Environmental shifts can cause epigenetic modi cations in corals, which are

associated with changes in gene expression and physiology, though it remains

unclear if associated bacteria can also induce such changes. Here, we inoculate

nubbins of the coral Pocillopora verrucosa with an opportunistic pathogen,

Vibrio coralliilyticus, and/or a coral probiotic, Cobetia sp., and subject the

nubbins to heat stress. We show that pathogen exposure leads to distinct DNA

methylation changes compared to the control, probiotic, and co-inoculation

groups. We also con rm that DNA methylation broadly correlates with coral

gene expression; however, individual correlations are restricted to a subset of

genes. We then highlight genes altered by pathogen inoculation that show

similar responses in their expression and methylation. Notably, coral probiotic

exposure mitigates speci c epigenetic changes caused by pathogen inocula-

tion, which correlates with increased stress resilience and higher coral survival

rates. Although many aspects remain to be resolved, evidence that bacteria

alter coral epigenomes may help clarify the role of microbiome interactions in

coral resilience.