The Effect Of Multi-stage Ketogenic Diet On The Structural Characteristics Of Gut Microbiota In Obese People

In recent years,the incidence of obesity is increasing,leading to increased risk of cardiovascular and cerebrovascular diseases,type 2 diabetes,coronary heart disease and other diseases.How to control the occurrence of obesity has developed into an urgent public health problem in the world.The Ketogenic Diet(KD)is a formula diet with high fat content and low carbohydrate content which can be used to treat epilepsy,diabetes,obesity and other diseases.Domestic and foreign studies have shown that the ketogenic diet affects the composition of the gut microbiota,but there is still no consensus on the specific impact of the gut microbiota.Based on the American Gut Project(AGP)database,this project has conducted research on large-scale obese people.By analyzing the overall characteristics of the gut microbiota in obese people,the composition and internal interaction differences of the gut microbiota between obese and normal weight people,the key bacteria of the gut microbiota of obese people was explored.Meanwhile,the effect of ketogenic diet and hypocaloric balanced diet on gut microbiota and function of obese people was explored,laying a theoretical foundation for the analysis of the mechanism of gut microbiota in obesity and the development of microbiota targeted food microbial resources,which is of great significance to improve the overall health level of the whole people.The main results are as follows.(1)Abnormal Body Mass Index(BMI)is associated with decreased diversity of gut microbiota.Blautia,Ruminococcus,Phascolarctobacterium,Megasphaera,Catenibacterium,Dorea,Eubacterium,Lactococcus,Acidaminococcus,Collinsella,and Bilophila are the key genera of gut microbiota in obese people.The interaction of obesity key bacteria such as Blautia,Ruminococcus,and Dorea in the gut microbiota of obese people is more stable.Lachnospira is negatively related to obesity,and the degree of interaction with other bacteria in the intestine of obese people is reduced.The lack or weakening of the interaction between Butyricimonas or Akkermansia and other bacterial genera is one of the reasons for the reduced complexity of the gut microbiota co-occurrence network in obese people.(2)Compared with a hypocaloric balanced diet,the multi-stage ketogenic diet significantly reduced the BMI,waist circumference,hip circumference,body fat,body fat percentage,and visceral fat area of obese subjects,and the weight loss effect was more significant with the weight loss success rate of 87%.After dietary intervention,the overall structure of gut microbiota in obese subjects changed,and the relative abundance of Blautia and Eubacterium?hallii?group in obese subjects decreased significantly.The initial high abundance of Blautia in the gut of obese people can respond to dietary intervention,which may be related to whether weight loss is effective.The ketogenic diet reduced the degree of interaction between Blautia and other bacterial genera in the intestines of obese subjects,so that the gut microbiota co-occurrence network of obese subjects tended to that in normal weight subjects(3)Metagenomic analysis showed that after ketogenic diet intervention,the species abundance of Blautia obeum under the genus Blautia was significantly correlated with changes in obesity status.The multi-stage ketogenic diet has a significant effect on the metabolic pathways of gut microbiota in obese people.Furthermore,B.obeum and Eubacterium hallii are the main contributor to the key metabolic pathways.Therefore,the multi-stage ketogenic diet can improve the symptoms of obesity by changing the abundance and metabolic function of B.obeum and E.hallii,which may be a key target for intervention in obesity based on gut microbiota.