Acetylated cellulose suppresses body mass gain through gut commensals consuming host-accessible carbohydrates

Effective approaches to preventing and treating obesity are urgently needed. Although current strategies primarily focus on direct modulation of host metabolism, another promising approach may involve limiting nutrient availability through regulation of the gut microbiota, which links diet and host physiology. Here, we report that acetylated cellulose (AceCel), which markedly alters gut bacterial composition and function, reduces body mass gain in both wild-type and obese mice. AceCel limits carbohydrate oxidation and promotes fatty acid oxidation in the host liver in a microbiota-dependent manner. We further show that acetate enhances carbohydrate fermentation by the gut commensal Bacteroides thetaiotaomicron, depleting host-accessible simple sugars in the gut of AceCel-fed mice. These findings highlight the potential of AceCel as a prebiotic that regulates carbohydrate metabolism in both bacteria and host, offering promise as a therapeutic strategy for obesity.