Kampo medicine for IBS and microbiome alternation

Diarrhea-predominant irritable bowel syndrome (IBS-D) is treated with traditional Japanese (Kampo) medicine in Japan, however, its clinical effect and influence on the gut microbiome are unknown. We compared the IBS-D patients with healthy controls, and conducted a prospective clinical study to investigate the effectiveness and safety of Kampo treatment on IBS-D and the gut microbiome alteration. Newly diagnosed IBS-D male patients and healthy controls (HCs) were recruited in this study, and received a 4-week Kampo treatment (hangeshashinto or rikkunshito). Overall clinical improvement, scores on quality of life (QOL), gastrointestinal symptoms, diarrhea, anxiety, and depression were obtained. Fecal microbiomes were analyzed comparing at 4-time points; before treatment (1) with mild symptoms and (2) with a flare-up of symptoms, (3) after treatment, and (4) at 4 weeks follow-up after treatment.