Yakult Knowledge
Login

Latest News

Climate Change and Gut Health: Why the Connection Matters

Many health risks can be traced back to environmental factors, which are increasingly shaped by climate change.1 Far from being a distant issue, climate change is now part of our everyday reality. Driven largely by human activities, rising carbon dioxide and greenhouse gas levels are warming our planet at an unprecedented rate. This disrupts ecosystems, threatens biodiversity, and reduces the resilience of natural systems that support life.2

Beyond environmental impacts, climate change affects human health, including the gut microbiome. From soil quality, food production and nutrient availability to air quality, climate change shapes the conditions that nourish or challenge our gut microbial communities.3 The gut microbiome is shaped by a complex interplay of factors, including diet, both in terms of availability and nutritional quality, and environmental microbial exposures such as enteric pathogens. Each of these determinants is sensitive to climate change, meaning shifts in climate may alter microbial composition, diversity, and functional capacity. These changes can influence immunity, chronic disease risk, nutrition, and even mental wellbeing.3 The figure below illustrates how climate change drivers influence food and pathogens, with downstream effects on the gut microbiome and vulnerable populations. It also serves as a visual summary of the key themes explored throughout this blog.

Figure 1. Climate change drivers influence food and pathogens, leading to downstream impacts on the gut microbiome and vulnerable populations.

Climate Change impact on food availability

Rising temperatures, extreme weather events, and pest outbreaks can significantly reduce crop yields, sometimes leading to complete crop failure, famine, and undernutrition.4,5 Starvation has been shown to increase intestinal permeability, alter the gut lumen, and promote colonisation by enteric pathogens.6 These effects are particularly severe in children in low-income settings, where malnutrition is associated with increased Enterobacteriaceae, gut inflammation, and impaired microbiota development.7 Importantly, a malnourished gut microbiome may hinder recovery even when adequate nutrition is reintroduced, due to the loss of microbial taxa critical for energy metabolism. Such dysbiosis can persist over time and increase vulnerability to chronic disease, including type 2 diabetes.4,5 

Climate impact on food composition, nutritional quality and gut microbiota

By 2050, climate change could leave over 100 million people protein-deficient and nearly 200 million zinc-deficient.8 Rising CO₂ and temperatures reduce the nutritional quality of crops by lowering protein and mineral content, increasing carbon-to-nitrogen ratios, and making foods less digestible.8 Key staples like wheat, rice, and maize may see declines in iron, zinc, and protein under these conditions.9 Climate-driven soil degradation, including erosion, nutrient depletion, and loss of organic matter, further compounds these effects by limiting plant nutrient uptake.10 Disruptions to the soil microbiome, which plays a crucial role in nutrient cycling and mineral bioavailability, also diminish crop nutritional quality, with downstream consequences for human gut health.10 Hidden hunger is predicted to increase by 10% due to decreases in the bioavailability of dietary nutrients.11

Climate change also affects the nutritional quality of specific food types. Heat stress in plants can reduce antioxidants, such as polyphenols, and increase contaminants like arsenic, which may impact gut microbiota diversity.12,13 In livestock and poultry, heat stress lowers the nutritional quality of meat and dairy, with poultry also experiencing fat accumulation and protein degradation.14,15 Warmer waters reduce omega-3 fatty acids in marine foods while increasing methylmercury bioaccumulation, altering microbial composition and function.16 Shifts toward more climate-resilient crop and animal varieties can change macronutrient ratios, with high-fat, low-protein diets decreasing Bacteroidetes, increasing Firmicutes, raising gut permeability, and promoting inflammation.17 Even small changes in nutrient or vitamin concentrations can shift gut microbial communities toward dysbiosis. Specific micronutrient deficiencies exacerbate these effects: low nitrogen reduces Lactobacilli and increases E. coli and other coliforms,18 iron deficiency causes long-lasting shifts in microbial abundance, reduces propionate and butyrate, and decreases Lactobacilli,19 and zinc deficiency increases gut inflammation and certain microbial taxa while worsening arsenic toxicity.20 Cold stress also influences the microbiome in a duration-dependent manner: short-term exposure can increase microbial diversity, whereas prolonged exposure reduces richness and α-diversity, compromising stability.21,22

Climate Change, Enteric Pathogens, and the Gut Microbiome

Climate change may further compromise gut microbiome integrity by increasing the prevalence and transmission of enteric pathogens. Rising temperatures accelerate bacterial growth, survival, and infectivity, while extreme rainfall and flooding increase runoff and contamination of water sources with fecal pathogens such as E. coli and Salmonella.23,24 Elevated pathogen pressures can challenge colonisation resistance, increase gut permeability, provoke inflammation, and shift microbial community composition toward pathogenic taxa. These effects are especially concerning in low-income regions with limited sanitation infrastructure.3

