Choosing a Probiotic Product 

Not all probiotics are the same. Different strains of even the same species may function differently, and different commercial probiotics have been studied for different effects. Furthermore, each person has unique colonizing microbes, host genetics, and diet and medication usage; therefore, each person has the potential to respond to probiotics differently. Those interested should choose a probiotic made by a reputable company and tested for the desired outcomes. Pragmatism may rule the day; if after 2 to 3 weeks a probiotic does not seem to be working, it should be exchanged for another one.

Frequently Asked Questions

Do we naturally harbor probiotics in our bodies?

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We naturally harbor many potentially beneficial bacteria. Probiotic bacteria are frequently derived from these normal colonizing bacteria. Commensal microbes may be beneficial; however, until they are isolated, characterized, and shown in human studies to impart a health benefit, they cannot be accurately called “probiotic.”

Are the best probiotics isolated from a human?

Some hypothesize that a probiotic isolated from a human has properties that make it better able to function in a human. However, bacteria that are native to one person are foreign to another. Furthermore, several probiotic strains not isolated from humans have been shown to have health benefits (such as strains of Bifidobacteriumanimalis subsp lactis). It is important to know whether human studies have shown the probiotic in question to be effective and safe.

Are refrigerated probiotics best?

In general, microbes survive better at lower temperatures. However, technologies for keeping probiotics alive at room temperature have been developed by product manufacturers. It is not necessarily the case that refrigerated products will be superior to those that are not refrigerated. 

Many probiotic yogurts and other food products contain added sugar. Does this negate any health benefits from probiotics?

There is no evidence that the sugar added to sweetened yogurt negates the health benefits associated with the probiotics contained in the yogurt. Sugar is digested and absorbed in the small intestine and would not be expected to interfere with microbial effects farther down the intestinal tract. However, studies comparing identical probiotic products with and without added sugar have not been conducted. When choosing probiotic foods, these foods should be part of a balanced diet. 

Are probiotics still alive if they are dried?

If bacteria are dried and stabilized properly, they remain alive (although dormant) and start to grow again after they reach the moist environment inside your body.

How do probiotic foods differ from fermented foods?

Probiotics must be researched and shown to have health benefits. Unless the cultures in a fermented food have been defined and the food shown to have health benefits due to the live microbes in it, fermented foods do not reach the standard of a probiotic. This is contrary to many popular press communications touting the so-called probiotic benefits of fermented foods such as kim chi, sauerkraut, aged cheeses, kefir, and kombucha tea. Emerging research suggests that our microbiota is deficient and that adding live microbes (including those from fermented foods) may be beneficial to health. However, those assertions are untested hypotheses, not the subject of controlled research. Although fermented foods are tasty, nutritious, and beneficial to health, their study falls short of the scientific rigor needed to elevate them to the status of probiotic. Some probiotic yogurts that are researched are fermented foods that are also probiotic foods.

Can products containing live bacteria that have not been tested in human studies still be effective?

Some companies know very little about the specific health effects of the bacteria they are selling. Scientific studies are expensive to conduct, and not all companies sponsor them. If studies have not been conducted on a strain, it is not known if the strain can survive and function as a probiotic in the human body. A strain that has not been studied for human health effects might be effective. But such a product, in general, cannot be strongly recommended. It is best to purchase a product made by a trustworthy company that can provide documentation of its health effects.

Which are better: foods or supplements?

Probiotics from either foods or pills can be effective. The important consideration is that you are getting high enough numbers of a strain or combination of strains that have been tested for efficacy and work for you. Food sources of probiotics have the advantage in that they can offer good nutrition along with the probiotic bacteria. Supplements can be more convenient for some people and may provide higher levels of probiotic, depending on the specific products.

Mary Ellen Sanders, PhD, is a consultant with Dairy & Food Culture Technologies in Centennial, Co.


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