Antiaging Effects of Human Fecal Transplants with Different Combinations of Bifidobacterium bifidum LTBB21J1 and Lactobacillus casei LTL1361 in d-Galactose-Induced Mice

The feces of healthy middle-aged and old people were first transplanted into d-galactose-induced aging mice to construct humanized aging mice with gut microbiota (FMTC) to confirm the antiaging effect of probiotics produced from centenarians. The mouse model was then treated with centenarian-derived Bifidobacterium bifidum (FMTL), Lactobacillus casei (FMTB), and their mixtures (FMTM), and young mice were used as the control. Compared with the FMTC group, the results demonstrated that the probiotics and their combinations alleviated neuronal damage, increased antioxidant capacity, decreased inflammation, and enhanced cognitive and memory functions in aging mice. In the gut microbiota, the relative abundance of Lactobacillus, Ligilactobacillus, and Akkermansia increased and that of Desulfovibrio and Colidextribacter decreased in the FMTM group compared with that in the FMTC group. The three probiotic groups displayed significant changes in 15 metabolites compared with the FMTC group, with 4 metabolites showing increased expression and 11 metabolites showing decreased expression. The groups were graded as Control > FMTM > FMTB > FMTL > FMTC using a newly developed comprehensive quantitative scoring system that thoroughly analyzed the various indicators of this study. The beneficial antiaging effects of probiotics derived from centenarians were quantitatively described using a novel perspective in this study; it is confirmed that both probiotics and their combinations exert antiaging effects, with the probiotic complex group exhibiting a larger effect.