Introduction
When people think about biodiversity, they often picture colorful birds, rare mammals, or tropical rainforests. Yet biodiversity may provide another benefit that receives far less attention: protection against disease. Increasing evidence suggests that healthy ecosystems can influence how pathogens spread, how hosts interact, and how disease risks emerge. The concept that Biodiversity Protects Health is becoming an important area of research within ecology, epidemiology, and One Health.
Scientists have discovered that species loss can alter disease dynamics in unexpected ways. Diverse ecosystems often contain natural mechanisms that help suppress pathogens and regulate host populations.
Could protecting biodiversity also help reduce the risk of future disease outbreaks?
Biodiversity Protects Health Through the Dilution Effect
One of the most widely discussed concepts linking biodiversity and disease is the “dilution effect.”
The dilution effect proposes that higher biodiversity can reduce disease transmission by increasing the number of species that are poor hosts for pathogens [1]. When pathogens encounter a wider variety of animals, many transmission chains become less efficient because not every species effectively spreads infection.
Research on Lyme disease has helped illustrate this principle. In some ecosystems, greater vertebrate diversity reduces the dominance of highly competent hosts, making pathogen transmission less effective.
When Predator Loss Changes Disease Risk
Predators play a critical role in maintaining ecological balance. However, their influence may extend beyond regulating prey populations.
The loss of predators can allow populations of rodents and other small mammals to increase. Many of these species serve as important reservoirs for pathogens that affect humans and animals. As host populations expand, opportunities for disease transmission may also increase [2].
Researchers have linked predator declines to changes in disease risk involving hantaviruses, Lyme disease systems, and other zoonotic pathogens. These findings highlight how ecological relationships can influence public health outcomes.
Why Some Ecosystems Naturally Suppress Pathogens
Not all ecosystems respond to pathogens in the same way. Some environments appear to possess characteristics that naturally reduce disease transmission.
Healthy ecosystems often support complex food webs, diverse host communities, and balanced predator-prey relationships. These ecological interactions can limit opportunities for pathogens to spread unchecked [3].
Ecosystem stability itself may contribute to disease regulation by preventing individual host species or pathogens from becoming dominant.
Understanding these natural controls is becoming an important area of disease ecology research.
Biodiversity Loss and Emerging Diseases
Recent studies suggest that biodiversity loss may contribute to broader patterns of disease emergence.
Habitat destruction, land-use change, deforestation, and wildlife population declines can alter interactions between humans, animals, and pathogens. These changes may increase opportunities for zoonotic spillover events, where diseases move from animals into human populations [4].
Disease emergence is influenced by environmental change, human behavior, climate conditions, and ecosystem disruption, with biodiversity being one important factor.
A One Health Perspective
The concept of Biodiversity Protects Health aligns closely with the One Health approach because it highlights the connections between ecosystem health, animal health, and human health.
Disease risks do not arise solely from pathogens themselves. They are often shaped by ecological conditions that influence host populations, wildlife interactions, and environmental stability. Protecting biodiversity can therefore contribute to healthier ecosystems that support disease regulation and resilience.
One Health encourages collaboration across disciplines to better understand these interconnected relationships.
Conclusion
The relationship between biodiversity and disease is more complex than many people realize. Growing evidence suggests that Biodiversity Protects Health through mechanisms that influence pathogen transmission, host populations, and ecosystem stability.
From the dilution effect to predator-driven disease regulation, ecological diversity may help reduce certain disease risks while supporting healthier environments overall. As biodiversity declines worldwide, understanding these connections becomes increasingly important.
Protecting species is not only an environmental goal. In many cases, it may also be an investment in long-term public health and disease prevention.
References
- Keesing, F., Holt, R.D. and Ostfeld, R.S., 2006. Effects of species diversity on disease risk. Ecology Letters, 9(4), pp.485–498.
https://doi.org/10.1111/j.1461-0248.2006.00885.x - Ostfeld, R.S. and Holt, R.D., 2004. Are predators good for your health? Evaluating evidence for top-down regulation of zoonotic disease reservoirs. Frontiers in Ecology and the Environment, 2(1), pp.13–20.
https://doi.org/10.1890/1540-9295(2004)002[0013:APGFYH]2.0.CO;2 - Johnson, P.T.J., de Roode, J.C. and Fenton, A., 2015. Why infectious disease research needs community ecology. Science, 349(6252), 1259504. https://doi.org/10.1126/science.1259504
- IPBES, 2020. Workshop Report on Biodiversity and Pandemics. Available at: https://ipbes.net/pandemics
