<i>Bifidobacteriuradm bifidum G9‐1</i> Intake Improves Gastrointestinal Symptoms in Type 2 Diabetes Mellitus: An Open‐Label, Randomized Controlled Trial (Binary <scp>STAR</scp> Study)

AIMS: To evaluate the effects of probiotics Bifidobacterium bifidum G9-1 (BBG9-1) on gastrointestinal symptoms in patients with Type 2 diabetes mellitus (T2DM) with diarrhoea or constipation. MATERIALS AND METHODS: In a 12-week open-label randomised controlled trial, 100 participants were randomized 1:1 to a control or BBG9-1 group, with 12 mg of Bifidobacterium administered daily. The primary endpoint was the change in total Gastrointestinal Symptom Rating Scale (GSRS) score (range: 1-7) in the full analysis set (BBG9-1: n = 43; control: n = 51). RESULTS: . Among the GSRS subscales, BBG9-1 showed a significantly greater mean reduction in constipation scores than control (-0.79 ± 1.38 vs. -0.13 ± 1.04; p = 0.013). Although the mean change in diarrhoea scores did not differ significantly (-0.42 ± 1.14 vs. -0.06 ± 1.08; p = 0.14), the follow-up diarrhoea score was significantly lower with BBG9-1 (2.04 ± 1.00 vs. 2.58 ± 1.44; p = 0.049). Through gut microbiota analysis, the relative abundance of genera Phocaeicola increased significantly in the BBG9-1 group (from 15.98 ± 13.75 to 19.56% ± 14.79% vs. from 18.14 ± 14.17 to 18.21 ± 13.58, p = 0.042). Assessment of faecal short-chain fatty acids (SCFAs) revealed no significant changes associated with BBG9-1 administration. The incidence of adverse effects were similar between the groups. CONCLUSIONS: BBG9-1 administration significantly improved gastrointestinal symptoms in patients with T2DM. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCTs051220127).