About intestinal microflora, probiotics and dysbiosis
Alexey Yakovlev aka Russian doctor in the tropics specially for RIA NovostiPart 1. Intestinal flora and what it is eaten with
Advertising is the art of making a whole lie out of a half–truth.
There is a lot of bitter truth hidden in this famous aphorism of Edgar Shoaff, especially for us doctors. Almost a quarter of all commercials and posters in Russia are devoted to hygiene products, dietary supplements and medicines, most of which in fact does not cure anything. In recent years, all kinds of yogurts and bacterial preparations designed to eliminate the mystical "dysbiosis", correct our upset digestion and strengthen the immune system have not come off the TV screens. Alas, all these advertising promises do not pull even half-truths.
The human intestinal flora is exceptionally diverse. About 300-500 species of bacteria live in the intestines of each of us, and the total number of their cells is 10 times greater than the number of our own. Our joint evolution has led to the emergence of complex symbiotic relationships: bacteria control the growth and function of the intestinal epithelium, supply us with energy, vitamins and other substances, modulate our immunity, displace pathogens, and in return receive optimal habitat and food. Our body is a wonderful incubator for several hundred grams of bacteria. And this whole intestinal microcosm is a very labile system, sensitive to invasions of microbes from the outside, to antibiotics and, to a very small extent, to what we eat. Fortunately, thanks to the constant excretion of feces, which consist of 60-70% bacteria, as well as the ability of bacteria to quickly divide and replenish the population, the intestinal microflora quickly recovers as soon as the destabilizing factor is eliminated.
The idea that the normal intestinal flora can be displaced by a pathogenic infection is incorrect. Equally false are the claims about the ability of specially grown beneficial crops (in the form of probiotics, that is, drugs or products containing live bacteria) to colonize our intestines. In both cases, if the alien bacteria overcome the barrier of gastric and pancreatic juices and end up in the large intestine, they can only become transit guests.
This is explained by the fact that the mutual adaptation of our intestines and its flora occurs immediately after birth. The first bacterial settlers modulate the expression of intestinal epithelial genes in such a way as to form living conditions for themselves, and the ecosystem created in this way becomes unsuitable for colonization by bacteria entering the intestine in the future. Even if the intestinal flora is exposed to the most powerful antibiotics, after stopping taking the drug, it independently recovers in the same composition. No sticks of yoghurts and bifidobacteria of probiotics will take root, but they will inevitably be replaced by the very pioneer flora that settled in us from the first days of life.
However, all of the above does not mean that probiotics are completely useless. There is a certain benefit from them, it just gets too inflated and becomes overgrown with myths thanks to the active advertising of manufacturers.
The proven positive effects of probiotics are much more modest than we can learn from advertising. Of these , the following can be distinguished:
– Some probiotics have proven themselves well in the treatment of acute diarrhea, mainly in cases of rotavirus infection occurring in children.
– Probiotics can slightly accelerate recovery with the development of diarrhea associated with taking antibiotics.
– Feeding weakened and frequently hospitalized children with milk mixtures with probiotics has demonstrated a decrease in their cases of diarrhea.
– Yogurt bacteria secrete microbial lactase into the fermented milk product – an enzyme that breaks down milk sugar. It is milk sugar that leads to digestive disorders in people who lose their own enzyme with age (which is completely normal). There are a lot of such people: 5-15% in Europe and the North. America and 50-100% in Africa, Asia and South America. For many of them, the "live" yogurt containing the enzyme becomes the only available fermented milk product.
This, perhaps, exhausts the list of proven positive effects of probiotics.
A large study published in 2009 in the professional medical journal The Lancet showed that a probiotic with lactic acid bacteria did not improve the condition of children with severe nutritional deficiency (in other words, malnutrition). At the same time, the children of Malawi were studied, whose diet is really catastrophically poor and unbalanced. In this case, how can such drugs help our children?
