CD8A and type 1 diabetes mellitus: These results suggest that trehalose may have a potential prophylactic and/or therapeutic role in humans (e.g., use of trehalose and Ruminococcus strains as a prebiotic and probiotic, respectively), as a tool to induce CD8+ regulatory T cells in order to prevent the development of type 1 diabetes and/or counteract the immune-mediated β-cell destruction shortly after the onset of the disease.