Maternal Bifidobacterium bifidum BD-1 supplementation during late gestation modulates offspring gut microbiota succession and responses to DSS-induced acute colitis in a delivery-mode-dependent manner

Purpose Early-life gut microbiota establishment critically influences long-term host health. This study investigated whether maternal Bifidobacterium bifidum BD-1 supplementation during late gestation, combined with delivery mode, affects offspring responses to DSS-induced acute colitis. Methods Pregnant mice received B. bifidum BD-1 (1×10^9 CFU/day), ceftriaxone (100 mg/kg), or saline by gavage from gestational day 14 to 21. Offspring were delivered vaginally (VD) or by cesarean section (CS). Acute DSS-induced colitis was induced with 3% dextran sulfate sodium at postnatal day 42. Results VD offspring showed relatively stable microbial succession and comparatively limited variation in DSS-induced colitis-related outcomes across maternal treatment groups. In CS offspring, maternal BD-1 supplementation was associated with enrichment of beneficial genera, maintenance of α-diversity, higher fecal butyrate and propionate levels, increased expression of tight junction-related genes, and lower histopathological inflammatory scores compared with NS-CS-DSS offspring. Conclusion Maternal B. bifidum BD-1 supplementation was associated with lower indices of acute DSS-induced colitis, with more pronounced effects observed in CS offspring, supporting its potential as a prenatal probiotic candidate requiring further validation.