Beer and bread have been staples of the human diet for over 7,000 years. Over that period, a bacterium has evolved almost exclusively within the human gut that is able to eat its way through the yeast in these food products. A new study now suggests this bacterium may provide the basis for new treatments for yeast infections and autoimmune diseases, such as Crohn’s disease.
The study – led by Newcastle University in the UK and the University of Michigan Medical School, and published in the journal Nature – set out to identify the complex mechanism by which the common bacteria found in the human gut is able to target and feast upon yeast carbohydrates.
These carbohydrates, derived from the yeast cell wall, are called mannans and are usually found in fermented foods such as bread, beer, wine and soy sauce. However, research has suggested that, in some cases, mannans are harmful to human health.
Previously, scientists had believed that the mechanism behind the breaking down of mannans was related to the “recycling” ability of common gut bacteria. In this process, cells hosting carbohydrates are constantly shed and renewed, which keeps the intestinal lining healthy.
Instead, the researchers found it is just one bacterium specific to the human gut – Bacteroides thetaiotomicron – that is responsible for hunting out and degrading the yeasts we consume from our bread and beer.
Co-author Eric Martens, PhD, of the University of Michigan’s Department of Microbiology and Immunology, says that one of the big surprises in the study – which involved feeding laboratory mice a diet consisting of 50% yeast leavened bread – was how B. thetaiotaomicron is sensitively “tuned” to recognize the complex yeast carbohydrates found in beer, wine and bread.
Read more at: Medical News Today