Clec7a drives gut fungus-mediated host lipid deposition

BACKGROUND: Compared to that of bacteria, the role of gut fungi in obesity development remains unknown. RESULTS: Here, alterations in gut fungal biodiversity and composition were confirmed in obese pig models and high-fat diet (HFD)-fed mice. Antifungal drugs improved diet-induced obesity, while fungal reconstruction by cohousing or fecal microbiota transplantation maintained the obese phenotype in HFD-fed mice. Fungal profiling identified 5 fungal species associated with obesity. Specifically, Ascomycota_sp. and Microascaceae_sp. were reduced in obese mice and negatively correlated with fat content. Oral supplementation with fungi was sufficient to prevent and treat diet-induced obesity. Clec7a, which is involved in fungal recognition, was highly expressed in HFD-fed mice. The Clec7a agonist accelerated diet-induced obesity, while Clec7a deficieny in mice resulted in resistance to diet-induced obesity and blocked the anti-obese effect of antifungal drugs and fungi. CONCLUSIONS: Taken together, these results indicate that gut fungi/Clec7a signaling is involved in diet-induced obesity and may have therapeutic implications as a biomarker for metabolic dysregulation in humans. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40168-023-01698-5.