Temporary colonization of the intestine by probiotic bacteria can last no more than 2-3 weeks. A number of studies have demonstrated that during this period the phagocytic activity of circulating leukocytes increases moderately. Based on these data, the assumption is based that probiotics are able to activate the immune response both in the intestine itself and throughout the human body. However, this assumption has not yet been confirmed.
A number of theories have been put forward about the ability of probiotics to prevent the development of intestinal cancer. But even here there is no convincing evidence yet.
In any case, it is a priori clear that the effect on the immunity of our own microflora is always an order of magnitude greater than the effect of probiotic bacteria. Firstly, the aliens do not do anything that our own flora is not capable of (they were originally obtained from the intestines of people like us). Secondly, the mass of bacteria in a dose of probiotic is a drop in the ocean compared to the hordes of microorganisms inhabiting our intestines, and even long courses of antibiotics, as a rule, do not change this ratio.
Thus, the commercial interests of pharmaceutical and dairy companies should not obscure our minds.
Carefully designed clinical trials are required to substantiate the benefits of probiotics and prebiotics (substances that are not digested by humans, but are food for a number of bacteria).
In the meantime, even the proven effects of the above are insignificant for our lives. No matter how delicious and nutritious yogurts are, they are unlikely to be able to modulate our immunity, as it is demonstrated in advertising, where even the Latin "immuno-" sounds in the product names.
However, like any other fermented milk product, yogurt is a valuable addition to our diet, and live yogurt is always fresher than pasteurized, in which, moreover, preservatives and stabilizers are often added.
In general, it is necessary to take care of the intestinal flora, but not by fruitless attempts to supplement it with alien bacteria, but with the help of a balanced diet – after all, our flora feeds on what we eat ourselves. And although I have already made a reservation that the diet affects the qualitative and quantitative composition of our microflora only very insignificantly, eating a sufficient amount of plant food is the best way you can maintain a healthy balance of your intestinal flora. If your diet is poor in vegetables, fruits and grains, eat a few dried fruits a day and replace the sliced loaf with coarse bread.
Part 2. Dysbiosis – the myth of Russian medicineIn my previous note, I touched on the topic of intestinal microflora.
In Russia, it sounds especially loud, because not only manufacturers of fermented dairy products and probiotic drugs, but also practitioners continue to speculate on it. The favorite Russian diagnosis-the myth of "dysbiosis" (according to the latest fashion, "dysbiosis") remains practically indestructible.
Nowhere in developed countries does such a disease simply exist. Neither the bourgeoisie nor their brethren from poorer countries want to suffer and be treated for it. There is no such thing in the international classification of diseases (ICD-10), according to which diagnoses should be made in Russia. There is no mention of "dysbiosis" in the regulatory document of the Ministry of Health of the Russian Federation "Standards (protocols) for the diagnosis and treatment of diseases of the digestive system", which should guide all our doctors.
Nevertheless, as a tribute to the dense Soviet traditions, "dysbiosis" continues to fly off the tongue of many practitioners, especially pediatricians. As before, the standards of medical examinations of babies include testing feces for "dysbiosis". At the same time, it has long been known that looking for a correlation between the composition of flora in feces and its real ratio in the crypts of the intestine is like guessing on coffee grounds. Firstly, the basis of the intestinal flora is made up of bacteroids that do not grow on nutrient media. Secondly, the ratio of bacteria at the outlet has very little to do with what lives in the gut. Thirdly, all the time while you collect and carry your priceless feces to the laboratory, life in them does not stop, and after a few hours the entire flora and fauna of feces radically changes. Therefore, all the conclusions about the "predominance of pathogenic flora over normal" in such an analysis are simply ridiculous.
In general, we all need to understand that there is no such independent disease as dysbiosis in nature.
There are only a number of temporary conditions of the body (the same viral diarrhea or prolonged antibiotic therapy), which can lead to a temporary imbalance of the normal flora. At the same time, this imbalance, as a rule, is not qualitative, but quantitative. As an example, I can cite the excessive growth of the bacterium Clostridium difficile with the development of pseudomembranous colitis against the background of long-term antibiotic therapy.
