Host Genetics and Interactions Within the Microbiome
Contributed by Azarene Foutouhi
A common view of host-microbe interactions, particularly in the gut, involves the interactions between host diet, host health, and the microbiome. However, it is becoming increasingly clear that a much more complicated dynamic is present. Findings detailing the role of host genetics on shaping the microbiome have identified a new dynamic in microbiome composition and stability. In a previous post reviewing two studies; the firs, Barton et al. discussed how herpesvirus latency confers protection from bacterial infections well before a specific adaptive response can be mounted. In the second, MacDuff et al. found that HOIL-1 KO genetically immunodeficient mice were rescued from Listeria lethality by latent HV68 infection, suggesting the metagenome (including virome) can help link phenotype and genotype. The relationship between host genetics and the microbiome is bidirectional.
In the same vein as the Barton et al. study, Moeller et al. explored the effect on lentivirus on the gut microbiome. Examining the composition of the gut microbiome in wild chimpanzees long term before and after SIV infection, Moeller found that SIV induced instability of the gut microbiome, and in an unexpected way. While current thinking leans towards the existence of a ‘healthy’ or ‘diseased’ microbiome and a loss of diversity indicative of disease, recent work suggests there is no signature microbiome characteristic of a healthy or diseased state. While the community composition changed after SIV infection, there was neither a decrease in diversity, nor a consistent profile of diseased individuals. Not only this, but consecutive samples recovered before and after SIV infection showed that while the gut microbiomes may have been relatively stable in health, the microbiomes of SIV positive chimps continued to change over time.
While the few studies examining interactions within the microbiome are focused on the interplay between virus and bacteria, it is clear that not only host genetics, but also the dynamics within the microbiome should be carefully considered when exploring host-microbe interactions.
- Barton, Erik S., Douglas W. White, and Herbert W. Virgin. “Herpesvirus Latency and Symbiotic Protection from Bacterial Infection.” Viral Immunology22.1 (2009): 3–4. PMC. Web. 11 July 2017.
- MacDuff, Donna A et al. “Phenotypic Complementation of Genetic Immunodeficiency by Chronic Herpesvirus Infection.” Ed. Stephen P Goff. eLife4 (2015): e04494. PMC. Web. 11 July 2017.
- Goodrich, Julia K. et al. “Human Genetics Shape the Gut Microbiome.” Cell159.4 (2014): 789–799. PMC. Web. 19 Sept. 2017.
- Moeller, Andrew H. et al. “SIV-Induced instability of the Chimpanzee Gut Microbiome.” Cell host & microbe14.3 (2013): 340–345. PMC. Web. 19 Sept. 2017.