Coral-associated bacteria make steroids that influence their host's heat response

Coral Endozoicomonas bacteria were shown to produce steroid hormones and affect immune signaling in stress experiments.

Wild Lands Ecological Intelligence Editor
Wild Lands Institute · 23 October 2026

Evidence: Peer-reviewed
Geography: Saadiyat reef, Arabian Gulf near Abu Dhabi, UAE; laboratory isolates
System: Coral reef microbiomes / thermal stress

WHAT THE EVIDENCE SAYS

Combining sampling of Acropora pharaonis, multi-omics and lab work with three Endozoicomonas isolates, scientists demonstrated bacterial capacity to convert cholesterol to testosterone and progesterone. Immune response assays associated these hormones with pro-survival signaling and reduced inflammatory responses under heat stress.

WHY IT MATTERS / OUR READ

Microbial function may help explain why corals experiencing similar heat differ in their responses. It identifies a mechanistic hypothesis worth testing, not a field-ready remedy.

CAVEATS / UNCERTAINTY

Laboratory metabolism and host signaling results are not evidence that adding these bacteria restores or saves whole reefs.

SOURCE

Nature Microbiology — Mohamed et al. (2026)
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