Gastrointestinal Symptoms in Autism Spectrum Disorder: A Systematic Review

Abstract

This systematic review aims to offer an updated understanding of the relationship between gastrointestinal symptoms (GIS) and autism spectrum disorder (ASD) in children and adolescents. The databases PsycINFO, Medline, Cinahl, and ERIC were searched using keywords, and relevant literature was hand-searched. Papers (n = 3319) were systematically screened and deemed eligible if they were empirical studies published in English since 2014 and measured the GIS of individuals with ASD who were under 18 years old. Thirty studies were included in the final review. The study findings were synthesized under eight themes, including the prevalence and nature of GIS and their relationship with developmental regression, language and communication, ASD severity, challenging behavior, comorbid psychopathology, sleep problems, and sensory issues. The review found that GIS were common and that there was contradictory evidence concerning their relationship with co-occurring conditions. It also identified evidence of some causal relationships that support the existence of the gut–immune–brain pathways. Future research needs to use large prospective designs and objective and standardized GIS measurements to provide a nuanced understanding of GIS in the context of ASD.

Dietary Intake, Nutritional Status and Sensory Profile in Children with Autism Spectrum Disorder and Typical Development

“…Hence, interest in the effect of special diets and nutrition on autism is increasing, particularly as a way to improve behavior, attention span, social interaction, and eye contact [ 4 ]. Many studies have shown that some children and adolescents with autism are on a gluten and casein free (GFCF) diet [ 5 , 6 ]. Graf-Myles et al reported that diet restrictions can impact dietary intake of cereals and dairy and may also lead to a lower intake of calcium and grains supplemented with folate in ASD group as compared to TD group [ 7 ].…”

“…On the other hand, neurotypical children around the age of six often show a preference for certain foods and a rejection of others as a part of their developmental age [ 3 , 4 ]. Many influencing factors can affect an individual’s food choices, and studies suggest that eating disorders in autism may be one significant contributor to comorbidities such as gastrointestinal symptoms [ 2 , 5 , 6 ]. Additionally, some studies show that children with ASD have greater rates of overweight or obesity than typically developing (TD) ones, and this fact could be related to unusual dietary patterns and decreased opportunities for physical activity [ 7 ].…”

Evaluation of Gastroesophageal Reflux Disease in Children on the Autism Spectrum: A Study Evaluating the Tolerance and Utility of the BRAVO Wireless pH Monitoring

“…There are no studies reporting the use of the BRAVO wireless pH to evaluate GER in children with ASD. Also, guidelines for evaluation of gastrointestinal manifestations in children with ASD are not clear due to lack of evidence supporting the evaluation of ASD children with potential GER (21), and a recent systematic review emphasized the potential association between gastrointestinal symptoms and presence but not severity of ASD (22).…”

Fecal Microbiota Transplantation in Autism Spectrum Disorder

“…4 Children with ASD are at least three times more likely to experience co-occurring gastrointestinal symptoms, including constipation, diarrhea and abdominal pain, than neurotypical children. 5 Recent studies have confirmed differences in the composition of gut microbiota between ASD patients and neurotypical people. 6 Microbial communities play a central role in the maturation and development of the immune, neural and gastrointestinal systems and are also responsible for important metabolic pathways.…”