Protective effects of lactic acid bacteria on influenza A virus infection

Abstract

Gut microbiota is essential to regulate the whole body metabolism and the immune system of the host animals. Lactic acid bacteria have as a major characteristic to produce lactic acid from glucose. As probiotics, lactic acid bacteria provide many beneficial effects on human health by regulating the gut microbiota or the cell function. Recently, we have reported that oral administration of a probiotic strain,Lactobacillus gasseri SBT2055 (LG2055) induced IgA production by increasing the population of IgA+ B cell in Peyer’s patch and propria mucosae of small intestine in mice. Furthermore, we demonstrated that oral administration of LG2055 increased the survival rate of mice infected with influenza A virus and decreased the ratio of body weight losses. The virus titer was significantly decreased and the amount of inflammatory cytokine, IL-6 in the lung tissue was reduced by LG2055 administration. The expression of antiviral genes in the lung tissues was increased by LG2055. Therefore, LG2055 administration is shown to be effective for the protection against influenza A virus infection by inhibition of viral replication through the induction of antiviral genes expression. In the future, the constituents of LG2055 to have the effects on the induction of antiviral genes should be clarified for the development of novel influenza drugs.