I’ve said it a million times and I’ll say it again. The ability of microbes/viruses/fungi and their associated metabolites + proteins to alter human gene expression is at the root of human inflammatory disease. This is especially true of intracellular pathogens, which have direct access to human transcription, translation and DNA repair processes. Here are two of my favorite 2018 studies related to the topic:

Coordinated host-pathogen transcriptional dynamics revealed using sorted subpopulations and single, Candida albicans infected macrophages

Lead author: Christina Cuomo, Broad Institut

The team found that the fungus Candida albicans‘s transition from extracellular to intracellular pathogen was accompanied by a coordinated, time-dependent shift in gene expression for both the host and the fungus. These gene expression changes led to a gradual decline in pro-inflammatory cytokine activation by the host immune system. The findings are an excellent example of how the human immune response changes over time in response to different pathogen survival states.

Variation in gut microbiota composition impacts host gene expression

Lead author: Francesca Luca, Wayne State University

The study found that gut microbes exposed to epithelial cells from the human colon modified the expression of over 5000 human genes. Interestingly the microbial taxa with the strongest influence on gene expression altered the response of genes associated with specific complex traits.