Table 1 Summary of characteristics of studies in the current meta-analysis
Study (year) | Diagnosis (Criteria) | Design | Comparison | N | Duration (weeks) | Outcome | Psychotropic medications | Mean age (years) | Female (%) | Country |
|---|---|---|---|---|---|---|---|---|---|---|
Billeci (2023) | ASD (DSM-5) | RCT | Probiotics: multiple strains | 20 | 24 | 1.Overall = ADOS CSS 2.Adaptation = VABS-II | Allow | 3.88 (1.5–6) | 23.9 | Italy |
Placebo | 26 | |||||||||
Liu (2023) | ASD (DSM-5) | RCT | Probiotics: single strain | 41 | 8 | 1.Overall = ASEBA 2.Irritability = ASEBA aggression 4.Hyperactivity = ADHDT 5.Inattention = ADHDT 6.Anxiety = ASEBA anxiety | Allow only psychostimulant | 4.82 (2.5–7) | 12.2 | Taiwan |
Placebo | 41 | |||||||||
Schmitt (2023) | ASD (DSM-5) | RCT/ Crossover | Probiotics: single strain | 15 | 4 | 1.Overall = CGI-S 2.RRB = ABC Stereotype 3.Social = ABC lethargy 4.Communication = ABC inappropriate speech 5.Irritability = ABC Irritability 6.Hyperactivity = ABC Hyperactivity 7.Adaptation = Vineland adaptive behavior composite score | Allow | 20 (15–45) | 0 | USA |
Placebo | 15 | |||||||||
Kong (2021) | ASD (DSM-IV TR/−5) | RCT | Probiotics: single strain | 18 | 16 | 1.Overall = ABC total 2.RRB = ABC Stereotype 3.Social = ABC lethargy 4.Communication = ABC inappropriate speech 5.Irritability = ABC Irritability 6.Hyperactivity = ABC Hyperactivity | Allow | 10.26 (3–25) | 25.8 | USA |
Placebo | 17 | |||||||||
Li (2021) | ASD (DSM-5) | RCT | Probiotics: multiple strains + ABA | 21 | 12 | 1.Total = ATEC 2.Social = ATEC social behaviors 3.Communication = ATEC communication | Allow | 4.55 (3–6) | 24.4 | China |
ABA only | 20 | |||||||||
Santocchi (2020) | ASD (DSM-5) | RCT | Probiotics: multiple strains | 6 | 24 | 1.Total = ADOS CSS 2.Social = ADOS Social affect 3.RRB = ADOS RRB 4.Adaptation = VABS-II 5.Parental stress = PSI | Allow | 4.14 (1.5–6) | 16.4 | Italy |
Placebo | 4 | |||||||||
Arnold (2019) | ASD (DSM-5) | RCT/ Crossover | Probiotics: multiple strains | 31 | 8 | 1.Overall = SRS total 2.RRB = ABC Stereotype 3.Social = ABC lethargy 4.Communication = ABC inappropriate speech 5.Irritability = ABC Irritability 6.Hyperactivity = ABC Hyperactivity 7.Parental stress = PSI 8.Anxiety = PRAS-ASD total | Allow | 8.85 (3–12) | 40 | USA |
Placebo | 32 | |||||||||
Liu (2019) | ASD (DSM-5) | RCT | Probiotics: single strain | 36 | 4 | 1.Overall = ABC-T total 2.RRB = SRS autism mannerism 3.Social = ABC-T social and self-help 4.Communication = SRS social communication 5.Irritability = CBCL aggressive behaviors 6.Hyperactivity = SNAP-IV 7. Inattention = SNAP-IV 8.Anxiety = CBCL anxiety | Allow | 10.01 (7–15) | 0 | Taiwan |
Placebo | 35 | |||||||||
Sanctuary (2018) | ASD (ADOS) | RCT/ Crossover | Probiotics: single strain + BCP | 8 | 5 | 1.Overal = ABC total score 2.RRB = ABC Stereotype 3.Social = ABC lethargy 4.Irritability = ABC Irritability 5.Hyperactivity = ABC Hyperactivity | Allow | 6.8 (2–11) | 12.5 | USA |
BCP | 8 | |||||||||
Emmanuel NCT03369431 | ASD (ADI-R, DISCO, ADOS) | RCT/ Crossover | Probiotics: multiple strains | 64 | 12 | 1.Overall = ATEC total 2.RRB = ABC Stereotype 3.Social = ABC lethargy 4.Irritability = ABC Irritability 5.Hyperactivity = ABC Hyperactivity 6.Communication = ABC inappropriate speech 7.Parental stress = APSI | Allow | 7.8 (3–16) | 17.4 | UK |
Placebo | 64 |