Protective Effects of Akkermansia muciniphila and Amuc_1100 Protein on Rats on High-Fat Diet Combined with Streptozotocin Injection

  Objective  To explore the protective effects of live or pasteurized Akkermansia muciniphila and Amuc_1100 protein on a rat model of diabetes mellitus induced by high-fat diet (HFD) combined with streptozotocin (STZ).

  Methods  A total of 96 Sprague-Dawley (SD) rats were randomly assigned to 8 groups, including 6 experimental groups and 2 control groups, with 12 rats in each group. HFD combined with STZ injection was given to the rats to create a simulated model of the progression of diabetes mellitus type 2. In addition, the rats were treated with different doses of live or pasteurized Akkermansia muciniphila or Amuc_1100 protein by way of gavage for 8 weeks simultaneously. Plasma samples were collected to determine the level of parameters related to lipid and glucose metabolism, and inflammation mediators. Colon tissue specimens were collected for HE staining. Stool samples of the rats were collected for 16S rRNA gene sequencing.

  Results  Compared with the HFD control group, rats in the group treated with Akkermansia muciniphila exhibited significantly lower body mass gain (P<0.01) and lower plasma TNF-α level (P<0.05). Administration of Akkermansia muciniphila or Amuc_1100 protein increased the number of goblet cells and mucin secretion. The β diversity analysis of the samples showed no overall difference in the intervention groups.

  Conclusion  Oral administration of Akkermansia muciniphila can effectively ameliorate HFD-induced metabolic disorders, including body mass gain and systemic inflammation. Akkermansia muciniphila and Amuc_1100, to a certain degree, improved the gut barrier function. After eight weeks of intervention, there was no significant impact on the structure of the gut microbiota.