TLR2 and asthma: Prevotella is a gut microbiome associated with chronic inflammatory diseases, which can activate Toll-like receptor 2, induce Th17-mediated immune responses, and ultimately promote asthma development (Myxedema and conservative heart failure, 1970; Arumugam et al., 2011; Wu et al., 2011; Yadava et al., 2016).