What’s the Difference Between Prebiotics, Probiotics & Postbiotics?
You’ve heard about probiotics, the friendly bacteria that colonize your gut with the sole intention of reestablishing order and balance to your gastrointestinal and digestive system. But what are prebiotics and postbiotics? Most importantly, do they matter?
Pre and Probiotics: The Breakdown (… Get it? Don’t worry, you will)
Prebiotics are a type of food fibre that our bodies don’t break down. Instead, they serve the purpose of nurturing probiotics. This ensures that all the yogurt and fermented veggies we’re eating actually pays off in a nice, healthy crop of gut bacteria.
As opposed to their proteges, prebiotics are quite tough and transverse the baleful journey toward the gastrointestinal tract unharmed. This is vital for their purpose as their work is done primarily in the lower tract.
Prebiotics like to stick around mucous membranes and naturally inhabit breast milk, saliva, and plants. They are a carbohydrate made of soluble fiber and can be found in starchy veggies, grains, and legumes.
So to break it down, prebiotics are a food fiber. Preiotics nurture probiotics and in order to be classified as such, they must meet the following three requirements:
- A prebiotic is a non-digestible food fiber, meaning that it should survive the journey to the lower tract unharmed by the digestive activities of the host; it should resist absorption and adsorption by the digestive juices in the digestive tract.
- A prebiotic must travel to the lower tract specifically and once there, it must be fermented by the local microflora.
- A prebiotic is there to boost probiotic development. Therefore, it must stimulate the activity of friendly bacteria, usually by way of nutrition.
Types of prebiotics include oligosaccharides, arabinogalactans, fructooligosaccharides, and inulin. In food terms, vegetables, grains, and roots are rich in prebiotics. Also, some probiotic-rich fermented foods contain them.
Understanding Soluble & Insoluble Fiber
In order to understand the importance of prebiotics, we must first understand the mechanisms of our body’s use of fiber.
The main role of insoluble fiber in our diets is to promote healthy bowel movements. Insoluble fiber is a non-digestible substance that does not dissolve in water. It promotes digestion through its ability to retain water, hydrating the stool and making it easier to pass.
Soluble fiber does dissolve in water and it is the type that serves as a prebiotic. Soluble fiber aids in digestion differently than insoluble fiber. While the former makes it easier to go, soluble fiber fuels bacterial growth in the colon, creating an efficient environment for healthy digestive activity.
Food For Flora: Why Prebiotics Matter
Probiotics can only be as beneficial as their quality allows. This is the main reason we consume probiotics in the first place- to improve the bacterial environment in our gut. Prebiotics ensure that any probiotics we introduce thrive to accomplish their goal, which is to improve the overall heath of our digestive health.
Prebiotics optimize the function of probiotics by fermenting in the digestive tract and serving as food for the friendly bacteria living there. While our main digestive system does not actually digest prebiotics, they are technically being digested by our gut flora.
Prebiotics are essential to probiotic activity because they selectively feed the good bacteria, thus ensuring that our gut environment is composed of the right kind of microflora.
Concerns Regarding Prebiotics
Fructooligosaccharides (FOS) , classified as an oligosaccharide, and inulin fiber, are short-chain fructose molecules with prebiotic properties. Pretty much all prebiotic supplements are FOS or inulin fiber.
Inulin and FOS are used as prebiotics because they feed bacteria colonizing the gut. The basic principle is “feed the good bacteria, the good bacteria grow, the more good bacteria, the better”. While prebiotics do indeed enable good bacteria to thrive in the gut, they can be problematic for people with preexisting digestive issues.
The main issue regarding prebiotics is the increased risk of developing small intestinal bacterial overgrowth or SIBO, in patients with certain gastrointestinal issues including irritable bowel syndrome, Crohn’s disease, diabetes mellitus, low stomach acid, and celiac disease. The risk is also higher in patients who suffer from liver cirrhosis, renal failure, or pancreatitis, as well as those who’ve undergone more than one course of antibiotics.
SIBO is very hard to treat and can cause a host of debilitating gastrointestinal issues, including poor absorption of nutrients, leaky gut syndrome, increased incidence of of food allergies and generalized autoimmune deficiencies.
The overcrowding of bacteria in the gut not only causes competition between bacterial species, but also competition between the main host for nutrition. Protein, amino acids, B vitamins and vitamins A and D are all up for grabs.
If you happen to be at high risk for developing SIBO, there are still ways to ensure that the probiotics you are consuming will be viable and it is a simple matter of researching supplement brands and reading labels. Probiotics that contain the supernatant, that is, the medium in which the bacterial strains present were grown in, are already prepped to thrive. The supernatant, as opposed to prebiotics, is already strain specific, therefore ensuring that the nutrition it provides will enable the growth of pre-selected bacterial strains- those that are serving as the probiotic.
What Are Postbiotics?
Postbiotics are byproducts of probiotic metabolism and some think, a key factor in maintaining long-term digestive health. While they had previously been considered simply as the metabolic waste of probiotic activity, they are now being researched as an alternative to the use of whole bacteria.
Those interested in postbiotics, maintain that their probiotic-produced, soluble makeup could elicit the same effect on gastrointestinal health as probiotics themselves.
Research on postbiotics as an alternative treatment for digestive health is still in progress.
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