- André Biernath – @andre_biernath
- BBC News, Brasilia and London
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The gut microbiota is made up of over 100 trillion bacteria and other microscopic creatures.
Different species of bacteria are threatened with extinction – and the best way to preserve them is to deposit samples of faeces 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…
In the future, this initiative, which brings together universities from several regions of the world, could also lead to new treatments for various chronic non-communicable diseases, such as obesity and asthma.
But what is the importance of the creation of this bank? And what is behind this widespread disappearance of bacteria in the world?
To read also on BBC Africa:
A silent extinction
Known as the Microbiota Vault, the project, which is in its pilot phase, was inspired by a similar initiative: a bank of more than 1.1 million seed types from around the world, deposited in Svalbard, a archipelago belonging to Norway.
The aim of the seed bank is to store these materials in a safe place – and thus have a reserve guaranteeing the food supply in the future, if these species were to disappear from nature for any reason, which would jeopardize the food security of one or more peoples.
The same principle applies to the vault of bacteria. Microbiologist Maria Gloria Dominguez-Bello, who leads the international initiative, told the BBC that the diversity of these microscopic beings has declined dramatically over the past few decades.
Photo credit, Disclosure
On its official website, the authors of the initiative talk about creating a “safe for humanity”.
By studying the indigenous peoples of the Amazon, she found that the variety of bacteria they carried in their gut was almost double that detected in an individual from the United States living in a large city.
“And when we delved into that, villages that started to have health service contact and antibiotics also experienced a loss of bacterial diversity very quickly,” describes the microbiologist, a professor at Rutgers University. , in the USA.
It should be remembered here that the intestinal microbiota is a complex system of microorganisms that we transport in the digestive system. More recent estimates indicate that it is made up of 100 trillion living things, which are fundamental to our health.
This veritable microscopic city inside our bellies is made up of various species 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 linked to a series 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 to collaborate with 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 in us and also in nature,” he warns.
“This is a serious problem, which manifests itself 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?
The comfort 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.
“From that time on, we were able to refrigerate and preserve food better and make it available in large quantities. Meats, for example, became cheap, accessible and easy to store at home,” he explains. .
“On the one hand, this means more security for a large part of the population. On the other hand, it has profoundly changed our eating habits,” he adds.
And these dietary changes have been further accentuated in recent decades, with the greater availability of processed, ultra-processed or low-nutrition foods.
“Over the past 20 years, Brazilians have drastically decreased their consumption of beans, which used to be one of the country’s staple foods and one of the main sources of fiber in the diet,” Hoffmann recalls.
Fiber is essential to our health. Some of them serve as food for the bacteria that make up the intestinal microbiota. In balance, these microscopic beings help us take advantage of the nutrients in food.
The other part of the fibers is essential to form a faecal bolus of good consistency, capable of crossing the intestine and being expelled through the anus without great difficulty.
Academics point to a second reason behind the silent extinction of microbes: the advent of antibiotics.
This class of drugs is essential for fighting bacterial infections – it has saved millions of lives since its discovery in 1928 – but its effect on the microbiota can be harmful.
Indeed, antibiotics work like a bomb: they kill all types of bacteria, whether they are harmful (like the ones that cause the infection) or beneficial (like the species that inhabit the intestine and make us aid in digestion).
In other words, when we take one of these drugs, we cause an imbalance in the microbiota. The death of “good” bacteria decreases diversity and can allow “bad” microorganisms to take over.
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Antibiotics treat bacterial infections, but also kill microorganisms essential to health.
The third factor behind this phenomenon is the increase in cesarean deliveries. Indeed, when the baby passes through the vaginal canal during normal or natural childbirth, it “absorbs” many bacteria from the mother’s body. This set will be used to form the microbiota of the newborn from that moment on.
This does not happen in caesarean sections, during which the baby is born from a cut in the uterus and has practically no contact with the woman’s microorganisms.
None of these three elements is inherently bad. Industrialization allows people to have better access to food. Antibiotics treat bacterial infections that are potentially fatal. Caesarean section represents a safe alternative for childbirth in cases where there is a risk for the woman or the baby.
All of these, however, have a side effect on bacterial diversity, and this impact is greater in wealthy, highly industrialized countries, where access to many of these amenities is easier than in rural or remote communities.
“To top it off, we are destroying ecosystems. And the fundamental unit of any environment is the bacterium. So the extinction of our gut microbiota is happening in the soil, in the water, and throughout the natural environment,” adds Dominguez-Bello. She is also part of the documentary “The Invisible Extinction”, which deals with precisely this question.
But what are the repercussions of microbial extinction on our health?
Dominguez-Bello asserts that there are two types of evidence for the impact of the silent extinction of microbes on the human organism.
“The first of these comes from epidemiology. The data show a significant association between being born by caesarean section or having used antibiotics and a higher incidence of certain diseases, such as asthma”, she says.
The microbiologist adds that the studies establish links, but do not determine a cause and effect relationship. In other words, these studies do not yet allow us to fully understand how one thing (antibiotics or cesarean section) 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 grow larger and more obese throughout their lives,” explains Maria Gloria Dominguez-Bello.
This preliminary research also shows that transplanting the microbiota of a healthy animal into one that is sick can also work as a kind of treatment – and improve chronic and inflammatory conditions, including obesity, diabetes and asthma.
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The profile of bacteria present in the gut can influence the onset of a number of diseases.
For Hoffmann, all these observations only reinforce the dependence between bacteria and other living beings (like us).
“Life on the planet depends on this balance and this joint development of different organisms. Bacteria depend on us and we depend on them,” he explains.
A threat to our own species
Although scientists agree on the importance of the microbiota, there is a whole microscopic universe to explore. After all, we still do not know the function of each species, what it means for our health and what it may represent as an opportunity 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 are up to, it represents a lost chance to address current and future issues (like the rise in chronic and inflammatory diseases, for example).
And this is exactly where Microbiota Vault comes in: the proposal is to keep samples of various species of microorganisms in a safe place.
Initially, the initiative revolves around two main axes. First, the collection of human faeces from different parts of the world. This is a simple method to obtain part of the intestinal microbiota.
Second, store foods fermented by different types of bacteria, such as cheese and yogurt.
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Bacteria are also essential for the production of certain foods, such as cheese.
“Our goal is to encourage researchers of different nationalities to create their own collections, which will be stored in their country of origin,” explains Dominguez-Bello.
“From there, they can also send some of these samples to the Microbiota Vault, which will serve as a backup. They will be kept free of charge under two conditions. First, that only the responsible scientist can access this content. Second, that we will be authorized to perform genetic sequencing of this species, and that this information will be freely available to the public,” she added.
Initially, the vault will be located in Switzerland – but due to recent instabilities related to the Covid-19 pandemic and the war in Ukraine, project officials are also exploring other options, such as keeping more copies in other territories, such as Greenland or Argentine Patagonia.
Hoffmann believes it’s time to do something about the extinction of microbes…
“For me, the vault represents hope for the future health of humanity and the planet itself,” concludes Dominguez-Bello.