Publication date: Jun 25, 2026
Dysbiosis of the gut microbiota is common in children with autism spectrum disorder (ASD). Probiotics have the potential to improve outcomes in ASD by modulating the gut microbiota-brain axis. In a pilot randomised trial, children (2 to 5 years) with confirmed ASD (DSM-5 criteria) received either a multi-strain probiotic (450 billion CFU twice daily for one month, followed by once daily for three months) or placebo supplementation. Faecal microbiota profiles were assessed using pre- and post-supplementation samples. The primary outcome involved changes in gut microbiota diversity. Secondary outcomes included faecal short-chain fatty acid levels and behavioural changes. Difficulties in recruitment and loss to follow-up for reasons including COVID-19 resulted in the enrolment of only 23 (probiotic: 9; placebo: 14) instead of the planned 40 children. There was no evidence of changes in the gut microbiota in probiotic-supplemented children. The common phyla were Bacillota_A (~50%), Bacteroidota (~18%) and Actinobacteriota (~10%). Alpha- and Beta-diversity showed no significant difference between pre- vs. post-supplementation samples. Bifodobacteriaceae increased significantly in the probiotic-supplemented group (p = 0. 046). The increase in faecal Bifodobacteriaceae supports an evaluation of probiotics in ASD. Addressing the reasons for loss to follow-up is important when designing trials in this field.
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | Autism |
| disease | MESH | Dysbiosis |
| disease | MESH | autism spectrum disorder |
| disease | MESH | strain |
| disease | MESH | included |
| disease | MESH | COVID-19 |