Gut Microbiota in Health, Diverticular Disease, Irritable Bowel Syndrome, and Inflammatory Bowel Diseases: Time for Microbial Marker of Gastrointestinal Disorders

Abstract

Few data exist on differences in gut microbiota composition among principal gastrointestinal (GI) diseases. We evaluated the differences in gut microbiota composition among uncomplicated diverticular disease (DD), irritable bowel syndrome (IBS) and inflammatory bowel diseases (IBD) patients. DD, IBS, and IBD patients along with healthy controls (CT) were enrolled in our Italian GI outpatient clinic. Stool samples were collected. Microbiota composition was evaluated through a metagenomic gene-targeted approach. GI pathology represented a continuous spectrum of diseases where IBD displayed one extreme, while CT displayed the other. Among Phyla, Biplot PC2/PC3 and dendogram plot showed major differences in samples from IBS and IBD. DD resembled species CT composition, but not for Bacteroides fragilis. In IBS, Dialister spp. and then Faecalibacterium prausnitzii were the most representative species. Ulcerative colitis showed a reduced concentration of Clostridium difficile and an increase of Bacteroides fragilis. In Crohn's disease, Parabacteroides distasonis was the most represented, while Faecalibacterium prausnitzii and Bacteroides fragilis were significantly reduced. Each disorder has its definite overall microbial signature, which produces a clear differentiation from the others. On the other hand, shared alterations constitute the “core dysbiosis” of GI diseases. The assessment of these microbial markers represents a parameter that may complete the diagnostic assessment.

The Obesity-Related Gut Bacterial and Viral Dysbiosis Can Impact the Risk of Colon Cancer Development

“…Indeed, the Tumor group showed only a slight decrease of bacterial diversity, but, at the same time, showing a peculiar bacterial composition, suggestive of a role for microorganism in CRC. The CRC gut microbiota showed higher abundance of Proteobacteria and Verrucomicrobia, phyla usually present at low amount with respect to Firmicutes and Bacteroidetes in the gut [25,26]. The same increase trend was observed in the Obese group, suggesting a similar dysbiotic gut picture.…”

Comparison of the metabolomic profiles of irritable bowel syndrome patients with ulcerative colitis patients and healthy controls: new insights into pathophysiology and potential biomarkers

“…Metabolomic profiles involve both host and microbial‐produced metabolites and can be significantly impacted by dietary intake and alterations in gut microbial composition. Some studies have shown differences in gut microbial composition in UC and IBS patients, and it is possible that the differences in urinary metabolic profiles we observed could be related to altered gut microbiota. Indeed, gut microbiota are involved in the production of a range of neurotransmitters such as dopamine and it has been shown that metabolic activity of the gut microbiota may also influence the fatty acid composition of different host tissues .…”

Dietary fibre intake and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies

“…Several animal studies have shown that a low-fibre diet substantially increases the rates for colonic diverticula [36][37][38][39]. Some studies have suggested differences in the gut microbiota of diverticular disease patients compared to controls [40][41][42][43][44][45] and one study suggested that patients with diverticular disease have depletion of microbiota with anti-inflammatory activity [40]. Further studies are needed to clarify whether and how fibre intake might interact with the microbiota in reducing diverticular disease risk.…”