Sustainable Diets and Microbiome Implications

Climate mitigation strategies may also influence gut health. Plant-based meat and dairy alternatives, while reducing greenhouse gas emissions, often differ in nutrient composition from animal products, and their effects on the gut microbiome remain uncertain.3,25, Similarly, planetary health diets designed to balance nutrition with environmental sustainability have not yet been fully explored for microbial impacts. Agricultural adaptation strategies, such as cultivating climate-resilient crops and livestock, may help maintain yields and nutritional quality under future conditions, but if selection focuses mainly on yield rather than nutrient density, shifts in dietary nutrient intake could alter gut microbiota.3,26

Addressing Climate Change Impacts on Gut Health

Understanding how climate change affects the gut microbiome requires multidisciplinary collaboration across climate science, nutrition, microbial ecology, medicine, and public health.3 Key questions include how shifts in food availability and nutrient composition affect gut microbes, which crops and livestock are most climate-sensitive, and how changing pathogen pressures influence microbial communities. This knowledge is essential for designing interventions, including probiotics to counter pathogen exposure, targeted nutrient supplementation to prevent dysbiosis, and microbiome-based therapies such as faecal microbiota transplantation.27 Adaptation strategies should also include optimising fertiliser use, promoting dietary diversity, cultivating climate-resilient crops and livestock, and improving sanitation, particularly in low- and middle-income countries.3

Conclusion

Climate change is reshaping the foods we eat and, in turn, the microbes that support our health. While these challenges are complex, they also open the door to solutions that strengthen resilience. By encouraging dietary diversity, safeguarding sustainable food systems, and supporting beneficial microbes through approaches such as probiotic interventions, we can help protect gut health in a changing world. 

At Yakult, we’re doing our part by aligning with the Yakult Group Environmental Vision 2050—to realise a society where people and the planet co-exist as one through a value chain with zero environmental impact—with the goal of achieving net zero carbon by 2050. The Yakult Group Environmental Targets 2030 outline key priorities, which are climate change mitigation and adaptation, transitioning to sustainable packaging, responsible water source management, and biodiversity conservation. With these targets and our dedication to promoting gut health through microbiome science, Yakult demonstrates that protecting human health and the planet can truly go hand-in-hand. 

Together, these strategies remind us that nutrition and microbiome science are not just about surviving climate pressures, they’re about enabling individuals and communities to thrive.

References:

