Repair Mechanism Of Fermented Wheat Germ On Gut Microbiota In Aging Mice Damage Induced By D-galactose

BackgroundWith the progress of socialization in world,the aging of the population has been increasingly prominent.Functional food not only consumed directly as food but also provides health benefits and it was the premises for a specific population that needs the transition from "passive medical treatment" to "active health".As a targeted and accurate nutritional product,FWG has antioxidant and anti-aging effects,but it is a lack of animal experiments to support the operative characteristics of FWG.In recent years there has been increasing that in aging processes,the intestinal microbiota plays an important role,so this subject has been speculated FWG could regulate the composition of gut microbiota to anti-aging.ObjectiveThrough the aging mice model to judge whether FWG can be anti-aging,and Elucidate the underlying mechanism from the point of view of gut microbiota.MethodsFirstly,the key parameters in the fermentation process were investigated by single factor and response surface analysis,the composition changes and the structure of FWG system in the fermentation process were determined.Secondly the aging model induced by D-gal was established,and the differences among control mice,aging mice and aging mice supplemented with FWG were compared from the point of view of phenotype,physiology,biochemistry and oxidative stress.Finally,High-throughput sequencing targeting in bacteria 16 S r RNA genes was used to analyze the changes of gut microbiota of aging mice and the effect of FWG on gut microbiota of aging mice,in order to further explore the intervention mechanism of FWG on aging.Results(1)Preparation and characterization of FWG: The optimal fermentation process was noticed after Baker's yeast fermentation,lasting for 3.2 h;Lactobacillus plantarum was inoculated,and the fermentation continuous for 14.8 h,in which the ratio of baker's yeast to L.plantarum(V:V)was 1:2.Fermentation continuous for 14.8 h,in which the ratio of Baker's yeast to L.plantarum(V:V)was 1:2.With the progress of the fermentation process,the protein concentration and protease activity in the fermentation system gradually increased,the starch content gradually decreased,the pH value gradually decreased and the TTA content gradually increased,the number of Baker's yeast and Lactobacillus plantarum gradually increased.At the end of fermentation,all indexes tend to be stable.With the development of fermentation,the protein was degraded gradually,and the content of free amino acids with antioxidant activity increased significantly.And changes in the secondary structure of FWG and massive released of sulfhydryl groups,the surface of FWG became uneven during the fermentation.(2)Effects of FWG on behavioral characteristics of aging mice: In the Morris water maze test,FWG could significantly shorten the time of aging mice to find the escape platform(P < 0.05)and increased the times of entering the escape platform(P < 0.05).In the new object recognition experiment,FWG could significantly increase the exploration index of different objects in aging mice(P < 0.05).(3)Effects of FWG on physiological and biochemical indexes and antioxidant capacity of aging mice: In order to exploring the phenotypic verification basis of FWG intervention in aging,a FWG diet intervention model was established in D-gal induced aging mice to explore the effects of FWG on organ index,blood lipids,blood glucose levels and antioxidant capacity of serum and tissue in aging mice(P < 0.05).The results showed that FWG could increase the brain index,decrease the liver index and spleen index of aging mice,decrease the levels of TC,TG and GLU in serum of aging mice(P < 0.05),increase the activities of T-AOC,SOD and GSH-Px in serum and tissue of aging mice,and decrease the content of MDA(P < 0.05).(4)Effect of FWG on gut microbiota of aging mice: It was found that fermented wheat germ could significantly increase the Sobs index and Bootstrap index of gut microbiota in aging mice by Alpha diversity analysis.PCA showed that the gut microbiota of the three groups could be significantly distinguished,and the FWG group was closer to the control group.FWG could significantly increase the abundance of Bacteroidetes,Lachnospiraceae,Muribaculaceae,Lactobacillus,norank_f__Muribaculaceae(P < 0.05)and decrease the abundance of Firmicutes,Ruminiococcacea,Mycoplasmataceae,Enterococcaceae,Helicobacteraceae,unclassified_f__Ruminococcaceae(P < 0.05),Mycoplasma and Enterococcus in the gut microbiota at the three levels of door,family and genus.Functional prediction of gut microbiota showed that the microbial abundance of metabolic pathways such as fatty acid metabolism and synthesis and bacterial infection in aging group was significantly higher than that in control group and FWG group.ConclusionsFWG can effectively interfere with cognitive impairment,physiological and biochemical disorder,oxidative stress and gut microbiota disorder caused by aging.It is speculated that FWG establishes MGBA relationship through immune system mediation,nervous system regulation and short-chain fatty acid regulation,which further reveal the mechanism of FWG intervention on aging.