Effect Of Bioactive Peptides From Andrias Davidianus On Intestinal Flora

The breeding quantity of giant salamander increased year by year,and the deep processing,including the development of active peptide,became a hot spot.Active peptide of giant salamander is a bioactive product obtained from meat protein of giant salamander by enzymolysis,separation and concentration.In this paper,we studied the changes of body weight during the growth of obese mice induced by gavage of high fat diet with active peptide of giant salamander,as well as the changes of biochemical indexes,intestinal flora and fecal metabolites after the experiment,in order to explain the mechanism of regulating intestinal flora and improving obesity by active peptide of giant Salamander at the molecular level.The main conclusions of the research are as follows:1.SPF ICR mice with obesity caused by high fat diet were given gavage of active peptide of giant salamander at low doses(2.5 m L/kg·BW),medium doses(5 m L/kg·BW)and high doses(10.0 m L/kg·BW)for 30 days.Gavage of active peptide of giant Salamander did not affect normal growth activities and food intake of the mice.In addition,the body weight and Lii index of mice in the salamander active peptide group were significantly lower than those in the model group.Salamander active peptide gavage could regulate the blood indexes of mice,reduce triglyceride and total cholesterol of mice,which proved that active peptide of salamander had certain lipid lowering effect.2.The active peptides decreased the proportion of Firmicutes to Bacteroidetes,and decreased the proportion of Bacillus,Erysipelas,Rhodiatinella and Saccharimonadia,while increased the proportion of Clostridium,Bacteroidetes and δProteobacteria at class level.At the order level,the proportions of Lactobacilli,Erysipelicae,Bifidobacteria,Ruatominales,Saccharimonadales,Campylobacteriales and deferribaciliales decreased,while the proportions of Clostridium,Bacteroides and desulfurvibrio increased.At the family level,the abundance ratio of Lactobacillaceae,erysipelinaceae,Bifidobacteriaceae,Bacteroideae,Riyanaceae and Iglesiaceae decreased,while the abundance ratio of Spirillaceae,murinobacteriaceae,ruminococcus and Vibriovibriaceae increased,indicating that active peptides of the giant salamanders had prominent regulation effects on intestinal flora of mice.3.Compared with the model group,369 different metabolites were found in the active peptide group,including 92 up-regulated metabolites and 277 down-regulated metabolites.There were 230 different metabolites in the negative ion model,of which 20 metabolites were up-regulated and 210 were down-regulated.These metabolites are mainly lipids and lipid molecules,organic acids and derivatives,benzene ring compounds and organic heterocyclic compounds.By further analysis of potential biomarkers,21 and 12 metabolites with significant differences were obtained by positive and negative ion modes,respectively.The content of cholic acid and its metabolites in feces of mice fed with active peptide of giant salamander group decreased.Therefore,active peptide ameliorated metabolic disorders caused by high fat diet.