Scientists have put forward plans for a microbial “Noah’s ark” to preserve beneficial bugs found in the guts of people living in some of the most remote communities on Earth.

The move to save the microbes is driven by concerns that modern lifestyles are wiping out organisms that have colonised human intestines for millennia and are vital for good health.

The repository would store existing collections of “friendly” germs gathered from people around the world so they could be studied before they disappear. Research on the bugs could potentially lead to new treatments for modern diseases ranging from obesity to diabetes, the scientists believe.

“We want a backup for all of these collections in a safe, neutral country where they can be preserved until we fully understand them,” said Maria Dominguez Bello, a biologist at Rutgers University in New Jersey. “We hypothesise that they perform important, crucial functions and we can’t afford to lose them.”

Published in the journal Science, the proposal calls for a microbial equivalent of the Seed Vault, a secure cavern built into a mountainside on Svalbard Island in Norway where scientists hope to preserve the natural biodiversity of plants. Instead of storing seeds, the microbial vault would hold collections of human stools and the rich mix of microbes that lurk inside.

Studies have shown that people in isolated, traditional communities tend to have far more diverse gut “microbiomes” than those in western and urban populations. For example, the microbiomes of most Americans are half as diverse as those of hunter-gatherers in isolated Amazonian villages. The discrepancy is blamed on a raft of factors, from antibiotics and chlorinated water to antiseptics and caesarean sections.

But Dominguez Bello said traditional communities are steadily losing their richly diverse microbiomes as they increasingly come into contact with the wider world. “Every time we go back to the villages they integrate more and more,” she said. “Their first contact is typically with doctors so they start taking antibiotics, which we think are part of the equation.”

Dominguez Bello and her colleagues argue that the progressive decline in gut microbiome diversity may play a role in a host of modern diseases, from obesity, asthma and diabetes to inflammatory bowel disease, autism and food allergies. “We believe that changes in the human microbiota occurring concomitantly with industrialisation may be an underlying factor,” they write.

Analyses of microbes found in human intestines suggest that specific groups of bugs are being lost, including a variety called Oxalobacter formigenes. This bacterium breaks down indigestible oxalic acid, and its loss could make people more susceptible to kidney stones, which are calcium oxalate deposits.

“This is just the beginning of our knowledge about the impacts of living in an industrialised world,” the scientists write. “We need to better understand which strains in human populations are diminishing and what the functional and pathological implications are for these losses.”

Under the plans, universities and other organisations that hold collections of gut microbes would deposit samples in the vault for safekeeping. Access to the bugs would be only through the depositing organisation.

John Cryan, a leading microbiome researcher at University College Cork, said there was a “compelling case for creating a microbiome repository”.

“It is clear,” he said, “that through industrialisation, climate change and lifestyle changes we have lost and are continuing to lose many of the microbes that our ancestors had. It will take many years, if not generations, to fully determine the complex interactions between specific bacteria and humans and the extent to which these missing microbes impact our health.

“This is an altruistic call to arms to enable future generations to understand how the way we live affected our microbes. Any such repository will need to be supported by large scale metadata regarding the genetic makeup, diet, health and social environment of the donor.”

Source: The Guardian