Scientists have proposed a new model of animal diseases that includes the role of the microbiome. Their research suggests that climate change may lead to the emergence of new infectious diseases.
The COVID-19 pandemic has brought the threat of infectious disease to the fore. At the time of writing, there have been more than 9 million recorded cases of the disease worldwide.
Infectious diseases, particularly those crossing species boundaries (zoonoses), are rising as a result of human activities. This increase is partly due to climate change, which is encouraging some pathogen-carrying species to move outside their current habitat range.
For example, the tiger mosquito, which transmits the viral disease Chikungunya, is currently expanding its geographic range across Europe and the Americas, putting millions of people at risk.
A paper that Trends in Parasitology recently published includes a synthesis of research into infectious diseases in humans and wildlife. It presents a new model of infectious disease dynamics that takes account of the role of the microbiome — the “good” bacteria that live on and inside us.
The scientists behind the work suggest that environmental changes, including climate change, could destabilize this model and lead to new infectious diseases arising from changes in the microbiome of animals.
In disease ecology, scientists traditionally use a “disease triangle” to demonstrate the roles of the host, pathogen, and environment in the spread of disease.
The authors of the new study, who represent institutions in France, Germany, and the United States, suggest that this concept gives an “oversimplified” view of the dynamics of infectious diseases. They have, therefore, broadened the concept to include the microbiome.
The microbiome describes the communities of microorganisms, including bacteria, viruses, and fungi, in a particular context. In an animal context, microbial communities live on and inside the host and perform important roles, including protecting against pathogens and helping break down food.
Research has shown that microbial communities are important for the health of ecosystems, wildlife, and people. The human gut alone is h