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Healthy Bugs
by author Jacques Goulet, PhD

Most of us have heard of healthy bacteria, the kind we need to keep the unhealthy bugs that live in our gastro-intestinal tracts in check.

Probiotics is the name for these beneficial bacteria, which the World Health Organization (WHO) and the Food and Agriculture Organization of the US (FAO) define as “live microorganisms, which when administered in adequate amounts confer a health benefit on the host.”

For the producer, the person prescribing them, and the person using probiotics (a.k.a. “the host”), a major concern is the concentration and viability of the microbial strains that are to be incorporated in commercial products.

How can producers maximize the health benefit potential of probiotics? The most reliable new research tells us there are five factors involved.

1. Selecting multi-strains

Since the intestinal tract is colonized by a large diversity of bacteria (300 to 400 different strains), and since many bacteria also produce antimicrobial compounds against other bacteria, it is very unlikely that a single strain of probiotic bacteria will perform well in the gastro-intestinal tract of every user. There is now a growing scientific consensus that multi-strain probiotic products have a wider scope of application and are more likely to show health benefits in a larger proportion of users. This is due mainly to the diversity and synergy of the selected strains.

2. Producing the most highly active strains

Probiotic bacteria are cultivated in carefully formulated nutrient broths, under sterile conditions, and within stainless steel fermentors. They are grown and harvested under conditions that maximize their viability and probiotic activities. In order to preserve the integrity of their cellular structures and enzymatic activities, they are ultimately dehydrated by freeze-drying.

3. Providing adequate dosage

According to the WHO/FAO definition, we need “adequate amounts” of probiotic microbial cells to confer health benefits to the host. It is now generally recognized that minimal concentrations should not be less than 100-million live cells per gram for fermented products like yogurts, and one-billion viable cells per dose (usually one capsule) for most freeze-dried probiotic products.

4. Preserving viable cells

The best storage condition for all fresh and dried products is refrigeration. However, we see more and more commercial products claiming very good stability at room temperature due to the development of improved preservation technologies.

5. Delivering viable cells

Even though carefully selected bacteria are produced and stored under the best conditions to preserve their viability and probiotic activities, there is still one major obstacle to overcome in order to insure maximum potency—the acidity of the stomach.

The delivery of highly active bacteria in the intestinal tract, under minimal physiological stresses, can now be achieved with enteric-coated capsules. This is a very efficient vehicle to bypass the acidic environment of the stomach and weaken the effect of bile salts. Since the bacteria will rehydrate when they’re in a nonaggressive environment, their viability will be maximized as well as their physiological, beneficial activities, and they will be less diluted (by the food bowel) during their transit through the intestinal tract. This maximizes their dosage and their potential for improving the health status of the person taking them.

Multi-strain, shelf-stable, enteric-coated probiotic products are most likely to give us the best of what the “healthy bugs” have to offer to help keep our gastro-intestinal tracts in balance.

Jacques Goulet, PhD, is a professor of Food Science and Nutrition at Laval University, Quebec. He can be reached at 418-656-2131 ext. 5454, or by e-mail: jacques.goulet@aln.ulaval.ca.

Source: alive #260, June 2004