A study involving Waterloo biologist Josh Neufeld and post-doctoral fellow Michael Lynch finds that bacteria in the human gut contribute to the physical and psychological symptoms of irritable bowel syndrome (IBS), paving the way for new treatments against the most common digestive illness worldwide.
The study, led by researchers from the Farncombe Family Digestive Health Research Institute at McMaster University, was published this week in the journal Science Translational Medicine.
In a series of novel experiments, the researchers wanted to see if microorganisms living in the large intestine might be causing IBS. They transferred fecal bacterial communities from human patients experiencing IBS, with and without anxiety, into healthy mice.
Surprisingly, results showed mice that received the IBS bacteria developed both the physiological and psychological symptoms of their human donors, even mirroring cases with anxiety-like behavior. According to the researchers, the microbiota living inside us are not only influencing our gastrointestinal sensitivity and transit time, but our mood as well.
Neufeld and Lynch characterized the microbial communities being transferred using DNA extraction, sequencing and 16S rRNA gene analysis.
“The key message is that gut microorganisms can contribute to IBS and this approach may be effective for investigating microbiome-level treatment options in the future,” says Neufeld, a professor in the Department of Biology and a member of the Water Institute.
IBS is the most common chronic gastrointestinal condition, affecting 10 to 15 per cent of the population globally. IBS symptoms include painful cramping, gas, diarrhea, and constipation, as well as depression and anxiety. Unfortunately, treatment options are limited because the exact root cause remains unknown.
The Canadian Institute for Health Research and Nestle Switzerland supported the study.