Prebiotics – What Are They & Why You Should Care

By in Nutrition

Prebiotics are relatively new to the nutrition scene and consequently many people don’t know what they are. In short, prebiotics are substances that act as food for probiotics. Probiotics are the microorganisms in your gut which keep you healthy. So our friendly prebiotics are feeding your probiotics. But why do you care?

Too much importance has been placed on the concept of getting all of your micronutrients (vitamins and minerals) and other “miracle substances” (shark cartilage, goji berries, anti-oxidants) in order to achieve health. This has caused many people to focus on “getting more” in their diets instead of “getting less”.

Once you’re past the basic understanding of macronutrients (protein, fat, carbs), 80% of success in nutrition is avoiding the wrong stuff, as opposed to making sure to get enough of the “right stuff”. This idea is not popular (it’s much easier to focus on popping pills and taking the right stuff versus avoiding highly tempting foods) but study after study has shown this to be true. Just look at the ability of caloric restriction to provide enormous health benefits across all species. The mild stress of not always being in complete abundance is very beneficial to organisms in ways that we are only beginning to understand.

Having said that, there are some substances that are good to have in one’s diet. Prebiotics are one of them.

Probiotics are friendly micro-organisms that reside in our gut and influence our digestion, immune function, and according to some interesting recent research, even the state of our mind. People have long known about the importance of keeping our little intestinal friends healthy, hence the popularity of probiotic supplements and yogurt that contains live cultures. But what feeds them? Prebiotics, of course.

Prebiotics are readily found in nature in the fibers of common fruits and vegetables such as peaches, leeks, garlic, bananas, onions and artichokes. They are also found in non-digestible plant-based fibers such as inulin (chicory root), isomalto-oligosaccharides, and fructo-oligosaccharides. While these are not digested in the upper GI tract like regular food, they still serve as effective and helpful prebiotics – food for your gut bacteria.

Providing food for the good bacteria in our gut has a whole host of benefits, but I only want to focus on one here – the ability of prebiotics to stop hunger. I was surprised to learn about this but it helps explain something I’ve experienced and never understood. A lot of research has been done on the effects of probiotics on hunger with both animal and human subjects. Researchers found that prebiotics increase anti-hunger peptides in the colon. These peptides directly suppress appetite so that we don’t experience the same feelings of hunger we feel when prebiotics aren’t present. They also help the body use insulin more effectively, which is always a good thing.

Other studies have found that prebiotics may help prevent fatty liver disease (which is becoming very common) and the formation of fat tissue.

The American Journal of Clinical Nutrition published a human study of 48 overweight but healthy people. They were given either a prebiotic or a placebo for 12 weeks and they were told not to make any lifestyle changes. The prebiotic group lost an average of 2.27 pounds while the placebo group actually gained 1 pound. The prebiotic group reported much less hunger and they also had marked improvements in their blood sugar readings and insulin function.

This may explain something that many Quest customers routinely report – that Quest Bars have a strong ability to reduce hunger disproportionately to their calorie content. In other words, eating a 170 calorie Quest Bar seems to reduce hunger much more than eating 170 calories of other foods.

Maybe it’s the prebiotics (isomalto-oligosaccharides) that are responsible for this effect.


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