Obesity-driven microbial GABA depletion promotes metabolic rewiring and colorectal cancer progression.
Obesity is a major risk factor for colorectal cancer (CRC), yet the mechanisms linking obesity-associated gut dysbiosis to tumor progression remain unclear. Here, we show that a high-fat diet and fecal microbiota from patients with obesity-associated CRC deplete the GABA-producing commensal Bacteroides ovatus, resulting in reduced luminal GABA and accelerated tumorigenesis. Microbial GABA activates epithelial GABAB receptor signaling and induces TPI1 through the PI3K-HIF1α pathway. Increased TPI1-derived glyceraldehyde-3-phosphate inhibits PPP1CA, maintains YAP phosphorylation, restricts nuclear YAP activity, and suppresses pentose phosphate pathway flux, thereby limiting tumor growth. Consistently, obesity-associated CRC exhibits reduced fecal GABA, decreased TPI1 expression, and metabolic rewiring. A GABA-deficient B. ovatus mutant fails to restore GABA or suppress tumors despite normal colonization, whereas oral GABA supplementation or recolonization with wild-type B. ovatus markedly reduces tumor burden. These findings identify a microbiota-neurotransmitter-metabolism axis linking obesity to CRC and suggest microbiota-based GABA restoration as a potential preventive strategy.
Authors
Guo Guo, Sun Sun, Wang Wang, Li Li, Li Li, Yue Yue, Yin Yin, Ma Ma, Li Li, Xu Xu, Liu Liu, Zhang Zhang, Zhang Zhang, Feng Feng, Ma Ma, Ren Ren, Liu Liu, Liu Liu, Gao Gao, Chen Chen, Li Li
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