It’s possible to use metagenomic shotgun sequencing to look at complex microbial communities and see what types of microbes are present there, as well as their functions. However, sequencing does not give information about how quickly different species of bacteria within the community are growing. Microbial growth rates change based on different environmental conditions, give information about which microbes may be active contributors to community phenotypes, and can even be associated with multiple disease characteristics, so this information would be highly useful for assessing the effect of different microbes on human health. However, existing techniques to determine microbial growth rates have been difficult to utilize, and have important limitations.
Our Associate Director of the JAX CRC, Julia Oh, and Postdoctoral Associate, Akintunde Emiola, recently published a paper in Nature Communications, where they developed a new method to measure microbial growth rates, called Growth Rate InDex (GRiD). In a JAX Research Highlight, Mark Wanner explains that, “GRiD provides a more accurate inference of growth rate [of] bacteria in a microbiome, even those that are very low abundance or those which have no known genome reference. Importantly, GRiD can be applied to thousands of different bacteria simultaneously, allowing biological insights at the microbial community, and not single isolate, level.” Using GRiD in a high-throughput manner allows for new associations between bacterial growth dynamics to be discovered, which could even be used to give information about the association between microbes and host characteristics.