The intestinal microenvironment
Our digestive system, and especially the intestine, is colonized by many microorganisms that together constitute the bacterial flora.
If the various folds, villi, microvilli and crypts are leveled, the surface of the intestinal mucosa is approximately 200 m2.
In addition to the bacterial flora, mycetes contain mycetes, clostridia and viruses, which do not exert any pathogenic effect under equilibrium conditions.
During pregnancy the fetus's intestine is perfectly sterile, but soon after birth it is colonized by billions of bacteria. These microorganisms settle in the intestine, entering from the outside through the mouth and anus. The first months of life are very important to build a healthy and balanced bacterial population. In fact, breast milk favors the proliferation of bifidobacteria, a strain that is particularly beneficial for human health.
Under normal conditions, the bacterial flora is in perfect symbiosis with the organism. Let us remember, for those who do not know, that by symbiosis (from the Greek: life together) we mean a particular relationship of coexistence between two organisms, from which both derive their own benefit.
In the symbiotic relationship between the human organism and the intestinal flora, the (host) man supplies undigested material for the maintenance of the bacteria. On the other hand these microorganisms (symbionts) perform various functions useful to man.
When the bacterial flora and the organism live in perfect harmony, we speak of eubiosis.
Functions
What are the functions of intestinal bacterial flora?
TROFIC FUNCTION (nourishment):
The bacterial flora guarantees the integrity of the intestinal mucosa.
The bacteria present in our intestine ferment the undigested material, generally consisting of polysaccharides of vegetable origin. Following this fermentation, the bacterial flora produces short-chain fatty acids, such as acetic, propionic and butyric acid. These molecules are very important for our well-being, as they represent an energy source for the epithelial cells of the intestine. It also appears that butyric acid protects against colon cancer.
PROTECTIVE FUNCTION AGAINST THE INVASION OF PATHOGENIC BACTERIA
the bacterial flora enhances the barrier effect of the intestinal mucosa, thanks to the trophic function mentioned above.
The symbiont bacterial population also produces antimicrobial substances, thanks to which it prevents the adhesion of pathogens to the intestinal epithelium. This effect is enhanced by the physical obstacle that the "friendly" microflora exerts by occupying the possible sites of adhesion to the walls of the intestine.
Finally, the bacterial flora modulates components of the intestinal immune system with a pro-inflammatory action.
ADDITIONAL FUNCTIONS
- promotes digestive processes and absorption, keeping the intestinal mucosa healthy and effective.
- Prevents disorders such as colitis, diarrhea, constipation.
- It produces some vitamins, primarily vitamin B12 and vitamin K.
- It produces some amino acids (arginine, glutamine, cysteine)
- Intervenes in the metabolism of bile acids and bilirubin.
Changes in intestinal flora
When the number of beneficial bacteria decreases, the balance of the bacterial microflora breaks and there is talk of dysbiosis. Under similar conditions there is a hyperproliferation of pathogens in the intestine. These microorganisms are particularly dangerous, as they are potentially capable of colonizing other body areas, causing, for example, vaginal, respiratory and even dental infections. Over time, intestinal diseases such as diverticula, Crohn's disease and tumors of the digestive system may also appear.
In the case of dysbiosis, an impairment of intestinal permeability may also occur, since the trophic function of the symbiont microflora fails. As a result, allergies and autoimmune diseases can develop. In fact, due to the altered permeability, certain molecules can be absorbed and recognized as foreign by the immune system, which reacts by triggering allergic reactions or real autoimmune diseases.
A further negative consequence of dysbiosis is the absorption of real toxic substances, harmful above all to the liver and pancreas. The consequence of these processes can be, at best, the appearance of digestive problems, but also and above all the onset of chronic fatigue not attributable to other causes.
Finally, dysbiosis increases the stasis time of fecal material in the intestine, causing alteration of various nutrients. For example, the alteration of amino acids can lead to the formation of toxic amines (lysine: cadaverine; ornithine: putrescine; tryptophan: indole and scatol).
Causes Disbiosis
What can be the causes of dysbiosis?
The causes of dysbiosis are really numerous:
- little diets with few fibers and many refined foods can contribute;
- too quick meals, little chewing.
- Irregular and frenetic rhythms of life, with changes in the frequency and consistency of the meals.
- Sedentary life and psychophysical stress.
- Drug abuse (analgesics, sleeping pills, antidepressants, laxatives), often used to research that sense of health and well-being that tends to escape due to the frenetic pace imposed by the modern lifestyle. However, with the passage of time, the frequent use of these chemical substances, which do not cure the cause but simply attenuate the symptoms, ends up worsening the situation further.
- Also the pollutants contained in foods (dyes, solvents, hormones, pesticides, etc.) negatively affect the stability of the intestinal microflora.
Strengthen the bacterial flora
How to improve the functionality of the bacterial flora?
In the presence of dysbiosis, the treatment of first choice involves the administration to the patient of probiotics (vital microorganisms capable of maintaining or improving the intestinal bacterial flora). In order to be able to speak of probiotics, and not of simple lactic ferments, these microorganisms must:
be alive and biochemically active; resist the action of gastric acid and bile; adhere to the intestinal epithelium; produce antimicrobial substances against pathogens; preserve their vitality within the digestive tract.
The second provision consists in the intake of prebiotics, that is substances that arrive undigested in the colon, where they are fermented by the local bacterial flora. The metabolites that are formed thus provide useful nutrients for the growth of beneficial bacterial species.
Prebiotics are contained, although in limited concentration, in various foods such as chicory, artichoke, leeks, asparagus, garlic, soy and oats. In pharmaceutical preparations containing these substances, the FOS (fruit-oligosaccharides) and inulin, a fructose polymer, are added.
Finally, to improve the vitality of our intestinal bacterial flora, it is essential to avoid as much as possible any source of stress and adopt a correct lifestyle, supported by a balanced diet.
