We hear a lot these days about probiotics and prebiotics. They can be found in many foods and supplements. But what is the difference between the two? What are their health benefits? Should you consume them? Here are the answers to all theese questions!
The colon contains up to 100,000 billion live bacteria that make up the gut microbiota. Among these, there are about 400 species of health-beneficial bacteria that help digest and absorb food, stimulate the immune system and provide a defense barrier against disease. Usually, “good” and “bad” bacteria coexist in the intestine and form a certain balance. On the other hand, good bacteria living in the intestines may be disrupted by various factors such as age, food choices, antibiotics, stress or immune system disruption.
Probiotics are living bacteria or yeasts that, when ingested in sufficient quantities, can have beneficial effects on health. The most common are Lactobacilli and Bifidobacteria. Probiotics are found in supplement form as well as in certain foods such as certain kinds of yogurt and cheese, kefir, uncooked sauerkraut and kimchi. However, not all fermented foods contain living organisms. For example, beer and wine are made via fermentation but are then subjected to processes that eliminate organisms such as yeasts that allowed the fermentation. Other fermented foods are heat-treated or preserved and canned, which inactivates organisms, so they do not contain any probiotic activity. Although all yogurts contain lactic acid bacteria for preservation purposes, only some have probiotic strains that are able to survive the acidity of the stomach and can arrive intact in the intestines.
Prebiotics, on the other hand, are fermentable carbohydrates (types of dietary fiber) called oligosaccharides and short chain polysaccharides, which are beneficial to the microbiota and gastrointestinal health by selectively promoting the growth of good probiotic bacteria. In simplified terms, good bowel bacteria, called probiotics, feed on certain types of dietary fiber called prebiotics. Prebiotics are found in many foods, though mostly from plant sources, including fruits, vegetables, legumes and whole grain products. Thus, it is important to include in your diet many plant-based foods in order to optimize the presence of good bacteria in your intestines. Their high fiber content, including prebiotic fibers, improves intestinal health and overall health. In Europe, the fiber recommendation is set to 30 grams per day. In Canada, fiber requirements are set at 25 grams per day for women and 38 grams per day for men. According to Health Canada, most Canadians consume only half of these fiber amounts.
Many studies have looked at the health effects of taking a probiotic supplement. However, many different strains of probiotics exist. It is important to know that each strain of probiotics has specific effects. Indeed, each strain has a genus, a species and a designation. The beneficial effects of a strain of probiotics can only be attributed to the strains tested, and not to the species or the whole group of bacteria. For example, Lactobacillus Rhamnosus GG may be effective in reducing bad LDL cholesterol, but Lactobacillus Casei DN-114 001 is not necessarily effective for that purpose. In addition, to be effective, it is necessary that the probiotics arrive alive in the colon and in sufficient numbers. They should not be destroyed after passing through the stomach and must be able to withstand gastric acidity and pancreatic enzymes. Several factors such as storage temperature and the presence of food additives can also affect the growth and survival of probiotics. While some studies have shown beneficial effects of some strains of probiotics on health, research in the world of probiotics is still relatively recent and future years will be able to specify even further the specific recommendations for their use.