Probiotics modulate the gut microbiota composition and immune responses in patients with atopic dermatitis: a pilot study.

PURPOSE: Many studies have investigated the association between intestinal barrier impairment and the onset of atopic dermatitis (AD). The gut microbiota is essential to maintain physiological homeostasis and immune regulation of host. Therefore, the objectives were to determine the effects of probiotics on the clinical symptoms, immune responses, and gut microbiota in AD patients. METHODS: 109 patients were randomly divided into 4 groups, including placebo group, oligosaccharides group, Bifidobacterium bifidum CCFM16 group, and Lactobacillus plantarum CCFM8610 group. At the end of the experiment, serological indicators, SCORAD, and DLQI indices were assessed. V3-V4 region of the 16S ribosomal RNA gene was sequenced to evaluate changes in the gut microbiota. Linear discriminant analysis (LDA) effect size was used to uncover microbial biomarkers and PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was used to predict gene family abundances based on 16S information. RESULTS: The results demonstrated that CCFM8610 significantly decreased the SCORAD index, and increased the serum IL-10 levels. Supplement with CCFM8610 and CCFM16 significantly influenced the alpha diversity, increased the proportion of Bacteroidetes, and reduced the F/B ratio. CCFM8610 treatment downregulated the functional genes of gut microbiota involving Staphylococcus aureus infection and upregulated the steroid hormone biosynthesis. CONCLUSION: The results indicated a positive correlation between decreased SCORAD index and CCFM8610 treatment, and that CCFM8610 regulated the immune responses in AD patients. CCFM8610 treatment influences the gut microbiota composition and functional changes. In conclusion, L. plantarum CCFM8610 exerts the strain-specific amelioration effects on patients with AD. TRIAL REGISTRATION: ChiCTR1800015330 (Clinicaltrials.gov Identifier).

Bifidobacteria adolescentis regulated immune responses and gut microbial composition to alleviate DNFB-induced atopic dermatitis in mice.

PURPOSE: Emerging studies have reported gut microbial composition plays a key role in alleviating AD clinical symptoms during the probiotic intervention, but the correlation among clinical symptoms, immune responses and gut microbial alteration needs to be explored. Therefore, the objective was to investigate the correlation during Bifidobacterium adolescentis intervention in DNFB-induced AD mice. METHODS: The mice were randomly divided into nine groups and fed B. adolescentis for 3 weeks. At the end of the experiment, clinical and immune indicators were assessed. Flow cytometry was performed to explore the effect of B. adolescentis on regulatory T cells in the spleen. V3-V4 region of the 16S ribosomal RNA (rRNA) gene was sequenced to evaluate changes in the gut microbiota. RESULTS: Bifidobacteria adolescentis treatments reduced ear and skin thickness and suppressed eosinophils and mast cells infiltration. Th1- and Th2-type responses were regulated and the Tregs population was promoted in the spleen by B. adolescentis treatments. Bifidobacteria adolescentis increased the relative abundance of Lactobacillus but decrease Dorea and Pediococcus. Propionic and butyric acids were increased but isovaleric acid was decreased by B. adolescentis treatment. Besides, the functional modules, such as fatty acid biosynthesis, antigen processing and presentation were upregulated by B. adolescentis Ad1 treatment compared to the DNFB group. CONCLUSION: Collectively, these results imply that B. adolescentis with the role of immunomodulation promotes Treg differentiation and suppresses Th2 responses, and increases the proportion of Lactobacillus that is positively correlated to increase in propionic acid production, and thus has the potential for AD amelioration.