IUCN launches group to conserve at-risk microbes vital to life on Earth

Microbial communities, though invisible to the naked eye, are vitally important to planetary health and to Earth’s ecosystems. But they are often neglected in conservation strategies.
Like other branches of life, microbial communities are under threat due to climate change, pollution, land use change and a wide range of other human actions. Degraded microbial communities can have harmful consequences for human well-being, ecosystems health and wider planetary processes.
A newly launched specialist group under the International Union for the Conservation of Nature (IUCN) aims to place microbes on the conservation agenda.
The new IUCN group plans to develop conservation strategies aimed at identifying and protecting at-risk microbial species vital to planetary health and create a Red and Green List, similar to those that exist for threatened animals and plants.

Invisible in their trillions, microbes dwell in our bodies, grow in soils, live on trees and are integral to planetary health. Yet the huge oversized roles these teeming biodiverse microbial communities play as a foundation for life on Earth is often overlooked. And so, too, are the threats microorganisms face, especially from humanity’s actions.

But this scientific inattention is about to end, as a newly launched International Union for Conservation of Nature (IUCN) species survival commission focuses on microbiology and dire threats to microbial species.

“I think this is a huge milestone for microbiologists, but also for conservation overall, because for the first time, we have an official recognition that microbes need to be included in the conservation agenda,” says Raquel Peixoto, co-chair of the IUCN specialist group and chair of the Marine Science Program at King Abdullah University of Science and Technology in Saudi Arabia.

“We cannot talk about either climate change or biodiversity loss without talking about microbes, because we need them to keep the ecosystems healthy and working, and we need them to keep the organisms working,” she adds.

All plants and animals host invisible communities of microbes. These vast unseen microbiomes are fundamental to life as we know it, but these invisible ecosystems are also threatened by numerous intensifying pressures, including pollution, climate change and land use change.

Prochlorococcus microorganisms in the world’s oceans produce vast amounts of oxygen via photosynthesis. Increasing water temperatures could cause declines of this invaluable microbe. A recent study estimates that their productivity would fall by 17% if global temperatures rise by 2° Celsius (3.6° Fahrenheit), likely to occur between the 2030s and ‘50s. — *Prochlorococcus* microorganisms in the world’s oceans produce vast amounts of oxygen via photosynthesis. Increasing water temperatures could cause declines of this invaluable microbe. A recent study estimates that their productivity would fall by 17% if global temperatures rise by 2° Celsius (3.6° Fahrenheit), likely to occur between the 2030s and ‘50s. Image by Chisholm Lab via Flickr (Public domain).

Triage for unseen species

The new specialist group plans to develop conservation plans for microbial ecosystems currently under threat by habitat destruction and other human activities. The research team also plans to develop a microbe-specific Red List, identifying and studying threatened microbes and developing conservation strategies. This is no easy task, says Jack Gilbert, co-chair of the specialist group, as assessment tools developed for bigger plants and animals don’t easily fit microorganisms.

“It’s a big problem trying to identify these [microbial] criteria, as well as overcoming people’s general expectation that microbes will survive and thrive no matter what you do,” says Gilbert, who is also jointly appointed at the University of California San Diego’s Scripps Institution of Oceanography and the School of Medicine’s Department of Pediatrics.

“I think it’s incredibly important to understand that microbes are under threat, just like animals and plants,” Gilbert adds.

Marine microorganisms produce vast amounts of oxygen, vital to many marine species. But climate change is threatening the microorganisms responsible for life in the world’s oceans. Image courtesy of Gregory Piper/Ocean Image Bank.

Microbes vital inside the body, at sea and on land

Gilbert underlines researchers’ concerns for microbes at risk by pointing to research showing that infants in industrialized countries are losing an important species of bacteria (called Bifidobacterium infantis) that helps digest breast milk. “Our modern lifestyle, isolation from the outside world, the foods we eat, the medications we take, are eradicating that organism from intergenerational transfer,” he says.

Other changes caused by human activity are playing out in the microbial world that could have profound implications for planetary health, he adds. This is evident in the world’s oceans which, thanks to cyanobacteria, produces large amounts of the world’s oxygen supply.

But a paper published in 2025 found that key oxygen-producing microorganisms in the world’s oceans (called Prochlorococcus) could face sharp declines due to climate change and increasing water temperatures. These tiny organisms produce as much as 20% of the oxygen in global seas.

Radical changes in human dietary consumption are one reason for the loss of beneficial microbes in the human gut microbiome, resulting in degraded human health. Image by Daniel Albany via Pixabay.

“If you damage certain species of bacteria in the oceans, you could wipe out the entire food system production,” he explains. Harming or losing microbial communities can reverberate up the food chain, a cascading effect that ultimately threatens fish and other marine species, along with human health and planetary ecosystem stability, he says.

“We now recognize that biodiversity loss is happening across every scale of life, including the microbial world,” says Guilherme Becker, an associate professor in the Department of Biology at Pennsylvania State University who isn’t involved in the new IUCN specialist group. “Microorganisms underpin the health of ecosystems everywhere, so it is long overdue that we begin treating microbial conservation with the same urgency as we do plants and animals.”

A researcher applies a coral probiotic at the Red Sea Coral Probiotic Village in the Middle East. Restoring the microbiome of corals could help them and other organisms survive as marine heat waves are intensified by climate change, says researcher Raquel Peixoto, co-chair of the IUCN specialist group. Image courtesy of Morgan Bennett-Smith.

