A prebiotic is not a probiotic. Most people now know that a probiotic is a bacteria which is put in yogurt or other dairy products. Probiotics are also available in pill or powder forms in a wide array of different bacteria formulas. A prebiotic, however, is different. It is, in fact, a food fiber that grows in plants.
What is the Story on Fiber?
We humans have been eating plant fiber for as long as we have been around. In the very distant past, this likely reached 50-100 grams a day as our hunter-gatherer forebears relied on wild plant food for much of their nutrition. Animal foods were infrequently available at that time. So, the bacteria in our bowel became accustomed to and depended on a steady dose of fiber. We now know that fiber comes in two different types – insoluble and soluble fiber. Each plant will have some of each. Wheat, for instance is 90% insoluble, oats is about 50/50 and psyllium is mostly soluble fiber.
All fiber passes through the small intestine unchanged. The enzymes and juices there do not digest food fibers. The insoluble fibers are found in wheat, rye and barley and do not dissolve in water. The bacteria in the colon do not digest or ferment this insoluble fiber. However, insoluble fiber does retain water and in so doing promotes a larger, softer stool, which is easier to pass. It is a benefit we can feel and see.
Soluble fiber does dissolve in water. As with all fiber, it also goes through the small intestine unchanged. In the colon, however, soluble fiber is fermented by bacteria. They actually are the fuel for the bacteria’s own growth. It is here that some amazing and healthy things begin to happen.
The Remarkable Colon Bacteria Factory
My separate essay The Amazing Colonic Cauldron describes what happens within our colon. The short version is that our colon is a seething, fermenting factory of very actively growing bacteria. They are there for a purpose. When they are properly fed by an adequate amount and by the right types of fiber, certain health benefits occur. We and our colon bacteria are mutually dependent on each other. We provide them a moist, warm, oxygen-free environment and feed them properly with the right kinds of food fiber. They, in turn, provide a very impressive list of health benefits such as:
- Dramatically increase the number of good bacteria
- These good bacteria then produce acidic substance that our own colon cells use to maintain their own health.
- Decrease some of the potentially dangerous bacteria in the colon
- Increase the absorption of calcium and magnesium
- Strengthen the bones and increase bone density
- Maintain a robust immune system in the colon
- Modulate blood sugar
- In animal studies, they seem to turn off signals that can lead to colon polyps and cancer.
- Aging, appetite and weight loss – there is some early research suggesting benefits.
- And yes, they can reduce or eliminate stinky flatus.
What Are the Best Prebiotics?
The two prebiotic soluble fibers with the most research behind them are:
- oligofructose (FOS)
These are found in many plants including chicory root, wild yams and other root vegetables, wheat, onions, garlic, bananas, leeks, artichokes, jicama and agave. Another recently described prebiotic is GOS (galacto-oligosaccharide). This is present naturally in breast milk. It is rather remarkable that mother’s milk gives the newborn infant the right fibers to get the baby’s own colon bacteria growing in the best way. Otherwise, GOS is made commercially from the milk sugar, lactose. There is still not a lot of research data available on GOS but it is encouraging up to this point.
Prebiotics and Colon Diseases
It is a fact of life that our diets have changed dramatically in the last 100 years. Our grandmothers would simply not recognize what we now call the Westernized diet. Simply put, food manufacturers and industry now sell “imitation” types of food in boxes, packages and bags, each with dozens of “nutrients” and chemicals added to them. Our intake of fresh vegetables and fruits has dropped dramatically while our use of very cheap animal meats has risen in a similar manner. Additionally, high fructose corn syrup has quietly invaded our lives and intestinal tracts in soft drinks, packaged foods and almost anywhere a sweetener is used. Along with these monumental changes in the types of food we eat, there has occurred the following:
- An epidemic of obesity and diabetes
- Colon diverticulosis
- Colon cancer and polyps
- Ulcerative colitis
- Crohn’s disease
- Irritable bowel syndrome
Well, one might say – so what? All of this could be just coincidence and not a cause and effect. However, present research on the colonic bacteria factory and how it thrives when adequate amounts of prebiotic fibers reach it is rather impressive. We know it is good for the otherwise healthy individual and my guess is that it will play a role in addressing some of the above conditions. While prebiotics are still a game in play at this moment, the real demonstrated health benefits for the otherwise healthy person can simply not be disregarded. So one could say – eat right – your life may depend on it.
© Frank W. Jackson, M.D.