Meta-analysis on preventive and therapeutic effects of probiotic supplementation in infant atopic dermatitis

A systematic review and meta-analysis of nutritional and dietary interventions in randomized controlled trials for skin symptoms in children with atopic dermatitis and without food allergy: An EAACI task force report

This systematic review and meta-analysis aimed to consolidate evidence on dietary interventions for atopic eczema/dermatitis (AD) skin symptoms in children without food allergies, following PRISMA 2020 guidelines. Systematic review updates were conducted in May 2022 and June 2023, focusing on randomized placebo-controlled trials (RCTs) involving children with AD but without food allergies. Specific diets or supplements, such as vitamins, minerals, probiotics, prebiotics, symbiotics, or postbiotics, were explored in these trials. Exclusions comprised descriptive studies, systematic reviews, meta-analyses, letters, case reports, studies involving elimination diets, and those reporting on food allergens in children and adolescents. Additionally, studies assessing exacerbation of AD due to food allergy/sensitization and those evaluating elimination diets' effects on AD were excluded. Nutritional supplementation studies were eligible regardless of sensitization profile. Evaluation of their impact on AD clinical expression was performed using SCORAD scores, and a meta-analysis of SCORAD outcomes was conducted using random-effect models (CRD42022328702). The review encompassed 27 RCTs examining prebiotics, Vitamin D, evening primrose oil, and substituting cow's milk formula with partially hydrolyzed whey milk formula. A meta-analysis of 20 RCTs assessing probiotics, alone or combined with prebiotics, revealed a significant reduction in SCORAD scores, suggesting a consistent trend in alleviating AD symptoms in children without food allergies. Nonetheless, evidence for other dietary interventions remains limited, underscoring the necessity for well-designed intervention studies targeting multiple factors to understand etiological interactions and propose reliable manipulation strategies.

Effects of probiotic supplementation in adult with atopic dermatitis: a systematic review with meta-analysis

BACKGROUND

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. The effect of probiotic administration on the severity of AD in adults has shown inconsistent results.

OBJECTIVES

To determine the effectiveness of probiotic supplementation as a therapeutic tool for adult AD.

METHODS

PubMed, Scopus and Embase were systematically searched to collect data from studies in which probiotics were administered to treat adult AD.

RESULTS

Out of 413 publications, 9 papers were included in the meta-analysis. Significant differences in the ScORing Atopic Dermatitis tool favouring probiotics were observed [relative risk (RR) -5.93, 95% confidence interval (CI) -8.43 to -3.43]. Lactobacillus salivarius presented with largest effect size (RR -9.79, 95% CI -13.04 to -6.54), followed by L. acidophilus (RR -5.77, 95% CI -10.82 to -0.72) and L. plantarum (RR -3.76, 95% CI -6.36 to -1.16). No benefit was observed with L. fermentum. Based on the severity of AD, probiotics showed better results in people with moderate-to-severe AD (RR -9.12, 95% CI -12.17 to -6.08) than in individuals with mild disease (RR -2.67, 95% CI -4.67 to -0.66). Serum levels of IgE and eosinophil count remained significantly unchanged after the probiotic intervention (RR 0.25, 95% CI -0.10 to 0.60; RR -0.27, 95% CI -0.68 to 0.13, respectively).

CONCLUSIONS

Current evidence supports a role for some probiotics as a therapeutic tool for the treatment of adult AD, particularly in patients with severe AD. The efficacy of probiotics is strain specific, with L. salivarius and L. acidophilus having the largest clinical benefit. Such benefit is apparently independent of IgE levels and eosinophil count. Despite these encouraging results, the decrease in AD severity did not translate into a clinically meaningful better quality of life as assessed by the Dermatology Life Quality Index. There currently is not enough reliable data to reach conclusions about the optimal dose and duration for probiotic treatment.