by Different species of bacteria are in danger of extinction — and the best way to preserve them is to deposit samples of feces and other biological materials from around the world in a large vault located in Switzerland.
This is the proposal of a group of scientists, who have already started working on this collection of microorganisms. The researchers argue that this effort is necessary to better understand the role that many of these living things play in our health.
In the future, the initiative, which brings together universities from different parts of the world, may also lead to new treatments for various non-communicable chronic diseases, such as obesity and asthma.
But what is the significance of creating this stool bank? And what is behind this widespread disappearance of bacteria around the world?
a silent disappearance
Known as the Microbiota Vault (“Microbiota Vault”, in free translation), the project, which is in a pilot phase, was inspired by another similar initiative: a bank of more than 1.1 million types of seeds from around the planet deposited in Svalbard, an archipelago belonging to Norway.
The goal of the seed bank is to store these materials in a safe place — and thus have a reserve that guarantees a food supply in the future, should these species disappear from the wild for some reason, which would endanger the food security of one or more people.
The same principle applies to the bacterial vault. Microbiologist Maria Gloria Dominguez-Bello, who leads the international initiative, explains to BBC News Brasil that the diversity of these tiny creatures has decreased dramatically in recent decades.
When he studied the indigenous people of the Amazon, he noticed that the variety of bacteria they carried in their guts was practically double that detected in a person from the United States living in a big city.
“And, when we looked deeper, the villages that started to have contact with the health services and started to receive antibiotics also suffered a loss of bacterial diversity very quickly,” describes the scientist, who is a professor at Rutgers University, in the United States. .
It is worth remembering here that the intestinal microflora is a complex system of microorganisms that we carry in the digestive system. More recent estimates indicate that it consists of 100 trillion living beings, which are fundamental to our health.
This veritable tiny city inside our belly is made up of many types of bacteria. What researchers have begun to detect in recent years is precisely the loss of this diversity: different types of microorganisms are gradually disappearing.
And, as you will see below, this loss is associated with a number of chronic diseases, which are becoming a growing problem, especially in urban environments in industrialized countries.
Microbiologist Christian Hoffmann, who is currently the only Brazilian representative working with the Microbiota Vault, explains that this disappearance of bacteria is not limited to our intestines.
“In the same way that we are losing plants and animals, we are also going through a process of extinction of the microorganisms that live inside us and in nature,” he warns.
“This is a serious problem, which appears very quickly,” adds the researcher, who is a professor at the School of Pharmaceutical Sciences at the University of São Paulo (USP).
But what is behind this disappearance of bacteria?
Amenities of modern life
Hoffmann explains that the process of microorganism extinction began with the Industrial Revolution, at the turn of the 18th and 19th centuries.
“Since then, we have been able to refrigerate and preserve food better and make it available in large quantities. Meat, for example, became cheap, accessible and easy to preserve at home,” he says.
“On the one hand, this represented more security for a large part of the population. On the other hand, it profoundly changed our eating habits,” he adds.
And these changes in diet have deepened even more in recent decades, with the greater availability of industrialized, highly processed, or low-nutrition foods.
“Over the past 20 years, Brazilians have significantly reduced their consumption of beans, which were one of the mainstays of the country’s diet and one of the main sources of dietary fiber,” Hoffmann recalls.
Fiber is essential for our health. A part of them serves as food for the bacteria that make up the intestinal microflora. In balance, these tiny creatures help us take advantage of the nutrients in our foods.
The other part of the fiber is necessary to form a stool cake with good consistency, able to pass through the intestine and be expelled through the anus without great difficulty.
Academics point to a second reason behind the silent disappearance of microbes: the advent of antibiotics.
This class of drugs is essential for fighting bacterial infections – and has saved millions of lives since its discovery in 1928 – but its effect on the microflora can be harmful.
That’s because antibiotics work like a pump: they kill every type of bacteria, whether they’re bad (like the ones that cause infection) or beneficial (like the kind that live in the gut and help us digest).
