I get many questions from my patients that suffer from GI issues on what is healthy and what should they eat and why. I am a big fan of nutrition through whole foods rather than supplements and I spend a lot of time to educate my patients on the importance of the normal flora and bacteria that help breakdown and absorb nutrients from our foods. One of the most important ‘nutrients’ in our diet should be a source of Prebiotics. Prebiotics are non-digestible carbohydrates (non-digestible to humans) that help ‘feed’ the good bacteria in our lower GI tract. They are long chains of sugar molecules and are non-digestible to humans because of the way they are held together (Beta 2-1 glycosidic bonds). Our stomach and small intestines do not have the right enzymes to breakdown these sugars, so they travel down into the large intestines-where we do have the right stuff to break these bonds and create nutrients for our gut flora.
The bacteria in the large intestines break the linkages of the long chains of fibers/prebiotics, into smaller chains of sugars. These smaller chains are then converted into gases, acids or alcohols in a fermentation process, much like making beer or kombuchi. These new chemicals are further broken down or converted into small chain fatty acids and that is the good stuff that our gut flora really likes. The natural flora in the gut thrive on the SCFA because they are lower in Ph level-which means ‘bad’ bacteria can’t survive. Many studies suggest that they help to keep inflammation down, decreasing the risk of certain diseases like cardiovascular disease, obesity and colon cancer (Slavin, 2013). SCFA are also the preferred form of energy for mucosal cells and when they are healthy so is our immune system. These non-digestible fibers-also known as oligosaccharides are naturally occurring in many vegetable; leeks, onions, garlic, artichokes and dandelion greens. There are many other food sources of prebiotics and they should be a part of a healthy diet.
Bruso, J (2015) Examples of Prebiotic Foods Retrieved February26, 2015 http://www.livestrong.com/article/279878-examples-of-prebiotic-foods/
International Scientific Association of Prebiotics and Probiotics. (2014). Prebiotics: A Consumer Guide for Making Smart Choices. Retrieved from http://www.isapp.net/Probiotics-and-Prebiotics/Resources
Slavin, J. (2013). Fiber and Prebiotics: Mechanisms and Health Benefits. Nutrients, 5(4), 1417–1435. doi:10.3390/nu5041417