Table 1.
Basic characteristics of studies included in the systematic review.
| Author (Year) | Country/Region | Type of Trial | Age (Year) | Sample Size | Intervention Group |
Compare Group | Intervention Duration | Scale on Autism | GI Symptoms Are Measured |
|---|---|---|---|---|---|---|---|---|---|
| Niu M (2019) [24] | China | RCT | 3–8 | 65 |
n = 37 probiotics +ABA 3.6 ×1010 CFU/day |
n = 28 ABA |
4 weeks | ATEC | Yes |
| Li YQ (2021) [25] | China | RCT | 3–6 | 41 |
n = 21 Bifidobacterium triple live dispersion +ABA 9 × 107 CFU/day |
n = 20 ABA |
3 months | ATEC | Yes |
| Liu YW (2019) [23] | Taiwan (China) |
RCT | 7–15 | 71 |
n = 36 Lactobacillus plantarum PS128 3 × 107 CFU/day |
n = 35 placebo |
4 weeks | CGI-I ABC-T SRS SNAP-IV |
No |
| Santocchi E (2020) [27] | Italy | RCT | 1.5–6 | 63 |
n = 32 DSF 9 × 1011 CFU/day |
n = 31 placebo |
6 months | ADOS-CSS, GI Severity Index Score |
Yes |
| Wang Y (2020) [26] | China | RCT | 2–8 | 11 |
n = 7 probiotics * + FOS 1010 CFU/day |
n = 4 placebo |
108 days | ATEC 6-GSI |
Yes |
| Arnold LE (2018) [28] | America | crossover controlled trials | 3–12 | 10 |
n = 10 DSF 4.5–9 × 1012 CFU/day |
n = 10 placebo |
8 weeks | ABC, SRS | Yes |
| Parracho H (2010) [31] | Britain | crossover controlled trials | 3–16 | 17 |
n = 17 Lactobacillus plantarum WCFS1 4.5 × 1010 CFU/day |
n = 17 placebo |
6 weeks | DBC | Yes |
| Sanctuary MR (2019) [29] | America | crossover controlled trials | 2–11 | 8 |
n = 8 Bifidobacterium infantis +BCP 2 × 1010 CFU/day |
n = 8 BCP |
5 months | ABC, GIH |
Yes |
| Simmons S (2022) [30] | America | crossover controlled trials | 5–11 | 64 |
n = 64 DSF 4.5 × 1011 CFU/y |
n = 64 placebo |
12 weeks | ATEC GHI ABC |
Yes |
| Alfy MSE (2019) [32] | Egypt | RCT | 2–10 | 100 |
n = 50 Lacteol Fort 2 × 108 CFU/day |
n = 50 standard treatment |
12 weeks | ATEC 6-GSI |
Yes |
ABA: applied behavior analysis; Bifidobacterium triple live dispersion: contains Bifidobacterium longum, Lactobacillus acidophilus, and Enterococcus faecalis; DSF: a patented mixture (containing 8 probiotic strains, each containing 450 billion lyophilized bacteria, including Streptococcus thermophilus, Bifidobacterium brevis, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus para-casei, and Lactobacillus delbrueckii subsp. Bulgaricus) already approved for use in children, marketed as Vivomixx® in EU, Visbiome® in USA; FOS: fructo-oligosaccharide; BCP: bovine colostrum product; Lacteol Fort: a mixture of Lactobacillus deuteri and Lactobacillus fermentum; ATEC: autism treatment evaluation checklist; CGI-I: clinical global impression-improvement; ABC-T: autism behavior checklist-Taiwan version; SRS: social responsiveness scale; SNAP-IV: the Chinese version of the Swanson, Nolan, and Pelham-IV; ADOS-CSS: the total autism diagnostic observation schedule-calibrated severity score; 6-GSI: 6-GI severity index; ABC: aberrant behavior checklist; DBC: development behavior checklist; GIH: gastrointestinal history; *: a probiotic blends (Bifidobacterium infantis Bi-26, Lactobacillus rhamnosus HN001, Bifidobacterium lactis BL-04, and Lactobacillus paracasei LPC-37).