Induction of inflammation as a possible mechanism of probiotic effect in atopic eczema-dermatitis syndrome.

Abstract

The immunomodulating mechanisms of Lactobacillus GG (LGG) and other probiotics are poorly understood. We studied in vivo the immunologic effects of probiotics in infants with atopic eczema-dermatitis syndrome (AEDS) and cow's milk allergy (CMA). Two hundred thirty infants with AEDS and suspected CMA received, concomitant with elimination diet, either LGG, a mixture of 4 probiotic strains (MIX), or placebo for 4 weeks. All available paired pretreatment and posttreatment plasma samples (n = 132) were analyzed for concentrations of IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-gamma, soluble intercellular adhesion molecule 1, soluble E-selectin, TGF-beta1, TGF-beta2, and C-reactive protein. In infants with IgE-associated AEDS, treatment with LGG induced higher C-reactive protein levels than in the placebo group (geometric mean, 0.83 microg/mL [95% CI, 0.56-0.81] vs 0.42 microg/mL [95% CI, 0.27-0.65]; P = .021). Concomitantly, IL-6 levels increased after treatment with LGG ( P = .023) but not with MIX or placebo. Soluble E-selectin levels were higher after probiotic than after placebo treatment in infants with IgE-mediated CMA (LGG geometric mean, 86.7 ng/mL [95% CI, 75.2-100]; MIX geometric mean, 91.6 ng/mL [95% CI, 74.8-111.9]; and placebo geometric mean, 64.9 ng/mL [95% CI, 53-79.3]; analysis of covariance, P = .035; LGG vs placebo, P = .023; MIX vs placebo, P = .020). Use of MIX induced an increase in plasma IL-10 levels ( P = .016). Probiotics induced systemically detectable low-grade inflammation, which might explain the clinical effects of probiotics in AEDS and CMA.