Study On The Relationship Between Tobacco Smoking And Gut Microbiota

Backgrounds:A variety of diseases can be caused by smoking,such as cancers,cardiovascular diseases and chronic obstructive pulmonary disease.Throughout the world,about 6 million people die each year from smoking-related diseases,costing the economy$1.436 trillion.Europe countries and the United States have carried out a lot of researches and made significant progresses in smoking behaviors and addiction,but there were very limited studies on the Chinese population.This project aimed to study the correlation between smoking and gut microbiota in Chinese population.Methods:Our research group collected 401 fecal samples and phenotypic data in Shanxi Province.Bacterial abundance information in these samples was obtained through fecal DNA extraction,16S rRNA sequencing and bacterial annotation.Through correlation analysis and sample selection,92 healthy subjects(53 smokers and 39 non-smokers)were selected as the discovery dataset.First,LefSe,MaAsLin and randomforest methods were used to search for smoking-related bacteria.Then,PICRUSt was used to predict the bacterial pathway information and LefSe was used to find the bacterial pathway related to smoking.Finally,using MaAsLin to look for bacteria that are related to nicotine metabolism.Results:The discovery dataset was used to analyze the correlation between smoking and gut microbiota.The results showed a significant correlation between smoking and gut microbiota(r2==0.07,p<0.01).26 genera were related to smoking,and 5 genera were present in analytical results of LefSe,MaAsLin and randomforest.Among these 5 genera,Clostridium was enriched in smokers,while Prevotella,Butyricimonas,Odoribacter and Victivallis were under abundant in smokers.A total of 240 bacterial pathways were predicted by PICRUSt,92 of which were related to smoking(LDA score log10>2,p<0.05).Among them,the pathway of EnvironmentalInformation Processing was significantly enriched in the smokers.The pathway of nicotinate and nicotinamide metabolism and some pathways of Genetic Information Processing were underabundant in smokers.Prevotella was positively correlated with nicotinate and nicotinamide metabolism pathway,while Clostridium was significantly positive correlated with this pathway.Conclusion:In this study,a total of 26 genera and 92 bacterial pathways were found to be related to smoking.Clostridium and Prevotella are not only associated with smoking,but also correlated with the nicotinate and nicotinamide metabolism pathway.Environmental Information Processing and Genetic Information Processing were related to smoking,and it could be speculated that chemicals in smoking may enter the intestinal tract through the digestive tract or blood circulation and affect the physiological function of gut microbiota.