Our extended genotype—An argument for the study of domesticated microbes

Summary We interpret the domesticated organisms—plants, animals, and the domesticated microbes used for food fermentation—as an extended genotype of humans due to their close relationship with our species. We propose to analyse the role of microbes in traditionally fermented food with the approaches used in the human microbiome project, and we expect to find associations with ethnic groups, explaining part of human (culinary) culture.