Gastrointestinal symptoms have a minor impact on autism spectrum disorder and associations with gut microbiota and short-chain fatty acids

Abstract

Children with autism spectrum disorder (ASD) experience gastrointestinal (GI) issues more frequently and severely than children who are typically developing (TD). The connections between gastrointestinal problems, microbiota, and short-chain fatty acids (SCFAs) in ASD are still being debated. We enrolled 90 children, 45 of whom were diagnosed with ASD, and examined the impact of GI disorders on ASD. The six-item GI Severity Index questionnaire was used to evaluate gastrointestinal symptoms, while the Social Responsiveness Scale was used to evaluate autism symptoms. Further, the Children’s Sleep Habits Questionnaire and the Children’s Eating Behavior Questionnaire are used to assess sleep and eating disorders in children. We assessed fecal microbiota by 16S rRNA gene sequencing, and SCFA concentrations by gas chromatography/mass spectrometry. The results revealed that children with ASD exhibited a high rate of gastrointestinal issues (78%), as well as higher rates of social impairment and poor sleeping habits, compared to TD children. However, GI disturbances have a minor impact on autism. In addition, the levels of propionic acid, butyric acid, and valeric acid were significantly higher in the ASD group. Besides, the ASD, TD, and GI subgroups possessed distinct microbiome profiles. These findings suggest that gastrointestinal disturbances have no discernible effect on the core symptoms of autism. Although autism may not cause an increase in GI symptoms directly, alterations in metabolites, such as SCFAs, may cause GI symptoms.

Sodium butyrate facilitates CRHR2 expression to alleviate HPA axis hyperactivity in autism-like rats induced by prenatal lipopolysaccharides through histone deacetylase inhibition

“…However, the role of SCFAs in ASD pathology remains controversial. Some clinical studies also reported no difference or even higher concentrations of SCFAs in ASD children ( 32 , 33 ). These altered fecal SCFAs can be related to many factors, such as increased probiotic use, gut dysbiosis, impaired gut permeability, and so on ( 34 ).…”

Interaction of Heavy Metal Lead with Gut Microbiota: Implications for Autism Spectrum Disorder

“…Moreover, it can lead to gliosis, a neuro-inflammatory response [118]. Curiously, high levels of Bacteroidetes and elevated PPA levels were reported in children suffering from ASD [121,122]. Additionally, PPA administration used to generate a rodent model of ASD resulted in brain morphological changes, including alterations in the size and structure of the cortex, hippocampus, and amygdala, brain regions that are associated with the regulation of social behavior and cognition [123].…”

Interaction of Heavy Metal Lead with Gut Microbiota: Implications for Autism Spectrum Disorder

“…Moreover, it can lead to gliosis, a neuro-inflammatory response [104]. Curiously, high levels of Bacteroidetes and elevated PPA levels were reported in children suffering from ASD [107,108]. Additionally, PPA administration used to generate a rodent model of ASD, resulted in brain morphological changes, including alterations in the size and structure of cortex, hippocampus and amygdala, brain regions that are associated with regulation of social behavior and cognition [109].…”