Anti-allergic effects of probiotic Dahi through modulation of the gut immune system

The alarming increase in allergy in the last few decades demands the development of new anti-allergic prevention strategies, and consumption of functional foods (i.e. probiotic Dahi, which has already been proven to enhance immunity by modulation of the gut mucosal immune system) may be one of them. In the present study, we evaluated anti-allergic effects of a Dahi (yogurt) containing probiotic Lactobacillus acidophilus, L. casei and normal Dahi culture Lactococcus lactis biovar diacetylactis (named probiotic Dahi) on ovalbumin induced allergy in mice.

Allergy was induced by injecting (i.p.) ovalbumin at 0 and 14 days. Animals were fed with standard diet (control), milk, control Dahi or probiotic Dahi for 21 days. Total and ovalbumin-specific IgE, cytokines and lymphocyte proliferation index were examined after 7, 14 and 21 days.

Feeding of probiotic Dahi completely suppressed the elevation of total and ovalbumin-specific IgE in the serum of ovalbumin-injected mice. Similarly, splenocytes collected from mice fed with probiotic Dahi entirely lost the total and ovalbumin-specific IgE production property during in-vitro culture. Production of T helper (Th)-1 cell-specific cytokines, i.e. interferon -γ and interleukin (IL)-2, increased, while Th2-specific cytokines, i.e. IL-4 and IL-6, decreased in the supernatant of cultured splenocytes collected from mice fed with probiotic Dahi compared to the other groups. Moreover, ovalbumin-stimulated lymphocyte proliferation was strongly suppressed by feeding of probiotic Dahi in comparison to milk and control Dahi.

Results of the present study indicate that probiotic Dahi suppressed ovalbumin-induced allergic consequences characterized by decreasing levels of total and ovalbumin-specific IgE and lymphocyte proliferation and skewed ovalbumin-induced Th2-specific immune response towards Th1-specific response.