Differences in the Plasma Bile Acid-Gut Microbiota Axis Between IBS-D and IBS-C: GI Signals

Motility retrospective · Aug 18, 2026 · J Gastro Hep · IF 3.5

Differences in the Plasma Bile Acid-Gut Microbiota Axis Between IBS-D and IBS-C.

Basic scienceIBSmicrobiomebiomarkertranslational

Clinical takeawayNo clinical action yet. This observational study describes associations between bile acids, microbiota, and IBS phenotypes but does not establish causality or test therapeutic interventions; whether modifying these factors improves symptoms remains unknown.

What it foundIBS-D is characterized by elevated plasma bile acids (total, primary, secondary, conjugated, and unconjugated) with reduced Ruminococcus and Clostridium, while IBS-C exhibits reduced bile acids with Bacteroides and Clostridium enrichment; specific bacterial taxa correlated differentially with distinct bile acid species.

ContextBuilds on prior evidence linking dysbiosis and bile acids to IBS by characterizing subtype-specific, opposite patterns (IBS-D: elevated bile acids; IBS-C: reduced), suggesting mechanisms for their different clinical manifestations.

Reinforcessuggested applicable standard· American College of Gastroenterology, 'ACG Clinical Guideline: Management of Irritable Bowel Syndrome', 2021

Decision at stakecategorize IBS patients by subtype to enable subtype-specific pharmacotherapy

… IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

From our summary of this standard, unedited — the part the paper bears on. … marks omitted text. Our wording, not the guideline's; read the source for its own text. The rest of this standard includes IBS-C.

Our full summary of this standard

Diagnosis: use a positive diagnostic strategy based on Rome IV criteria rather than a strategy of exclusion (strong for cost-effectiveness, high quality; consensus for time-to-therapy), and categorize by IBS subtype (consensus). In patients with IBS and diarrhea symptoms: check celiac serology (strong, moderate) and, in those WITHOUT alarm features, fecal calprotectin (or fecal lactoferrin) plus CRP to rule out IBD (strong; moderate quality for CRP/calprotectin, very low for lactoferrin). Recommend AGAINST routine stool testing for enteric pathogens (conditional, low) and AGAINST routine colonoscopy in patients younger than 45 without warning signs (conditional, low). Anorectal physiology testing only when symptoms suggest a pelvic floor disorder and/or for refractory constipation not responding to standard medical therapy (consensus). Treatment, all subtypes: soluble, not insoluble, fiber (strong, moderate); a LIMITED trial of a low-FODMAP diet (conditional, very low); gut-directed psychotherapies for global symptoms (conditional, very low); TCAs for global symptoms (strong, moderate); peppermint suggested (conditional, low); antispasmodics for abdominal pain (conditional, low); AGAINST probiotics (conditional, very low), AGAINST fecal transplant (strong, very low). IBS-C: chloride channel activators (strong, moderate) and guanylate cyclase activators (strong, high); AGAINST PEG products for global IBS-C symptoms (conditional, low); tegaserod reserved for women younger than 65 with ≤1 cardiovascular risk factor who have not adequately responded to secretagogues (strong/conditional, low). IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

American College of Gastroenterology, 'ACG Clinical Guideline: Management of Irritable Bowel Syndrome', 2021 · reviewed 2026-07-21 ↗

Chengjiao Y … Liming L · Journal of Gastroenterology and Hepatology · IF 3.5 · PubMed ↗Permalink