reid probiotics definition

You’d think we’d know probiotics by now

Prof. Gregor Reid, PhD MBA, Lawson Research Institute, University of Western Ontario, Canada

When I took my MBA, it was primarily to understand business and its relationship with science. I thought I learned quite a lot, but some things puzzle me to this day. Marketers know that messages are more effective when repeated. But, a guy called Thomas Smith (maybe related to Scotland’s famous Adam Smith who pioneered political economy, whatever that means!) wrote a guide in 1885 (yes that long ago!) called “Successful Advertising,” that noted:

The 1st time people see or read something, they don’t see it.
The 2nd time, they don’t notice it.
The 3rd time, they are aware that it is there.
The 4th time, they have a fleeting sense that they’ve seen it before.
The 5th time, they actually read the ad.
The 6th time, they thumb their nose at it.
The 7th time, they get a little irritated with it.
The 8th time, they think, “Here’s that confounded ad again.”
The 9th time, they wonder if they’re missing out on something.
The 10th time, they ask their friends or neighbors if they’ve tried it.
The 11th time, they wonder how the company is paying for all these ads.
The 12th time, they start to think that it must be a good product.
The 13th time, they start to feel the product has value.
The 14th time, they start to feel like they’ve wanted a product like this for a long time.

This goes on and on. It made me think about the definition and interpretation of probiotics. The version published in 2001 through two large respected organizations (WHO and UN FAO) has pretty much been universally accepted, and again reiterated in 2014 in a highly prestigious journal. That article is widely cited, so you’d think people would get it, right? They’d know what a probiotic is and what it’s not, right?

Yet, I speak at events around the world, and the same things keep coming back. Whether it is the 6th or 7th response (thumbing noses or being a little irritated) or a speaker confidently talking about probiotics and getting most of it completely wrong, I have scratched my head to the point my hair is falling out (a good research topic if someone would like to investigate this correlation). I even told a first year dentistry class of 55 students three times that the definition of probiotics would be an exam question. Only 8 got it correct!

I went back to the literature, as all scientists do, and asked the question “Why can’t people see what’s right in front of them?” It turns out either they believe you don’t have the answer, or you can’t have the answer, or you can’t have the answer right here and now, or they believe the answer needs to look like something else. This has a name – it’s called a schotoma – which seems appropriate, like people taking a shot at probiotics, or taking a shot at defining it, or providing their version of what it is.

With my hair now almost as thin as Glenn Gibson’s, I’m at a loss. Probiotics are not dead, not undefined/unstudied fermented foods, not in you unless you’ve taken them, not synonymous with “acidophilus”. They don’t typically colonize and they don’t have to be isolated from a human to work for humans. Products with lots of strains or a huge dose are not necessarily better products.

If you want to find the right probiotic for you, too often your doctor or health shop worker doesn’t give the best advice, because they haven’t read the articles. You should go or and find something suitable for your needs. If you want some good general guidance, check out ISAPP infographics and ISAPP videos. If you are a company, don’t call your product a probiotic unless the contents have been tested in humans at the dose you are delivering at end of shelf-life. Call it strains of lactobacilli or something along those lines. Not being on one of these charts might be a sign that you’ve not done the needed work to call your product a probiotic.

But hey, maybe you need to read Thomas Smith’s guide. Probiotics are really quite simple. But, then again it’s only the hundredth time I’ve said that.

As for prebiotics, I’ll let someone else go bald on that one.

probiotics larson photo

Probiotics: the importance of the complete product

February 11, 2018. By Dr. Olaf F.A. Larsen, Assistant Professor (0.2 FTE) at Athena Institute, VU University Amsterdam, The Netherlands, and Science Manager at Yakult Netherlands.

Probiotics are, according to the WHO and later updated by a consensus panel convened by ISAPP, defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Most scientific literature ties probiotic properties to individual strains, although evidence suggests that some health benefits may generalize to the species or genus level. Another important factor in how a probiotic performs is the type of matrix (e.g., a milk drink) that carries the probiotic. Indeed, many successful commercial probiotic products are largely defined by both the probiotic contained and the final product format. A plethora of probiotic products are available, ranging from fermented milks/yogurts, cereal products, juices and freeze-dried products (powders and pills). Some products claim to be probiotic but lack substantiation, such as “probiotic” pizzas and mattresses. It is likely that the probiotic properties are not solely determined by the probiotic strain itself, but also by the harbouring matrix. Hence, in order to fully understand the parameters that drive functionality of a specific probiotic, the total product should be evaluated.

Recently, the influence of the matrix on measures of probiotic functionality was reviewed. The data suggest that the matrix impacts several parameters, including number of viable probiotic microorganisms present in the product through shelf life and survival of the probiotic through the gastrointestinal tract. As an example, the number of viable microorganisms in the product as a function storage time can be profoundly different depending on the combination of probiotic strains and matrices used. Some products in which lyophilized probiotics are incorporated into a peanut butter matrix can have storage times up to 50 weeks. Whey proteins present in milk may improve gastrointestinal tract survival. Therefore, one should be aware that it is likely that viability of the probiotic will be impacted by the carrier matrix.

Another way that matrix can be important is through delivery of additional beneficial substances. For example, milk products contain various vitamins, calcium and high quality protein. In the case of a fermented probiotic product, the fermentation process may yield functional substances such as antihypertensive peptides. These effects can be considered as “additional benefits” of the matrix, beyond the impact of matrix on probiotic survival both in the product and in your body.

The body of scientific evidence falls short, however, of proving the importance of matrix on health endpoints. For a given amount of probiotics delivered, we lack comparative studies that prove that the end-benefit of one carrier matrix is better than another. Many supportive studies suggest that this will be the case, but until head-to-head human studies are conducted, we don’t know for sure.

Given the impact the matrix exerts on probiotic survival, and the possible effect on probiotic effectiveness, keep in mind the importance of efficacy studies conducted on the complete probiotic product. We need more research to fully understand the role of matrix on probiotic effectiveness, but the strongest evidence comes from studies conducted on the complete probiotic product.

Figure: Determinants of probiotic product parameters (adapted from Flach et al. 2017). Mark B. van der Waal is gratefully acknowledged for producing the artwork.

probiotics larson photo


For another perspective see Does the delivery format affect probiotic efficacy?, March 28, 2018 by Mary Ellen Sanders.