TLR9 and microsporidiosis: Conversely, in this study, TLR9-deficient mice showed an increase in regulatory T cells, with a consequent impairment in the immune response to both oral Microsporidia infection and vaccination with the mutant form of Escherichia coli labile toxin (LT) as a mucosal adjuvant; additionally, antibiotic administration in TLR9−/− mice resulted in a worse immune response to oral infection [100]