The digestive system is home to trillions of microorganisms, both good and bad, collectively known as the gut microbiome. For optimal overall health, a balanced gut population is vital, and fibers such as prebiotics provide the necessary environment for a healthy digestive tract. Here we’ll discover what prebiotics are, how they function, and why they are more important than the oh so popular probiotics.
What are Prebiotics?
A balanced microbial population is primarily defined by diet- the chief source of energy for their growth comes from nutrition [R]. In particular, non-digestible carbohydrates and plant fibers, known as prebiotics, are able to modify the composition and the function of the gut. They can be found in foods such as whole grains, greens, onions, bananas, garlic, and artichokes.
Beneficial gut microbes are able to extract energy from these prebiotics by fermenting them. This means prebiotics can influence the gut to selectively grow good bacteria and, in fact, without the presence of prebiotics, good bacteria struggle to grow and survive. To put simply, prebiotics feed probiotics so without prebiotics, probiotics cannot thrive.
Prebiotics vs Probiotics
Probiotics are live bacteria that are found in certain foods (like sauerkraut/kimchi) and supplements. They’re also very important for gut health because they contain the live microorganisms that maintain the good bacteria population. However, just like all living things, they can’t survive very long without the necessary nutrients for energy production. Again, prebiotics act as food for these microorganisms. Without them, probiotics wouldn’t have the required energy for optimal functioning.
Functions of Prebiotics
Prebiotics’ roles aren’t limited to aiding the growth of beneficial bacteria. They’re also involved in many bodily functions. When they are first fermented in the gut, they’re converted into short-chain fatty acids (SCFAs). These molecules are able to diffuse through the gut lining and enter the bloodstream. As a result, prebiotics can affect other organs and systems in the body besides the digestive tract [R].
Their effects include helping the gut absorb more calcium, influencing the rate at which foods cause spikes in blood sugar levels, fermenting foods at a high rate so they spend less time in the digestive system, and keeping cells in the gut healthy and optimally functional. In addition, prebiotics have protective effects on the central nervous system, the immune system and the cardiovascular system [R].
Prebiotics and Disease
Some studies evaluated the effects of prebiotics on gastrointestinal disorders such as irritable bowel syndrome (IBS) and Crohn’s disease as well as colorectal cancer. One study showed that after consuming the prebiotic fructooligosaccharide (FOS), IBS symptoms improved [R]. Another study found that FOS supplementation increased the concentrations of beneficial bacteria and decreased Crohn’s disease activity [R].
Furthermore, the by-products of prebiotic fermentation offer protection against the risk of colorectal cancer as well as its progression by promoting cancer cell death [R, R].
Take-Home Message
Prebiotics are key to a balanced gut, which is fundamental for overall health. Taking a probiotic that does not contain prebiotics, OR taking a probiotic while consuming a diet low in prebiotics, will not be very beneficial. If you are going to spend your hard earned dollars on supplements, make them worth your while. Pick a probiotic that contains prebiotics OR implement a diet high in fiber, and plants (especially artichokes, and bananas). These little details may seem insignificant, but they make a world of difference for your gut, and therefore your overall immune system as well.