Khoshbin, Katayoun

Altered intestinal permeability plays a role in many pathological conditions. Intestinal permeability is a component of the intestinal barrier. This barrier is a dynamic interface between the body and the food and pathogens that enter the gastrointestinal tract. Therefore, dietary components can directly affect this interface, and many metabolites produced by the host enzymes or the gut microbiota can act as signaling molecules or exert direct effects on this barrier. Our aim was to examine the effects of diet components on the intestinal barrier in health and disease states. Herein, we conducted an in-depth PubMed search based on specific key words (diet, permeability, barrier, health, disease, and disorder), as well as cross references from those articles. The normal intestinal barrier consists of multiple components in the lumen, epithelial cell layer and the lamina propria. Diverse methods are available to measure intestinal permeability. We focus predominantly on human in vivo studies, and the literature is reviewed to identify dietary factors that decrease (e.g., emulsifiers, surfactants, and alcohol) or increase (e.g., fiber, short-chain fatty acids, glutamine, and vitamin D) barrier integrity. Effects of these dietary items in disease states, such as metabolic syndrome, liver disease, or colitis are documented as examples of barrier dysfunction in the multifactorial diseases. Effects of diet on intestinal barrier function are associated with precise mechanisms in some instances; further research of those mechanisms has potential to clarify the role of dietary interventions in treating diverse pathologic states.

Goals: To evaluate the diagnostic yield of colonoscopy and esophagogastroduodenoscopy with biopsies and to identify predictors of positive colonic histology in patients with chronic diarrhea. Background: Colonoscopy with biopsies is performed in chronic diarrhea with negative initial work-up. Study: We reviewed electronic medical records of 1022 consecutive patients with chronic diarrhea referred for a first colonoscopy (including 25% open-access referrals). Predictors of positive colonic histology were investigated using logistic regression. Results: Four hundred thirteen patients with macroscopically normal colon were divided into derivation (n=275) and validation (n=138) cohorts. All patients underwent colonoscopy; 369 had ileoscopy (biopsies in 43%), and 289 underwent esophagogastroduodenoscopy (duodenal biopsies in 93%). In patients with endoscopically normal colon, histology was positive in 13.3%: 10.6% microscopic colitis; 1.5% other colitides. Among 358 patients with negative histology, the recorded diagnoses were: 48% unexplained, 25% irritable bowel syndrome, 5.6% small intestinal bacterial overgrowth, and 4.7% bile acid diarrhea. The rates of diagnoses based on positive histologies were 4% for ileal and 5% for duodenal biopsies. Older age [odds ratio (OR)=1.05] was a positive predictor, whereas body mass index (OR=0.93) and duration of diarrhea (OR=0.98) were negative predictors of positive histology. A clinical diagnostic scoring system could correctly predict 41% to 54% of patients with normal colonic histology, with a false-negative rate of 0.8% to 2.6% and a negative predictive value of 95% to 98%. Conclusions: Positive colonic biopsies were detected in <15% of patients with chronic diarrhea with normal colonoscopy; a clinical score correctly predicts likelihood of normal histology in about half the patients.

AbstractBackgroundColonic transit measurement [geometric center (GC) at 24 and 48 hours] identifies slow transit constipation (STC) in patients with chronic constipation.AimTo evaluate the utility of the difference between GC24 and GC48 (Δ48‐24) to identify STC in adults with chronic constipation.MethodsWe reviewed medical records of 250 patients, aged 18‐75 years, who underwent colonic transit by scintigraphy during 1994‐2019 for investigation of chronic constipation. Data collected included demographics, medical and surgical histories, and anorectal manometry. We used colonic transit from 220 healthy controls to identify the 5th percentile for diagnosing STC: 1.3 at 24 hours, and 1.9 at 48 hours. In addition, the 5th percentile for Δ48‐24 was 0.38 for females and 0.29 for males. Data are reported as median and IQR [Q1, Q3]).Key resultsAmong the 250 patients [median age 42.5 years (IQR 30.75, 56), 84% female], based on GC24 < 1.3, 52 (20.8%) had STC (3 males, 49 females); and based on GC48 < 1.9, 28(11.2%) had STC (3 males, 25 females). Colonic transit was normal in 74.8%. In the groups with normal GC24 and GC48, Δ48‐24 identified an additional 32(15.1%) of 212 female patients and 4 (10.5%) of 38 male patients with slow progression of colonic transit between 24 and 48 hours. Among these 36 patients with abnormal Δ48‐24, 13(36.1%) had evidence of rectal evacuation disorder.Conclusions & InferencesΔ48‐24 measurement on scintigraphic colonic transit can identify an additional 9.2% of STC in patients with constipation without rectal evacuation disorder and can help individualize treatment of chronic constipation.

OBJECTIVES: Although systemic sclerosis (SSc) is known to affect the gastrointestinal (GI) tract, most of the literature focuses on esophageal, small intestinal, or anorectal manifestations. There have been no reviews focused on large bowel SSc complications in over 30 years. The aim of this study is to perform a systematic review of colonic manifestations and complications of SSc. METHODS: An experienced librarian conducted a search of databases, including English and Spanish articles. The search used keywords including “systemic sclerosis,” “scleroderma,” and “colon.” A systematic review was performed using Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Case reports/series were screened for validity by adapting from criteria published elsewhere. RESULTS: Of 1,890 articles, 74 met selection criteria. Fifty-nine of the 77 articles were case reports/series. The most common article topics on colonic SSc complications were constipation/dysmotility (15), colonic volvulus (8), inflammatory bowel disease (7), microscopic colitis (6), megacolon (6), and telangiectasia (6). Colonic manifestations constituted 24% of articles on GI complications of SSc. There were a total of 85 cases (84% women, with a median age of onset of colon complication of 52 years). Limited cutaneous SSc phenotype (65.6%) was more common than diffuse (26.2%). Patients frequently had poor outcomes with high mortality related to colonic complications (27%). Recent studies explore contemporary topics such as the microbiome in SSc and prucalopride for chronic constipation in SSc. DISCUSSION: Colonic complications comprise a large proportion of the published reports on GI symptoms afflicting patients with SSc and require raised diagnostic suspicion and deliberate action to avoid potentially serious complications including death.