Coral reefs provide important benefits to coastal communities and are in worldwide decline due to rapid environmental change. Stony corals that build reefs are comprised of the cnidarian host, symbiotic algae and additional bacteria, fungi and viruses that are collectively termed the "coral holobiont". Disruptions that affect the healthy holobiont, such as high temperature stress due to climate change, are hypothesized to increase the incidence of coral bleaching and disease via immune suppression of the coral host.</p><p>Recirculating aquarium experiments used antibiotics, heat stress and LPS exposure to stimulate changes to Pocillopora spp. corals gene expression.