The holobiont mind: A bridge between 4E cognition and the microbiome

All life on earth is intrinsically linked. At the very foundation of every evolutionary interaction are microorganisms, integral components in the composition of both organisms and ecosystems. The available data and this perspective on the order of life challenge the traditional conception of monogenetic biological individuals, suggesting living beings are actually composite multi-species complexes: holobionts. In the present article, we introduce our perspective on the concept of the holobiont mind, a biogenic conception of cognition compatible with the 4E approach and the holobiont theory. We furthermore expand on the idea of the mind as the emerging product of multi-genomic morphology of a composite animal-agent, in ever-changing interaction with its ecological niche. We thus briefly review recent evidence on the brain–gut–microbiome axis and the Microbiome of the Built Environment in order to provide a bridge between the Holobiont Mind and the 4E approach to Cognition, two complementary lines of evidence that have not been linked before, opening novel venues for research with direct impact on health and disease.