Huge thank you to my mentors @ksxue.bsky.social, KC Huang, David Relman, @benjaminhgood.bsky.social, @petrovadmitri.bsky.social, and everyone else involved in the work for their valuable feedback and suggestions throughout, and I’m super excited to finally have this out in the world!

Overall, our findings demonstrate that initial conditions can have a lasting impact on the outcomes of species introductions, and that these impacts are especially pronounced in diverse communities.

Using a consumer-resource model and metabolomics, we identified niche overlap between introduced and resident species as a strong predictor of the importance of initial dose.

The answer? It’s complicated, of course, and depends on the identity of the introduced microbes and which species are already present. Across a set of mixtures of gut microbial communities, we observed a range of species colonization behaviors from dose independence to strong dose dependence.

To do this, we mixed a set of in vitro gut microbial communities together at various initial ratios ranging over six orders of magnitude, and we used 16S sequencing to track the final relative abundances of each species after ~40 generations of growth.

I’d love to be added, thanks!