CBC documentary featuring two Guelph professors investigates myths and facts about poo
The CBC’s The Nature of Things has come out with a new episode and it’s all about poo. From fecal bacteria on your toothbrush to producing drinking water from sewage, the show explores the “myth or science” behind some of the more commonly held conceptions about human waste. It also features two University of Guelph professors: Dr. Cezar Khursigara and Dr. Emma Allen-Vercoe.
In the documentary, Khursigara debunks the myth that we can’t digest corn by comparing a fresh kernel with one that has been digested by the presenter. While at first glance the digested kernel appears mostly intact, Khursigara explains that the only thing that hasn’t been broken down by the digestive microbes is the cellulose shell.
Allen-Vercoe, a microbiologist, focuses on the human intestinal biome and the effects that different conditions or human-microbe interactions can have on those organisms. In order to do that, Allen-Vercoe explains, “we culture a lot of microbes that were once considered to be ‘unculturable.’ They turn out to be nutritionally very fastidious and many find even a whiff of oxygen highly toxic. So, we created a ‘life support system’ to be able to grow these microbes in the lab in vitro, using conditions that mimic those in the gut.”
Allen-Vercoe describes how they can use this system to demonstrate disruptions to the microbiome and estimate the possible repercussions to human health. “We have a project allowing us to study, for example, the premature infant gut microbiota and how it develops, and how this development may go awry in some infants and cause serious disease — this would not be easy to study in vivo [in the living organism] for obvious reasons,” she states.
“The study of the human gut microbiome is relatively uncharted territory that science has only started looking at within the last 15 years or so. I’ve been lucky to have been involved in this field for most of this time, and what fascinates me the most is how much we have underestimated the importance of microbes to human health. We know far more about microbes that cause disease, and yet these represent only a tiny fraction of microbial species in our bodies,” said Allen-Vercoe.
Allen-Vercoe also tackles another common myth: a vegetarian diet makes your poo smell better. For the smell test, Allen-Vercoe created “smell-alikes” of each sample of vegetarian poo and meat poo, and had volunteers rank the smells, with higher ratings smelling worse than lower ratings. The meat poo came out on top, with a lower ranking of 7.2, while the vegetarian poo was a close second with a ranking of 7.3, debunking the myth that vegetarian poo smells better.
The full episode of “Myth or Science: The Power of Poo” can be viewed at cbc.ca.