That is: when we take such a drug, we cause an imbalance in the microflora. The death of “good” bacteria reduces diversity and can make room for “bad” microorganisms to take over.
The third factor behind the phenomenon is the increase in cesarean deliveries. This is because when the baby passes through the birth canal during normal or natural childbirth, it “takes on” many of the bacteria from the mother’s body. This set will serve to form the microflora of the newborn from then on.
This does not happen in a caesarean section. In this sterile procedure, the baby is born through an incision in the uterus and has almost no contact with the woman’s micro-organisms.
None of these three elements is inherently bad. Industrialization allows people to have greater access to food. Antibiotics treat bacterial infections that are potentially fatal. Caesarean section represents a safe delivery alternative in cases where there is a risk to the woman or the baby.
All of this, however, has this negative effect on bacterial diversity—and this impact is greater in rich, highly industrialized countries, where access to many of these amenities is easier, compared to rural or remote communities.
“Plus, we’re destroying ecosystems. And the fundamental unit of any environment is bacteria. So this extinction that’s happening in our gut microbiota is happening in the soil, in the water, and throughout the natural environment,” he adds. Dominguez-Bello. The researcher also participates in the documentary “The Invisible Extinction”, which deals with exactly this topic.
But what are the effects of the disappearance of microbes on our health?
The rise of chronic diseases
Dominguez-Bello says there are two kinds of evidence about the impact of the silent disappearance of microbes on the human body.
“The first of these comes from epidemiology. The data show a significant association between cesarean birth or antibiotic use with a higher incidence of certain diseases, such as asthma,” he says.
The researcher believes that studies find connections, but do not establish a cause and effect relationship. In other words, these papers still don’t allow us to fully understand how one thing (antibiotics or C-sections) causes the other (diseases).
“The second piece of evidence comes from animal experiments. When you interfere with the microbiota of very young guinea pigs, they generally get bigger and fatter throughout their lives,” explains the microbiologist.
This preliminary research also suggests that transplanting microbiota from a healthy animal to a sick one might also work as a kind of therapy—and improve chronic and inflammatory conditions like obesity, diabetes, and asthma.
For Hoffmann, all these observations simply reinforce the dependence between bacteria and other living things (like ourselves).
“Life on the planet depends on this balance and the joint development of various organisms. Bacteria depend on us and we depend on them,” he explains.
Keep what we don’t know (yet).
Although there is consensus among scientists about the importance of microbiota, there is a whole microscopic universe to be explored—after all, we still don’t know the function of each of the species, what they mean for our health, and what opportunities they may represent for future treatments.
Therefore, the risk of extinction of these microorganisms is a threat to our own species. If they disappear from the map before we know what they’re doing, it represents a missed opportunity to address current and future problems (like the rise of chronic and inflammatory diseases, for example).
And that’s exactly where the Microbiota Vault comes in: the proposal is to keep samples of various kinds of microorganisms in a safe place.
In principle, the initiative has two main axes. First, the collection of human feces from various parts of the world. This is a simple method to obtain part of the intestinal microflora.
Second, stock foods that have been fermented by different types of bacteria, such as cheese and yogurt.
“Our goal is to encourage researchers of various nationalities to create their own collections, which will be kept in their countries of origin,” describes Dominguez-Bello.
“From there they will also be able to send some of these samples to the Microbiota Vault, which will serve as a backup. They will be kept free under two conditions. First, that only the responsible scientist can access this content. Second, that we will be authorized to access it, sequence this species and that information will be freely available to the public,” he adds.
Initially, the vault will be located in Switzerland – but, due to recent instabilities related to the Covid-19 pandemic and the war in Ukraine, those responsible for the project are also studying other options, such as keeping more copies in other regions, such as Greenland or Argentine Patagonia.
Hoffman thinks it’s time to do something about the disappearance of microbes. “If we delay, it will be too late,” he believes.
“For me, the vault represents hope for the future health of humanity and the planet itself,” concludes Dominguez-Bello.
– This text was published at https://www.bbc.com/portuguese/curiosidades-64457799
