Gastrointestinal flora and gastrointestinal status in children with autism – comparisons to typical children and correlation with autism severity

Abstract

BackgroundChildren with autism have often been reported to have gastrointestinal problems that are more frequent and more severe than in children from the general population.MethodsGastrointestinal flora and gastrointestinal status were assessed from stool samples of 58 children with Autism Spectrum Disorders (ASD) and 39 healthy typical children of similar ages. Stool testing included bacterial and yeast culture tests, lysozyme, lactoferrin, secretory IgA, elastase, digestion markers, short chain fatty acids (SCFA's), pH, and blood presence. Gastrointestinal symptoms were assessed with a modified six-item GI Severity Index (6-GSI) questionnaire, and autistic symptoms were assessed with the Autism Treatment Evaluation Checklist (ATEC).ResultsGastrointestinal symptoms (assessed by the 6-GSI) were strongly correlated with the severity of autism (assessed by the ATEC), (r = 0.59, p < 0.001). Children with 6-GSI scores above 3 had much higher ATEC Total scores than those with 6-GSI-scores of 3 or lower (81.5 +/- 28 vs. 49.0 +/- 21, p = 0.00002).Children with autism had much lower levels of total short chain fatty acids (-27%, p = 0.00002), including lower levels of acetate, proprionate, and valerate; this difference was greater in the children with autism taking probiotics, but also significant in those not taking probiotics. Children with autism had lower levels of species of Bifidobacter (-43%, p = 0.002) and higher levels of species of Lactobacillus (+100%, p = 0.00002), but similar levels of other bacteria and yeast using standard culture growth-based techniques. Lysozyme was somewhat lower in children with autism (-27%, p = 0.04), possibly associated with probiotic usage. Other markers of digestive function were similar in both groups.ConclusionsThe strong correlation of gastrointestinal symptoms with autism severity indicates that children with more severe autism are likely to have more severe gastrointestinal symptoms and vice versa. It is possible that autism symptoms are exacerbated or even partially due to the underlying gastrointestinal problems. The low level of SCFA's was partly associated with increased probiotic use, and probably partly due to either lower production (less sacchrolytic fermentation by beneficial bacteria and/or lower intake of soluble fiber) and/or greater absorption into the body (due to longer transit time and/or increased gut permeability).

The intestinal microbiome, probiotics and prebiotics in neurogastroenterology

“…40 GI disturbances are prevalent in children with autism and the number of GI symptoms is shown to be associated with the severity of autism. 41 Several studies have now reported changes in microbiota profile in patients with autism. [41][42][43][44][45][46][47] While this area of research is new and consensus across studies has not yet been established, several interesting observations are worth noting.…”

“…41 Several studies have now reported changes in microbiota profile in patients with autism. [41][42][43][44][45][46][47] While this area of research is new and consensus across studies has not yet been established, several interesting observations are worth noting. In one recent study, an increased diversity of microbiota was observed in patients with severe autism compared with matched controls; and in particular Bacteroidetes was significantly increased in patients with autism, whereas Firmicutes was observed to be higher in controls.…”

A dysbiotic subpopulation of alcohol-dependent subjects

“…10,11 ) and the development of profound social impairment as observed in autistic spectrum disorders. [12][13][14] The paper we are commenting on here, 15 even though focusing on alcohol-dependence, also relates to depression and anxiety, as these Keywords: alcohol dependence, alcohol use disorders, behavior, depression, gut permeability, gut-brain axis, gut microbiota, leaky gut, negative reinforcement symptoms are an important dimension of alcohol-dependence. In the first part of the discussion, these aspects will be evoked at the light of the negative reinforcement process, that is a major dimension of the addictive process, 16 especially in chronic addiction.…”

Commensal Bugs from the Gut-Shaping Human Health and Disease

“…It has been proved that there is a significant difference between the stool sample from autistic and normal children in terms of frequency of occurrence of four bacterial phyla specifically viz. in fecal samples of children with autistic behavior as compared to the normal healthy children with same sex and age [181][182][183][184][185][186][187][188]. Evidence suggests that high occurrence of Bifidobacterium and Lactobacillus species is a biological indicator for healthy gut microbiota in breast-fed infants as they serve important probiotic function in the gut [189][190][191].…”