A Randomized Trial of Rifaximin vs Low FODMAP Diet for Symptom Outcomes and Microbiome Changes in Irritable Bowel Syndrome (Clinical GI & Hepatology)

Sixty-five adults with IBS-D were randomized to LFD or rifaximin for 5 weeks. Primary endpoints were changes in mean daily abdominal pain and bloating at week 5 versus baseline. Secondary endpoints included changes in IBS Symptom Severity Score (IBS-SSS) and Bristol Stool Form Scale (BSFS) at week 5 versus baseline. Exploratory endpoints included responders defined as ≥30% reduction in abdominal pain or bloating. Stool samples collected at weeks 0, 2, 4, and 5 underwent 16S rRNA sequencing, and glucose breath testing (BT) was performed at weeks 0 and 5.