Prebiotics and Probiotics - what are they?
Prebiotics and Probiotics - what is the difference? In a nutshell, prebiotics provide food for your good gut bacteria, and probiotics are live good gut bacteria (Yoo & Kim 2016).
Prebiotics are basically high fibre foods, particularly soluble fibre, such as garlic, onions, artichokes, leeks, asparagus, cabbage, beans (as in red kidney, black, black-eyed etc), legumes, oat bran, and sweet potatoes to name a few. The daily use of onions and garlic may be a very important component (alongside the use of olive oil and antioxidant-rich fruits & vegetables) of the health benefits of the Mediterranean Diet.
Probiotics are foods or supplements containing beneficial bacteria, such as yoghurt, cheese, sour cream, cultured butter, miso, sauerkraut, tempeh, kimchi, kefir, and kombucha. There is insufficient evidence to say how much of the beneficial bacteria contained in these foods survives the stomach, however there has been a recent study on the benefits shown in humans by a heat-killed Lactobacillus strain from plants (Higashikawa et al. 2016), so the body of evidence is slowly growing. New technology which delays digestion of the gel caps in probiotic supplements means we now have an efficient delivery system into the intestines, which is why I choose to use a probiotic supplement as well as consume probiotic foods.
The possible synergistic (working together) effect of food components should also not be underestimated. For example sauerkraut contains not just beneficial bacteria, but also food on which they feed (cabbage). Even if those bacteria don't survive the stomach's acidic environment, sauerkraut will have beneficial effects. The dead bacteria still act as stimulants for our immune system (Binns 2013) - think of it like exercise, training, or a fire drill - ensuring it is primed & ready to go in case of an attack. The cabbage, as it's digested, will provide food for beneficial bacteria in the intestines.
The more food you provide for them, the healthier and stronger their colonies will become, and be able to withstand an attack from pathogens. If your gut is colonised by good bacteria, there is no room for the bad!
Binns, N 2013, 'Probiotics', Prebiotics and the Gut Microbiota, p. 32.
Higashikawa, F, Noda, M, Awaya, T, Danshiitsoodol, N, Matoba, Y, Kumagai, T & Sugiyama, M 2016, 'Antiobesity effect of Pediococcus pentosaceus LP28 on overweight subjects: a randomized, double-blind, placebo-controlled clinical trial', European Journal of Clinical Nutrition, vol. 70, pp. 582-587.
Yoo, JY & Kim, SS 2016, 'Probiotics and prebiotics: Present status and future perspectives on metabolic disorders', Review, Nutrients, vol. 8, no. 3.