For the last few years we’ve been hearing a lot about probiotics — what started as the ‘latest’ health trend has proven to have staying power as more and more research confirms the body’s need for “good” bacteria.
But other words have appeared alongside “probiotic,” such as; “microbiome,” “gut health,” and “prebiotic.” We’re learning that it’s about more than good bacteria or probiotics — our bodies are host to a complex micro-environment that supports probiotic “colonies,” and just like plants in a garden, these friendly bacteria need optimal conditions to thrive. All these words relate to the fact that we have complex micro-environments in our GI tract that can determine our state of health. Understanding the difference between prebiotic vs probiotic benefits is important to make sure you’re encouraging positive digestive health.
What is a Probiotic?
The word “probiotic” is a combination of “pro,” meaning “for,” or to “promote,” and “biotic,” from “bio,” meaning “life.” Think of “biology,” the study of life, and it makes sense. Probiotics are good bacteria that promote gut health.
There are hundreds of strains and types of probiotics — think of the hundreds of varieties of roses available and you’ll get the idea. One large category, “bifidobacterium,” helps digest fiber and carbohydrates. Bifidobacteria have been linked to reducing the risk of heart disease because of this fiber-digesting characteristic.
Another large group of probiotics is “lactobacillus,” a class of bacteria that helps break down milk sugars. There are dozens of sub-strains of these groups, each with unique characteristics and functions.
What is the Microbiome?
The microbiome in our gut is teeming with any number of micro-life forms, good, bad or otherwise. According to experts, “microbiome” is the name for this garden, the community of bacteria in the digestive tract — but this microbiome is much more than healthy bacteria happily hanging out in the gut — they do several important jobs.
Research has determined that the microbiome contributes to the synthesis of vitamins and nutrients, modulates the nervous system (hence the reference to the gut as the “second brain”), protects us from pathogen invaders, and plays an important role in supporting immune system health.
Microbiome Imbalances: What is Dysbiosis?
Imbalances in the microbiome, caused by things like excess sugar, stress, or poor diet, lead to “dysbiosis.” If the microbiome is like a garden, dysbiosis would be akin to an overgrowth of weeds and pests that compete with friendly plants for food and space. Left untended, unwanted organisms can overwhelm this microscopic world, crowding out health-supporting probiotic bacteria.
Dysbiosis is blamed for a variety of conditions. According to one paper published in the International Journal of Molecular Sciences, “Intestinal dysbiosis is thought to be an important cause of disease progression and the gastrointestinal symptoms experienced in patients with inflammatory bowel disease (IBD).”
If the microbiome is like a garden, dysbiosis would be akin to an overgrowth of weeds and pests that compete with friendly plants for food and space.
This condition has also been linked to food allergies. One paper states, “Gut dysbiosis likely precedes the development of food allergy, and the timing of such dysbiosis is critical. Gut microbiota associated with individual food allergies may be distinct.” The author adds that dysbiosis may affect Type 2 immunity, linked to asthma and allergies.
Another condition associated with dysbiosis is “leaky gut.” This happens when the intestinal walls become inflamed by imbalances in the microbiome. While leaky gut is a much-debated theory, many health practitioners see it as a very real condition — it is associated with general inflammation along with other health concerns.
What is a Prebiotic?
Prebiotics are dietary fiber molecules that nourish the healthy probiotic colonies within the microbiome. More specifically, prebiotics are plant-sourced “soluble” fibers that are used as food by the resident colonies of the microbiome. Many of the benefits of prebiotics can be found in foods rich in soluble fiber.
The most common prebiotic in the food industry is inulin — most comes from \ chicory root. It has been approved by the Food and Drug Administration as an additive to improve the nutritional value of manufactured foods.
Chicory root is just one source of inulin — this form of fiber can be found in 36,000 other plant species. Notably, because of its resistance to digestive enzymes, inulin travels intact all the way through the GI tract until it reaches the colon. There it is broken down as a food source for the microbiome, but this process, a type of “fermentation,” can also cause discomfort and pressure from the gas created as a byproduct.
One paper asserts that, “While all prebiotics are fibers, not all fibers are prebiotics.” To qualify as a prebiotic, a fiber must resist being digested by stomach enzymes and stimulate the growth of intestinal bacteria. According to the author of this paper, “Foods high in prebiotics have been consumed since prehistoric times. Archaeological evidence from dry cave deposits in the northern Chihuahuan Desert show intensive utilization of desert plants that were high in inulin.”
Amazingly, evidence shows that the adult male hunter-gatherer consumed about 135 grams a day of inulin fiber — studies report that the average modern American male consumes about 12 to 13 grams of fiber a day.
Psyllium as a Prebiotic
Is psyllium, found in a number of over-the-counter fiber products, a prebiotic? According to the Microbiome Bulletin, “The short answer, using a narrow definition, is ‘no.’ The longer answer, using a broader definition, is increasingly, ‘yes.’”
One of the qualities of a prebiotic is that it must be ‘fermentable’ in the gut, producing biochemicals that feed healthy bacteria colonies. Psyllium does indeed have these characteristics, alongside an array of additional health benefits, such as promoting healthy blood sugar levels and supporting cardiac health.
The article goes on to state, “Psyllium can shift fermentation to where bacterial communities are the largest, resulting in production of butyrate, a short chain fatty acid (SCFA) that is a primary source of sustenance for cells that line the intestinal wall and serve as a barrier to pathogens.
“While this mechanism is indirect, and by itself does not demonstrate that psyllium itself is a traditionally defined prebiotic, as a purely functional or practical matter, its presence in the colon does appear to confer prebiotic effects.”
How to Get More Prebiotics
Assuming you’re getting plenty of probiotics by supplementation and consuming probiotic-rich foods such as kimchi, kefir, miso, or sauerkraut, how do you support that balanced gut microbiome you’re building?
While there are prebiotic supplements, including prebiotic-rich foods in your diet is an excellent (and enjoyable) way to feed the gut microbiome. Prebiotic foods include:
- Asparagus
- Psyllium
- Onions
- Jicama
- Apples
- Garlic
- Dandelion Greens
Given the returns on the investment in a happy gut microbiome, including improved digestion and elimination, a strong immune system, a defense against food allergies, and clear skin, it seems like little effort goes a long way. To a happy gut!
References:
Prebiotic Digestion and Fermentation
The Gut Microbiome in Food Allergies
Fiber and Prebiotics: Mechanisms and Health Benefits