Differences in fecal microflora between patients with atopic dermatitis and healthy control subjects

Abstract Background: The prevalence of allergic diseases, such as atopic dermatitis (AD), has been increasing. However, few investigations have been made of the intestinal microflora in Japanese patients with AD. Objective: The purpose of this study was to determine the differences in microflora, fecal serum IgA concentrations, and skin IgA contents between patients with AD and healthy control subjects. Methods: This trial was conducted as a case-control study using 30 minor patients with AD and age- and sex-matched healthy control subjects (n = 68). One week after a questionnaire was administered, fecal specimens and 24-hour skin secretion specimens were collected from all subjects. Fecal microflora, fecal IgA concentrations, and IgA contents on the skin surface were analyzed. Results: The counts of Bifidobacterium (in log 10 colony-forming units per gram) were significantly lower in patients with AD than in healthy control subjects (9.75 ± 0.68 vs 10.10 ± 0.50 log 10 colony-forming units/g, P Bifidobacterium were significantly lower in patients with severe skin symptoms than in those with mild skin symptoms (40% ± 6% vs 19% ± 6%, P Staphylococcus was significantly higher in patients with AD than in healthy control subjects (83% vs 59%, P Bifidobacterium than healthy control subjects, and the frequency of Staphylococcus was higher in patients with AD than in control subjects. Disorder of the intestinal microflora might play a role in the onset of AD and the aggravation of skin symptoms. (J Allergy Clin Immunol 2003;111:587-91.)