Probiotics for the treatment of eczema: a systematic review

P>Background Probiotics have been proposed as a treatment for eczema, but the results of intervention trials have been mixed. Objective To evaluate the efficacy of probiotics for treating eczema by performing a systematic review of randomized-controlled trials (RCTs). Design We searched the Cochrane Skin Group Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO, AMED, LILACS, ISI Web of Science, the reference lists of articles, ongoing clinical trial registers and conference proceedings. RCTs of live orally ingested microorganisms for the treatment of eczema were eligible for inclusion. Results Twelve trials (781 participants) were identified. Meta-analysis of data from five of these trials showed that there was no significant reduction in eczema symptoms with probiotic treatment compared with placebo (mean difference -0.90 points on a 20-point visual analogue scale; 95% confidence interval -2.84, 1.04). Meta-analysis of data from seven trials showed no significant difference in investigator rated eczema severity between probiotic and placebo treatments. Subgroup analysis by eczema severity or presence of atopy did not identify a specific population in which probiotic treatment was effective. There was significant heterogeneity between studies; however, the results of three studies that used the same probiotic strain were concordant. The adverse events search identified case reports of sepsis and bowel ischaemia caused by probiotics. Conclusions Currently, probiotics cannot be recommended for treating eczema. The heterogeneity between studies may be attributable to probiotic strain-specific effects, which means that novel probiotic strains may still have a role in eczema management.