Prebiotics work with probiotics. They are saccharides, sugar molecules that are about half as sweet as sugar. Initial research focused on their use as low-calorie sweeteners. As the research grew, however, it became apparent that these food molecules could play an important role in health maintenance.

Studies found they stimulate the growth of good bacteria, such as bifidobacteria and lactobacilli, while promoting a reduction in disease-producing bacteria, such as clostridia, klebsiella, and enterobacter. They make the intestinal pH more acidic, creating an environment that enhances absorption of essential minerals, including calcium, magnesium, iron, and zinc.

We ingest prebiotics through our food. They pass through the digestive system whole and become fermented by the colonic microflora. There, they produce lactate and short-chain fatty acids, especially butyrate, the main energy source for the colonic cells. Butyrate helps cells maintain good function and repair.

Because the great majority of gut bacteria are in the colon, butyrate is essential to protect the mucous lining and prevent leaky gut syndrome and translocation of bacteria to other organ systems. Fructooligosaccharides (FOS) and inulin, two prebiotics that have been well-documented, are naturally found in our food.

FOS has been shown to reduce serum triglyceride levels, protect against colon cancer, and help normalize insulin levels. Because of their health-building qualities, inulin and FOS are being researched as possible functional food additives by companies throughout the world.

Dosages as low as 2.75 grams will dramatically increase bifidobacteria. They have also been shown to be antagonistic to at least eight disease-producing microbes including salmonella, listeria, campylobacter, shigella, and vibrio. On average we consume about 2.5 grams per day of FOS alone.

These fibers have been shown to increase levels of bifidobacteria in the colon. In addition, FOS has been shown to increase acidophilus. Foods containing FOS and inulin include Jerusalem artichokes, onions, chicory, garlic, leeks, fruit (especially bananas), soybeans, peas, legumes, eggplant, burdock root, asparagus, sugar maple, Chinese chive, and (in small amounts) whole rye and whole wheat.

A recent study looked at the effect of honey on the growth of bifidobacteria in comparison to FOS, galactooligosaccharide (GOS), and inulin. Researchers reported that the honey worked as well to promote the production of lactic and acetic acid by the bifidobacteria.

This study was a test-tube study, but it just may be helpful to add a spoonful of honey to your beverages. Yum! Many people experience gas and bloating when they first begin to take FOS and prebiotics. This passes after a period of a couple of weeks. You can either persist or lower your dosage and increase gradually.

Human studies show that the most growth of beneficial bacteria is seen in the people who need it most. Benefits increase up to 10 grams daily. After you stop taking prebiotics, your bacterial levels go back to where they were in about two to three weeks. They work synergistically with probiotics and can be taken together for best results—together they are being called synbiotics.

Probiotic Supplements

Because flora do not permanently stay in the gut, we need to get them either in our foods, such as yogurt or kefir, or to use a supplement. The composition of intestinal flora usually remains fairly constant in healthy people, but it can become unbalanced by aging, diet, disease, drugs, poor health, or stress.

In fact, problems due to imbalanced flora have become widespread. Eating yogurt and cultured dairy products can maintain healthful friendly flora colonies in people who are already healthy, but once disease-producing microbes have colonized, probiotic supplements are necessary.

Taking daily probiotics increases our body’s ability to protect itself from illness. Because of their acidloving nature, they easily survive the high-acid environment of the stomach. Once in the intestinal tract, they colonize and replace less desirable residents.

However, not all probiotic supplements provide the same benefits. According to Natasha Trenev, an expert on probiotics, various strains of acidophilus can differ genetically by as much as 20 percent. This is a huge difference, when you consider that the genetic difference between mice and man is about 2 percent.

What to Look for in a Probiotic Supplement

1. Look for Lactobacillus acidophilus and Bifidobacteria bifidum.

2. Choose an age-appropriate product. For a baby or toddler, B. infantis is appropriate; for children and adults, the moststudied strain of L. acidophilus is DDS-1.

3. Choose a product that is condition appropriate when it’s available. There are now supplements that are specific for lactose intolerance, sugar malabsorption, irritable bowel syndrome, and diarrhea. There may soon be other specific products for psoriasis, vaginal infections, inflammatory bowel disease, and other health conditions.

4. Most of the best products come refrigerated. There are some viable products on the market that are stored at room temperature.

5. Bacteria multiply very quickly, but they need enough food once they reach the intestines. Some products contain inulin, FOS, or other prebiotics that help the flora grow. This can vastly improve the viability of the product. Just note that some people bloat from FOS.

6. Combination supplements with several types of flora are helpful. Bacteria compete for the same food supply, so look for freeze-dried products. Freeze-drying puts the flora into suspended animation, keeping them dormant until placed in water or in your body.

For preventive measures, take about a billion microbes of each protective species once a day. This is usually about ¼ to 1½ teaspoons or 1 to 3 capsules. For therapeutic purposes, take this amount three times a day or more. In one study, those with ulcerative colitis used 350 billion organisms.

If you take probiotic supplements and have sudden bloating, diarrhea, gas, or worsening of symptoms, this is not necessarily a bad sign. As the diseaseproducing bacteria and fungus are killed, they release chemicals that aggravate symptoms. If this happens, begin again with tiny amounts and build up your dosage slowly to avoid the die-off reaction.

Probiotic supplements are also important for the prevention of traveler’s diarrhea. If you plan to travel outside the United States, take a probiotic supplement daily. Studies show that it significantly increases your ability to withstand the new microbes you will be exposed to.