Researchers at UC Davis Health, California have discovered that feeding gut microbes dietary fiber can help them maintain gastrointestinal (GI) health. The research was published on August 11 in the journal Science. The result is significant for scientists in identifying a potential therapeutic target for favorably influencing gut microbiota in edging out harmful bacteria. Furthermore, it expand our understanding of the puzzling interplay between tens of trillions of bacteria and dietary fiber. The host receptor identified in this defense mechanism is peroxisome proliferator receptor gamma (PPARg).
The scientists identified how the by-products produced by these beneficial resident gut bacteria can act as fuel to aid intestinal cells combat against infectious agents, including various aerobic enteric pathogens. For instance, in the same issue, an article published under Insights / Perspectives highlighted the role of these gut bacteria in forming a robust defense mechanism against pathogens such as Salmonella and Escherichia coli.
Breakdown of Dietary Fiber by Gut Bacteria Decreases Oxygen Availability to Gut Lumen
The resident gut bacteria prefers feeding on dietary fiber for their sustenance and generate signals that limit resources for the part of GI tract harboring harmful bacteria, states one of the senior authors of the study. These dietary fiber, usually considered indigestible, when metabolized by these resident gut bacteria produces short-chain fatty acids. The process signals the cells lining the large intestine to increase their oxygen intake. As a result, the amount of oxygen available to the gut lumen decreases; this open area within the intestine is responsible for promoting the growth of harmful aerobic bacteria that cause common intestinal infections.
Since these gut bacteria do not thrive in environments rich in oxygen, they are especially suitable for promoting the new defense mechanism discovered, opines one of the researchers authoring the study.