A comparative study on dietary diversity and gut microbial diversity in children with autism spectrum disorder, attention-deficit hyperactivity disorder, their neurotypical siblings, and non-related neurotypical volunteers: a cross-sectional study.

BACKGROUND: Previous research has shown a significant link between gut microbiota in children with autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). However, much remains unknown because of the heterogeneity of disorders and the potential confounders such as dietary patterns and control group variations. METHODS: Children aged 6-12 years who had been clinically diagnosed with ASD and/or ADHD, their unaffected neurotypical siblings, and non-related neurotypical volunteers were recruited cross-sectionally. The ASD diagnosis was confirmed using the Autism Diagnostic Observation Schedule-2 (ADOS-2) in all patients, including those with ADHD. Standardized DNA extraction and sequencing methods were used to compare gut microbial alpha-diversity among the groups. Dietary diversity was calculated from a standardized dietary questionnaire form. We compared the difference in gut microbiome between patients with ASD and/or ADHD with neurotypical siblings and non-related neurotypical controls. RESULTS: Ninety-eight subjects were included in the study (18 with ASD, 19 with ADHD, 20 with both ASD and ADHD, 13 neurotypical siblings, and 28 non-related neurotypical controls). The alpha-diversity indices, such as Chao 1 and Shannon index, showed a significant difference between the groups in a Linear mixed-effect model (F(4, 93) = 4.539, p = .02), (F(4, 93) = 3.185, p = .017), respectively. In a post-hoc pairwise comparison, patients with ASD had lower alpha-diversity compared with non-related controls after Bonferroni correction. Dietary diversity shown in Shannon index did not differ among the groups (F(4, 84) = 1.494, p = .211). CONCLUSIONS: Our study indicates disorder-specific microbiome differences in patients with ASD. In future research on gut microbiota in neurodevelopmental disorders, it is necessary to consider the impact of ASD and ADHD co-occurrence, and strictly control for background information such as diet, to elucidate the gut-microbiota interaction in ASD and ADHD for exploring the potential of therapeutic interventions.

Gastrointestinal symptoms and sensory abnormalities associated with behavioral problems in children with neurodevelopmental disorders.

Behavioral problems directly affect the quality of life of caregivers and children with autism spectrum disorder (ASD) and/or attention-deficit/hyperactivity disorder (ADHD), and is known to be associated with clinical factors such as gastrointestinal (GI) symptoms, sensory abnormalities, intellectual abilities, and use of medication. However, previous studies have not considered these relationships comprehensively. We conducted a cross-sectional study of 6-12-year-old children with diagnoses of ASD and/or ADHD at two hospitals in Japan. Scores for the aberrant behavior checklist (ABC), autism-spectrum quotient (AQ), and Conners 3, as well as information on daily sleep and exercise, GI symptoms, and Short Sensory Profile, were collected. Each factor was subjected to a correlation analysis to investigate its effect on ABC scores. A stepwise multiple linear regression analysis for the factors with p < 0.05 was performed. Data were obtained from 60 patients with a mean age of 8.3 years; 21 had ASD alone, 18 had ADHD alone, and 21 had ASD + ADHD. The correlation analyses identified six factors associated with ABC severity: (a) methylphenidate use, (b) Conners hyperactivity score, (c) Conners inattention score, (d) AQ score, (e) SSP score, and (f) GI symptom score. The multiple regression showed that "GI symptoms" and "sensory abnormalities" were independently associated with ABC severity. Although further studies are needed to show a causal relationship, appropriate assessment of GI symptoms and sensory abnormalities may help alleviate some problematic behaviors and improve the quality of life of children with neurodevelopmental disorders and their families. LAY SUMMARY: Behavioral problems in children with neurodevelopmental disorders are known to be associated with many factors. This study aimed to comprehensively investigate the known factors. We have discovered that "gastrointestinal symptoms" and "sensory abnormalities" were independently associated with Behavioral problems. Our results suggest that it is important for clinicians and caregivers to pay more attention to children's GI symptoms and sensory abnormalities that may not present as obvious symptoms or complaints.