Autism spectrum disorders and intestinal microbiota

Abstract

Through extensive microbial-mammalian co-metabolism, the intestinal microbiota have evolved to exert a marked influence on health and disease via gut-brain-microbiota interactions. In this addendum, we summarize the findings of our recent study on the fecal microbiota and metabolomes of children with pervasive developmental disorder-not otherwise specified (PDD-NOS) or autism (AD) compared with healthy children (HC). Children with PDD-NOS or AD have altered fecal microbiota and metabolomes (including neurotransmitter molecules). We hypothesize that the degree of microbial alteration correlates with the severity of the disease since fecal microbiota and metabolomes alterations were higher in children with PDD-NOS and, especially, AD compared to HC. Our study indicates that the levels of free amino acids (FAA) and volatile organic compounds (VOC) differ in AD subjects compared to children with PDD-NOS, who are more similar to HC. Finally, we propose a new perspective on the implications for the interaction between intestinal microbiota and AD.

Keywords: ASD; dysbiosis; intestinal microbiota; metabolome; perspective.

Figure 1.

Schematic representation of gastro-intestinal (GI) microbiota-gut-brain axis in relation to autism spectrum disorders (ASD). Abbreviations: CNS, central nervous system; ENS, enteric nervous system; HPA, hypothalamus-pituitary-adrenal axis; SCFA, schort-chain fatty acid; FAA, free amino acids; GAD, glutamic acid decarboxylase; AD, autistic; PDD-NOS, Pervasive developmental disorder not otherwise specified; HC, healthy children.

Figure 2.

Schematic representation of colonic fermentation of carbohydrates and proteins by microbial enzymes.

Figure 3.

Permutation analysis of the correlation data between the active bacterial genera and short chain fatty acids found in feces of pervasive developmental disorder not otherwise specified, autistic and healthy children. The genera that showed values ​​less than 0.1% of the total metabolically active bacterial were grouped together on the same phylum (others Actinobacteria, others Bacteroidetes, others Firmicutes, others Proteobacteria).