Enterococcus faecalis is significantly increased in patients with alcoholic hepatitis compared with patients without alcohol use disorder and in particular, the presence of E. faecalis strains that produce cytolysin (a bacterial exotoxin) correlates with worse outcomes: in 2019, a study showed that mouse models treated via oral gavage with phages specifically targeting cytolysin-positive E. faecalis showed reductions in ethanol-induced liver disease [199]. This evidence concerns the gene PRF1 and alcoholic hepatitis.