Recent experimental evidence suggests that, (1) α-synuclein plays a role in immunity and inflammation, (2) microbial gut amyloids stimulate α-synuclein aggregation, and (3) α-synuclein harbors antimicrobial properties under conditions of viral or bacterial infection after nasal or systemic inoculation [1, 17, 117, 204, 236, 243, 244, 246]. This evidence concerns the gene SNCA and bacterial infectious disease.