June 24, 2020

Guest Blog by Lynne V. McFarland, PhD

Choosing the best probiotic is not an easy task. There are over 250 different types of probiotic products found on the market (grocery stores, pharmacies, on-line websites, etc.), but relatively little guidance on how to choose one probiotic over another. As more research is done, the guidelines of how best to use probiotics continue to be updated.

This post is to help you choose a good probiotic for what you need-either to prevent you from getting a C. difficile infection after exposure to antibiotics or to prevent a recurrence of C. difficile infection after you have recovered.

Why should I consider using probiotics to prevent C. difficile? Probiotics are living microbes that are especially beneficial when the normally protective microbiome has been disrupted. C. difficile infections occur after your normal gut microbes have been disrupted, typically after you have been given antibiotics to treat an infection.

How does bacteria in my gut protect me?  Normally, the “good” bacteria in your gut protects you from disease-causing organisms.  In addition to digesting your food, your normal microbiome (all the different types of microbes in your gut) also form a protective barrier that repels disease microbes.  However, this protective barrier can be disrupted. Taking antibiotics is the major culprit in killing off your good microbes. Once this happens, disease-causing microbes use this opportunity to infect your gut.  You are now susceptible to infection.

Why doesn’t everyone who gets antibiotics come down with C. difficile? The type of antibiotic and other factors (age, other medications, other current diseases) can make you more or less likely to be infected with C. difficile.  But you also have to be exposed to C. difficile. Once exposed to C. difficile spores (either already in low numbers in your gut or from external sources like other patients or room surfaces in healthcare facilities), these inactive spores germinate (like seeds sprouting) and C. difficile infects your gut.  Once C. difficile sets up housekeeping in your gut, it produces toxins that cause inflammation and diarrhea.

How can probiotics help?  Some types of probiotics can reduce the inflammation caused by C. difficile, some can kill the C. difficile bacteria directly, some can prevent C. difficile from attaching to your gut surface and some can destroy the toxins that cause the diarrheal symptoms.  Only certain types of probiotics can be helpful in preventing C. difficile infection.

Aren’t all probiotics alike?  No. Recent research has found that how well a probiotic works is different by the type of disease it is being used for (called ‘disease-specificity’) and that the choice of probiotic strain is important (called ‘strain-specificity’).  Some types of probiotics are useful against C. difficile, while many are not effective.

How do I know what strain or strains are in a probiotic product?  The label on the probiotic product should list all the microbes (bacteria or yeasts) contained in that product. Each microbe has a three-part name: the genus (for example, Lactobacillus), the species (for example, acidophilus) and the strain (for example CL1285).  As an example, a border collie is scientifically named as: Canis (the genus) lupus (the species) familiaris (the strain).  Just as not all dogs are like collies, not all Lactobacilli are alike.

If it says ‘probiotics’ on the label, can I use this for C. difficile?  Not all the products found on pharmacy shelves fulfil the definition of probiotic. The World Health Organization defined probiotics as living organisms that have an adequate dose and show a health effect. This means the probiotic is alive (can be a bacteria or yeast), must have a good number of organisms (dose) and shows an effect on health. Typically, effectiveness is shown by doing a clinical trial.  Not all types of probiotic products on the market fulfill even these three simple requirements.

Why aren’t the labels more helpful in choosing a probiotic? In the United States, most probiotics are sold as ‘dietary supplements’ available over-the-counter and can only have health claims on their labels, which give no specific guidance on how to use the probiotic for a specific disease or illness.  Because dietary supplements do not go through the rigorous FDA approval process as do prescription medications, your physician is not the usual role of recommending your medication.  The choice is left open to you as an individual.  Dietary supplements, by law, can not claim to ‘treat’ or ‘cure’ a disease.

How should I choose an appropriate probiotic?  One way is find a scientific review that provides you guidance on which probiotics are best.  I have listed a few good practical guides below.

Five tips for choosing a probiotic.

Another way is to look for these five tips of what a good probiotic product should have on the label (see box).  If the probiotic doesn’t meet all five criteria, you should just put it back on the shelf and choose another probiotic.

  1. FDA Disclaimer. All dietary supplements (including probiotics) are required to have an FDA disclaimer on the label.  “FDA Disclaimer:  The FDA has not evaluated this claim. This product is not intended to cure, mitigate, treat, diagnose or prevent a disease.”  Does your product have this disclaimer? If not, put it back.
  2. Which strains? Does the label list each strain of bacteria or yeast that is present in the product?  Some products just say “A Probiotic”, but do not list which strain or strains are present.  If no listing of each strain is given, don’t buy it.
  3. Dose. Is the daily dose or concentration given on the label?  This is usually listed as “number of cfu” (colony-forming units or number of organisms).  The number of bacteria or yeasts should be at least 5 billion per day. If the probiotic gives no dose information, don’t buy it.
  4. Who made the probiotic?  A reliable manufacturing company should have a history of producing a high-quality product and is certified by the appropriate authority.  If there is no information on who made the product, you should be suspicious. Although not required by law, most reputable probiotics list a website or source for more information.  This can be helpful for you to see if there are good clinical trials that might support their claims for a health benefit.
  5. Health claim. Dietary supplements are allowed to make ‘structure or function claims’ by law.  Allowable health claims include “boosts your immune system” or “strengthens your intestinal function”.  If the product claims that it ‘cures cancer’ or ‘treats diseases’, don’t buy it.

