“…Although some microbes are parasites that can cause disease, many others lie on the spectrum between commensalism and mutualism and may significantly influence their hosts' nutrition (Dethlefsen et al, 2007), development (Bates et al, 2006) and disease resistance (Macpherson and Harris, 2004;Koch and Schmid-Hempel, 2011). The use of model organisms such as the fruit fly Drosophila melanogaster, the nematode Caenorhabditis elegans, the house mouse Mus musculus and the zebrafish Danio rerio has facilitated understanding of the mechanisms by which certain biological functions of the hosts are modulated by their microbiota (Rawls et al, 2004;Turnbaugh et al, 2006;Cabreiro and Gems 2013;Erkosar et al, 2013). As interest in environmental genomics emerges, the roles of microbiota in the ecology and evolution of an increasing number of non-model organisms are being investigated, revealing a high diversity in the types of effects observed (Fraune and Bosch, 2010;Engel et al, 2012;Koch and Schmid-Hempel, 2011;Brucker and Bordenstein, 2013).…”