sex-specific pattern in the postmortem intestinal microbiome dynamics

Gut microbes form a complex and dynamic symbiotic relationship with their host. However, the microbial response during the early stages following host death remains largely uncharacterized. Gut microbes may actively sense host death, passively adapt to the postmortem environment, or employ a combination of both strategies to respond to the host's death. In this study, we employed a mouse model to systematically characterize the postmortem response of the intestinal microbiota, and analyzed the dynamic changes in microbial composition during the early stages after death in both male and female mice (at 0, 0.5, 2, 6, 12, and 24 hours postmortem). Our findings revealed a distinct sex specific pattern in the postmortem intestinal microbiome dynamics, underscoring the influence of host sex on microbial composition and function following death. Notably, the observed retention of regulatory capacity by intestinal microbes after host death offers a novel perspective on the conceptualization of death itself. We propose the term "ecological death" to describe the irreversible collapse of the host-associated microbial ecosystem following death, marking a critical transition in the functional and structural integrity of the intestinal microbiota.