It's All About the Strains


Would you use a pack of chihuahuas to pull your dog sled or give your grandmother a Saint Bernard as a lap dog? Even though all dogs are from the same species and subspecies, Canis lupus familiaris, their traits and behaviors vary by breed. Similarly, even though bacteria from the same species may share certain characteristics, their functions can vary by strain.

When you buy a bottle of probiotics, the genus and the species are used to identify the different types of bacteria in the product. For example, in Lactobacillus acidophilus, Lactobacillus is the genus and acidophilus is the species. Some companies also include the strain at the end of the name. The strain may appear as letters (Lactobacillus rhamnosus GG), numbers (Bifidobacterium infantis 35624), or a combination. There is no standardized format for strain naming, so you may even see the company name within the strain name. Regardless of the naming system used, strains help us distinguish between benign, helpful, or harmful bacteria from the same species.

Probiotics are often called “beneficial bacteria” because these particular species provide a helpful service for us. When research is performed on probiotics to investigate the positive effects, only one strain of a particular species is tested. Lactobacillus rhamnosus GG is an extensively studied bacterial strain that has been shown to reduce diarrhea and shorten the duration of GI-symptom episodes in marathon trainees. But just because one strain of Lactobacillus rhamnosus shows a therapeutic effect, does not mean that all strains of this species will have the same benefit.

When purchasing probiotics, it’s essential to identify what you hope to achieve by taking them and then select a probiotic that uses strains that have been shown to provide the benefits you are looking for. If you are searching for a probiotic supplement to support your endurance racing, as I assume you are, then you've found the right place

by Katelyn Collins

Katelyn Collins, is a future registered dietitian with a passion for probiotics, a knack for nutrition communications, and a love of athletic pursuits on both land and sea.