Adipocyte-specific FFA2 deletion leads to increased adipose inflammation and is associated with altered intestinal lipid handling in mice

Obesity and related metabolic disorders are often characterized by chronic adipose tissue inflammation, driving systemic insulin resistance and general metabolic dysfunction. Free Fatty Acid Receptor 2 (FFA2) has emerged as a potential modulator of adipocyte function, inflammation, and metabolism. To investigate the role of FFA2 expressed in the adipose tissue, we generated adipose-specific FFA2 knockout mice (Adipoq-F2-KO) and assessed metabolic outcomes under standard laboratory chow and high-fat, high-sugar Western diet conditions, with and without dietary fiber supplementation. We found that adipose-specific FFA2 deletion had minimal metabolic consequences under standard dietary conditions but significantly reduced body weight and adiposity when mice were fed a fiber (fructooligosaccharide)-supplemented Western diet. Subsequent fecal analyses and transcriptomic profiling indicated impaired intestinal lipid absorption as the primary driver of reduced adiposity, suggesting disrupted adipose-intestinal communication. Unexpectedly, the lighter Adipoq-F2-KO mice also exhibited heightened adipose inflammation, characterized by increased macrophage infiltration and pro-inflammatory cytokine expression. Furthermore, in vitro loss-of-function experiments in adipocytes revealed that FFA2 knockdown impaired adipocyte maturation, lipid storage, and anti-inflammatory signaling. Additional studies using intestinal epithelial cells exposed to adipocyte-conditioned media implicated adipose-derived signals in driving intestinal dysfunction. Collectively, our findings highlight adipose-specific FFA2 as critical in regulating adipose tissue inflammation, lipid metabolism, and inter-organ communication.