The Spring 2017 Lab

The Spring 2017 Lab
Rina, Mauro, Debs, Rob, Daniel

Lab Members

Debs Gore-Lloyd
Rob Hicks
Mauro Moreno

Could you fill a beaker with the fungi in your body?

The mycobiome is starting to get a little traction!

When will we know the weight of the fungi on and in our bodies? The human microbiota has been recognized as hugely important in the last few years, but that has almost entirely focused on bacteria. I’ve been interested in the mycobiome of the human built environment for a while, and I certainly haven’t been alone. People tend to think of fungi as a problem in buildings, on or in plants, and in the outside air. However, there is still so much unknown about the mycobiota of animals including humans. Only last year, there was a key discovery about mammal-fungal interactions in the gut that may drive some rather sever disease  in humans (ulcerative colitis)*, and it appears things are starting to pick up pace for the mycobiome, largely with the help of sequencing technology.

Using over 5 million sequences of a standard fungal ID rDNA fragment, Findley et al. show specific fungal communities on human skin that shift with location on the body while bacteria shift depending on the site physiology. They also found startling fungal commensal diversity on the skin. Most of the identification they did was only to genus level, but for the predominant fungal genus, Malassezia, they identified species. Unlike Candida, which I think is basically a single species of human commensal out of a diverse group of environmental Saccharomycetales yeasts, Findley et al. found 11 of the 14 described species of Malassezia species consistently on the body. More interestingly it was mostly in the distribution of these species that the structure of the fungal community over the core body emerged. Different core body locations were dominated by different Malassezia species. The feet were another thing altogether. The fungal community on feet was vastly different from the core body and much more diverse. The fungal communities also differed from each other depending on site on the foot (toe nail, toe web, heel), but only really in feet showing clinical signs of infection (skin flaking etc.).

They also found a kind of outlier individual who had a short course of treatment oral antifungal treatment months previous to the study. This individual had vastly different fungal community composition than the others but the bacterial community was not different.

Having seen this I wonder how much abundance plays a role. Sometimes when abundance is high communities are less diverse. I think there could be parallels in other kinds of mycobiomes for what they’ve found on humans. Another clear thing to think about is the long-term effect on fungal communities of application of antifungals/fungicides. It’s exciting to see this level of detail in a study, but obviously, with only ten people studied, the Findley et al. work is small scale and a lot more patterns could emerge with new studies. Let’s get sequencing the Tube fungal community!

*As an aside, I have often wondered how much the amphibian disease community cares about the immune response effects of Basidiobolus on amphibians infected with Batrachochytrium  

Iliev, I., Funari, V., Taylor, K., Nguyen, Q., Reyes, C., Strom, S., Brown, J., Becker, C., Fleshner, P., Dubinsky, M., Rotter, J., Wang, H., McGovern, D., Brown, G., & Underhill, D. (2012). Interactions Between Commensal Fungi and the C-Type Lectin Receptor Dectin-1 Influence Colitis Science, 336 (6086), 1314-1317 DOI: 10.1126/science.1221789

Findley, K., Oh, J., Yang, J., Conlan, S., Deming, C., Meyer, J., Schoenfeld, D., Nomicos, E., Park, M., Becker, J., Benjamin, B., Blakesley, R., Bouffard, G., Brooks, S., Coleman, H., Dekhtyar, M., Gregory, M., Guan, X., Gupta, J., Han, J., Hargrove, A., Ho, S., Johnson, T., Legaspi, R., Lovett, S., Maduro, Q., Masiello, C., Maskeri, B., McDowell, J., Montemayor, C., Mullikin, J., Park, M., Riebow, N., Schandler, K., Schmidt, B., Sison, C., Stantripop, M., Thomas, J., Thomas, P., Vemulapalli, M., Young, A., Kong, H., & Segre, J. (2013). Topographic diversity of fungal and bacterial communities in human skin Nature DOI: 10.1038/nature12171 Huffnagle, G., & Noverr, M. (2013). 

The emerging world of the fungal microbiome Trends in Microbiology DOI: 10.1016/j.tim.2013.04.002