Diet microbiome has variable effects on different immune responses

Several years ago, Arun Prakash and Imroze Khan set up an ambitious experimental evolution study in the lab, infecting populations of flour beetles with the pathogen Bacillus thuringiensis (Bt). They found that different selection regimes led to the evolution of mutually exclusive immune responses – beetles either evolved better basal resistance to Bt, or immune priming (Khan et al 2017, Proceedings B). Curious whether these evolved responses relied on the flour microbiome, they then tested if immune function was similar in UV-treated vs. normal flour. In a new paper, we report that the ability to mount an immune priming response is indeed dependent on access to flour microbes, but evolved basal resistance is unchanged. Much remains unclear still, but this was a fun little project with surprising results! Read the paper to know more.