Altered gut microbiota composition and feeding behaviours in children with Autism Spectrum Disorder: a comparative pilot study.

Background: Autism Spectrum Disorder (ASD) is a prevalent condition with poorly understood aetiology. Studies indicate that children with ASD exhibit more gastrointestinal alterations, nutritional deficiencies due to selective eating, and distinct gut microbiota profiles compared to neurotypical peers.

Aim: To investigate the differences in gut microbiota composition and feeding behaviours between children with ASD and their typically developing peers.

Subjects and methods: Faecal samples from 10 male children with ASD (mean age 6.2 years), and 10 male neurotypical controls (mean age 6.1 years) were analysed using 16S rRNA sequencing to assess gut microbiota composition. Guardians completed questionnaires on demographics, birth data, initial feeding habits (i.e. feeding practices after breastfeeding), gastrointestinal symptoms, stool characteristics, and feeding behaviours, which were assessed using the Brief Autism Mealtime Behaviour Inventory (BAMBI) scale. Additionally, a 48-hour dietary recall was collected to analyse the children's nutritional intake.

Results: Significant differences in gut microbiota beta diversity were observed. Bacteroidota predominated in the control group, while Firmicutes, Actinobacteriota, and Proteobacteria were dominant in the ASD group. Genera Blautia and Bifidobacterium were enriched in controls, whereas Clostridium sensu stricto 1, Ruminococcus_torques_group, Lachnospiraceae_UCG004, and Bifidobacterium breve were more prevalent in ASD. Comorbidities, sodium intake, and BAMBI scale scores highlighted greater feeding-related behavioural issues in the ASD group.

Conclusion: Children with ASD show notable differences in gut microbiota composition and feeding behaviours. The findings emphasise the need to address gastrointestinal and nutritional factors in ASD management.