Probiotics: Hope or Hype?

Posted on | March 24, 2008 | Comments Off on Probiotics: Hope or Hype?

A look at the “hot” food product in 2007… What does the science say?

Foods with probiotics were the "it" products in 2007. Dannon’s Activia yogurt alone accounts for 40% of it’s U.S. sales. In 2008, as the the products become even more prevalent, consumers and health experts are asking, does this stuff really work? Well, the Journal of the American Dietetic Association published an interesting review on the state of pre- and probiotics, based on the scientific evidence that exists today. Here’s my summary of the review article.

First, disclosures – gotta love ’em. The article authors received funding to write this article and to give a presentation at the 2007 Food, Nutrition Conference and Expo. The funders were California Diary Council and Dannon.

Probiotics are live microorganisms that provide a health benefit to the host. That’s the scientific definition. There is no legal definition to-date.

Here’s what we know about probiotics:

microbes influence immune development and resistance to infection
microbes are "co-residents" of our bodies (befriend the microbe – they help make vitamin K and they keep the pipes clean)
compared to our ancestors, we consume fewer microbes and we have less environmental exposure (long live the antibiotic)

The hypothesis is that this lack of exposure could be related to health problems, including allergy disorders. The concept behind probiotics is they can support overall health **IF** the right microbe is consumed in the right amount.

Health Benefits of Probiotics

So where are we with the scientific evidence? The literature reports the following benefits:

regulate immune function
prolong remission in people with pouchitis
decrease duration of infectious diarrhea in infants
enhance GI tolerance to antibiotics
control of lactose intolerance symptoms

According to the authors, there is new evidence "still emerging" to support the following benefits. (Note: emerging meaning, we still don’t know.) Please post links to studies that support or refute any of these claims.

decreased symptoms and incidence of allergic disease
improved therapeutic outcomes with bacterial vaginosis
improved IBS symptoms
decreased dental caries
decreased severity of symptoms and incidence of respiratory infections
decreased C. diff toxin in patients with antibiotics
decreased absence in the workplace

The authors also noted reputable studies with outcomes that did not support the following claims.

antibiotic associated diarrhea
prevention of surgical infections
improvement of IBS (note, this was reported above as a benefit… more evidence that we just don’t know yet)
remission of Chron’s disease
post antibiotic vaginal yeast infections

Now, all this being said, it is important to remember that scientific research is difficult and expensive. Companies that spend significant dollars on research need to recoup costs and that could get passed on to you. Evidence is important – and necessary – but when you can try a special yogurt and only spend a few bucks, that might be the way to go. Everyone is different. If it works for you (placebo effect or not) then that’s still a good outcome, right? If it doesn’t work for you, spend your money elsewhere. Just my rationalization here.

Probiotics in the Food Industry

One of the challenges is that the term probiotic is used in the food industry even when minimum scientific criteria is not met. Further, it is rare that the manufacturer provides third party analysis to the public that verifies the product is what it claims to be. Uh oh. What’s the lesson? Buyer beware. You’re going to have to do some leg work if you want to be sure you are getting your money’s worth.

Use product labels and their websites to determine:

type of microbe (most common are: lactobacillus, bifidobacterium, enterococcus, bacillus, escheria, sacchromyes cerevisie – last one is a yeast, the rest are bacteria)
levels in the product through the end of the shelf life – is it high enough? Stomach acid is very strong so there has to be enough of these microbes to survive that environment to make it to the small intestine and do their "work"
whether the claims can be substantiated – are there human studies that demonstrate benefits?

Open this chart for a list of strains of probiotics that are supported with scientific evidence.

Dose

It’s tough to accurately generalize a minimum dose because it varies depending on the strains and desired health effects. The literature shows at least 10^8 colony forming units (CFUs) are required, but much higher doses may be needed. Studies show up to a 4-fold difference in the dosages needed to create an effect.

Retaining viability is also a challenge and it can affect the dose. Products are sensitive to heat, light, moisture, oxygen and acid. These are controlled for in food processing, but all bets are off once the package is opened.

In addition, survival after consumption is strain-specific so your particular strain may not even make it past the stomach to do it’s magic. There are products with an enteric coating, but a good rule of thumb is to look for the human studies and make sure your product has that amount.

Labeling

No health claim to use with probiotics has been FDA approved. Products may contain truthful claims about structure and function. The article authors did mention that reports have shown failure of some products to meet their label claims. So some products may not be what they say they are.

Final Word

Do your homework and try to make the best choice for your health issue. See what works for you. One product may and another may not.