Histological analysis of atopic dermatitis and changes in gut microbiome composition induced by apple pectin administration

Abstract

Apple pectin is a prebiotic that is expected to be effective against allergic diseases. At a previous conference, we presented that apple pectin affects the diversity of gut microbiome, improves the immune balance of atopic dermatitis (AD), and is effective for AD. In this study, we investigated histological analysis in AD skin and changes in the composition of gut microbiome.

To induce AD, a picryl chloride solution was applied to shaved back skin of male NC/Nga mice. Treatment groups of AD mice then received an oral apple pectin solution (0.4％ or 4％) for 35 days.

Histological evaluation showed that apple pectin treatment (0.4％, 4％) attenuated epidermal thickening and decreased the number of mast cells and CD4⁺ cells in AD-induced mice (epidermal thickening: p = 0.12, p < 0.05, mast cells: p < 0.05, p = 0.11, CD4⁺ cells: p < 0.01, p < 0.05). Apple pectin treatment reduced serum IgE concentration (p < 0.05, p = 0.09). In the gut microbiome of the apple pectin-treated groups, β-diversity analysis showed that a cluster distinct from the other groups, and Anaerostipes, Roseburia, and RF39, which are related to Treg expression, were detected.

Our finding suggest that ingestion of apple pectin increased gut microbiome related to Treg expression, normalized the immune response, and improved AD histologically.