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-α, IFN-γ, soluble intercellular adhesion molecule 1, soluble E-selectin, TGF-β1, TGF-β2, 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 μg/mL [95% CI, 0.56-0.81] vs 0.42 μg/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.
2005. Vol. 115, no 6, 1254-1259 p.