Because of the current FDA regulations for dietary supplements, you should not find any probiotics in the US claiming to treat or cure C. difficile infections. However, in the future some probiotics may be granted permission to say this if they are approved by the FDA as a medication or medical food. Other countries have different regulations that also may allow them to state different claims for their probiotic.

How do I know which probiotics can be used to prevent a C. difficile infection? Fortunately, there is over 35 years of research done in different countries with clinical studies and randomized controlled trials that have shown which probiotic strains are effective for different types of diseases. In 2020, the American Association of Gastroenterology recommends four probiotics to prevent C. difficile infections after antibiotic exposure, but five others types of probiotics were not found to prevent C. difficile infections. Only two of the probiotics had multiple trials to support this claim:  Saccharomyces boulardii CNCM I-745 [Florastor®, Laboratories Biocodex] and a three-strain mixture of L. acidophilus CL1285 + L. casei LBC-80R + L. rhamnosus CLR2 [Bio-K+, Bio-K PLUS International].

When should I start taking the probiotic to prevent C. difficile infection?  The probiotic should be started as soon as possible after the antibiotic is started (best within 24 hours) and continued while you take your antibiotic course and then for at least 2 weeks after the antibiotic is stopped to allow your normal gut microbiome to be restored. This combination (giving probiotic with antibiotic) has been tried in over 10 hospitals and has reduced their overall hospital rates of C. difficile significantly with no apparent side-effects.

If I’ve already had at least one episode of C. difficile, are probiotics useful to prevent further recurrences of diarrhea?  About 1 of 5 people with one episode of C. difficile infection will develop at least one more episode (recurrence).  Two clinical trials have shown when S. boulardii CMCM I-745 is given along with standard antibiotics to treat C. difficile infections, the recurrence rate is significantly reduced, especially if a high dose (2 grams/day) of vancomycin is given.  The probiotic should be started at the same time of the vancomycin and continued for at least four weeks to allow the normal microbiome to become restored.

Are probiotics safe to take?  Evidence from carefully monitored clinical trials has not found serious adverse reactions or side-effects for the probiotics described above. Generally, probiotics have been safe to take, reflecting the long history of clinical and safety trials.  However, probiotics are generally not recommended for severely ill patients with central catheters.

To summarize, remember that just because a product says it is a ‘probiotic’, does not necessarily mean it is one.  Also, not all probiotics are effective for the same type of health effect, so it is important to link the type of probiotic with the health effect that you need.

Lynne V. McFarland, earned her PhD in Infectious Disease Epidemiology at the University of Washington in Seattle in 1988 documenting how C. difficile was spread in the hospital. Since then, she has continued her research in C. difficile and branched out into the field of probiotics. She has published over 160 articles in scientific journals, is on the editorial board of several journals and has reviewed papers on probiotics and C. difficile for over 50 journals. She also has co-authored two books on probiotics including “The Power of Probiotics by Gary Elmer, Lynne McFarland and Marc McFarland”. She worked as a scientist for the Veteran’s Administration and as an affiliate associate professor at U. Washington, Seattle. She currently is active with the Public Health Reserves Corps fighting the COVID pandemic.

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  1. I am so grateful for this post! I was unsuccessful in researching which product (other than Florastor) contained the recommended probiotics, and this blog provided the answer and much more. Thank you!!!

    1. Colleen says:

      Glad I came across this info. Diagnosed w cdiff without toxins yesterday. Started vancomycin but would like to get a yogurt that has probiotics that can help ease discomfort..Can you please recommend a yogurt? There are so many and I’m confused.
      Thank You

      1. Amanda says:

        Here are a couple of ideas from when I had c. diff: Dairy-based anything killed my gut. I opted for Silk almond milk yogurts and/or So Delicious coconut milk yogurts. So Delicious at least includes the probiotic strains. Califia also has a smoothie, though it’s not as readily available. I added a mild tasting miso to a lot of foods too. Try Bio K if these don’t work out. They do officially sell through Amazon now, but their website has a search tool to find places that sell it. Feel better!

      2. Karla says:

        Activia.. it says on label that it has thousands of probiotics

    2. Sebastian says:

      Obviously a “paid” comment, otherwise Susan would have mentioned what “product” contained the answer. …moving on to find it myself by calling my neighbor doctor.

      1. Christian says:

        Hi Sebastian, it’s not a paid post. Florastor is probably the best known probiotic. I would assume Susan didn’t mention what she used because it is something that should be decided with your doctor.

  2. Kathy says:

    Thanks for your article. I am currently taking Align along with dificid for a reoccurrence. Is this a good probiotic.i am 68yrs old.

