Neonatal overfeeding accelerates age-related sarcopenia and metabolic disorders through lifelong gut mucosa and microbiota programming in mice

Early-life nutrition shapes lifelong health, yet the long-term consequences of childhood overnutrition, particularly on musculoskeletal aging, remain unclear. Here, we show that neonatal overfeeding acts as a developmental insult that accelerates age-related sarcopenia in both sexes. Using different mouse models, early overnutrition shortens lifespan and exacerbates late-life muscle atrophy, accompanied by metabolic dysfunction. Mechanistically, neonatal overfeeding disrupts goblet cell development, leading to persistent mucus barrier defects and consequently reduced Akkermansia muciniphila (A. muciniphila) colonization during aging. Fecal microbiota transplantation transfers the sarcopenic phenotype, implicating gut dysbiosis in disease propagation. Loss of A. muciniphila reduces acetate production, impairs muscle mitochondrial function at least in part via suppressed GPR43 signaling, and aggravates sarcopenia. Conversely, A. muciniphila reconstitution or acetate supplementation restores mitochondrial homeostasis and improves muscle performance in aged mice. These findings reveal a developmental origin of age-related sarcopenia and define a gut-muscle axis linking early-life overnutrition to muscle aging, highlighting the preventive potential of optimizing early nutrition to support healthy aging. Here, the authors demonstrate that neonatal overfeeding in mice shortens lifespan and accelerates late-life muscle loss. This originates from persistent gut mucus defects and depleted Akkermansia muciniphila, revealing a targetable developmental origin for sarcopenia.