Are Probiotics Actually Effective at Preventing C. diff?

Like many other nurses and health care providers, I was taught that probiotics are vital in preventing Clostridioides difficile (C. diff). Years ago a co-worker of mine attended an event in which she learned a nurse manager had implemented the use of the probiotic Saccharomyces boulardii (Florastor) or probiotic yogurt for patients taking antibiotics both during their treatment and for 8 days after completing the antibiotics. As a result, that facility saw a dramatic decrease in facility acquired (health-care associated infections) C. diff cases. This story remains taped up on the side of the wall shelf by one of the nurse stations. This inspired my own facility to create a new standing order for Florastor and probiotic yogurt and to be sure we administered one of these for residents or patients that were on antibiotics. I later wrote this into our policies to make it official. Then came a day that our medical director asked me what evidence there was that this actually worked. When I looked into it, I found it was much less cut and dry than I had anticipated.

The majority of studies reviewed do suggest that probiotics, mainly the Lactobacillus and Saccharomyces genera, can be useful in preventing as well as treating C. diff. A combination of probiotics instead of one may also prove to be more successful. Although nearly all the studies mention that more research needs to be done. One study noted a difference in efficacy related to the state the probiotic was in when administered. Mice were given oral antibiotics along with an injection of clindamycin before being infected with C. diff. Some were given probiotics prophylactically and others for treatment after the fact. Those treated with Lactobacillus reuteri in its biofilm state fared better than those given the probiotic in its planktonic state. This shows that the form in which a probiotic is taken can make a difference in how well it works in the body.

Other researchers came to less positive conclusions. One study reached the conclusion that the evidence out there is not persuasive enough to warrant the use of probiotics. One of the concerns pointed out was that many probiotics sold over the counter do not truly contain what is says on the label. For highly acute patients it was felt that this could be adding to the risk of infection. It was suggested by another review that probiotics could potentially lead to complications in immunosuppressed patients. 

Looking more broadly at antibiotic-associated diarrhea and not just at C. diff there is promising research. A randomized trial used probiotic yogurt to reduce the incidence of antibiotic-associated diarrhea. Many patients reported fewer side effects when taking probiotic yogurt. Eating yogurt is simple, affordable, and does not require a prescription. There are even dairy-free and plant-based probiotic yogurt options for those that cannot take dairy/animal-based products. Probiotics are also (suggested to be) beneficial for other gastrointestinal conditions such as Helicobacter pylori and inflammatory bowel disease.

There are no consistent patient population, dosage, or parameters between studies so that is part of the reason why it is hard to say definitively what works and what does not. The results of studies tend to remain unclear if there is a benefit and suggest more research is needed. One could assume if all the studies came to the conclusion that probiotics were useless, we could be done with the whole debate. Instead, there is room for more studying and learning and building of knowledge.

I personally conclude that the pros outweigh the cons for the average patient. I have yet to experience a patient having a bad reaction to a probiotic or yogurt. The biggest issue that I have seen come up is that a patient does not like the taste of yogurt and would rather take the pill. Although there may not be overwhelming evidence that they will prevent C. diff, there are rarely side effects to taking one. For an extremely ill patient in a highly acute setting, I can see the greater reason for pause and not wanting to add anything not absolutely necessary to a patient's medication regimen.

It is also important to remember that there are still many other factors that are key in lowering rates of C. diff. These include things such as increased staff education for everyone and not just nurses, donning/doffing and hand hygiene competencies for all staff, more in-depth discussion and conversations about transmission-based precautions, and collaboration with pharmacy and providers to ensure proper antimicrobial stewardship. While probiotics and yogurt are not the definitive solutions to preventing C. diff infections, they are certainly a tool a facility or provider can choose to use to implement.