FFAR4 and obesity due to melanocortin 4 receptor deficiency: 2010). However, intestine‐specific FFAR4 deficiency in mice exhibits the opposite phenotype, resistance to obesity (Yasuda et al. 2023). In addition, FFAR4 mRNA expression in the intestine is generally up regulated by HF feeding, although it was down regulated in our experiments using ileal mucosal mRNA. Considering the higher expression of FFAR4 mRNA in the jejunum compared to the ileum (Yasuda et al. 2023), it is likely that most fatty acids were absorbed in the duodenum and jejunum, not in the ileum, in our mouse model, which may also explain a cause of colon atrophy.