In the opinion of Francisco Guarner, director of the Digestive area of the Vall d'Hebron Hospital, "we are in a particularly difficult moment due to the confusion that some gurus who offer global miracle diets continually introduce, and which are very dangerous". This is what he warned at the XI conference of update in Nutrition, organized by the University of Navarra.

According to the expert, one of the leading specialists in microbiota (microorganisms responsible for gastrointestinal health), diets with only raw foods, dairy-free diets, gluten-free diets, etc., "have not been subjected to serious tests that prove their benefits or that make them recommendable for everyone. "have not been subjected to serious programs of study to prove their benefits or to make them recommendable for everyone. In fact, scientific advances lead us to personalized diets, adapted to the needs of each individual, not to global remedies that were more typical of past centuries".

In this regard, Francisco Guarner recalled that although the relationship between the microbiota of our intestine and diseases such as obesity, cancer or depression has already been demonstrated, "current analyses only allow us to know 20 or 40% of the diversity of bacteria that inhabit the intestine of an individual, which is why it has not yet been possible to extend the treatment of fecal transplants from healthy people to sick people. It has been successfully tested in experimental models where this transplantation has even allowed reversing some metabolic disorders such as diabetes subject 2". 

Food intolerances and allergies: a problem of the immune system

On the other hand, Francisco Guarner confirmed that the programs of study on the microbiota of the individuals allows us to know that both in Europe and in the USA this microbiota is "less diverse, poorer, probably because of the effect of antibiotics -their intake kills the bacteria that cause disease but also kills beneficial bacteria-. This microbiota is "less diverse, poorer, probably due to the effect of antibiotics -their intake kills the bacteria that cause disease but also kills beneficial bacteria-, the extension of hygiene and the change in our per diem expenses".

"In fact," continues the expert, "in rural areas of Africa or the Amazon, people have a more diverse microbiota and there are almost no autoimmune diseases, colon cancer, allergies or intolerances. It is true that there is greater mortality, but not as much as one might think, since their greater diversity of bacteria has allowed them to have an immune system that works better". According to Dr. Guarner, the profusion of allergies, intolerances and gastrointestinal ailments in developed countries are the result of an immune system that does not work well, and generates intolerances to foods that would not necessarily be harmful, as is the case with gluten.

As a recommendation to enrich this gastrointestinal flora, researcher recommends "feeding our bacteria, not only our body, with fiber, probiotics and prebiotics, polyphenols or flavonoids, which are present in tomatoes or fresh vegetables. In general: it is about using personalized nutrition to strengthen that organ that lives in our colon, weighs about a kilo and is called microbiota", he concluded.

The XI conference of update in Nutrition, coordinated by the Full Professor of Nutrition of the University of Navarra and CIBERobn member Alfredo Martínez, was attended by 200 professionals and students of Nutrition.