by Lisa Keilhofer

Probiotics – High potential with potentially high risk

Probiotics are harmless, aren't they? (Picture: © Andrii Zastrozhnov -

The pharma industry has a new showpiece: probiotics. And we are already highly influenced by the marketing strategies of the companies. Are you ready for a little proof test? Let’s go! Which of the following keywords have you heard of: Hyaluronan, antioxidants, L casei cultures. And what specific effect do they have? No clue? Don’t worry, if there is a button on your yogurt suggesting some positive effect, then it should be all right and you can give it a try. Right?

With this article, we would like to sort out facts from dangerous half-knowledge. As a matter of fact, this we can tell you in advance, probiotics are a good thing and can support our health a lot. In most cases, however, they are just a waste of money and in some cases even cause severe damage. Here are the facts:

What are probiotics?

The fact that FAO (Food and Agriculture Organization of the United Nations) and WHO (World Health Organization) had to come up with a common definition shows the complexity of the question and the confusion that came along with it. The definition of the year 2001 was confirmed by the International Scientific Association for probiotics and prebiotics (ISAPP) in 2013. Probiotics are live microorganisms that, when administrated in adequate amounts, confer a health benefit to the host. Consequently, yogurt – often named as probiotic food – does not contain any probiotics, by definition. Only if the intended probiotic of a specific product is classified regarding genus, species, and strain, and its effect is scientifically confirmed, the product may legally call itself probiotic.

>>> Detailed information about probiotics and prebiotics

And what are probiotics good for?

We definitely hand it to the average consumer to not be able to recite the above definition, but still has a certain understanding of probiotics being live organisms in our food. But, be honest, what is it that probiotics are exactly doing? (and “makes you healthy” does not count as an answer!) Right, we actually do not know. Only that it is said to be good in some way.

Probiotics should change our intestinal flora in a way that fosters the developing and sustaining of a stable microbiome. This can be achieved by metabolites or by targeted elimination of pathogenic bacteria with anti-bacterial substances. The effect ceases with the excretion of the probiotics. So, to ensure a permanent effect, the probiotic has to be taken regularly.

>>> The best food for your microbiome

There’s no harm in trying, is it?

All clear so far. We are talking about food supplements that often come as capsules, sometimes also as directly added bacterial cultures, and are said to be fostering our intestinal health. What can go wrong in trying?

>>> A warning comes from the US-channel CNN: Probiotics are mostly a hype with little effect. The USA are among the high-consumption countries in probiotics. Between 2007 and 2015, the number of consumers quadruplicated. In the US, as in Europe, probiotics can be purchased over the counter. You can get it in pharmacies, where at least you can get consultation when you ask for it. Or you simply get it in supermarkets without further restrictions. According to CNN, this is exactly where the danger potential lies.

Probiotics are demonstrably useful for our organism. But not any probiotic cures every problem. In fact, most probiotics do not have any effect, at all, because they are either consumed without indication or – and it is getting complicated here – because they do not have any specific effect, what makes them not a probiotic in the first place, according to the definition above.

Is that allowed?

Only a few probiotics are useful, so it is up to the consumer to choose them carefully! (Picture: © Andrii Zastrozhnov -

To sum things up, every product can call itself “probiotic” (which is often wrong, as a matter of fact, but no one seems to care) and the stuff can be sold over the counter without further consulting. It is solely within the responsibility of the consumer to select the right one for a specific therapy. And let’s get back to our little test at the beginning of this article: Let’s be honest, we have all bought one the other probiotic-something, just because it sounded pretty healthy and probiotics are considered good, anyway.

You feel a bit caught out? Good. Most likely, the only thing that happened so far is that you spent money for a thing that doesn’t really harm you, but does not help much, either. And that’s a pity, because probiotics can help a great deal.

What is good for what and what is not?

A study by the University of Washington, the CNN article refers to, confirms probiotics to be reasonable dietary supplements when selected wisely. In doing so, it is important to know the exact strain and chose the proper one for our intended therapy. So, in order to find the perfect match, we need to exactly scrutinize our microbiome, find out where the deficiencies lie and focus on those in our therapy.

Common preparations on the market are not helpful here, as they are too unspecific. Self-medication and self-guided therapies are mostly without success. Under medical supervision, with the right, clinically confirmed strain of bacteria in the adequate dosage, given as vital supplement that is resistant to the acidity in the stomach, probiotics can achieve remarkable effects.

Certain probiotics can help premature babies. Also, in preventing infection with Clostridium difficile, probiotics turned out useful. However, after the outbreak of the disease, a therapy based on probiotics showed to significant success. The same goes for Crohn disease, ulcerative colitis or irritable bowel syndrome.

What is the worst case?

A very interesting fact is that studies indicate we should refrain from probiotics therapies of gastroenteritis with diarrhea with children in the USA, while other studies prove children with diarrhea in developing countries to show a shortening in the duration of the illness after the administration of probiotics. These seemingly contradictory outcomes underline the importance of knowing the patient’s gut microbiome and select the bacterial strain accordingly.

One of the leading scientists of the study points out that some strains are indeed known to be very helpful and probiotics should not be dismissed completely. At the same time, it is to be considered that wrong therapies can cause infections. We are dealing with live organisms, at last. The worst-case scenario is, these live organisms get into our blood stream and cause sepsis.

All of you who have thought that it cannot be too bad to take a daily pill of a probiotic cocktail and just give things a try with no effect at all as worst-case, should be taught better now. The market is full of so-called probiotics that actually are none per definition. Or the consumer deals carelessly with a live organism that we should not just let our system enter like that.

Lisa Keilhofer
Lisa Keilhofer

Lisa Keilhofer studied at the University of Regensburg. She works in internationalization and as a freelance editor.

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