Diversity Of Gut Flora In Navy Officers And Soldiers Involved In Long Voyage

Objective: The gastrointestinal(GI)tract is colonized by a dense resident microbial community which referred to as the gut microbiota,coevolved with the host,and it is essential for many physiological processes of the host participating in a myriad of immunogenic and metabolic interactions.The gut microbiota contributes to the maintenance of host health.However,when healthy microbial structure is perturbed,a condition termed dysbiosis,the altered gut microbiota can trigger the development of various diseases There is a growing body of evidence suggesting that multiple intrinsic and extrinsic factors,such as genetic variations,diet,stress,and medication,can dramatically affect the balance of the gut microbiota.Therefore,these factors regulate the development and progression of GI diseases by inducing dysbiosis.At present,the role of intestinal flora in the occurrence and development of intestinal-related diseases and its mechanism is not yet mature.There are still many problems to be solved urgently.In addition,many diseases such as obesity,diabetes,myocardial infarction,depression and other areas of the disease are associated with the intestinal flora.In order to analyze the structure and diversity of intestinal flora in the long voyage mission officer,this study focuses on the significance of diversity of gut flora in navy officers and soldiers involved in long voyage,and found measures to cope with those adverse changes.To provide long voyage officers and soldiers the basis for the quality of life.Methods:In this study,the total DNA of the stool samples was acquired by collecting fecal samples of 29 officers and soldiers involved in the long voyage from different time nodes at beginning,the 45 th days,90 th days and 135 th days by using the high-throughput sequencing technique.Using the Illumina Miseq platform to amplify the DNA of intestinal microflora according to the bacteria’s 16 S r DNA V3-V5 district.We acquired the sequencing results by spiced Reads,OTUs(operational taxonomic units)clustering,species annotation,alpha diversity analysis,NMDS analysis,and finally get the abundance of fecal flora species information.Results: Among the 116 samples,11 phylum were found,accounting for 99% of the intestinal flora,which were Bacteroidetes,Firmicutes,Proteobacteria,Fusobacteria,Actinobacteria.A total of 48 genus is measured,the top 10 are: Bacteroides,Prevotella,Lachnospira,Ruminococcaceae,Alistipes,Phascolarctobacterium,Parabacteroides,Sutterella,Roseburia,Dialister.Among them,Bacteroidetes had the highest abundance in the four groups,and 60.01%,62.56%,65.05% and 57.51% respectively,the proportion of the 116 samples was 61.30%.Then secondly high abundant phylum were firmicutes in the four groups,respectively accounted for 34.62%,32.19%,27.21%,37.6%,and the proportion of the 116 samples was 32.90%.Other high abundance phylum were Proteobacteria,Fusobacterium,Actinobacteria.In addition,the differences of four groups on the phylum classification level were as follows: the abundance of Bacteroidetes in group B was higher than that in group A(60.01% vs 62.56%,P<0.05),the abundance of group C was higher than that of group B(65.05% vs 62.56%,P<0.05),the abundance of group D was lower than that of group C(57.51% vs 65.05%,P<0.05),and there was significant difference between group A and group D(60.01%% vs57.51%,P<0.05).The abundance of the Firmicutes in group A was higher than that in group B(34.62% vs 32.19%,P<0.05,the abundance of group B was higher than that of group C(32.19% vs 27.21%,P<0.05,the abundance of group C was lower than that of group D(27.21% vs 37.60%,P<0.05,and there was significant difference between group A and group D(34.62% vs 37.60%,P<0.05.The α diversity analysis showed that the diversity of intestinal flora in group A and D was higher than that in group B and C,which indicates that the diversity of gut flora in navy officers and soldiers continues to decrease,but in the end it generally returned to the normal level.The results of the OTUs show that there has been some change in the flora structure since the beginning of the long voyage on the phylum classification level,the Chloroflexi were newly found,on the class classification level,the Cytophagia,Sphingobacteriia,Anaerolineae,Bacilli were newly found,and on the genus classification level,the Pontibacter,Desulfovibrio,Pseudomonas,Thermomonas were newly found.At the same time,some species disappeared after 45 days of long voyage,including Melainabacteria and Verrucomicrobiae on the class classification level,and Hungatella,Marvinbryantia,Cltrobacter,Cloaclbacillus,Akkermansia genus on the genus classification level.Conclusions: These results indicate that the structure and diversity of intestinal flora in the process of long voyage mission have changed greatly,but it is gradually restored after returning.At the same time,we also found the number of pathogens in the intestinal flora of the navy officers and soldiers was higher than that of the healthy population,while some friendly Bacteroideaebacteria were lower than the healthy population,and aquatic genera species also exist after the long voyage.