Hui-Ling Chen, Ying-Chen, Li-Shun Wang
This study highlights the potential of microbiota-modifying interventions, particularly probiotics such as B. pseudolongum, to control pathobionts, reduce inflammation, and improve intestinal health in ulcerative colitis.
The safety of fecal microbiota transplantation in early life remains unclear. We established murine models using two age groups (3-week-old and 8-week-old mice) and two inoculation doses (low, 100 μL; high, 400 μL), with age-matched saline controls. High-dose fecal microbial administration in 3-week-old mice was associated with reduced weight gain, mild hypothermia, diarrhea, and multi-organ pathological changes, together with altered gut tight junction gene expression, elevated serum IL-6 and IL-1β, and increased Proteobacteria-associated bacterial DNA signals detected in extraintestinal tissues. In contrast, these effects were not observed in 8-week-old mice under the same conditions. Our findings suggest that early life may represent a susceptible window for adverse effects to high-dose fecal microbial exposure and support the need for age- and dose-stratified safety evaluation before pediatric application.