Relationships of Microbiome Markers with Extra-intestinal, Psychological Distress and Gastrointestinal Symptoms, and Quality of Life in Women with Irritable Bowel Syndrome

INTRODUCTION: Altered microbial diversity has been associated with gastrointestinal (GI) symptoms in persons with irritable bowel syndrome (IBS). Less is known about the relationship of microbiome with extra-intestinal pain and psychological distress symptoms and quality of life (QOL) in persons with IBS. We aimed to evaluate the relationship of fecal microbiota to GI symptoms, stool consistency, psychological distress, extra-intestinal pain, and QOL in participants meeting Rome III criteria for IBS. METHODS: Seventy-six women completed a 28-day diary that included GI, stool consistency, psychological distress, and extra-intestinal pain ratings. Participants completed the IBS-Specific-Quality of Life questionnaire. Stool samples were collected and analyzed by 16S rRNA gene sequencing. Principal component analysis was performed and the first two components (PC1, PC2) were used to test relationships among bacterial families and clinical measures. RESULTS: Participants were categorized as IBS-constipation (n=22), IBS-diarrhea (n=39), IBS-mixed (n=13), and IBS-unsubtyped (n=2). There was a significant group effect for the Firmicutes to Bacteroidetes (FB) ratio and PC1. Lower microbial diversity and richness were associated with increased urgency and extra-intestinal pain, worse QOL, and looser stools. Lower extra-intestinal pain was associated with increased Rikenellaceae, Christensenellaceae, Dehalobabacteriaceae, Oscillospiraceae, Mogibacteriaceae, Ruminococcaceae, Sutterellaceae, Desulfovibrionaceae, and Erysipelotrichaceae abundances. QOL was positively associated with many of these same bacterial families. Higher FB ratio was positively associated with loose stools. There were no statistically significant relationships between daily psychological distress or abdominal pain and bacterial families. CONCLUSION: Stool microbial diversity and composition are linked to daily extra-intestinal symptoms, stool consistency, and QOL in women with IBS.