For example, proinflammatory cytokines IL1β and tumor necrosis factor α (TNF-α), belonging to inflammatory cytokines and receptors, were activated in response to V. anguillarum infection in ayu (Plecoglossus altivelis), and the relative abundances of 16 taxa in the gut, including Clostridiales, changed consistently during infection (54). Here, IL1B is linked to infection.