Wednesday, March 21, 2018

More on Blastocystis and Gut Bacteria...

As an appropriate follow-up on yesterday's post, I feel like guiding your attention to the paper by Laforest-Lapointe and Arrieta from University of Calgary, Canada with the title 'Microbial Eukaryotes: a Missing Link in Gut Microbiome Studies', which elaborates on some of the issues that we have already been highlighting several times in the past.

Nevermind, in their article, which just appeared in the ASM-based journal "mSystems", they speculate that the reason for the observed link between Blastocystis colonisation and increased bacterial diversity (which was mentioned several times in the paper that I referred to yesterday) might be due to predation by Blastocystis on bacteria, a process which selects for higher diversity. They argue that

"In the absence of Blastocystis, a strong bacterial competitor dominates the community, which limits species richness and community evenness; when [Blastocystis is] present, its predation on abundant bacterial taxa lowers the competition for nutrients and space, which leads to an increase in bacterial richness and community evenness."

Since predation on bacteria by Blastocystis has only been documented once (I believe) to date, the authors are right in encouraging colleagues to study engulfment of bacteria by Blastocystis.

Those of us who take a special interest in the public health impact of common intestinal parasites and who work in the field of clinical microbiology and infectious diseases might benefit from taking some lessons from experts in 'food web theory' and micro- and macroecology.

The article can be accessed here.

Tuesday, March 20, 2018

Associations Between Intestinal Parasites and Bacteria

For those interested in exploring the presence/absence of intestinal parasites in a gut microbiome context, Dr Mark van der Giezen and I did this small opinion paper for Trends in Parasitology. In it, we summarize data from studies looking at the associations between single-celled intestinal (luminal) parasites and gut bacteria, and we tried to come up with a hypothesis for the factors governing the presence/absence of e.g. Blastocystis.

The paper just appeared online, and you can access it here.