Science & Nature
May 1, 2017
I, THE COLECTIVE BEING
Have you ever stopped to think that you are not one, but many? I am not referring only to the historical legacy, what you have assimilated from your parents, genes, tics, ways of speaking, etc. I am referring to the number of organisms that make you what you are, in which your life depends on and, even, make the way you live it.
They are billions, they are more than your cells and they give you capabilities you would not have without them. They live in and within you. I'm talking about your bacteria. Or is it you who is theirs?
When in 1673 Van Leeuwenhoek, with his newly invented microscope, discovered what he called animalcules, the microorganisms we now commonly call bacteria, he was far from aware of the full impact that this discovery would have. At the time the origin of the diseases was not attributed to them immediately. Also the idea of their use was not immediate, although man had already been using them for many thousands of years without knowing it.
It is only in 1859, that Louis Pasteur reveals the role of bacteria in fermentation and, later, together with Robert Koch (who would give his name to the bacillus responsible for Tuberculosis) create the microbial disease theory.
Although the discovery that, bacteria also played a beneficial role in the fermentation of milk to obtain cheese, wine, vinegar or beer, it was like villains that they came to be seen.
In fact, the lack of capacity to control this "invisible enemy" was responsible for many deaths from Tuberculosis, Tetanus, Cholera, Syphilis, Pneumonia, among others. It is only in 1928, after several years of research because of the number of deaths, by infections, among the soldiers of the First World War, that Alexander Fleming discovers, it is said that by chance, penicillin. Various antibiotics, the "atomic bombs" of bacteria, were then developed.
From villains to allies
Although there have been promising indications, since 191,7 for the beneficial use of bacteria, not only in fermentation but also in the production of, for instance, acetone; the so-called biotechnology was only used in food processing - fermentation and soil enrichment; and it is only with the genetic modification of bacteria that begins the great revolution of biotechnology. First, in 1978 with the experience of Herbert Boyer, in the production of human insulin by the bacterium Escherichia Coli and, later, in 1980, with the decision of the US Supreme Court to assign a patent to a genetically modified bacterium (in this case to decompose crude), used, for example, in spills. This decision ended up opening the economic viability of private investments in the biotechnology industry in general and in the investigation of biodegradants for pollution in particular - bioremediation.
After the aseptic "fundamentalism" of the late 1990s and the beginning of the new millennium, the scientific community was developing studies that demonstrated, on the one hand, the essential role of bacterial in human health and, on the other hand, health and Human being as a result of a whole system of balance, not only with the external environment, but also with the interaction with the bacteria that live in us and on which depends the quality of our health and our own life.
The collective Self
Based on what was already known about the intestinal flora, that is, the role of the bacterial community in regulating the functioning of the intestine and how the alteration of its balance through food can cause diarrhea or constipation, investigations extended to other organs.
These have revealed different bacterial communities in the mouth, esophagus and stomach, as well as in other systems such as the respiratory, nose, pharynx and lungs, and the skin. This characterization eventually resulted in what was called a human microbiome and revealed surprising information such as the existence of more bacteria in our bodies than cells, in a ratio of 1 to 10, distributed by about a thousand different species. Or how it is possible to determine from our "bacterial landscape" our eating habits, sex, age, location, and even if we have children, dog or cat. It is a kind of bacterial fingerprint with the difference that it changes with age and with our habits and environment.
The effect is reciprocal and, just as our behaviors affect them by altering the balance of their environment, so the quantity and type of bacteria we end up affects our health such as, for instance, a greater or lesser propensity to be sick or even for obesity.
This cooperative evolution allowed us to dispense some organic functions that are performed by bacteria, such as the synthesis of some vitamins and the production of enzymes that accelerate the digestion of nutrients. And it can be much deeper than one might assume, as the studies on mitochondria show (see box).
The immune system is another benefit of this "close friendship". Bacteria not only serve to stimulate and "fine-tune" our immune system, which eventually "perceives and distinguishes" the good and bad bacteria, but also in what quantities and where they are dangerous. In addition, "good" bacteria turn out to be the first line of defense, since any other organism who tries to infiltrate the body will first have to compete for space and nutrients with those already there.
In the course of our life we are going through different levels of interaction with the environment which reflect in our microbiome. Investigations have revealed that the fetus is completely devoid of bacteria, but the moment of birth is crucial to establishing the microbiome, in what is called bacterial colonization.
It has recently been found that the difference in the type of delivery (natural or cesarean) results in babies with a greater or lesser propensity for respiratory and intestinal diseases, since the passage and contact with the vaginal canal of the mother initiates, with beneficial effects, precisely colonization in the respiratory tract and in the digestive system of the baby. In contrast, caesarean-born infants were initially colonized with bacteria from their mother's skin.
Nowadays in many hospitals, in cesarean deliveries, is practiced what is called the culture of the microbioma, that is, the collection of the mother's bacteria that are then placed in the baby.
From this general perspective, we turn to the current challenges that are being explored by the investigations such as, for example, to perceive the exact variation of each bacterial community according to the changes of habits, or the total importance and function they play in each environment of the body where they develop. This is the origin of a major project called the Human Microbiome Project that brings together university and research centres collaborations around the world and has given many results to the level of knowledge of this new human being. Also a whole new potential has opened up on the industrial and commercial level with new types of medicines and probiotic and prebiotic feeding that "cultivate" or help develop "bacterial communities".