Fig. 1

Coral microbiome transplantation. A field-based probiotic strategy to support coral heat tolerance during global ocean warming. Over the past years, microbiome transplantation has already been successfully employed as a clinical therapy for the treatment of several human gastrointestinal disorders. Applied to corals, this technique aims to expose heat-sensitive corals to bacterial communities of heat-resilient conspecific donor corals. Such donors can likely be found in reefs of environmental variability or extremes. CMT has several benefits. It bypasses time-consuming culturing and screening effort of bacterial isolates, which is required for the production of lab-cultured probiotics. Most importantly, this strategy enables the transmission of the “unculturable” fraction of the microbiome. Furthermore, reintroduction of CMT recipient corals will not clash with ethical considerations, since donor colonies can be locally sourced from reef habitats at the location of the application. As such, this approach can become a feasible, local management strategy for coral reefs. As ocean warming is progressing rapidly, an expeditious strategy like the CMT could represent a powerful probiotic intervention for corals