Lactobacillus rhamnosus GG induced protective effect on allergic airway inflammation is associated with gut microbiota

Great interest has been taken in the use of beneficial bacteria for allergic diseases recently, but the underlying mechanisms through which probiotics induces immune regulation or immune tolerance are poorly understood. We aimed to explore whether Lactobacillus rhamnosus GG (LGG)-induced beneficial effect relates to the change of microbiota. LGG was administered orally to mouse model of ovalbumin (OVA)-induced allergic airway inflammation. Our findings manifested that LGG-treatment contributes to protect against OVA-induced allergic airway inflammation by expanding mesenteric CD103(+) DCs and accumulating mucosal Tregs. Moreover, protective effect induced by LGG is associated with gut microbiota instead of lung flora. Collectively, our findings indicate that LGG induced protective effect is associated with gut microbiota and provide a new evidence of probiotic application in the allergic airway inflammation.