Bifidobacterium breve has garnered growing interest as a probiotic that may help support children with Autism Spectrum Disorder (ASD). The rationale for its use is based on the emerging understanding of the gut-brain axis, which posits that gut microbiota can influence neurodevelopment and behavior. Children with ASD often exhibit altered gut microbiota composition, increased gastrointestinal (GI) symptoms, and immune dysregulation.

Several small clinical studies and animal models have explored the effects of B. breve in ASD. In particular, a randomized, double-blind, placebo-controlled pilot study published in 2019 found that supplementation with B. breve significantly improved some behavioral symptoms and GI complaints in children with ASD compared to placebo. Mechanistically, B. breve is thought to help restore microbial balance, modulate inflammation, and improve intestinal barrier function—all factors potentially implicated in ASD symptomatology.

However, despite these promising early results, the overall body of evidence is still limited. Most studies involve small sample sizes, short intervention periods, and often use probiotic blends rather than B. breve alone, making it difficult to attribute effects specifically to this strain. More robust, large-scale clinical trials are needed to confirm efficacy and understand mechanisms. As such, use of Bifidobacterium breve for ASD is based on preliminary scientific findings rather than tradition, but current evidence supporting its use remains modest.