My ah-ha moment with probiotic supplements

During medical school, and then my internal medicine residency training, I don’t remember the topic of probiotics ever coming up. When I started my infectious diseases fellowship in 2009, there was one attending physician who routinely prescribed a particular probiotic supplement to patients taking antibiotics. He made sure to tell us fellows, that there was no strong evidence (at the time at least) to show that there was clear benefit to patients taking probiotics, in terms of clinical outcomes.

My last two blog posts discussed probiotics – first, what are probiotics, and then, examples of probiotic containing foods. To recap, probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host. Probiotics can be formulated into many different types of product, including foods, drugs and dietary supplements.

I have thought long and hard about probiotic supplementation and to me, it seems like common sense that replenishing the supply of good bacteria in the gut should be beneficial. I always believed that yogurt (with live cultures; avoid high sugar content), for instance, was a good food because it contained probiotics. In ‘mainstream’ medicine, a lot of what we do is evidenced based. There are guidelines put out by various professional organizations, which, after review of all the available studies, come up with recommendations to guide physicians in practice, on how to treat our patients on a day to day basis.

As of now, there are no official guidelines in the infectious diseases literature to my knowledge, regarding the use of probiotics. However, there is increasing research out there, particularly in the gastroenterology literature, regarding the benefits of probiotics. The World Gastroenterology Organization issued practice guidelines in 2011 on probiotics and prebiotics. These guidelines indicate that there is evidence for the use of probiotics in reducing the severity and duration of acute infectious diarrhea in children, in preventing antibiotic associated diarrhea, and in preventing Clostridium difficile associated diarrhea, among other conditions.

After completing my infectious diseases training, I continued to prescribe the brand of probiotic that my attending physician prescribed. But…I have to admit…I never looked into exactly what probiotic strain or strains the brand contained. Also, I had no idea how many live bacterial colonies were contained in one pill.

Over the past few months I have had several patients with the dreadful Clostridium difficile infection; a couple of them had multiple recurrences and one of those unfortunately lost her battle with the infection. Another patient was on the verge of death, but remarkably made it (so far, at least) after she had her entire colon removed (the colon is what gets infected with C. diff). Some of the other patients recovered to an extent, but their bodies, months later, still don’t feel like they are back to normal.

Because of the nightmares I witness from C. diff infection, I usually prescribe probiotics to patients who I am treating with antibiotics, for prevention. Recently, one such patient brought the box of probiotic pills with her to her follow up appointment. She said the pharmacist told her he did not have the one I prescribed, but gave her another one saying “it’s the same thing.” She then took out another box of probiotics from her bag, saying that it was another set she bought on her own. When I looked at the two boxes, the ingredients were different. That prompted me (for the first time, I am very embarrassed to say) to look up the ingredients of the probiotic brand I had been prescribing all along. It was different from the two the patient had with her. At that point, I realized that there is indeed a lot of confusion about probiotic supplements. You can say I had an ah-ha moment.

My next step, was to visit the pharmacy of one of the 4 hospitals I treat patients at, to see what probiotic they were dispensing to the patients when I prescribed my ‘preferred brand.’ By now, I had an idea of what the label should say. Lo and behold, one of the brands did not have the full name of the strain of probiotic it contained, and it did not specify the amount of live bacterial colonies in each pill. The other brand stated the full names of the two strains of probiotic it contained and the amount of colony forming bacteria. However, it stated that the number of colonies were present only at the time of manufacture. There was no stated guarantee that these colonies would be live up until the time of the expiration date. For all I know, the patients are getting capsules with dead bacteria, that will offer them zero benefit. This was an eye opener.

I then looked up the actual label of my ‘preferred brand’ of probiotic. It turns out that it is a blend of Lactobacillus acidophilus (80%), Lactobacillus bulgaricus (10%), Bifidobacterium bifidum (5%) and Streptococcus thermophilus (5%). It said it contained “2 billion cultures per serving at the time of manufacture.” So once again, unfortunately, there was no guarantee of viable bacteria present in the product until the expiration date.

So…given all this confusion, how does one go about choosing a probiotic supplement? Next week, in the final post of this series on probiotics, I will outline 9 factors to consider when choosing a probiotic supplement.