Intranasal administration of live Lactobacillus species facilitates protection against influenza virus infection in mice

► Lactobacillus species facilitates protection against influenza virus infection in mice. ► Intranasal administration bestowed higher protective efficacy than the oral route. ► Live bacteria conferred higher protection against influenza than dead bacteria. ► There were huge differences in protective effects of various Lactobacillus strains on influenza virus infection.