ASSESSMENT OF INTESTINAL MICROBIOCENOSIS IN PATIENTS WITH IRRITABLE BOWEL SYNDROME: A COMPREHENSIVE MINI-REVIEW

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder with multifactorial pathogenesis. Growing evidence suggests that dysbiosis of the intestinal microbiocenosis contributes significantly to symptom generation through altered microbial diversity, composition, and metabolic functions. This mini-review aims to synthesize findings from eight recent studies on intestinal microbiocenosis alterations in IBS patients compared to healthy controls. A targeted literature search was conducted in PubMed, PMC, and related databases for English-language studies (2019–2025). Eight high-quality case-control studies and meta-analyses using 16S rRNA sequencing or metagenomics were selected. Data on α- and β-diversity, taxonomic shifts, and functional changes were narratively synthesized. IBS patients consistently exhibited reduced α-diversity and distinct β-diversity profiles. Beneficial genera such as Bifidobacterium, Lactobacillus, Faecalibacterium, and Roseburia were depleted, while Escherichia coli, Enterobacteriaceae, and certain Bacteroides species were enriched. A decreased Firmicutes/Bacteroidetes ratio was frequently observed, with reduced short-chain fatty acid (SCFA) production capacity. Patterns showed partial subtype and geographic variations. Intestinal microbiocenosis dysbiosis is a reproducible feature of IBS and may contribute to visceral hypersensitivity, barrier dysfunction, and gut-brain axis disturbances. Microbiome-targeted therapies hold promise, but standardized assessment protocols and longitudinal studies are needed.