Two randomized controlled trials measured the effect of probiotics or synbiotics to prevent food allergy. They suggested little to no impact from using pro- or synbiotics.
The evidence was limited by imprecision, study limitations and indirectness.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis | |||||
| «Dissanayake E, Tani Y, Nagai K, ym. Skin Care and ...»1 | RCT | Pregnant women at 24-32 weeks of gestation. Maternity Hospital in Tokio. Babies born at term. | Group 1 synbiotics and skincare, group 2 synbiotics, group 3 skincare, group 4 no intervention | Primary: development of AD by one year of age | high |
| «Kallio S, Kukkonen AK, Savilahti E, ym. Perinatal ...»2 | RCT | Pregnant women carrying a fetus with a high-risk of allergy (at least one of the parents had physician diagnosed allergy). Helsinki area. | Probiotics for pregnant women from 36 weeks of gestation until delivery) and for first six months for their infants, vs placebo | Allergic diseases and sensitization at 13 years of age | moderate |
| Reference | Comments |
|---|---|
| «Dissanayake E, Tani Y, Nagai K, ym. Skin Care and ...»1 | Exclusion criteria: pre-term birth, complications due to severe underlying diseases,
HBV or HIV positivity of mother, any other inappropriate status ad judged by the physician
Secondary outcomes: Incidence of FA (questionnaire), Sensitization to food and/or inhalant allergens, EASI score, m TARC- score, blood samples at 9 months Intervention: synbiotics, 0,5 g of Bifidobacterium bifidum OLB6378 combined with 0.5 g of fructo-oligosaccharides The study was a prospective, 2x2 factorial randomized, non-treatment controlled trial. It was not blinded. Approximately 15-20 % of patients were lost to follow up in the study groups. According to the report the power of the study was not sufficient to detect difference between the groups. Food allergy was measured with a questionnaire at one year of age. |
| «Kallio S, Kukkonen AK, Savilahti E, ym. Perinatal ...»2 | Exclusion criteria: < 37 weeks of gestation, major malformations and the second born
of twins. Intervention: probiotics, Lactobacillus rhamnosus GG and LC705, Bifidobacterium breve Bb99 and Pro-pionibacterium freudenreichii. The study was a prospective, randomized, double-blinded placebo-controlled trial. It was blinded until 5 years. Missing data at 13 years of follow-up: intervention 176/506, control 200/512 Food allergy was measured with a questionnaire at 2, 5, 10 ja 13 years. |
| Reference | Number of studies and number of patients (I/C) | Follow-up time (years) | Absolute number of events (%) I | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| I= intervention; C=comparison; CI=confidence interval, RR=relative risk, OR=odds ratio | |||||
| «Dissanayake E, Tani Y, Nagai K, ym. Skin Care and ...»1 | 1 RCT (G1 137, G2 137, G3 138, G4 137) |
1 | G1 12/113 (10,8) G2 15/109 (13,9) G3 13/120 (11) |
15/117 (13) | RR 1.03 (0.63-1.68) |
| «Kallio S, Kukkonen AK, Savilahti E, ym. Perinatal ...»2 | 1 RCT I: mothers 610, infants 506 C: mothers 613, infants 512 |
13 | 75 (22.7) | 84 (26.9) | OR 0.798 (0,558-1,143) |
| Level of evidence: very low The quality of evidence is downgraded due to study limitations, indirectness (unclear how well the products represent Finnish context), imprecision. |
|||||