New methane-producing microbe discovered in the human gut

Archaea – an often-overlooked group of microbes – are quietly living in our guts, and scientists are finally starting to understand just how important they might be.

While most research on the human microbiome has focused on bacteria, a new species of methane-producing gut microbe is shifting that attention.

In a recent study, microbiologists from the Medical University of Graz, the DSMZ-German Collection of Microorganisms and Cell Cultures in Germany, and the University of Illinois, discovered a previously unknown methane-producing archaea species in the human gut. They named it Methanobrevibacter intestini sp. nov., strain WWM1085.

The team also isolated a new variant of Methanobrevibacter smithii, called GRAZ-2. These findings offer fresh insight into how our gut and its microbial inhabitants interact.

What makes archaea so unique?

Archaea are one of the three recognized domains of living organisms, along with bacteria and eukaryotes (which include animals, plants, and fungi).

Under a microscope, archaea might look a bit like bacteria – but they are fundamentally different. Their cell structure, metabolism, and genetic code all set them apart.

Most people associate archaea with extreme environments like hot springs and salt flats. But they also live in more familiar places, including in the human digestive tract.

One group of archaea, known as methanogens, produces methane by breaking down hydrogen and carbon dioxide. These microbes are vital to metabolic processes in animals – including humans.

Still, studying them isn’t easy. Archaea cannot tolerate oxygen, and they’re difficult to grow in the lab. That’s why research into their role in the human gut is only just beginning.

Small microbes may play a big role

“Our discovery is a further piece in the puzzle towards understanding how the human microbiome functions,” said Christine Moissl-Eichinger, professor of interactive microbiome research at Med Uni Graz.

While most microbiome studies center on bacteria, archaea have received little attention – despite the big role they might play in our health.

“Archaea have long been overlooked,” Moissl-Eichinger said. “They may play a significant role in gut function, microbial gas metabolism, and possibly even the development or progression of certain diseases.”

Gut microbes that produce methane

To identify the methane-producing gut microbes, the team used advanced techniques, including specialized anaerobic cultivation (growing organisms without oxygen), high-resolution electron microscopy, and DNA sequencing.

The experts found that Methanobrevibacter intestini WWM1085 stands apart from all known archaea species. It survives only in oxygen-free environments and produces methane.

More surprisingly, it also generates large amounts of succinic acid – a substance linked to inflammation in the body. This suggests a possible connection between archaea and certain health conditions.

The second discovery, GRAZ-2, is a strain of Methanobrevibacter smithii. It produces formic acid, which could disrupt how other gut microbes function. This suggests that even slight genetic variations in archaea might lead to very different roles within the gut.

What the “archaeome” might reveal

These findings support the idea that gut archaea are more diverse – and potentially more important – than previously believed.

Scientists are beginning to use the term “archaeome” to describe the full range of archaea living within us. This emerging field holds promise for revealing how these organisms influence human health. The ability to grow archaea in the lab is crucial for learning what they do.

“We can only conduct specific mechanistic investigations with cultivated strains,” said Viktoria Weinberger, the study’s first author. “This is essential in order to better understand the role of individual microorganisms in health and disease – and in the long term to develop therapeutic approaches as well.”

Understanding the new gut microbes

Understanding Methanobrevibacter intestini and GRAZ-2 could be just the beginning. These archaea may one day help shape more personalized approaches to gut health – ones that include not just the bacteria, but also the other overlooked players living quietly in our digestive systems.

The discovery of new archaea species in the human gut raises more questions than it answers. What other microbes are we missing? And how might they influence everything from digestion to disease?

As research expands, the once-overlooked archaea may become key players in shaping the future of microbiome science.

The full study was published in the International Journal of Systematic and Evolutionary Microbiology.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–