Young gut microbiota transplantation improves the metabolic health of old mice

The gut microbiome is a key hallmark of aging. Fecal microbiota transplantation (FMT) using young microbiota represents a novel rejuvenation strategy to delay aging. Our study provides compelling evidence that transplanting microbiota from young mice significantly improved grip strength, frailty, and body composition in aged recipient mice. At the molecular level, FMT improved aging-related metabolic markers in the gut and circulation. Additionally, FMT from young microbiota rejuvenated the amygdala of the aged brain by downregulating inflammatory pathways. This study highlights the importance of metabolic reprogramming via young microbiota FMT in improving physical and metabolic health in elderly recipients.