Prebiotics

GROWING HEALTHY BUGS

The media has mis-led the consumer to think that carbohydrates are bad for you and should be avoided, especially if you are trying to lose weight. The human machine, and especially the brain, actually function best on carbohydrates. The recommendation of recognized health professionals is that carbohydrates should form almost two-thirds of our daily calories, with the majority of the calories coming from starchy foods.

There are actually a variety of carbohydrates in our food. There are the starches (in pasta, rice, corn, and bread), sugars (in green peas, carrots, lima beans, and fruits), and dietary fiber (in whole grains, legumes, nuts, fruits and vegetables). A newly discovered family of carbohydrates has recently attracted significant attention. This family of carbohydrates, that is found in various plant foods, is recognized for its health-promoting properties.

Fructo-oligosaccharides consist of short and medium chains of fructose, the sugar commonly found in many fruits and honey. These non-digestible food components are found in a number of commonly eaten foods including garlic, onions, leeks, wheat, bananas, asparagus, and artichokes.

Fructo-oligosaccharides (FOS) are classified as prebiotics since they have the ability to selectively promote the growth of healthy intestinal bacteria (such as bifidobacteria and lactobacilli) at the expense of the less friendly putrefactive bacteria (such as bacteroides, clostridia, and other coliforms). Bifidobacteria produce acetic and lactic acids, which inhibit the growth of pathogenic bacteria and stimulate intestinal peristalsis.

What then is the health benefit of having these friendly micro-organisms (bifidobacteria) in the colon? There is a decreased risk of intestinal infections, and their mild laxative effect helps to relieve constipation. While FOS does not prevent traveler’s diarrhea, they can significantly increase the sense of well-being in those patients with traveler’s diarrhea.

Furthermore, the fructo-oligosaccharides (FOS) convey a number of other useful properties. They facilitate the absorption of calcium, and possibly magnesium also, and may somewhat lower the risk of osteoporosis. They also suppress the activity of cancer-causing enzymes in the large bowel. In addition, they have a significant effect on lowering blood triglyceride levels, modulate blood sugar peaks, and may lower the risk of cardiovascular disease.

Because of these properties, we can expect to see these carbohydrates added to various processed foods in the foreseeable future. The usual commercial source of FOS is chicory, the roots of which are extracted with water to produce inulin. Chicory, or blue sailor, grows wild along the highways in the mid-west. Roasted chicory roots provide a coffee-like aroma.

FOS offers a number of health benefits that are also provided by dietary fiber. However, FOS has a number of advantages over fiber. FOS are water soluble, and have a slightly sweet taste. Their lack of texture and viscosity facilitates their easy incorporation into processed foods.

Yacon, which looks like a potato, is a root vegetable from Peru. It has a sweet, juicy taste and is low in calories, since it is rich in fructo-oligosaccharides. Yacon can be successfully used in low-sugar drinks and bakery products.

It is interesting to observe that human milk also contains a significant level (5 to 8 g/L) of unique oligosaccharides (similar to the fructo-oligosaccharides discussed above). These sugar-like molecules are known to provide various health-promoting properties for the infant. These carbohydrates found in breast milk, which act as prebiotics, protect the baby’s intestinal tract from unwanted pathogenic bacteria, lower the risk of diarrhea, and modulate important immune responses in the baby. Breast-fed babies reap all these benefits from human milk, which are not afforded by cow milk.