How probiotics

On television, in print, in the supermarket, pharmacy ... probiotics and their potential health utilities are everywhere. The possibility of improving the body through the diet is one of the topics of the moment. However, there is still much that remains unknown about the so-called 'functional foods'.

A study published in the journal 'Science Traslational Medicine, sheds some light on the subject to clarify how they behave, at least probiotic fermented milk products, when in contact with the intestinal flora.

According to data obtained from studies in healthy humans and mice, eat yogurt with probiotics does not cause changes in species or type of microorganisms that colonize the intestine. However, these bacteria 'added' they can change the 'behavior' of the existing flora, ie are able to cause metabolic changes that influence, for example, how our body metabolizes carbohydrates.

"At first glance it may seem disappointing that probiotic bacteria are unable to colonize the gut, but what this study shows is that although the plant does not change, it takes on properties and biochemical characteristics of microorganisms that have been ingested " he told ELMUNDO.es Francisco Perez Jimenez, a specialist at the University Hospital Reina Sofia, Cordoba and researcher at the Center for Biomedical Research Network of the Pathophysiology of Obesity and Nutrition (CIBERobn).

"Until now we knew that in people with bowel disease, probiotics could improve symptoms, but did not know what the effect on healthy people," says Pérez Jiménez. "This study shows that generate modules, but can not jump to conclusions. We do not know if those changes are beneficial so the reality is that need further investigation , "he adds.

For the specialist, rather than by their findings, this study is key for its comprehensive methodology of research.

The researchers, led by Nathan McNulty of the University of Washington (USA), conducted a parallel investigation in humans and animals, according to Perez Jimenez, could mark a before and after in this field of research.

This is because the study analyzed the intestinal flora of seven pairs of twins before, during and after eating a specific yogurt and has also studied the effect of the probiotic in animal sample prepared to imitate the 'environment' of human intestine . Thus, the researchers used mice bred so that only bacteria that carry their intestines were 15 species that usually make up our intestinal flora.

"The methodological approach to study changes in the intestinal flora is very comprehensive and I think that is going to demand that from now on this type of study," says Pérez Jiménez.

The way to get scientific evidence to support the weight of a functional food use has focused for some time, a major debate in the scientific community and industry as the European Food Safety Authority (EFSA) has indicated that no case may advertise products using as bait the health effects that have not been convincingly demonstrated.