In recent years, medical research, aided by new technology, has made tremendous strides, while at the same time a new medical vocabulary has begun to take shape. Many diseases arise—assuming there is some genetic predisposition—from the combination of a specific dietary pattern with a certain type of gut microbiome, this "additional organ" that we often overlook.

This gut microbiome consists of bacteria present in our intestines: from this very combination, metabolites can be formed that are transported throughout the body, controlling and dominating each of our organs, even our brain. By changing our diet, or even modifying the gut microbiome (with prebiotics, probiotics, synbiotics, and in the future, with fecal transplants), we still have room for intervention.

Moreover, many diseases of adult life can be prevented with the correct nutrition of the pregnant woman, creating the optimum conditions for the embryo's development: diabetes and obesity are examples of conditions that could be addressed with such an approach.

In this book, the reader will find, if not the entirety, at least the majority of the new knowledge and the new vocabulary of medicine: systems biology, personalized medicine, "omics" technologies, network and complexity medicine. What is increasingly clarified through medical research, however, is that as individuals we are part of an ecosystem that is colonized by an extraordinarily large number of bacteria that guide and direct us, and which we must learn to recognize and respect.