CD8A and type 1 diabetes mellitus: Indeed, many microbial-based probiotics have been identified with potential benefit against T1D, for example, VSL3# which consists of eight beneficial Lactobacillus strains shown to prevent or delay T1D in NOD mice, this is mediated by releasing a number of molecules with anti-inflammatory activities, modulating the number of splenic CD8 T cells, enhancing the immune tolerance and the growth of beneficial bacteria in the gut [158,184,185] (Figure 2).