Impact of probiotic supplements on behavioural and gastrointestinal symptoms in children with autism spectrum disorder: A randomised controlled trial

Abstract

Objective: To investigate whether probiotic supplementation can improve behavioural and gastrointestinal (GI) symptoms in children with autism spectrum disorder (ASD) aged 2-9 years and further explore the correlation between these symptoms.

Design: Single-blinded, randomised, placebo-controlled study.

Setting: Five developmental paediatric outpatient clinics of 'Continua Kids'.

Patients: Children aged 2-9 years diagnosed with ASD along with their caregivers.

Interventions: Probiotic or placebo sachet reconstituted in 50 mL of lukewarm milk/water, taken two times per day for 3 months.

Main outcome measures: Change in behavioural (measured by Social Responsiveness Scale-2 (SRS-2) and Aberrant Behaviour Checklist-2 (ABC-2) tools) and GI (measured by GI Severity Index (GSI) score) symptoms after receiving intervention for 3 months.

Results: A total of 180 children with ASD were enrolled in the study (probiotic group: 90 and placebo group: 90). All children completed the study. The probiotic group showed a significant reduction in behavioural symptom severity as measured by the SRS-2 tool (47.77% vs 23.33%; p=0.000) compared with the placebo. Probiotic-treated children demonstrated significant reductions in severe symptoms, including social withdrawal/lethargy (40%), stereotypic behaviour (37.77%), hyperactivity (34.44%) and inappropriate speech (32.22%) post-intervention (p=0.000). They also had marked improvements in constipation (p=0.003) and diarrhoea (p=0.043) compared with the placebo group. Both groups exhibited a statistically significant correlation between behavioural and GI symptoms.

Conclusions: Probiotic supplementation improved behavioural and GI symptoms in children with ASD with no adverse effects. Both symptoms were significantly correlated. However, these results need to be validated in a larger sample size.

Trial registration number: CTRI/2021/11/038213.

Keywords: Child Health; Child Psychiatry; Neurology; Statistics.

Figure 1. Change in behavioural symptoms assessed by SRS-2 T scores after intervention. RRBI, restricted repetitive behaviours and interests; SCI, social communication and interaction; SRS-2, Social Responsiveness Scale-2.

Figure 2. Change in behavioural characteristics assessed by ABC-2 scores after intervention. ABC-2, Aberrant Behaviour Checklist-2.

Figure 3. Change in GI symptoms assessed by GI scores after intervention. GI, gastrointestinal; GSI, GI Severity Index.