Most often, abdominal discomfort is caused not by mythical diseases, but by a completely real rebellion of the body against any cola and other junk. If your child's stomach does not stop the "noise and din", first of all look at what he eats from you.
In adults, "dysbiosis" often hides irritable bowel syndrome, the syndrome of excessive bacterial growth in the small intestine, lactase deficiency, as well as other undiagnosed conditions in which the balance of the intestinal flora is disturbed. These disorders should be treated by acting on the cause of such an imbalance, and not the imbalance itself, which is only a consequence.
Various manufacturers of fermented dairy foods, probiotics (preparations with live bacterial cultures) and prebiotics (substances that are not digested by humans, but are food for a number of bacteria) actively parasitize on the topic of dysbiosis.
As I explained above, probiotic bacteria can only become transit colonists, whereas the purpose of all therapeutic measures is to restore the balance of their own microflora.
Among the numerous drugs for the correction of dysbiosis, I want to highlight a particularly absurd class of drugs – bacteriophages. Bacteriophages are viruses that infect bacteria. Once scientists suggested using them against staphylococci, E. coli and other causative agents of diarrhea. However, studies have shown that bacteriophages are completely destroyed in the stomach, and such drugs have long been abandoned around the world. More precisely, all over the world, except Russia – these pseudo-medicines are popular with us to this day, and especially ineffective drugs treat non-existent dysbiosis.
If your doctor confidently declares that your microflora is unbalanced, and you are already "suffering from dysbiosis", do not panic! Try to find a competent specialist who will not juggle non-existent diagnoses and prescribe fuflomycins, but will deal with conventional diagnostics that will distinguish infectious or organic pathology of the intestinal tract from physiological and psychosomatic disorders. And do not rush to splurge in pharmacies! It is better to save money on proper nutrition for yourself and your children, "feed" the microflora in a natural way – with healthy food. Vegetable fibers of vegetables, fruits and grains are the best support for intestinal bacteria!
Interestingly, each animal species has its own intestinal microflora. Moreover, within each population of one species, their own strains of bacteria circulate.
If a bacterium from the intestines of another mammal or bird (for example, chicken salmonella) gets into our intestines with food, we will develop gastroenteritis. Not so long ago, the media amicably scolded American chicken for salmonella found in the hams. The scandal around the "Bush legs" was inflated worse than mad cow disease! However, for some reason they did not explain to the people that salmonella is a normal component of the intestinal flora of any chicken, even "state", even ours. If you make flushes from Russian chicken, salmonella is sown in the same way. And there are especially a lot of salmonella on the eggshell, which is inevitably smeared with droppings, since eggs are laid through the cloaca. Here is the clearest example of manipulation of the consciousness of citizens: it is necessary to support domestic poultry farms (and the real motives were much more unsightly) – we will intimidate the consumer with stupid information.
Even if a completely human bacterium penetrates into our body, but characteristic of another population, diarrhea cannot be avoided. That is why when traveling after 7-10 days, we inevitably weaken, and some develop real diarrhea, and this is not "dysbiosis" at all. This phenomenon is called traveler's diarrhea, which is most often caused by various strains of E. coli, quite normal for the flora of other populations, but alien to our intestines. Fortunately, in people with good activity of gastric juice and pancreatic enzymes, "aliens" slip into the colon much less often. If you are traveling far away for just a week or two, try to be careful: wash your hands after using public toilets and before eating, eat only freshly cooked heat-treated food, and wash and peel fresh fruits and vegetables thoroughly. In addition to E. coli, viruses play an important role in travelers' diarrhea, and in addition, it can be elementary from the abundance of fiber of exotic fruits, which we, once in the tropics, begin to absorb immoderately.
In some cases, even your own intestinal bacteria can cause a lot of suffering. So, E. coli, less often other inhabitants of our own intestines, once they penetrate into other organs, cause cystitis and pyelonephritis in women and prostatitis in men. But this is a completely different topic.
Be healthy!
Portal "Eternal youth" http://vechnayamolodost.ru28.02.2011