Imbalances in the intestinal microbiota contribute to inflammatory diseases of the large intestine. Interestingly, exercise can improve intestinal health, but in general, little is known about the underlying mechanisms involved.
A recent review published in this year 2017 has represented a conceptual model that illustrates the role of exercise in the diversification of the intestinal microbiota to improve intestinal and systemic health.
Clarifying some terms before continuing
So that some concepts do not sound “Chinese” during the article and we know what they mean or what they refer to, apart from being able to consult them if we forget them, we have previously defined them:
- Symbiosis : intimate association of organisms of different species to benefit each other in their life development.
- Dysbiosis : alterations of the intestinal microbiota and the adverse host response to these changes.
- Microbiome : set consisting of microorganisms, genes and metabolites of the human body (gastrointestinal tract, genitourinary tract, respiratory tract and skin).
- Hostess, guest, host : that organism that shelters another inside it or that carries it on itself, whether in a symbiosis of parasitism, commensalism or mutualism.
- B cells : type of white blood cell that makes antibodies. B cells are part of the immune system that are formed from stem cells in the bone marrow. It is also called B lymphocyte.
- Pathogen : any external biological agent that lodges in a determined biological entity, damaging in some way its anatomy, from diseases or visible damages or not.
- Tumor necrosis factor (TNF-α) : member of a group of cytokines that stimulate the acute phase of the inflammatory reaction.
- Lymphocytes : type of leukocyte or white blood cell that is present in the blood as part of the group of cells that make up the immune system, exercising defense functions of the body.
- Butyrate : energetic substrate of the colon epithelium that regulates multiple cellular processes, having been described as a possible therapeutic agent against colorectal cancer.
The human microbiome: microbes (microorganisms) are a fundamental part of our life
Human beings have 10 times more microbes in our body than cells . These living beings have coexisted with our body throughout evolution and are absolutely fundamental for human life and health.
Human beings live in symbiosis with groups of microbes in various parts of the body that go from the skin , the intestine, the oral cavity, the vagina and other areas exposed to the environment.
This community can weigh up to two kilograms and is composed of approximately 100 trillion microorganisms , including 1000 different species of known bacteria with more than three million genes.
These bacterial communities are primary components of the microbiome that encompasses the complete genetic potential of a bacterial population, as well as the products of the microbiota and the host environment.
The intestinal microbiota and its functions: the intestine is a key site
The intestinal microbiota is the community of living microorganisms residing in the digestive tract.
Simply put, the gut microbiota is the set of bacteria that lives habitually in the intestine of humans and many animals.
Most of this set of bacteria are not harmful to health, and many are beneficial by participating in numerous physiological processes , participating primarily in multiple functions of the body.
Moreover, the gut microbiota has gone from being considered a companion companion, to being considered a “metabolic organ” , with functions in nutrition , regulation of immunity and systemic inflammation .
The majority of the microbiota is lodged in the large intestine and is subjected to stages during the life cycle of the host, with the most dynamic time being that of childhood.
It is recognized that one third of our gut microbiota is common to most humans, while the other two thirds are specific to the individual .
One third of our gut microbiota is common to most humans, while the other two thirds are specific to the individual
As a result, the microbiota can provide a personal identity . However, then it becomes difficult to define a healthy microbiota.
Despite this, it is generally accepted that the characteristics of a healthy microbiota include the stability of the community and a greater diversity of species .
The balance in the intestine regulates the energy harvest of the diet , as well as the metabolism of microbial chemicals and guest derivatives.
The intestine also plays a key role in immune modulation because 70% of the cellular components of the entire immune system are found at this site.
Likewise, all parts of the intestinal immune system are influenced by the microbiota , from the maturation of B cells and the development of the immune system of the intestinal mucosa to the prevention of the intrusion of pathogens.
Factors that contribute to changes in the intestinal microbiota
Any disturbance in the microbiota can interrupt intestinal homeostasis . As such, the accumulation of evidence suggests that the imbalance between the abundance of beneficial and harmful organisms (dysbiosis) contributes to the development of chronic diseases such as obesity , type 2 diabetes , inflammatory bowel disease and cancer .
It is believed that the westernization of society, increased hygiene, changes in diet , reduced physical activity and increased use of antibiotics have contributed to changes in the intestinal microbiota.
Exercise increases and improves microbial diversity and reduces the amount of pathogenic bacteria, among other aspects
Alternatively, it has been shown that both diet and exercise appear to modulate the expression of key proteins involved in maintaining the integrity of the epithelial membrane through tight junctions, as well as being involved in the inflammatory state of the intestine.
Therefore, the most common contributor to microbial changes is human behavior, through diet and exercise.
As for exercise , it is known that exercise exerts a beneficial role in homeostasis and energy regulation , and recent evidence suggests that this may be through an increase in microbial diversity.
In turn, it has been shown that exercise can improve microbial diversity in the presence of a high-fat diet , preventing weight gain and improving body composition as indicated by the decrease in fat mass.
However, the effects of exercise are not limited to increasing diversity. It is also known that exercise reduces inflammatory mediators, increases antioxidant enzymes and decreases the expression of tumor necrosis factor (TNF-α) in intestinal lymphocytes.
In addition, exercise can prevent morphological changes in the intestinal villi , regulate firm binding proteins and increase butyrate production.
Exercise represents a cornerstone in the primary prevention of at least 35 chronic diseases .
During the last two decades considerable knowledge about the importance of exercise as the first-line treatment of several chronic diseases has accumulated .
Few environmental factors, outside of the diet, exert an influence on a variety of physiological factors as exercise does.
Exercise produces a more diverse microbiota and seems to reduce pathogenic bacteria communities
In turn, although most of the experimental questions have focused on how exercise influences the microbiota, it is interesting to note that the performance of the exercise is strongly influenced by the microbiota itself and, to a greater degree, by one that appears to be diverse. and free of pathogenic bacteria.
Yes, exercise produces a more diverse microbiota and seems to reduce communities of pathogenic bacteria , increasing good communities.
This represents a cycle through which exercise manifests a microbiota that improves the colonization of more health promoting bacteria , reduces the burden of pathogenic bacteria and improves exercise performance .
In addition, the greater diversity and decrease of pathogenic species also represents a microbiota that is associated with a reduced risk of obesity and type 2 diabetes , suggesting once again that another mechanism by which exercise reduces the risk of disease is through changes beneficial in the microbiota.
The accumulation of evidence seems to suggest that exercise can reduce inflammation of the bowel .
Exercise can reduce inflammation of the intestine
Studies have indicated that exercise can increase antioxidant enzymes, anti-inflammatory cytokines and antiapoptotic proteins (proteins that intervene by controlling the mechanisms of cell death with anti-cell death activity) in intestinal lymphocytes.
It has also been observed, as I mentioned earlier, that exercise decreases the tumor necrosis factor (TNF-α) and other proinflammatory cytokines , which supports that exercise can modulate the intestinal immune response.
Every time we know more, but it is necessary to continue investigating
The proposed conceptual model is a work in progress , and many mechanisms must be understood to establish firm connections between changes in the microbiome and physiological outcomes.
What is certain is that:
- Exercise increases microbial diversity regardless of diet.
- Alterations of the microbiota as a result of exercise are more substantial in the previous stages of life (especially in childhood) compared to the later stages of it.
- The exercise capacity can be influenced by the presence of a diverse microbiota .
- Diets high in fat increase intestinal inflammation, and exercise can reduce this inflammation and improve the integrity of the intestinal epithelium.
The power of exercise is incredible, and once again it shows that exercise is absolutely essential in our lives , that you do not have the slightest doubt.