Journal Club: Probiotics show promise in reducing GI problems in ASD

Probiotic supplementation of conventional therapies for autism spectrum disorder (ASD) improves behavioral and gastrointestinal (GI) problems with no adverse effects, according to a study in 180 children in India. The 2- to 9-year-olds (mean age, about 4 years) with ASD were divided into 2 groups. One group received a probiotic supplement administered 2 times a day for 3 months, and the other group received a placebo. Both groups were receiving rehabilitation and standard therapies for ASD when the study was conducted.

Parents and caregivers of participants assessed changes in participants’ behavior and GI symptoms at baseline and at the end of the study period. They assessed behavior with the Social Responsiveness Scale-2 (SRS-2) and the Aberrant Behavior Checklist-2 (ABC-2). The SRS-2 tool addresses social communication and interaction (SCI) and restricted, repetitive behaviors and interests (RRBI). The ABC-2 scale measures psychiatric symptoms and behavioral disturbance. For GI symptoms, parents used the GI Severity Index (GSI scale), which is a composite questionnaire addressing 6 GI symptoms.

Whereas mean SRS total scores at baseline did not differ significantly between the 2 groups, they showed a greater decline in the probiotic group after the intervention, with more of the probiotic group having a significant reduction in symptom severity. Indeed, only 16.7% of the probiotic group had severe symptoms after intervention. Specifically, probiotic-treated children demonstrated a significant reduction in severe symptoms for social withdrawal or lethargy (40%), stereotypic behavior (37.8%), hyperactivity (34.4%), and inappropriate speech symptoms (32.2%). Irritability symptoms did not change markedly in either group, but behavioral scores improved remarkably in the probiotic group: a 26/7% reduction in severity and a subsequent 36.6% increase in mild symptoms. As to GI symptoms, the probiotic-treated children showed significant improvement in constipation and diarrhea compared with placebo-treated children. In both groups, behavioral and GI symptoms showed a statistically significant correlation, reinforcing the idea that improving gut health through probiotics can positively affect behavioral outcomes.

THOUGHTS FROM DR. FARBER

Researchers have been looking at the gut-brain connection for years without much success, so I remain skeptical, but this is a large blinded study, so they may be onto something. Presumably, by reducing GI distress, behavior improves, rather than probiotics having a direct effect on autism per se. At any rate, probiotics should be safe to try. 

Reference

Khanna HN, Roy S, Shaikh, Chhabra R, Uddin A. Impact of probiotic supplements on behavioural and gastrointestinal symptoms in children with autism spectrum disorder: a randomized controlled trial. BMJ Paediatr Open. 2025;4:9(1):e003045. doi:10.1136/bmjpo-2024-003045