Supplementary file 1_Maternal dietary taurine supplementation improves intestinal health of lambs via modulating gut microbiota and barrier function.docx

Pre-weaning lambs are often at risk of diarrhea, and thus, intestinal development and normal function are closely related to their health and survival. This study investigated whether maternal dietary supplementation of taurine (TAU) during gestation is associated with distinct microbial community features and alterations in microbial functional potential in the offspring’s gut microbiota, and whether these microbiota-associated alterations were accompanied by improvements in intestinal development, barrier function, immune homeostasis, and antioxidant capacity. Ewes were fed with different concentrations of taurine (0, 0.1 and 0.2%) during gestation, and lambs’ gut microbiota composition and intestinal barrier function were determined. The results showed that lambs’ body weights at day 15 after birth were elevated by maternal dietary taurine intake. Moreover, maternal taurine supplementation was associated with shifts in beneficial bacterial groups, including members of Lachnospiraceae (e.g., Coprococcus, Ruminococcus_gauvreauii_group, Lachnospiraceae_FE2018_group, Blautia), as well as Ruminococcus and Eubacterium, together with alterations in microbial functional potential. These microbiota-associated alterations were accompanied by increased villus height, reduced crypt depth, and upregulation of ZO-1, Claudin-1, Occludin and Mucin2 (MUC2) expression, along with reduced Notch2 expression. Importantly, dietary taurine supplementation downregulated IL-1β, IL-6, NF-κB and malondialdehyde (MDA) levels, and upregulated IL-10, Superoxide dismutase (SOD) and glutathione (GSH) contents. In conclusion, maternal dietary taurine supplementation during gestation was associated with distinct microbiota-related features and improved intestinal barrier integrity in pre-weaning lambs, which may contribute to increased body weight. Despite the relatively limited sample size, the observed associations were directionally consistent across microbial and host-level analyses; future studies with larger cohorts will be necessary to confirm and extend these findings.