We now have a much deeper appreciation that most organisms are ecosystems themselves a term often referred to as a holobiont. Understanding these microbial associations and their potential impact to the host is an active line of research and here I will discuss their impact on ant (Formicidae) hosts. As we have sampled more ant species we understand that many species rely on gut-associated microbes to aid in digestion and nutrient acquisition, but not all ants seem to have a stable or functional gut microbiome. In addition to diet we have uncovered other host factors that structure and determine microbiome associations including digestive compartment, habitat, and host evolutionary history (phylogeny). There can also be interactions between microbial associates, and we are beginning to understand this through sampling diverse microbes. Lastly, understanding the potential functional role for hosts is key to understanding these interactions. We have been able to demonstrate that gut-associated bacteria do enrich the diet of herbivorous ant species and this enrichment of nitrogen can then be used for several components of cuticle formation. Understanding the diversity, interaction, and function of host-associated microbes are key to uncovering the role of these intimate interactions on host ecology and evolution.
