Table 4.
Intervention trials of probiotics and synbiotics in ADHD.
| Study | Sample (N and Mean Age, in Years) | Intervention | Results |
|---|---|---|---|
| Probiotics | |||
| Pärtty et al. (2015) [87] | N = 75 A = birth to 13 years old |
One probiotic capsule or placebo/day 4 weeks before expected delivery 24 weeks after delivery, to the children or continuously to the mothers if breastfeeding Probiotic capsules contained 1 × 1010 CFU of Lactobacillus rhamnosus GG |
At the age of 13 y.o., in the placebo group (n = 35), three children were diagnosed with ADHD, one with Asperger Syndrome (AS), and two with ADHD and AS. In the probiotic group (n = 40), 0 children were diagnosed with ADHD and/or AS. |
| Kumperscak et al. (2020) [88] | N = 32 A (intervention group) = 11.4 ± 3.2 A (placebo group) = 12.5 ± 2.3 |
One probiotic capsule or placebo/day 12 weeks Probiotic capsules contained Lactobacillus rhamnosus GG (at least 1010 CFU) and the excipients hydroxypropyl methylcellulose (E464), maltodextrins, and the coloring titanium dioxide (E171) |
+ Pediatric Quality of Life Inventory (PedsQL) Child Self-Report total score x Pediatric Quality of Life Inventory (PedsQL) Parent Proxy Report total scale score x CBCL Teacher Report Form total scores |
| Sepehrmanesh et al. (2021) [89] | N = 34 A (intervention group) = 9.3 ± 1.3 A (placebo group) = 8.9 ± 1.0 |
One probiotic sachet or placebo/day 8 weeks 8 × 109 CFU/day probiotic sachet with Lactobacillus reuteri, Lactobacillus acidophilus, Lactobacillus fermentum, and Bifidobacterium bifidum (each 2 × 109) |
+ ADHD Rating Scale (ADHD RS) + Hamilton Anxiety Rating Scale (HAM-A) x Children’s Depression Inventory (CDI) |
| Ghanaatgar et al. (2022) [90] | N = 38 A (intervention group) = 9.0 ± 1.8 A (placebo group) = 8.6 ± 1.7 |
One multi-species probiotic capsule or placebo/day 8 weeks Probiotic capsules contained 14 strains of bacteria (Bio-Kult-protexin: 2 × 109 CFU/capsule), including Bacillus subtilis PXN 21, Bifidobacterium bifidum PXN 23, Bifidobacterium breve PXN 25, Bifidobacterium infantis PXN 27, Bifidobacterium longum PXN 30, Lactobacillus acidophilus PXN 35, Lactob. delbrueckii ssp. Bulgaricus PXN 39, Lactob. casei PXN 37, Lactob. plantarum PXN 47, Lactob. rhamnosus PXN 54, Lactob. helveticus PXN 45, Lactob. salivarius PXN 57, Lactococcus lactis ssp. lactis PXN 63, and Streptococcus thermophiles PXN 66 |
+ Conners Parent Rating Scale—short version (CPRS RS) scores at the 4th and 8th weeks + Clinical Global Impression-Severity scale (CGI-S) scores in all time intervals |
| Wang et al. (2022) [91] | N = 30 A = 6.9 |
One probiotic sachet in the morning and one in the evening/day 8 weeks 5 × 109 CFU/day probiotic sachet with Bifidobacterium bifidum (Bf-688) |
+ ADHD inattention and hyperactivity/impulsive symptoms assessed using the Swanson, Nolan, and Pelham Rating scale (SNAP-IV) |
| Synbiotics | |||
| Skott et al. (2020) [92] | N = 182 n children = 68 n adults = 114 Median age children = 12 (10–14) Median age adults = 36 (29–42) |
One synbiotic sachet or placebo/day 9 weeks Synbiotic 2000 (Synbiotics AB, Sweden), was a lyophilized composition of 4 × 1011 CFU per dose of three lactic acid bacteria: Pediococcus pentosaceus 5–33:3/16:1 (Strain deposit number: LMG P20608), Lactobacillus casei ssp paracasei F19 (LMG P-17806), Lactobacillus plantarum 2362 (LMG P-20606), and 2.5 g of each of the fermentable fibers beta-glucan, inulin, pectin, and resistant starch |
x ADHD symptoms, daily functioning, and comorbid autism symptoms + Autism symptoms in children with vascular inflammation + Emotion regulation in adults with vascular inflammation |
+ = improvements; x = no improvements.