Association Between Gut Microbiota and Irritable Bowel Syndrome (IBS)
1Babar Shahzad, 2Dr Mahmood A Bodla, 3Dr Beenish Nisar Ahmed, 4Qamar Abbas, 5Isma Abbas, 6Dr Hina Jabeen
Submission: 02 January 2026 | Acceptance: 04 February 2026 | Publication: 29 March 2026,
1Service Hospital Lahore
2Gastroenterologist Nescom Hospital Islamabad
3Assistant prof BUCM and KRL hospital islamabad
4PIMS Islamabad
5UHS Lahore
6Assistant Professor, Dow Medical college Karachi
Abstract
Background
Bloating, changed bowel habits, and abdominal pain are the hallmarks of Irritable Bowel Syndrome (IBS), a chronic functional gastrointestinal illness. According to this research, gut microbiota affects intestinal barrier function, immunological response, and gut-brain transmission, all of which are important aspects of the pathophysiology of IBS. The purpose of this study was to examine the relationship between the composition of the gut microbiota and IBS in a group of adult patients.
Methods
Eighty IBS patients with Rome IV criteria diagnoses and forty healthy controls participated in a cross-sectional observational study. 16S rRNA gene sequencing on the Illumina MiSeq platform was used to collect and analyze stool samples. QIIME2 and SPSS software were used to evaluate microbial diversity, the relative abundance of important taxa, and associations with the severity of clinical symptoms. The threshold for statistical significance was fixed at p < 0.05.
Results
Alpha diversity was considerably lower in IBS patients than in healthy controls (Shannon index: 3.25 ± 0.54 vs. 4.02 ± 0.48, p < 0.001). Different microbial community compositions between groups were shown by beta diversity analysis (PERMANOVA, p = 0.001). Increased Enterobacteriaceae and Lactobacillaceae and decreased Faecalibacterium and Bifidobacterium were significant changes in IBS patients (p < 0.01). Increased Enterobacteriaceae was linked to the level of stomach pain, whereas decreased Faecalibacterium and Bifidobacterium were linked to more severe symptoms. The most noticeable microbiological changes were seen in IBS-D patients.
Conclusions
The severity of clinical symptoms is correlated with gut microbiota dysbiosis, which is significantly linked to IBS, especially in diarrhea-predominant subgroups. These results demonstrate the promise of microbiota-targeted treatments as a tailored strategy for managing IBS. To investigate causal links and therapeutic implications, more long-term and interventional research is necessary.
Keywords
Irritable Bowel Syndrome, Gut Microbiota, Dysbiosis, 16S rRNA Sequencing, Microbial Diversity, IBS Subtypes, Enterobacteriaceae, Faecalibacterium, Bifidobacterium