Table 1.
Summary of characteristics of studies in the current meta-analysis
| Study (year) | Diagnosis (Criteria) | Design | Comparison | N | Duration (weeks) /FU time | Outcome | Psychotropic medications | Mean age (years) | Female (%) | Country |
|---|---|---|---|---|---|---|---|---|---|---|
| Liu [8] | ASD (DSM-5) | RCT | Probiotics: single strain (L. plantarum) | 41 | 8 /post-treamtent | CBCL anxious/ depressed | Allow only psychostimulant | 4.82 (2.5–7) | 12.2 | Taiwan |
| Placebo | 41 | |||||||||
| Rianda [23] | Children (1-6 yrs) in general population | RCT | RC + Probiotics: single strains ( L. reuteri) | 126 | 24 /10 ys later | CDI | N/A | 15.31 (10-18) | 53.0% | Indonesia |
| RC + Probiotics: single strains (L. casei) | 120 | |||||||||
| RC | 124 | |||||||||
| Sepehrmanesh [20] | ADHD (DSM‑IV‑TR) | RCT | Probiotics: multiple strainsa + MPH | 20 | 8 /post-treamtent | CDI | 100% MPH | 9.1 (8-12) | 20.6 | Iran |
| Placebo + MPH | 20 | |||||||||
| Wu [22] | Tourette syndrome (DSM-5) | RCT | Probiotics: single strain (L. plantarum) | 28 | 8 /post-treamtent | CDI | Allowed | 9.86 (5-18) | 15.79 | Taiwan |
| Placebo | 29 | |||||||||
| Slykerman [21] | Infant in general population | RCT | Probiotics: single strains (L. rhamnosus) | 104 | 104 /4 ys later | CES-DC | N/A | Treatment started at 35 gestation | N/A | New Zealand |
| Probiotics: single strains (B. animalis) | 97 | |||||||||
| Placebo | 97 |
ADHD Attention-deficit/hyperactivity disorder, ASD Autism spectrum disorder, B. Bifidobacterium, CBCL Child Behavior Checklist, CDI Children's Depression Inventory, CES-DC Center for Epidemiological Studies Depression Scale for Children, DSM-5 Diagnostic and statistical manual of mental disorders fifth edition, DSM-IV-TR Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision, FU Follow up, MPH Methylphenidate, N Number, N/A Not available, L. Lactobacillus, RC Regular calcium supplementation, RCT Randomized controlled trial, yrs years
Multiple strainsa: including Lactobacillus reuteri, Lactobacillus acidophilus, Lactobacillus fermentum, and Bifidobacterium bifidum