Gut Microbiota Changes In Children With Autism Spectrum Disorder

Background:Autism spectrum disorder(ASD)is a severe neurodevelopmental disorder,which affects children’s ability to communicate and interaction with others.ASD affected individuals have difficulties while interacting and communicating socially,and repetitive behaviors.Studies have revealed that gut microbiota plays an indispensable role in brain development and maturation,and also has a connection with neurological disorders.There are about 100,000,000 neurons surrounding the intestinal tract,which is second only to the central nervous system and thus called as the intestinal nervous system(ENS).ENS controls the digestive tract,which can modulate the gastrointestinal tract system independently,but also can communicate with the brain.Some studies have found that the gut microbiota influences brain function through the neuroendocrine,neuroimmune and autonomic nervous systems and via microbiotic toxin production.In addition,gastrointestinal symptoms are prominent in children with ASD,including constipation and diarrhea.It is suggested that gut microbiota may play a role in the pathogenesis of ASD.We therefore investigate the relationship between ASD and gut microbiota,and to study the impact of gut microbiota in the diagnosis of ASD.Materials and methods:Between November 2017 and August 2019,we collected fecal samples from a total of 127 children with 2 to 7 years old(77 children with ASD and 50 sex-and age-matched healthy children as controls).77 children with ASD were enrolled in the Third Affiliated Hospital of Zhengzhou University,China.50 sex-and age-matched healthy children were recruited from kindergartens in the Zhengzhou,China.We sequenced the bacterial 16S ribosomal RNA gene and analyzed the composition of the gut microbiota in children with ASD.Result:The children with ASD showed higher biomass,richness,and biodiversity of gut microbiota,and an altered microbial community structure compared with children in the healthy control group.At the genus level,there was a significant increase in the relative abundance of unidentified Lachnospiraceae,Clostridiales,Erysipelotrichaceae,Dorea,Collinsella,and Lachnoclostridium,whereas Bacteroides,Faecalibacterium,Parasutterella,and Paraprevotella were lower in the ASD group than in the control group.The presence of unidentified Erysipelotrichaceae,Faecalibacterium,and unidentified Lachnospiraceae was positively correlated with ASD severity.In addition,the 10 gut microbiota could predict ASD[area under the curve(AUC)=0.983,95%CI:96.5%–100%].Furthermore,the validation set was consistent with the test set(AUC=0.994,95%CI:97.9%–100%)in this study.In addition,the functional properties displayed significant differences between the ASD and HC groups.Conclusion:The gut microbiota has changed and is associated with the severity of symptoms in children with ASD,and could contribute to symptomology.Thus modulating gut microbiota may supply a new therapeutic strategy for ASD.