Study On Skin Microbiome Of 24 Chinese And Pakistani College Students

Objective: Skin microbiota plays a certain role in human health,but at the same time they are also affected by the host itself and the external environment,including their own skin aging,gender,living environment and other factors.There have been a lot of previous studies on the microbiome of human skin in geographically separated countries in different environments.However,there are few studies on the changes of skin microbiota of healthy people in different countries in the same living environment.The purpose of this study was to explore the composition and diversity of skin microorganisms in different skin parts of people from different nationalities in the same environment.Methods: With the development of high-throughput sequencing technology,the DNA sequencing technology is becoming more and more mature.We used 16 S r RNA sequencing technology to study the skin microbial community of healthy people.In a university,we selected Chinese and Pakistanis for healthy volunteers.We collected skin microorganisms from their forehead,cheek,jaw,opisthenar and palm with medical swabs soaked in sterile water,and then extracted DNA.After high-throughput sequencing,we solved the questions based on bioinformatics and some statistical analysis methods.Results:(1)By using “PERMANOVA” to analyze the differences of community members and community structure in R,it is concluded that body position and country are the most significant factors affecting the bacterial community structure of skin,while season and gender only affect the community members but not the bacterial community structure.(2)Firstly,by comparing the skin microbiological composition of Chinese and Pakistani,we found that the Proteobacteria is more abundant on the skin surface of Pakistanis than Chinese,which is due to the different lifestyles and genetic characteristics of their hosts.The Firmicutes on the Chinese skin surface are more abundant.Secondly,one-way ANOVA showed that the Shannon diversity of skin microorganisms in different body sites of Chinese people was significantly different.The Shannon diversity of skin bacteria in palm and opisthenar was significantly higher than that in forehead and jaw.There was no significant difference in Shannon diversity among Pakistanis.After pairwise comparison of body sites,it was found that there were significant differences in bacterial community structure and community members between forehead and opisthenar,forehead and palm,jaw and opisthenar,jaw and palm.(3)In this study,core microorganisms were defined in all samples(128 samples).Total 18 core microbial genera were selected by calculation and sorting them from high to low according to the average relative abundance.We found that Staphylococcus(22.78%)was the core with the highest average relative abundance in this study,which is also a common opportunistic pathogen.After comparing the core bacteria on Chinese and Pakistani skin,we found that the Staphylococcus and Deinococcus on Chinese skin surface are more abundant than those on Pakistani.(4)In order to compare the functional differences of human skin bacterial genes between the two countries from KEGG functional pathway,PICRUSTs prediction results showed that the functions of skin bacterial genes involved in glucose metabolism,lipid metabolism,xenobiotics biodegradation and metabolism of Pakistanis ginseng were higher than those of Chinese,but the amino acid metabolism of Chinese skin microorganisms was higher than that of Pakistanis ginseng.At the same time,we also compared the potential pathogenic bacteria in different parts of human skin microorganisms about healthy people from two countries.The related research of pathogenic bacteria is of great significance for further study of the treatment of skin diseases.We can see that Corynebacterium dominated the forehead of Chinese people,and dominated in the jaw of Pakistani people.(5)In order to comprehensively understand the status of human skin microorganisms in different altitudes,233 human skin samples from 8 altitudes in Western China were analyzed by meta-analysis.The results are consistent with the previous research results.The dominant phyla in these human skin samples are Proteobacteria,Firmicutes,Actinomycetes and Bacteroides.Spearman rank correlation analysis showed that with the increase of altitude,the diversity of skin microorganisms decreased first and then increased.The diversity of skin microorganisms was the lowest at the altitude of 1520 m in Lanzhou.This may be due to the dry climate,thus microorganisms are more fragile than other areas.Then we used the network analysis to show that the altitude and Lactobacillus,Flavobacterium,Acinetobacter showed a significant positive correlation.Conclusion:(1)Countries and skin sites have the greatest impact on the microbial community structure of human skin.There are more Proteobacteria on the skin surface of Pakistanis.The Shannon diversity of bacteria on the opisthenar and palm of Chinese was significantly higher than that in the face.(2)Staphylococcus and Deinococcus are the most abundant core microbial genera in Chinese skin samples.The skin core microorganisms of Pakistanis are rich in Bradyrhizobium,Sphingomonas,Aquabacterium,Curvibacter and so on.(3)There are more genes related to carbohydrate metabolism,lipid metabolism,xenobiotics biodegradation and metabolism function of bacteria on the skin surface of Pakistani students.(4)The relative abundance of Staphylococcus,which may be the opportunistic pathogen,is the highest in the forehead of Chinese and the jaw of Pakistanis.(5)The Shannon diversity of human skin microorganisms is lower than that of other altitudes,so the skin ecosystem may be more vulnerable.From the perspective of different skin parts of college students from different countries,our study expounded the differences in the composition and diversity of human skin bacterial community,and obtained the altitude variability of skin microbiome.