‘No conservation without microbes’

Placing a focus on microbial conservation and restoration could help stave off major biodiversity declines and protect entire ecosystems, experts say.

Peixoto notes numerous clear interconnections between conservation and microbial conservation. The core of her work is on links between corals and microbial communities and the risks they face. As climate change intensifies — setting ocean heat records for the ninth consecutive year in 2025 — the mutual relationship between coral and algae vital to their microbiome turns harmful, leading coral to expel the algae, resulting in coral bleaching.

Continued bleaching events could mean death for the world’s coral reefs in the next few decades — destroying the offshore nurseries that thousands of marine species rely on for life; species that millions of people also rely on for livelihoods and food security.

Peixoto’s team is using what it calls coral probiotics, adding beneficial microbes in high numbers to corals during times of stress, especially those produced by marine heat waves.

“We’ve been seeing, in real-world applications, that the corals have a better chance to survive when we restore the microbiome,” she says. “By restoring the microbiome of corals, we can improve coral health and we can also protect the other organisms in the reef.”

A pumpkin toadlet (Brachycephalus pitanga). This tiny amphibian, only about half an inch long, is native to Brazil’s Atlantic Forest. Like other amphibians, stressors including climate change-induced drought can disrupt its microbiome, leaving it vulnerable to diseases. — A pumpkin toadlet (*Brachycephalus pitanga*). This tiny amphibian, only about half an inch long, is native to Brazil’s Atlantic Forest. Like other amphibians, stressors including climate change-induced drought can disrupt its microbiome, leaving it vulnerable to diseases. Image courtesy of Alberto Lopez.

Terrestrial microbes also need rescue. Work by Becker’s lab has shown that endangered amphibians in tropical forests are tending to have lower microbiome diversity on their skin. That’s because climate change and drought are reducing skin microbiome diversity there, leaving amphibians more vulnerable to disease.

“From the microbial conservation perspective, we don’t want to lose these bacteria,” Becker says. That means adopting conservation strategies that not only support the amphibians, but also maintaining the health of associated microbiome diversity. “We need to start thinking about how to map, and how to assess, the endangerment status and the conservation status of these microorganisms as well,” he says.

The presence of tiny microbes — or the lack of them — can also have an outsized effect on important planetary processes and offset harm done by people. A recent paper, for example, conducted in Australia’s forests found that previously unknown microbial communities growing on tree bark uptake significant sums of methane (a greenhouse gas at least 20 times as powerful as carbon dioxide), along with carbon monoxide and volatile organic chemicals (VOCs), pollutants harmful to human health.

A wetland in Melaleuca, Australia. Recent research shows that microbial communities living on the bark of trees play a vital role in the cycling of methane (a powerful greenhouse gas) and carbon monoxide and volatile organic chemicals, both toxic to people. Image courtesy of Luke Jeffrey/Southern Cross University.

Further study could help reforestation efforts, the authors say, by enabling selection of tree species that host those microbes and suck up more of these polluting gases.

Microbial communities benefit trees and wider ecosystems in other ways; they’re vital for chlorophyll production and photosynthesis in both boreal and tropical forests, are crucial to the movement of nutrients and water through soils and much more. “Microbes play a fundamental role in planetary health by supporting the health of … trees,” Gilbert says.

Peixoto says there are a multitude of examples of beneficial connections between microbes, animals, humans and planetary health that show definitively there is “no conservation without microbes.”

“Microbes are the drivers of biochemical cycles; they shape the planet as we know it, and all meta-organisms [including humans] rely on their associated microbiome,” she says.

Next steps for the IUCN group are defining specific groups of threatened microbes crucial to planetary health and then developing plans to preserve them. This Herculean effort could require establishment of cryopreservation and biobanks across the world.

“We are getting to a point where we will have the necessary structure to start taking action in terms of microbe preservation, [and] also harnessing their power to protect other organisms and ecosystems,” Peixoto says.

Banner image: Soil microbes. Invisible to the naked eye, microbial communities play a huge role in planetary processes, such as nutrient cycling, and are vital to ecosystem and human health. Image by Pacific Northwest National Laboratory via Flickr (CC BY-NC-SA 2.0).

Citations:

Gilbert, J. A., Peixoto, R. S., Scholz, A. H., Dominguez Bello, M. G., Korsten, L., Berg, G., … Redford, K. (2025). Launching the IUCN microbial conservation specialist group as a global safeguard for microbial biodiversity. Nature Microbiology, 10(10), 2359-2360. doi:10.1038/s41564-025-02113-5

Greenspan, S. E., Peloso, P., Fuentes-González, J. A., Bletz, M., Lyra, M. L., Machado, I. F., … Becker, C. G. (2022). Low microbiome diversity in threatened amphibians from two biodiversity hotspots. Animal Microbiome, 4(1). doi:10.1186/s42523-022-00220-w

Jassey, V. E., Hamard, S., Lepère, C., Céréghino, R., Corbara, B., Küttim, M., … Carrias, J. (2022). Photosynthetic microorganisms effectively contribute to bryophyte CO2 fixation in boreal and tropical regions. ISME Communications, 2(1). doi:10.1038/s43705-022-00149-w

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