title: New evidences on the altered gut microbiota in autism spectrum disorders.
abstract: Autism spectrum disorders (ASDs) are neurodevelopmental conditions characterized by social and behavioural impairments. In addition to neurological symptoms, ASD subjects frequently suffer from gastrointestinal abnormalities, thus implying a role of the gut microbiota in ASD gastrointestinal pathophysiology.
  
  
  
  Here, we characterized the bacterial and fungal gut microbiota in a cohort of autistic individuals demonstrating the presence of an altered microbial community structure. A fraction of 90% of the autistic subjects were classified as severe ASDs. We found a significant increase in the Firmicutes/Bacteroidetes ratio in autistic subjects due to a reduction of the Bacteroidetes relative abundance. At the genus level, we observed a decrease in the relative abundance of Alistipes, Bilophila, Dialister, Parabacteroides, and Veillonella in the ASD cohort, while Collinsella, Corynebacterium, Dorea, and Lactobacillus were significantly increased. Constipation has been then associated with different bacterial patterns in autistic and neurotypical subjects, with constipated autistic individuals characterized by high levels of bacterial taxa belonging to Escherichia/Shigella and Clostridium cluster XVIII. We also observed that the relative abundance of the fungal genus Candida was more than double in the autistic than neurotypical subjects, yet due to a larger dispersion of values, this difference was only partially significant.
  
  
  
  The finding that, besides the bacterial gut microbiota, also the gut mycobiota contributes to the alteration of the intestinal microbial community structure in ASDs opens the possibility for new potential intervention strategies aimed at the relief of gastrointestinal symptoms in ASDs.
authors.affiliation: Computational Biology Research Unit, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all' Adige, Italy.|Centre for Integrative Biology, University of Trento, Via Sommarive 9, 38123, Trento, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Strati
authors.affiliation: Department of Biology, University of Florence, Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy.
authors.forename: Duccio
authors.initials: D
authors.lastname: Cavalieri
authors.affiliation: Computational Biology Research Unit, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all' Adige, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Albanese
authors.affiliation: Neonatal Intensive Care Unit, Siena University Hospital AOUS, Viale Bracci 16, 53100, Siena, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: De Felice
authors.affiliation: Computational Biology Research Unit, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all' Adige, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Donati
authors.affiliation: Child Neuropsychiatry Unit, Siena University Hospital AOUS, Viale Bracci 16, 53100, Siena, Italy.|Azienda Unità Sanitaria Locale Umbria 2, Via D. Bramante 37, 05100, Terni, Italy.
authors.forename: Joussef
authors.initials: J
authors.lastname: Hayek
authors.affiliation: Centre for Integrative Biology, University of Trento, Via Sommarive 9, 38123, Trento, Italy.
authors.forename: Olivier
authors.initials: O
authors.lastname: Jousson
authors.affiliation: Child Neuropsychiatry Unit, Siena University Hospital AOUS, Viale Bracci 16, 53100, Siena, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Leoncini
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Gastroenterology Unit, University of Florence, Viale Morgagni 40, 50139, Florence, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Renzi
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Gastroenterology Unit, University of Florence, Viale Morgagni 40, 50139, Florence, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Calabrò
authors.affiliation: Institute of Agriculture Biology and Biotechnology, National Research Council (CNR), Via Moruzzi 1, 56124, Pisa, Italy. carlotta.defilippo@ibba.cnr.it.
authors.forename: Carlotta
authors.initials: C
authors.lastname: De Filippo
mesh_terms: D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000175:diagnosis / Q000209:etiology / Q000382:microbiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D003013:Clostridium / Q000235:genetics / Q000302:isolation & purification; D003248:Constipation; D005243:Feces / Q000382:microbiology*; D005260:Female; D000068536:Bacillota / Q000235:genetics / Q000302:isolation & purification; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D005767:Gastrointestinal Diseases / Q000382:microbiology; D000069196:Gastrointestinal Microbiome; D041981:Gastrointestinal Tract / Q000382:microbiology / Q000503:physiopathology*; D006801:Humans; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D000072761:Mycobiome
keywords: Autism spectrum disorders; Constipation; Gut microbiota; Metataxonomy; Mycobiota