Microbiome, holobiont and the net of life.

Holistic emerging approaches allow us to understand that every organism is the result of integration mechanisms observed at every level of nature: integration of DNA from virus and bacteria in metazoans, endosymbiotic relationships and holobionts. Horizontal gene transfer events in Bacteria, Archaea and Eukaryotes have resulted in the chimeric nature of genomes. As a continuity of this genomic landscape, the human body contains more bacterial than human cells. Human microbiome has co-evolved with the human being as a unity called holobiont. The loss of part of our microbiome along evolution can explain the continuous increasing incidence of immune and inflammatory-related diseases. Life is a continuous process in which the organism experiences its environment and this interaction impacts in the epigenetic system and the genomic structure. The emerging perspectives restitute the great importance of Lamarck's theoretical contributions (the milieu) and Darwin's pangenesis theory.