Postbiotics is a relatively new term that’s been coined to refer to the metabolic byproducts of those probiotic bacteria, which seem to be responsible for many of the beneficial effects of probiotics.
Max writes: "I’ve heard you talk about prebiotics and probiotics but I just came across a reference to postbiotics. What are these and how do they affect our health or nutrition?"
All three of these terms (prebiotics, probiotics, and postbiotics) have to do with the trillions of bacteria that live and work in our digestive tracts. Understanding the complex interactions between us and our unseen guests has become the leading edge of nutrition and health research. Everything we thought we knew about nutrition, digestion, immunity, and metabolism is now being re-evaluated through the lens of the microbiome. Who knew these little critters were so important?
What Are Probiotics and Prebiotics?
Probiotic refers to the bacteria that we get from foods (and supplements) that are thought to have beneficial effects in the body. The lactobacillus and bifidobacteria that we get from yogurt, for example, are some of the more common types of probiotic bacteria.
See also: Fermented and Cultured Foods
Prebiotics refer to those foods that we consume which also provide fuel for the bacteria that inhabit our intestines. This fuel is mostly in the form of plant fibers from vegetables, grains, and legumes. We humans lack the enzymes to digest these fibers, so they arrive more or less intact in the large colon. Unlike us, the bacteria living there have the enzymes to digest them. Eating more of these foods can bolster the health and vitality of your intestinal population.
What Are Postbiotics?
Postbiotics is a relatively new term that’s been coined to refer to the metabolic byproducts of those probiotic bacteria. Metabolic byproducts is sort of a cleaned-up way of saying "waste products." But it just goes to show you that one organism’s trash is another organism’s treasure: these bacteria produce and excrete compounds into our digestive tracts, which seem to be responsible for many of the beneficial effects of probiotics.
As they go about their cellular business, bacteria produce (among other things) hydrogen peroxide. This may protect us from salmonella and other pathogenic bacteria or yeasts that might be hanging around the neighborhood looking for trouble.
Short-chain fatty acids are also byproducts of bacterial metabolism. One of these, acetic acid, is the substance that gives vinegar its distinctive tang. And this may be one of the ways that a healthy microbiome can promote healthy body weight. When you have more beneficial bacteria, they produce more acetic acid, which helps to regulate your blood sugar and gives your metabolism a modest boost.
Butyric acid is another short-chain fatty acid produced by the gut bacteria. It helps promote colon health by providing an energy source for colon cells.