During my recent lecture (slides & video) at the Griffith University in in Brisbane, Australia, I quoted Donald Rumsfeld, former US Secretary of Defense. What Rumsfeld said, concerned military issues and the “complexity” of the quote was a material for the seemingly never ending jokes in USA.
However, thinking more carefully, this is a very wise opinion that applies not only to the military but that applies perfectly to the science and the scientific knowledge. 
One of the major topics presented in the today’s, Jan. 5th, 2018, issue of the SCIENCE journal is the microbiota and the microbiome and description how they affect human cancer and human cancer therapy.
Definition of microbiota and microbiome is simple as it is presented in Wikipedia:
“…A microbiota is an “ecological community of commensal, symbiotic and pathogenic microorganisms” found in and on all multicellular organisms studied to date from plants to animals. A microbiota includes bacteria, archaea, protists, fungi and viruses. Microbiota have been found to be crucial for immunologic, hormonal and metabolic homeostasis of their host. The synonymous term microbiome describes either the collective genomes of the microorganisms that reside in an environmental niche or the microorganisms themselves…”
Human skin microbiome
The fact that different parts of our bodies are homes for diverse populations of bacteria is illustrated in the graph showing, as an example, distribution of different types of bacteria in different areas of human skin (source: Wikipedia).
The physiological importance of the microbiota and the microbiome in human health is one of the “things we don’t know we don’t know” about the effects of RF-EMF (and ELF-EMF).
The database EMF-Portal, as of Jan. 5, 2018, lists only a very small number of 14 articles examining the effects of radiation emitted by mobile communications on bacteria. This seemingly, so far, “unimportant” area of research should be urgently explored in the context of the known importance of the microbiota and the microbiome in human health.
Furthermore, considering that the deployment of the 5G technology and the Internet of Things, emitting millimeter-waves penetrating only the skin, examining the impact of millimeter-waves and other mobile communication frequencies on the bacteria residing in different areas of human skin becomes an urgent research need.
No matter how much money was so far used for the research on the mobile communications-emitted radiation, there are still “things we don’t know we don’t know” and research should continue.
BRHP - Between a Rock and a Hard Place 
Bacterial response to the exposure of 50 Hz electromagnetic fields.
Cellini L1, Grande R, Di Campli E, Di Bartolomeo S, Di Giulio M, Robuffo I, Trubiani O, Mariggiò MA.
https://www.ncbi.nlm.nih.gov/pubmed/18175330
I am very interested in any research made to demonstrate a direct or indirect relationship between the human microbiome and exposure to EMF. My belief is that if we study the human intestinal microbiome of EHS (electro-hipersensitive people) we might discover that they have a specific microbiome, like an ID card, that identify them: and it could become a diagnosis tool.. thank you to share any study, I will share on my blogs and sites. MA
Pingback: Targeted Individual, here's how they do it - The EMF Community
Agree, we should be very interested on effect of Gigahertz and Terahertz -range RF on bacteria, since environmental effects can be extensive. There are 2 very recent research papers with important findings related to A) RF & Listeria monocytogenes / Escheria coli , B) RF & candida:
Taheri, M., Mortazavi, S. M. J., Moradi, M., Mansouri, S., Hatam, G. R., & Nouri, F. (2017). Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli. Dose-Response: A Publication of International Hormesis Society, 15(1), 1559325816688527.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5298474/
+
Bayat, M., Hemati, S., Soleimani-Estyar, R., & Shahin-Jafari, A. (2017). Effect of long-term exposure of mice to 900 MHz GSM radiation on experimental cutaneous candidiasis. Saudi Journal of Biological Sciences, 24(4),
http://www.sciencedirect.com/science/article/pii/S1319562X15003095