Efficacy of a probiotic supplement in patients with atopic dermatitis: a randomized, double-blind, placebo-controlled clinical trial

Eur J Dermatol. 2021 Apr 1;31(2):225-232. doi: 10.1684/ejd.2021.4019.


Background: Atopic dermatitis (AD) is a multifactorial long-standing inflammatory skin disease with a high incidence worldwide in both adults and children. According to the recognized correlation between skin and intestine-the so-called "gut-skin axis"-gut unbalances can affect skin by inducing systemic inflammation and triggering dermatological diseases such as AD.

Objectives: To evaluate the efficacy of a food supplement containing selected strains of probiotics in ameliorating AD symptoms and skin conditions in adult volunteers.

Materials & methods: Eighty adult subjects showing mild-to-severe AD, skin dryness, desquamation, erythema and itching were enrolled in a randomized controlled trial to receive, for 56 days, a placebo or a mixture of lactobacilli (L. plantarum PBS067, L. reuteri PBS072 and L. rhamnosus LRH020). The latter was chosen according to the patients' production of post-biotic metabolites and B-group vitamins, anti-inflammatory and anti-oxidant capacity and anti-microbial activity. Clinical and instrumental dermatological evaluation was performed at T0d, T28d and T56d, and then at T84d (after a one-month wash-out). Inflammatory cytokine levels from skin tape stripping, sampled close to AD lesions at T0d and T56d, were also measured.

Results: Subjects receiving the probiotic mixture showed an improvement in skin smoothness, skin moisturization, self-perception, and a decrease in SCORAD index as well as in the levels of inflammatory markers associated with AD at T28d, with a positive trend up to T56d which was maintained at T84d.

Conclusion: Administration of selected probiotic strains resulted in a fast and sustained improvement in AD-related symptoms and skin conditions.

Keywords: SCORAD; adult subjects; atopic dermatitis; probiotics; randomized controlled trial.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Chemokine CCL17 / metabolism
  • Cytokines / metabolism
  • Dermatitis, Atopic / complications
  • Dermatitis, Atopic / physiopathology*
  • Dermatitis, Atopic / psychology
  • Dermatitis, Atopic / therapy*
  • Double-Blind Method
  • Edema / etiology
  • Edema / therapy
  • Erythema / etiology
  • Erythema / therapy
  • Female
  • Humans
  • Male
  • Probiotics / therapeutic use*
  • Pruritus / etiology
  • Pruritus / therapy
  • Self Concept
  • Severity of Illness Index
  • Skin Physiological Phenomena
  • Symptom Assessment
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism
  • Water Loss, Insensible


  • CCL17 protein, human
  • Chemokine CCL17
  • Cytokines
  • TSLP protein, human
  • Tumor Necrosis Factor-alpha