Effects of age, sex, and renal function on bowel movement‐improving effects of Bifidobacterium bifidum G9 ‐1 on constipation in patients with type 2 diabetes mellitus and chronic kidney disease: A prespecified subgroup analysis of the BIRDIE study

Introduction Type 2 diabetes mellitus and chronic kidney disease are associated with increasing risk of constipation. We previously reported that Bifidobacterium bifidum G9‐1 improved stool consistency, bowel movement, and quality of life of patients with type 2 diabetes mellitus, chronic kidney disease, and constipation. However, the effect of patients' background characteristics on the efficacy of B. bifidum G9‐1 has not yet been investigated. Materials and Methods This prespecified subgroup analysis of the BIRDIE study investigated the effect of age, sex, and baseline renal function on the efficacy of B. bifidum G9‐1. Results The primary endpoint, the percentage of participants with normal stool consistency at week 12, significantly increased in participants aged ≥65 years, male, and those with estimated glomerular filtration rate of ≥60 mL/min/1.73 m 2 . Regarding the secondary endpoints, although the improved variables differed according to subgroup, the constipation score on the Gastrointestinal Symptom Rating Scale and abdominal bloating among the abdominal symptoms significantly improved in most of the subgroups, except for the subgroup including only a few participants. Metformin users were more likely to experience relief from constipation, whereas insulin users were less likely to experience improvement. Discussion Patients aged ≥65 years, male, and those with estimated glomerular filtration of ≥60 mL/min/1.73 m 2 are more likely to benefit from treatment with B. bifidum G9‐1. These results may provide useful guidance for considering treatment options based on patients' background characteristics upon treatment of constipation in patients with type 2 diabetes mellitus and chronic kidney disease.