Study On The Relationship Between Neuromyelitis Optica Spectrum Disorder And Gut Microbes

ObjectiveIn recent years,gut microbes have become a research hotspot in the field of human central nervous system diseases.Neuromyelitis optica spectrum disorder is an inflammatory demyelinating disease of the central nervous system.There is evidence that the intestinal flora imbalance is related to NMOSD.Using 16S rRNA sequencing technology,by analyzing the distribution and functional information of the gut microbes of patients with different types of NMOSD and healthy people,looking for significantly different bacterial genera and functional pathways,in order to explore the pathogenesis of NMOSD,develop new diagnostic tools and potential treatment methods provide new clues.MethodsThis study collected 25 patients with NMOSD admitted to the Department of Neurology of the First Affiliated Hospital of Zhengzhou University from January 2020 to January 2021,including 15 patients with AQP4 antibody positive and 10 patients with AQP4 antibody negative.And recruit 10 healthy people of similar age as the control group.15 AQP4 antibody-positive patients were set as group P,10 AQP4 antibody-negative patients were set as N group,and 10 healthy controls were set as H group.Stool samples from three groups of subjects were collected.Extract DNA from stool samples,perform PCR amplification on the V3～V4 variable range of 16s rRNA,mix and purify PCR products,construct a small fragment library,and use the Illumina NovaSeq sequencing platform for on-machine sequencing.Effective data is obtained after splicing the obtained original data.And perform cluster analysis and species annotation,through Alpha diversity and Beta diversity analysis,can reveal the composition of gut microbes in the sample,and find species with significant differences between different samples or groups.Using Tax4Fun function prediction to perform functional annotations on the microbial communities in the sample,from the perspective of microbial function,further dig out the microbial function information in the sample and find significantly different functional metabolic pathways.Results1.Using Alpha diversity analysis,the results showed that the intestinal microbial diversity of the AQP4 antibody-positive group and the AQP4 antibody-negative group were reduced,the distribution of the flora was uneven,and there was a flora imbalance in patients with NMOSD.2.Using LEfSe analysis to find gut microbes with significant differences between the three groups,the results showed that there were 18 biomarkers with LDA score>4 among the three groups.AQP4 antibody-positive group has higher abundance:Subdoligranulum,Blautia;AQP4 antibody-negative group has higher abundance:Bacilli,Lactobacillales,Enterococcus_faecium,Enterococcaceae,Enterococ cus,Streptcoccaceae,Streptcoccus,Lactobacillus_salivarius;Among the healthy people,the abundance is higher:Faecalibacterium_prausnitzii,Faecalibacterium,Prevotellaceae,Prevotella,Prevotella_copri,Bacteroides_vulgatus,Ruminococcaceae,Negativicutes.3.The T-test was used to compare the two groups separately to find functional pathways with statistical differences(p value<0.05).The results showed that there was no significant difference in functional pathways between the AQP4 antibody positive group and the AQP4 antibody negative group(p value>0.05);there were significant differences in 11 functional pathways between the AQP4 antibody positive group and the healthy control group(p value<0.05));There are significant differences in the three functional pathways between the AQP4 antibody negative group and the healthy control group(p value<0.05);The AQP4 antibody-positive group has increased relative abundance in the two major functional pathways of genetic information transcription and endocrine and metabolic diseases in human diseases(glucagon signaling pathway).Relative abundance decreases in energy metabolism(oxidative phosphorylation),genetic information folding(RNA degradation),lipid metabolism(fatty acid synthesis and degradation),peptidases metabolism,amino acid metabolism(glycine-serine-threonine metabolic axis and tryptophan),terpenoid and polyketide metabolism(prenyltransferases),cell growth and apoptosis,and environmental information processing functional pathways(membrane transport).The AQP4 antibody-negative group has an increased relative abundance in the functional pathways of central carbon metabolism in cancer.The relative abundance is reduced in the two major functional pathways of peptidases metabolism and endocrine system(adipocytokine signaling pathway).Conclusion1.Both AQP4 antibody-positive patients and AQP4 antibody-negative patients have reduced intestinal microbial diversity,uneven distribution of flora,and imbalance of flora in NMOSD patients.2.Bacteria that are beneficial to the intestines,such as short-chain fatty acid-producing bacteria,have a significant decrease in relative abundance in AQP4 antibody-positive patients and AQP4 antibody-negative patients.The relative abundance of Subdoligranulum and Blautia increased significantly in AQP4 antibody-positive patients.The relative abundance of conditional pathogens such as streptococcus that may cause intestinal inflammation is significantly increased in AQP4 antibody-negative patients.3.AQP4 antibody-positive patients and AQP4 antibody-negative patients have decreased relative abundance of intestinal microbial oxidative phosphorylation metabolism pathways and decreased relative abundance of glycine-serine-threonine metabolic axis and tryptophan,fatty acid synthesis and degradation,enzymes and other substances.NMOSD patients have functional metabolic pathway disorders.4.In the occurrence and development of NMOSD,the diversity of gut microbes and changes in metabolic functions may have played an important role.