Diminished representation of vitamin-B12-producing bacteria in constipated elders with frailty.

Constipation and frailty are associated with intestinal dysbiosis. This study aims to identify intestinal microbial signatures that can differentiate between constipated elders accompanied by frailty and those without frailty. We collected stool samples from 61 participants and conducted 16S rRNA gene sequencing. Constipated patients with frailty (Constipation_F) exhibited reduced gut microbial diversities compared to constipated patients without frailty (Constipation_NF) and healthy individuals (C). From differential genera, random forest models identified 14, 8, and 5 biomarkers for distinguishing Constipation_F from Constipation_NF, Constipation_F from C, and Constipation_NF from C, respectively. Functional analysis revealed that pathways (P381-PWY and PWY-5507) related to vitamin B12 synthesis were reduced in Constipation_F, which aligns with the decreased abundances of vitamin-B12-producing Actinomyces and Akkermansia in this group. Our study unveils substantial differences in gut microbiota between constipated elders with frailty and those without, underscoring the diagnostic and therapeutic potential of genera involved in vitamin B12 synthesis.