Probiotic yogurts are beneficial, but their effect is lower

2012/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Osasuna
• Mikrobiologia
• Dietetika/Elikagaiak

In a recent study at the University of Washington, relevant information has been obtained on the influence of probiotic yoghurts.

The study, funded by the U.S. Institute of Health and the Danone company, aimed to check whether bacteria containing probiotic yoghurts affect the intestinal population of bacteria. In fact, it has been suggested that the bacteria of these yoghurts become part of the intestinal flora, which makes them beneficial for health. Furthermore, yogurt manufacturers have used this argument to extol their product.

However, the result of the research has probably not been as good as the producers and vendors of these yoghurts wanted. In fact, they have shown that yogurt bacteria do not influence the intestinal population.

To do this, they have carried out research with seven twins. One of the twins and the other not, have been provided with probiotic yogurts with five species of bacteria, twice a day for seven weeks. Samples of intestinal flora and feces have been taken before, during and after eating yoghurts and have observed that there is no change in the composition of the intestinal bacterial population. The research, directed by microbiologist Jeffrey Gordon of the University of Washington, has stated that this result "is not surprising", since the amount of bacteria that are supplied with yoghurts is a fragility compared to the one we have in the intestine.

However, researchers have investigated not only the twins, but also gnotobiotic mice. These mice are specially bred so that in their intestine only 15 species of bacteria that have humans. Well, in the intestine of gnotobia mice, the bacteria of yoghurts did not influence, but in the expression of some genes that encode important enzymes in the metabolism of carbohydrates.

Studying the urinary metabolites of mice, researchers have claimed that eating probiotic yoghurts alters metabolism. Therefore, it seems that probiotic yoghurts increase the expression of the genes of some enzymes, which improves the metabolism of carbohydrates.

The researchers themselves have recognized that there are few seven couples to draw definitive conclusions, but they have also stressed that gnotobiotic mice seem suitable for carrying out this type of research. The study was published in the journal Science Translational Medicine.