A commensal-derived sugar protects against obesity by regulating immunometabolism.

A bacterial exopolysaccharide containing phosphocholine from Clostridium immunis prevents and treats obesity in mice by regulating IL-22 levels.

• Why it matters: Obesity's regulation by microbiota involves unknown factors, and understanding these could lead to new therapeutic strategies.
• What they did: Researchers identified a phosphocholine-modified exopolysaccharide secreted by C. immunis that reduces visceral fat and depends on IL-22 and group 3 innate lymphoid cells, with gene analysis showing lower phosphocholine biosynthesis genes in humans with obesity.
• The result: This bacterial molecule and its structural motif may offer a clinically translatable approach to control obesity by modulating immunometabolism and reducing visceral fat.