How to Choose the Right Probiotic

By now you have probably heard about probiotics, and if you have chronic gastrointestinal problems chances are that you have tried taking them. Many of our patients report having tried probiotics at least once during the past year. However not as many of them are aware that probiotics are not all the same. A certain probiotic that might work in one circumstance may not be the most appropriate choice in another situation. While most experts agree that probiotics are unlikely to harm you, simply grabbing any old probiotic product off of the shelf and taking it is unlikely to help either. In order to get the right probiotic for the job, it is necessary to look beyond marketing and media hype and understand a bit about what probiotics are, and how they work.

What Are Probiotics?

Probiotics can prevent, mitigate, and treat many of the current health crises facing the world.

Robert Martindale, MD, PhD, Chief, General Surgery, Medical Director, Hospital Nutrition Support, Oregon Health and Sciences University

Probiotics are live microorganisms that confer a health benefit on the host when consumed in adequate amounts. Using this definition, we can identify some simple parameters to determine whether a given product may or may not be useful. More importantly, we will be able to see why it is recommended that you consult with a health professional familiar with probiotic usage when taking probiotics for specific health conditions.

Probiotics Are Live Microrganisms

Probiotics need to be alive in order to confer health benefits. For this reason, food products which have been pasteurized after being cultured or fermented cannot be probiotics as all of the microorganisms have been killed by the pasteurization process. Similarly, baked goods do not have any living microorganisms remaining after the baking process is completed.

Only food products with live microorganisms can be considered probiotic foods. These include cultured dairy products like yogurt and kefir, fermented vegetables such as sauerkraut and kimchi, and kombucha tea. Foods can also be fermented and cultured at home with proper instruction and training in prevention and identification of overgrowth of potentially pathogenic microbes such as Salmonella or certain strains of E. coli

Probiotics can also be consumed in capsule, tablet, or powder form. These forms of probiotics are much easier to standardize for specific dosages. However in order for the dosage to be maintained also requires that most probiotic supplements be kept refrigerated. Since probiotics are live organisms, they are very sensitive to changes in temperature and humidity, and due to the relatively limited amount of space in the capsule, probiotic microorganisms can consume all of their food substrate rather quickly if left out at room temperature or above. For this reason, it is important to obtain probiotics from a reputable distributor who can assure that the probiotic supplements were stored and shipped in the proper conditions. In some cases, manufacturers have devised ways to make probiotic formulas more shelf stable. Some manufacturers are also beginning to consider health applications for spore-forming probiotics, as these microorganisms remain largely dormant until they enter the body.

Finally, it is critically important to understand that probiotics need to stay alive in the digestive tract in order to confer health benefits. Functional probiotic foods and beverages are often considered by doctors and scientists to be a more efficient method of delivering probiotics as the presence of large amounts of food substrate help to keep probiotic colonies viable both outside and inside the human body. However, pill and powdered delivery formats have certain advantages as well. For example, probiotic supplements are typically cheaper to transport and hold because they weigh less per unit, and also have smaller volumes. They can also be added to foods and beverages right before consumption.

Probiotics Confer Health Benefits to the Host

Since probiotics- by definition- confer health benefits it might look like a no-brainer for anybody who is interested in general maintenance of health and wellness to consume probiotics on a regular basis. However for people seeking specific health benefits from probiotics it is important to be specific about the strains one is consuming.

It is very inaccurate and misleading to extrapolate results from research conducted on one bacterial strain to another.

Jason Hawrelak, ND (SCU), BNat(Hons), PhD, MNHAA

A considerable amount of scientific research demonstrates that the health benefits conferred by probiotic microorganisms are specific to the strain that is being consumed. Microbial strains are akin to breeds of dogs. Though all dogs are of the same species, and can interbreed, the behaviors of one specific breed can be very different from one to another. In the same way that a Portuguese Water Dog might behave very different from a Collie, different strains of the same microbial species have been shown to have confer specific health benefits.

These are just some of the probiotic strains that have scientifically documented therapeutic uses. While a 2010 survey of physicians revealed that 93% of their patients were taking probiotics, remarkably, most believed their use was not supported by scientific data. This wide discrepancy between the scientific literaure and physician awareness about the scientific literature is a cause for concern and perhaps rooted in a cultural bias against agents classified as dietary supplements rather than drugs. This may be due to a persistent myth among physicians and scientists that dietary supplements- including probiotics- are not regulated by FDA. In actuality, FDA does regulate dietary supplements and probiotics, however they are not regulated in the same way as drugs.

The bottom line for probiotics is that they have not been as extensively researched for specific conditions as have drugs. However, the scientific consensus is that probiotics are very likely to confer some benefit and not very likely to cause harm. This makes it very easy for a general practitioner or gastroenterologist to rationalize allowing their patients to take probiotics. However a medical doctor would be very unlikely to recommend taking a probiotic in lieu of a more established or conventional treatment.

Generally speaking, more doctors would probably be willing to agree to a trial of probiotics for patients with mild to moderate symptoms and no clear diagnosis or in functional bowel disorders such as irritable bowel syndrome, than they would for those with severe symptoms or advanced disease.

Although there is much attention being placed on using probiotics as a (very successful) therapy of last resort in the form of fecal microbiota transplantation, probiotics also have a role to play as a first line of defense for health maintenance and disease prevention, when utilized responibly, and perhaps more importantly, responsively.

Probiotics Must Be Consumed in Sufficient Amounts

Probiotic microorganisms must be consumed in sufficient amounts in order to confer health benefits to the host. In addition, a preponderance of research indicates that many of the health benefits conferred by probiotics require their continual consumption in order to be fully realized. This could be another reason why consuming probiotics daily as food may make a lot of sense as a general healthy dietary practice.

Many probiotic products do not contain sufficients amounts per dosage to support the various health benefit claims by the manufacturers. This, in part, has led to a number of probiotic advertising class action lawsuits in recent years. Few of these cases have been resolved on their own merits, however one of few cases that were resolved, a U.S. District Court found that the health claims made by the manufacturer were, in fact, substantiated with scientific evidence.

Nevertheless, when consuming probiotics for specific health benefits it is important to consume them in sufficient quantities substantiated by scientific research. Otherwise it would be unreasonable to expect to receive health benefits from probiotics solely from the claims made on the label. This is another reason why it is important to consult with a health professional knowledgable about probiotic health benefits rather than relying upon word-of-mouth or marketing materials found in stores or on the Internet.

Summary and Conclusion

Probiotics are live microorganisms that confer a health benefit on the host when consumed in adequate amounts. In order for a functional food or dietary supplement to live up to the term probiotic, the product must meet three specific criteria:

While probiotics continue to capture the attention of both scientists and the public, it will likely become increasingly necessary for a specialized regulatory framework to determine the parameters for how probiotics can be manufactured and administered, and for which health benefits may be claimed by which specific bacterial strains. For these reasons it is recommended that anybody seeking specific health benefits from probiotics consult with a health professional familiar with the scientific research to support their usage, and who is also knowledgable about potential side effects and interatctions with other herbs and medications.


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