  1. WHO We Must Fight One of the World’s Biggest Health Threats: Climate Change. Published 2023 Nov 3. Accessed on 6 Oct 2025)]. Available online: https://www.who.int/news-room/commentaries/detail/we-must-fight-one-of-the-world-s-biggest-health-threats-climate-change
  2. Malhi Y, Franklin J, Seddon N, et al. Climate change and ecosystems: threats, opportunities and solutions. Philos Trans R Soc B Biol Sci. 2020; 375, 20190104 doi: 10.1098/rstb.2019.0104
  3. Litchman E. Climate change effects on the human gut microbiome: complex mechanisms and global inequities. The Lancet Planetary Health. 9(2); e134 – e144 https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(24)00332-2/fulltext 
  4. von Schwartzenberg RJ, Bisanz JE, Lyalina S, et al. Caloric restriction disrupts the microbiota and colonization resistance. Nature. 2021; 595:272-277 https://www.nature.com/articles/s41586-021-03663-4 
  5. Gou W, Wang H, Tang XY, et al. Early-life exposure to the Great Chinese Famine and gut microbiome disruption across adulthood for type 2 diabetes: three population-based cohort studies. BMC Med. 2023; 21:414. doi: https://doi.org/10.1186/s12916-023-03123-y 
  6. Kelly P. Starvation and its effects on the gut. Adv Nutr. 2021; 12:897-903. doi: 10.1093/advances/nmaa135 
  7. Patterson GT, Osorio EY, Peniche A, et al. Pathologic inflammation in malnutrition is driven by proinflammatory intestinal microbiota, large intestine barrier dysfunction, and translocation of bacterial lipopolysaccharide. Front Immunol. 2022; 13, 846155. doi: 10.3389/fimmu.2022.846155 
  8. Smith MR, Myers SS. Impact of anthropogenic CO2 emissions on global human nutrition. Nat Clim Chang. 2018; 8:834-839. doi: https://doi.org/10.1038/s41558-018-0253-3 
  9. Soares JC, Santos CS, Carvalho SMP, et al. Preserving the nutritional quality of crop plants under a changing climate: importance and strategies. Plant Soil. 2019; 443:1-26. doi: https://doi.org/10.1007/s11104-019-04229-0 
  10. Fierer, N. Embracing the unknown: disentangling the complexities of the soil microbiome. Nat Rev Microbiol 15, 579–590 (2017). Doi: https://doi.org/10.1038/nrmicro.2017.87 
  11. Disability-adjusted life years due to chronic and hidden hunger under food system evolution with climate change and adaptation to 2050. Am J Clin Nutr. 2021; 114:550-563. doi: 10.1093/ajcn/nqab101. 
  12. Muehe EM, Wang T, Kerl CF, et al. Rice production threatened by coupled stresses of climate and soil arsenic. Nat Commun. 2019; 10, 4985. doi: https://doi.org/10.1038/s41467-019-12946-4 
  13. Chi L, Bian X, Gao B, et al. The effects of an environmentally relevant level of arsenic on the gut microbiome and its functional metagenome. Toxicol Sci. 2017; 160:193-204. doi: 10.1093/toxsci/kfx174 
  14. Liu J, Li  L, Chen X, et al. Effects of heat stress on body temperature, milk production, and reproduction in dairy cows: a novel idea for monitoring and evaluation of heat stress—a review. Asian-Australas J Anim Sci. 2019; 32:1332-1339. doi: 10.1093/toxsci/kfx174 
  15. Zaboli G, Huang X, Feng X, et al. How can heat stress affect chicken meat quality?—a review. Poult Sci. 2019; 98:1551-1556. doi: 10.3382/ps/pey399 
  16. Seki N, Akiyama M, Yamakawa H, Hase K, Kumagai Y, Kim YG. Adverse effects of methylmercury on gut bacteria and accelerated accumulation of mercury in organs due to disruption of gut microbiota. J Toxicol Sci. 2021;46(2):91-97. doi: 10.2131/jts.46.91.
  17. Zhang P. Influence of Foods and Nutrition on the Gut Microbiome and Implications for Intestinal Health. Int J Mol Sci. 2022 Aug 24;23(17):9588. doi: 10.3390/ijms23179588. 
  18. Corsetti G, Romano C, Pasini E, Testa C, Dioguardi FS. Qualitative Nitrogen Malnutrition Damages Gut and Alters Microbiome in Adult Mice. A Preliminary Histopathological Study. Nutrients. 2021 Mar 26;13(4):1089. doi: 10.3390/nu13041089.
  19. Balamurugan R, Mary RR, Chittaranjan S, et al. Low levels of faecal lactobacilli in women with iron-deficiency anaemia in south India. Br J Nutr. 2010; 104:931-934. doi: 10.1017/S0007114510001637
  20. Chen X, Jiang Y, Wang Z, Chen Y, Tang S, Wang S, Su L, Huang X, Long D, Wang L, Guo W, Zhang Y. Alteration in Gut Microbiota Associated with Zinc Deficiency in School-Age Children. Nutrients. 2022 Jul 14;14(14):2895. doi: 10.3390/nu14142895.
  21. Yi W., Cheng J., Wei Q., Pan R., Song S., He Y., Tang C., Liu X., Zhou Y., Su H. Effect of Temperature Stress on Gut-Brain Axis in Mice: Regulation of Intestinal Microbiome and Central NLRP3 Inflammasomes. Sci. Total Environ. 2021;772:144568. doi: 10.1016/j.scitotenv.2020.144568.
  22. Wang B, Liu J, Lei R, Xue B, Li Y, Tian X, Zhang K, Luo B. Cold exposure, gut microbiota, and hypertension: A mechanistic study. Sci Total Environ. 2022 Aug 10;833:155199. doi: 10.1016/j.scitotenv.2022.155199.
  23. Chua PLC, Ng CFS, Tobias A, Seposo XT, Hashizume M. Associations between ambient temperature and enteric infections by pathogen: a systematic review and meta-analysis. Lancet Planet Health. 2022 Mar;6(3):e202-e218. doi: 10.1016/S2542-5196(22)00003-1.
  24. Donnelly MC, Talley NJ. Effects of climate change on digestive health and preventative measures. Gut. 2023 Nov 24;72(12):2199-2201. doi: 10.1136/gutjnl-2023-331187.
  25. Beal T, Ortenzi F, Fanzo J. Estimated micronutrient shortfalls of the EAT-Lancet planetary health diet. Lancet Planet Health. 2023 Mar;7(3):e233-e237. doi: 10.1016/S2542-5196(23)00006-2. Erratum in: Lancet Planet Health. 2023 Jul;7(7):e546. doi: 10.1016/S2542-5196(23)00131-6.
  26. Leisner CP. Review: Climate change impacts on food security- focus on perennial cropping systems and nutritional value. Plant Sci. 2020 Apr;293:110412. doi: 10.1016/j.plantsci.2020.110412.
  27. Sheridan PO, Bindels LB, Saulnier DM, Reid G, Nova E, Holmgren K, et al. Can prebiotics and probiotics improve therapeutic outcomes for undernourished individuals? Gut Microbes. 2014 Jan-Feb;5(1):74-82. doi: 10.4161/gmic.27252.