Climate change is having a profound impact on human health, with effects ranging from heat-related illnesses to the spread of infectious diseases. One area that is often overlooked is the impact of climate change on gut health. Recent research suggests that climate change may be making us sick to our stomachs—literally.
In a new review article published in The Lancet Planetary Health, ecologist and Michigan State University Research Foundation Professor Elena Litchman highlights how the compounding effects of climate change could weaken human gut microbiomes, particularly in middle- and low-income countries. These regions are at greater risk due to factors such as food insecurity, malnutrition, and exposure to disease-causing pathogens, which could have a cascading effect on gut microbial ecosystems worldwide.
Heat stress, a common consequence of climate change, can lead to complex changes in the gut, including shifts in microbiota composition, increased oxygen levels, and overproduction of stress hormones. These changes can make individuals more susceptible to harmful organisms and disrupt important digestive and immune functions. The body’s ability to absorb vital nutrients may also be diminished, especially in regions where nutritious food is scarce.
In middle- and low-income countries, particularly those in the tropics, a surge in gastrointestinal diseases poses a multifaceted threat. Environmental changes promote the growth and spread of pathogens, while heat stress and food insecurity weaken the body’s natural immune defenses. These countries are less equipped to adapt to food shortages compared to high-income countries, resulting in a disproportionate impact on populations already facing heat stress, illness, and food insecurity.
Understanding how the availability and nutritional quality of food in at-risk areas affect the gut microbiome is crucial for mitigating the negative health outcomes associated with climate change. Litchman emphasizes the importance of interdisciplinary collaborations in addressing these emerging health challenges, pointing to the World Health Organization’s One Health Initiative as a model for cross-disciplinary projects.
Without concerted efforts to mitigate risks among vulnerable populations, the compounding effects of climate change on gut health could put millions of people at risk of illness and poor health outcomes. By taking a holistic approach and fostering interdisciplinary collaborations, we can work towards solutions that address the complex mechanisms and global inequities exacerbated by climate change.
Source:
Elena Litchman, Climate change effects on the human gut microbiome: complex mechanisms and global inequities, The Lancet Planetary Health (2025). DOI: 10.1016/S2542-5196(24)00332-2.
