A double-blind, randomized clinical trial in 42 healthy individuals with no known risk factors for T1D showed that the administration of 1 capsule/day containing 108 UCF of L. johnsonii N6.2 or placebo for 8 weeks increased the circulating effector Th1 cells (CD45RO+CD183+CD196–) and cytotoxic CD8+ T cells. This evidence concerns the gene CXCR3 and type 1 diabetes mellitus.