Do enteroviruses and/or bacteriophages in T1DM suppress the shikimate pathway and Akkermansia muciniphila, in association with decreased L. johnsonii and butyrate, to contribute not only to alterations in the mitochondrial melatonergic pathway in pancreatic β-cells, but also to the ‘bystander activation’ of memory CD8+ T cells in Peyer’s patches? The gene discussed is CD8A; the disease is type 1 diabetes mellitus.