On prebiotics and probiotics – what labels won’t tell you

Dear Dr. Mo: I would like to know more about prebiotics and probiotics, especially in treating specific conditions – I found it difficult to find information on their applications and effects different strains of probiotics may have.

Probiotics can be found in yogurts

Probiotics can be found in yogurts

Dear reader: In response to your interesting question about use and effectiveness of probiotics, I’ve been browsing the dairy sections (containing yogurts, kefirs and alike) of some popular supermarkets here in Vancouver, BC to actually see what are the health claims the manufacturers (are allowed to) put on their probiotic-containing products.

To my surprise I was unable to find any concrete or revealing claim, which would help a person (patient or clinician for that matter) decide which product to choose and whether or not this particular probiotic product is a right choice for a potential medical condition. Most claimed to support or improve a body function but not to treat a condition/disease. Similar case is with probiotics sold as supplements.

This situation makes your question all the more relevant because in spite of all the probiotic hype in the last 10 years or so, one gets very limited information on their potential effects on the body and our health.

Let me try to fill in the blanks here and give you some basic information about pre and probiotics and what relevant data has been coming out of the clinical studies.

First of all, when it comes to probiotics, their function happens in the intestines, mostly the large one and not the stomach. What they need to do is survive the acidic environment in the stomach as well as all the digestive juices in the upper small intestine and come down closer to and into the large intestine where they can actually play their role.

What is the difference between prebiotics and probiotics?

Main distinction is that prebiotics are not alive while probiotics are.

Prebiotics are usually indigestible carbohydrates present in foods and they yield health benefits indirectly by enhancing the growth and activity of “good” microorganisms already present in our gut.

Probiotics on the other hand are (as per FAO and WHO definition) “live microorganisms, which when administered in adequate amounts confer a health benefit on the host” that is, us.

Synbiotics combine a prebiotic and a probiotic.

The amount of probiotics in a given product (food or supplement) is expressed in Colony Forming Units (CFU) per gram or per capsule and the trick with the “adequate” amount is that it is still not possible to determine a “general dose” for probiotics.

So what’s in our gut that prebiotics and probiotics interact with to provide us with the mentioned health benefits?

Our gut contains a very rich microbial environment we call Microbiota or microflora – these little guys contribute to a variety of local and systemic functions vital to our health and well-being (development and maintenance of innate and adaptive immunity, integrity of intestinal barrier, digestive and metabolic actions, discouragement of growth of pathogenic (bad) microorganisms).

What probiotics have been shown to do is act directly or indirectly on the colonizing (domestic) microbiota in the gut. They can inhibit the growth of pathogens (bad guys) and strengthen the barrier function of the intestinal wall. They reduce cholesterol levels and synthetize folate and vitamin B12. Some preclinical data have shown that probiotics can have anti-inflammatory effects and may exert neuromodulatory actions that moderate our response to stress. These and other potential complex mechanisms help explain both the observed gastro-intestinal benefits and some effects outside this system like reduction in pain perception and reduction of incidence or duration of some acute respiratory diseases etc.

Other than in yogurt, probiotics can be found in kefir, microalgae, sauerkraut, miso soup, pickles, tempeh and even high quality dark chocolate. I know, you are probably surprised with this list and yet, it is not exhaustive – both prebiotics and probiotics can be found in a variety of healthy foods so I encourage you to research further.

And now on to some technical language, which in this case cannot be avoided but it could be useful to orient you around some specific probiotics for specific conditions, so bare with me.

Practical applications

Clinical evidence shows that probiotics like Saccharomyces boulardii (Florastor) and Lactobacillus rhamnosus GG – LGG (Culturelle) can be successfully used to treat acute infectious diarrhea in children and the World Gastroenterology Organization (WGO) does support this. These probiotics (and some other for adults) are also effective in treating antibiotic-associated diarrhea, especially in small children.

Other (less common but more severe) conditions can, according to studies also benefit from probiotic treatment:
Ulcerative Colitis and its post-surgical complication – Pouchitis (probiotic VSL#3); also, Inflammatory Bowel Disease and Irritable Bowel Syndrome (probiotic found to be most successful: Bifidobacterium Infantis), Functional Bowel disorders in children (LGG) Lactose intolerance (L. bulgaricus and S. thermophilus) and Necrotising Enterocolitis in pre-term infants.

Probiotics regularly found in yogurts (Lactobacillus acidophilus and Bifidobacterium) are also generally useful in temporarily augmenting our own microbiota, regulating our digestion and supporting other functions like immune response, metabolism etc.

Whether through yogurts, kefirs, other foods or supplements, probiotics have to be taken continuously when they are needed because they do not permanently colonize our intestines or change the composition of our own microflora and will be effective only while being taken.

And one more thing left to mention is that unless seriously immuno-compromised (seriously ill with extremely weakened immune response), probiotics are safe to use and without reported adverse effects.
Always discuss their use with your doctor to determine which type is best for your specific condition.

Yours in health,

Dr. Mo