Reduced incidence of Prevotella and other fermenters in intestinal microflora of autistic children

• Published in: PloS one Vol. 8; no. 7; p. e68322
• Main Authors: Kang, Dae-Wook, Park, Jin Gyoon, Ilhan, Zehra Esra, Wallstrom, Garrick, Labaer, Joshua, Adams, James B, Krajmalnik-Brown, Rosa
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.07.2013; Public Library of Science (PLoS)
• Subjects: Abnormalities; Adolescent; Analysis; Antibiotics; Autism; Autistic children; Autistic Disorder - complications; Autistic Disorder - epidemiology; Bacteria; Bacteroidaceae Infections - complications; Bacteroidaceae Infections - epidemiology; Biodiversity; Biology; Biotechnology; Carbohydrates; Child; Child, Preschool; Children; Clostridium difficile; Cluster Analysis; Deoxyribonucleic acid; Desulfovibrio; Diet; Digestive system; Digestive tract; Disease control; DNA; Female; Fermenters; Food habits; Gastrointestinal Diseases - complications; Gastrointestinal Diseases - epidemiology; Gastrointestinal Diseases - microbiology; Gastrointestinal tract; Gastrointestinal Tract - microbiology; Gram-negative bacteria; Gram-positive bacteria; Humans; Incidence; Intestinal microflora; Intestine; Life Sciences; Male; Medical research; Medicine; Metagenome; Microbiota; Microbiota (Symbiotic organisms); Microorganisms; Next-generation sequencing; Phylogeny; Prevotella - classification; Prevotella - genetics; Prevotella - isolation & purification; ROC Curve; Rodents; rRNA 16S; Statistical analysis; Statistical methods; Statistical tests; Studies; United States > US; Arizona
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0068322

High proportions of autistic children suffer from gastrointestinal (GI) disorders, implying a link between autism and abnormalities in gut microbial functions. Increasing evidence from recent high-throughput sequencing analyses indicates that disturbances in composition and diversity of gut microbiome are associated with various disease conditions. However, microbiome-level studies on autism are limited and mostly focused on pathogenic bacteria. Therefore, here we aimed to define systemic changes in gut microbiome associated with autism and autism-related GI problems. We recruited 20 neurotypical and 20 autistic children accompanied by a survey of both autistic severity and GI symptoms. By pyrosequencing the V2/V3 regions in bacterial 16S rDNA from fecal DNA samples, we compared gut microbiomes of GI symptom-free neurotypical children with those of autistic children mostly presenting GI symptoms. Unexpectedly, the presence of autistic symptoms, rather than the severity of GI symptoms, was associated with less diverse gut microbiomes. Further, rigorous statistical tests with multiple testing corrections showed significantly lower abundances of the genera Prevotella, Coprococcus, and unclassified Veillonellaceae in autistic samples. These are intriguingly versatile carbohydrate-degrading and/or fermenting bacteria, suggesting a potential influence of unusual diet patterns observed in autistic children. However, multivariate analyses showed that autism-related changes in both overall diversity and individual genus abundances were correlated with the presence of autistic symptoms but not with their diet patterns. Taken together, autism and accompanying GI symptoms were characterized by distinct and less diverse gut microbial compositions with lower levels of Prevotella, Coprococcus, and unclassified Veillonellaceae.