed fibrosis stage using liver biopsy. A rigorous analysis yielded six articles as having sufficient data to employ in evaluating the association of serum vitamin D levels in patients with NAFLD based on their liver fibrosis stage by histopathological analysis. The lead investigators of each of the six studies were contacted and the data were collected. To meta-analyze vitamin D levels in F0-F2 vs F3-F4 fibrosis, a random-effects meta-analysis fit using restricted maximum likelihood was applied. To examine trends across each stage of fibrosis with respect to vitamin D levels, a meta-regression was performed. P < 0.05 was considered statistically significant. RESULTS: A total of 937 subjects from six studies were included in the final analysis to evaluate the association of serum vitamin D levels in patients with NAFLD based on their liver fibrosis stage by histopathological analysis. The lead investigators of each of the six studies were contacted and the data were collected. First, the investigators performed a meta-analysis to compare serum vitamin D levels in patients with NAFLD with stage F0-F2 compared to F3-F4, which did not show significance [meta-estimate of the pooled mean difference = -0.86, P = 0.08 (-4.17, 2.46)]. A meta-regression evaluation of serum vitamin 25 (OH)D levels across the individual stages (F0-F4) of fibrosis did not show an association for the six included studies. CONCLUSION: Low vitamin D status is not associated with higher stages of liver fibrosis in patients with NAFLD.