Mediterranean-Like Dietary Pattern Associations With Gut Microbiome Composition and Subclinical Gastrointestinal Inflammation.

BACKGROUND & AIMS: Case-control studies have shown that patients with Crohn's disease (CD) have a microbial composition different from healthy individuals. Although the causes of CD are unknown, epidemiologic studies suggest that diet is an important contributor to CD risk, potentially via modulation of bacterial composition and gut inflammation. We hypothesized that long-term dietary clusters (DCs) are associated with gut microbiome compositions and gut inflammation. Our objectives were to identify dietary patterns and assess whether they are associated with alterations in specific gut microbial compositions and subclinical levels of gut inflammation in a cohort of healthy first-degree relatives (FDRs) of patients with CD. METHODS: As part of the Genetic, Environmental, Microbial (GEM) Project, we recruited a cohort of 2289 healthy FDRs of patients with CD. Individuals provided stool samples and answered a validated food frequency questionnaire reflecting their habitual diet during the year before sample collection. Unsupervised analysis identified 3 dietary and 3 microbial composition clusters. RESULTS: DC3, resembling the Mediterranean diet, was strongly associated with a defined microbial composition, with an increased abundance of fiber-degrading bacteria, such as Ruminococcus, as well as taxa such as Faecalibacterium. The DC3 diet was also significantly associated with lower levels of subclinical gut inflammation, defined by fecal calprotectin, compared with other dietary patterns. No significant associations were found between individual food items and fecal calprotectin, suggesting that long-term dietary patterns rather than individual food items contribute to subclinical gut inflammation. Additionally, mediation analysis demonstrated that DC3 had a direct effect on subclinical inflammation that was partially mediated by the microbiota. CONCLUSIONS: Overall, these results indicated that Mediterranean-like dietary patterns are associated with microbiome and lower intestinal inflammation. This study will help guide future dietary strategies that affect microbial composition and host gut inflammation to prevent diseases.

Cytomegalovirus positive ulcerative colitis: A single center experience and literature review.

AIM: To compare the clinical outcome of cytomegalovirus (CMV)-positive ulcerative colitis (UC) patients with and without antiviral therapy. METHODS: This was a retrospective case-controlled study. The database of UC patients in our institution was scanned for documented presence of CMV on colonic biopsies. Demographics, clinical data, endoscopy findings and pathology reports were extracted from the patients' charts and electronic records. When available, the data from colonoscopies preceding and following the diagnosis of colonic CMV infection were also extracted. The primary outcomes of the study were colectomy/death during hospitalization and the secondary outcomes were colectomy/death through the course of the follow-up. RESULTS: Thirteen patients were included in the study, 7 (53.5%) of them were treated with gancyclovir and 6 (46.5%) were not. Patients treated with antivirals presented with a more severe disease and 57% of them were treated with cyclosporine or infliximab before initiation of gancyclovir, while none of the patients without antivirals required rescue therapy. One patient died and another patient underwent urgent colectomy during hospitalization, both of them from the gancyclovir-treatment group. For the entire follow-up time (13 ± 13 mo), a total of 3 colectomies and one death occurred, all among the antiviral-treated patients (for colectomy: 3/7 vs 0/6 patients, P = 0.19; for combined adverse outcome: 4/7 vs 0/6 patients, P = 0.07). In 9/13 patients, immunohistochemistry for CMV was performed on biopsies obtained during a subsequent colonoscopy and was positive in one patient only. CONCLUSION: Gancyclovir-treated patients had a more severe disease and outcome, probably unrelated to antiviral therapy. Immunohistochemistry-CMV-positive patients with mild disease may recover without antiviral therapy.