However, recent science seems to indicate another, perhaps even better, method of increasing the body's colonies of good bacteria. That is, by adding "prebiotic" ingredients to the body as opposed to the bacteria themselves. Prebiotics are fiber sources that nourish the beneficial bacteria in the intestine. An increase in the good bacteria population helps to maintain healthy colon function and reduce gas and bloating, among other benefits.
The market has been largely created by three European producers of prebiotic nutrients. Other ingredient manufacturers are increasingly looking to promote the prebiotic effect of their products as evidence suggests that prebiotics could be even more useful than the probiotic bacteria that they feed. Here's more on the topic:
One new study recruited 39 healthy adult volunteers (average age 33.9) and assigned them to daily supplements of prebiotic or placebo for four weeks. The researchers found that, after four weeks of supplementation, the prebiotic group exhibited a 10-fold increase in Bifidobacteria levels (one of the "good" gut bacteria), while no such increases were observed in the placebo group. Moreover, the increases were sustained in the weeks following the end of supplementation. These results support the conclusion that prebiotics are able to sustain a significant level of beneficial bacteria for long periods after its cessation.
Recently, another study from the University of Reading in the U.K. suggested solid benefits for prebiotic supplementation. Their double-blind, placebo-controlled, crossover human study showed that both low and high doses (five and eight grams per day, respectively) boost the population of 'friendly' bifidobacteria in the gut without side effects. This study was published in the European Journal of Clinical Nutrition.
Prebiotics are being studied for their benefits to bone health and colorectal cancer, and scientists are now looking also at potential benefits for the immune system, weight management, and intestinal health.