Amuc attenuates high-fat diet-induced metabolic disorders linked to the regulation of fatty acid metabolism, bile acid metabolism, and the gut microbiota in mice

Int J Biol Macromol. 2023 Jul 1;242(Pt 2):124650. doi: 10.1016/j.ijbiomac.2023.124650. Epub 2023 Apr 28.

Abstract

Amuc_1100 (hereafter called Amuc) is a highly abundant pili-like protein on the outer membrane of Akkermansia muciniphila and has been found to be effective for in anti-obesity, which is probably through the activation of TLR2. However, the precise mechanisms underlying the contributions of TLR2 to obesity resistance remain unknown. Here, TLR2 knockout mice were used to decipher the anti-obesity mechanism of Amuc. Mice exposed to a high-fat diet (HFD) were treated with Amuc (60 μg) every other day for 8 weeks. The results showed that Amuc supplementation decreased mouse body weight and lipid deposition by regulating fatty acid metabolism and reducing bile acid synthesis by activating TGR5 and FXR and strengthening the intestinal barrier function. The ablation of TLR2 partially reversed the positive effect of Amuc on obesity. Furthermore, we revealed that Amuc altered the gut microbiota composition by increasing the relative abundance of Peptostreptococcaceae, Faecalibaculum, Butyricicoccus, and Mucispirillum_schaedleri_ASF457, and decreasing Desulfovibrionaceae, which may serve as a contributor for Amuc to reinforce the intestinal barrier in HFD-induced mice. Therefore, the anti-obesity effect of Amuc was accompanied by the mitigation of gut microbes. These findings provide support for the use of Amuc as a therapy targeting obesity-associated metabolic syndrome.

Keywords: Amuc; Bile acids; Gut microbiota; Intestinal barrier function; Lipid metabolism; TLR2.

MeSH terms

  • Animals
  • Bile Acids and Salts / pharmacology
  • Diet, High-Fat / adverse effects
  • Fatty Acids / pharmacology
  • Gastrointestinal Microbiome*
  • Metabolic Syndrome*
  • Mice
  • Mice, Inbred C57BL
  • Obesity / chemically induced
  • Obesity / etiology
  • Toll-Like Receptor 2
  • Verrucomicrobia

Substances

  • Toll-Like Receptor 2
  • Fatty Acids
  • Bile Acids and Salts