By freezing human feces to combat the loss of biodiversity? Such a project has started in Switzerland. This is not about the dramatic development in nature, where countless plant and animal species are disappearing: human biodiversity is also threatened.
“We have found that we are losing biodiversity in the intestine,” says medical microbiologist Adrian Egli from the University of Zurich to the German Press Agency. “There is much more diversity in the Amazon compared to the western population. This has to do with stress, antibiotics and also diet.”
Egli makes it clear what treasure everyone has within them with a comparison: “In one gram of stool there are a thousand billion bacteria, 125 times as many as there are people on the planet,” he says. “Incredible when you think about what lives inside you.” Between 300 and 500 different species occur in one person.
Safe like for plant seeds
In an international project, what can still be saved is now to be saved: with a huge vault for human feces, the “Microbiota Vault” – similar to the seed vault on Svalbard, where seeds from several varieties of food plants are stored. Bacteria can survive for decades in a special solution, as Egli says.
Research into intestinal flora is currently in its infancy. “It may be possible to develop therapies based on knowledge of the microbiome to positively influence obesity, diabetes, rheumatic diseases or chronic intestinal inflammation,” says Egli. The microbiome also includes fungi and viruses, but bacteria are particularly important because they have many significant metabolic properties.
Bacteria in glass plates
Zurich, Gloriastrasse, University of Zurich: In Adrian Egli’s laboratory, people in white coats work with all kinds of sterile tools and equipment. On the table are petri dishes, small transparent glass plates with contents. What lab manager Diana Albertos Torres is inspecting are bacteria she collected from stool samples.
To the untrained eye, only small dots can be seen on the red agar plate. Torres knows that it is probably Pseudomonas aeruginosa, a bacteria that causes, among other things, pneumonia. But there is no danger. “No, bacteria don’t jump out of the shell,” reassures Torres with a laugh. The laboratory works under the necessary safety precautions.
Microbiome influences diseases
Thanks to new machines and methods, it is now possible and affordable to genetically research intestinal bacteria. “There are new discoveries every week,” says Egli. “And all of humanity can benefit from the analysis of the bacteria.” For example, the microbiome is associated with diseases such as cancer and autoimmune diseases.
A special feature: Huge numbers of bacteria live in the digestive tract that cannot tolerate air, so-called anaerobic bacteria. They have not been studied much yet, as Egli explains. “There are certainly 1,000 times as many bacteria in the intestine that cannot tolerate air as those that we were able to isolate and know about.”
Helpful in the fight against cancer?
It is conceivable that one day the targeted use of bacteria could improve the response to cancer therapies, says Egli. Fecal transplants are a different field of medicine. “A stool sample with an optimal microbiome that is given to a sick person – studies have shown that this can contribute to recovery.”
The microbiologist Maria Gloria Dominguez-Bello, who comes from Venezuela and researches in the USA, has been campaigning for an intestinal bacteria safe for years. She was one of the first to determine how much bacterial diversity in humans differs depending on where they live and their living conditions, using samples from the Amazon region as an example.
Self-experiment in Africa
A few years ago, British epidemiologist Tim Spencer did an experiment: he spent three days with indigenous hunter-gatherers in Tanzania and shared their lifestyle and food, including baobab fruit casings and all kinds of meat. After just three days, the biodiversity in his intestines had increased by 20 percent, as he reported in the online journal “The Conversation.”
Why is diversity important? The intestinal bacteria can then, for example, prevent the colonization of pathogens that make people sick, a team led by microbiologist Frances Spragge from the University of Oxford just reported in the journal “Science”.
People themselves can contribute to a good microbiome. For example, a diet rich in fiber is important. This refers to largely indigestible plant-based food components. Among other things, they influence the satiety effect as well as how long ingested food remains in the stomach and intestines and how well nutrients are absorbed by the body.
Important: lots of fiber
A high fiber intake has protective effects on cardiovascular diseases, type 2 diabetes, obesity, high blood pressure as well as colon and breast cancer, according to the German Nutrition Society (DGE). Foods rich in fiber include legumes, nuts and seeds, whole grain products as well as vegetables and fruits such as artichokes, peppers and rhubarb.
Egli is working on the pilot team of the “Microbiota Vault” together with Pascale Vonaesch from the University of Lausanne and Nicholas Bokulich from the ETH University in Zurich. At Egli there are freezers in which around 2,500 stool samples have been frozen at minus 80 degrees, including from Ethiopia, Laos, Puerto Rico and Switzerland. It’s not easy: samples have to be frozen within hours to preserve the bacterial diversity. Dominquez-Bello flash-frozen samples using liquid nitrogen in remote Amazon regions. A continuous cold chain and a lot of paperwork are required for export to Switzerland.
Iceboxes will soon be full
According to Egli, the pilot project is almost complete, with largely positive results. Tens of thousands of samples from all over the world are expected to land in Zurich soon. To do this, a safe must be built for final storage, says Egli. The ice chests in his laboratory will soon no longer be enough.
