Researchers studying the comparative biology of aging examine differences between species of varying life spans, in search of insights into mechanisms of aging and potential interventions that might slow or reverse aging in our own species. This is a slow process. Even given the discovery of specific mechanisms that likely contribute to greater longevity or resilience in a given species, it tends to be challenging to determine how large a contribution is made by those mechanisms, and quite speculative as to whether any given mechanism can be used as a basis for therapy in our species. Still, there are many areas of ongoing study in various species in this part of the field, with the paper here as a representative example.
Crocodiles are flourishing large-bodied ectotherms in a world dominated by endotherms. They survived the Cretaceous extinction event, that eradicated the dinosaurs who are thought to be their ancestral hosts. Crocodiles reside in polluted environments; and often inhabit water which contains heavy metals; frequent exposure to radiation; feed on rotten meat and considered as one of the hardy species that has successfully survived on this planet for millions of years. Another capability that crocodiles possess is their longevity. Crocodiles live much longer than similar-sized land mammals, sometimes living up to 100 years. But how do they withstand such harsh conditions that are detrimental to Homo sapiens?
Given the importance of the gut microbiome on its' host physiology, we postulate that the crocodile gut microbiome and/or its metabolites produce substances contributing to their hardiness and longevity. Thus, we conducted a literature search on this topic and herein, we discuss the composition of the crocodile gut microbiome, longevity, and cellular senescence in crocodiles, their resistance to infectious diseases and cancer, and our current knowledge of the genome and epigenome of these remarkable species. Furthermore, preliminary studies that demonstrate the remarkable properties of crocodile gut microbial flora are discussed.
Given the profound role of the gut microbiome in the health of its' host, it is likely that the crocodile gut microbiome and its' metabolites may be contributing to their extended life expectancy and elucidating the underlying mechanisms and properties of these metabolites may hold clues to developing new treatments for age-related diseases for the benefit of Homo sapiens.