How do you evaluate clinical evidence?

Before selecting a probiotic strain for your product there are a few things to consider when evaluating the science and the clinical documentation. Everything from knowing the specific strain and how it has been tested to the design of the study and where it has been published, should be taken into consideration. In the video below Cristina Teixeira, PhD, Senior Scientist at Probi will share some insight and useful guidance in what to look for.

Video transcription:

There are a few things to consider when evaluating clinical evidence for a probiotic strain.

First of all, find out if the strain name of the probiotic in question is specified. For example, just stating L. plantarum or L. rhamnosus is not enough. There are many different strains of L. plantarum so knowing the strain name is very important since they can have very different effects.

Secondly, you need to consider if the probiotic strain has been tested in humans. If so, at what dosage, in what delivery format (capsules, tablets, powder, etc.) and in how many studies. Animal models and in vitro tests can give very useful hints on how a probiotic performs and can help us understand the mode of action, but they do not always translate well into evidence of efficacy in humans. To know if a probiotic is effective in humans, it must be tested in humans.

The probiotic should be tested on a sufficient number of participants. If there are too few people in a study, it is very hard to spot any difference between a probiotic and a placebo, especially in an already healthy population. Then, a much higher number of participants is usually required.

The group studied should also be representative of the demographic group targeted to use the probiotic. For example - people of similar health status, age, gender, etc. The dose of the probiotic used should be specified in CFU counts, and the one that produces an effect is the clinical dose. This is very important since we can never assume that a lower or a higher dose would have the same or an increased effect.

How important is the design of the clinical study?

A well-designed study increases the confidence that the beneficial effect comes from the probiotic and not from other factors. When it comes to the design of the study, the “golden standard” is often referenced. These are randomized, placebo-controlled trials, preferably double-blinded, meaning that neither the participant nor the staff knows who receives the probiotic or the placebo product.

The placebo or control group should ideally have the exact same treatment as the experimental group, with the only difference being that the active ingredient (the probiotic in our case) is not used in the placebo group product. This also reduces doubts about the effectiveness of the probiotic itself not being confounded with other ingredients or behaviors during the trial.

Any other aspects to consider?

It is important to verify if the study was peer-reviewed and in what journal the study was published. A peer-reviewed study has undergone the scrutiny of other experts in the same field and depending on the scientific journal, this examination process can vary significantly. During this process the quality, significance and validity of the study are assessed, errors are identified, and suggestions for improvement of the manuscript can be given to ensure the publication of high-quality research.

We hope you found this useful and know what to look for when evaluating clinical evidence for your probiotics. If you have more questions about clinically documented probiotics - please get in touch at expert@probi.com

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