The Internet is full of a variety of advertisements of so-called probiotics - supplements, which are said to "strengthen" intestinal bacteria and make the digestive system, and with it the whole body, more healthy. But is a healthy person really needed these probiotic supplements? A new research of scientists from Denmark puts this opinion in doubt.
"Many adult healthy people take them because they think they are healthy, but there is no evidence of any effect on their use," says Oluf Pedersen, a professor of medicine at the University of Copenhagen, noting that there is a significant difference between scientific evidence and flamboyant advertising products.
Recall that probiotics are living bacteria that, as specialists explain, are similar to "useful" microorganisms in the human intestine. Such bacteria inhabit some foods, for example, yogurt. They are also sold as a food supplement.
According to Danish scientists, despite the fact that probiotics are considered effective in the treatment or alleviation of symptoms of certain diseases of the gastrointestinal tract, the effect on the body of a healthy person has been practically studied.
However, many healthy people even without obvious evidence of the effectiveness of probiotics began to use them. Probably, inspired by promises of advertising about a healthy intestine, and consequently, a healthy body.
It is not necessary that such a trend is contrived. It is entirely permissible assumption that apparently healthy people can strengthen their intestines by adding "useful" bacteria to their food. But the truth can be somewhat more complicated.
Scientists from the University of Copenhagen conducted a systematic review of seven clinical trials in order to find out whether probiotics really have a positive effect on the body of healthy people. Each study, in turn, analyzed the short-term effect of probiotics on the fecal microbiota of a healthy person.
All studies consisted of a small sample in the range of 21 to 81 people, the age of participants ranged from 19 to 88 years. None of the subjects had gastrointestinal disorders. In addition, they did not take any other form of supplementation.
Within a few weeks, scientists analyzed the intestines of two groups: one took probiotics (in the form of cookies, milk drinks or capsules), the other did not take anything. It turned out that most of the people taking probiotics did not experience any significant changes in the community of intestinal bacteria. Of the seven studies that Danish scientists analyzed, only one provided evidence of significant changes.
"According to our systematic review, there is no conclusive evidence of the consistent effect of the probiotic probes on the composition of the fecal microflora in healthy humans, despite the significant use of probiotic products," concludes Nadja Buus Kristensen, one of the authors of the study.
Meanwhile, only in 2013-2014, world sales of these additives increased by 14 percent. Probably, the researchers, voluntarily or unwittingly, contributed to the growth of this "additional" industry. Scientific works on the potential benefits of a variety of food additives are published almost daily.
And although it is customary to think that a small capsule with prebiotics can improve the human body, it is only a hypothesis that has not yet been confirmed by science. Researchers from Denmark hope that after the publication of their work, people will be more attentive to this statement.
"There is some evidence that the use of probiotics can benefit those who suffer from an imbalance in the intestinal microflora, but there is little evidence of the same effect on the body of a healthy person," concludes Pedersen.
However, in his opinion, it is also necessary to pay attention to studies of the potential of probiotics, which contributes to the prevention of diseases in a healthy person.
The study is published in the scientific publication Genome Medicine.