    1. Martin says:

      I have had a 2nd recurrence and when reordering Align from amazon, I found for about the same cost there is an Align 5x extra strength which seemed to help after completing Dificd and back on Vancomycin and awaiting Rifaximin

  3. Liz says:

    I had a very severe case of Cdiff Christmas 2018, I recovered after I was giving Flagyl and a round of probiotics however before the three rounds of Clyndamyacin that kicked in the Cdiff three months in a row, I’m lucky to be alive! I had another issue last month about four weeks ago or so with a dental infection again, this time they gave me amoxicillin, I started a probiotic and continue to take it, I get severe anxiety so I was only taking one a day and sometimes I wasn’t even taking that I was taking a child’s probiotic to help keep me regular as well. None of that was good enough added with the Activa yogurt. I think it kept it at bay so far but I can tell this morning that I am suffering. I’m going to go to the pharmacy this morning and pick up what is suggested, they gave me an off brand of floor store and that’s what I was rarely taking had I’ve been taking it the way it was intended one in the morning and one at night, I would’ve had a better chance of not having any issues at all. I noticed after I take it about an hour or two later I feel a little better I know that sounds weird but maybe it’s helping. Thank you for the article! God bless and I hope everyone stays healthy.

  4. Amy says:

    This is SO helpful! I have yet to find a brand of probiotics that works well for me, and as you mentioned, there’s not much guidance out there for us c diff patients. Thank you for providing this resource!!

    1. Mary says:

      My sister has just been diagnosed with c-diff. What is the best probiotic for me to get for her please.

      1. Christian says:

        Hi Mary, we generally cannot recommend specific products, but we have heard good things about Bio-K Plus from a couple of our Advocates.

        1. JHS says:

          Watch out with Bio K! I KNOW I developed an enterococcus infection from it. This strain is present, but not listed!!

      2. Jen says:

        Florastor!! I was diagnosed with cliff a month back. Treated with vancomycin. I was better after a week and now I feel it coming back. Took 2 florastor this am an pm and it hasn’t gotten any worse.

  5. Amy says:

    Helpful article!! My mom was just diagnosed with a severe case of C.Diff and I’ve been on the hunt for the most specific probiotic to help with her condition

  6. I’m on DOXYCYCLINE HYCLATE 100 for sinus and ear infection. Dr. said to take ACIDOPHILUS LACIOBACILLIUS with this because I had C-DIFF a couple of years ago. WILL THIS PREVENT ME FROM GETTING C-DIFF BACK FROM TAKING THE PROBIOTIC ?

  7. Colleen says:

    Glad I came across this info. Diagnosed w cdiff without toxins yesterday. Started vancomycin but would like to get a yogurt that has probiotics that can help ease discomfort..Can you please recommend a yogurt? There are so many and I’m confused.
    Thank You

  8. Jill says:

    I am 48 and tested positive in 2017 for Cdiff after taking antibiotics for an infected tooth. My doctor had me take many different combinations of medications and quite a few hospital stays to no avail. No medications helped me. After a 3 day visit in ICU at the hospital my doctor advocated for me to get a fecal transplant. I truly believe this saved my life. I was on my 5th treatment for this horrible bacteria. I had my good days and of course days when I didn’t know if I would survive. It’s nice to find a forum to hear other people’s stories and struggles

    1. Maria says:

      I’ve had c.diff now for eight months. I’m getting a fecal transplant next week. I’m so afraid of it not working. Any advice on what to eat after I’m home

      1. Nicole says:

        Wondering if you can share your FMT experience. It’s something i’m very interested in, i live in Colorado. I have c-diff, SIBO, candida and hyppthyroid and don’t know what to do, what to treat first etc. Been going on for years! check out “breaking the vicious cycle” website about diet.

  9. Robert says:

    I contracted Cdiff this past summer and was very sick for about six weeks until I could get in to see the PA at a surgeon’s office who does colon rectal surgery. I told her that I was prescribed Clindamycin a few weeks before that. She had some tests done and sure enough I had Cdiff. I was given another milder antibiotic and got over it within two weeks, however I have IBS and I seem to get mucous more often from my colon. I take Align and was wondering if some other probiotic might help me overcome this better. The PA didn’t seem to know.

    1. Karen says:

      Orthobiotic is a very good probiotic for C-diff because it has Saccharomyces Boulardii in it. However, it is very expensive. If too pricey, there are other probiotics that contain this strain. I was told Orthobiotic is the best. I’m not sure about other brands.

  10. Becky says:

    Well, since this seems to be a current thread I’ll chime in to say that the only probiotic I found that contains S. Boulardii and also L Rhamnosis, which is also helpful for diarrhea, is Vitamin Bounty brand. I stumbled across it doing a google search and so far I feel like I guessed right. If it keeps helping me I’ll take it forever. I’m taking the lowest dose they have, 5 cfu.

  11. Laura says:

    My 4th bout with C-diff hit me today, exactly 1 week after finishing a tapered extended dose of Vancomycin. I have been taking Florastor for the past several months. Thinking of switching to the Bio K+, wondering if the liquid is more effective than pill form? I am desperate to get rid of this, I have been dealing with it since a MVA in August.
    Would it make any difference to continue the Florastor and also take the Bio K+ along with it?

  12. Anonymous says:

    Hi guys. I never re-tested for cdiff after getting it back in August of 2020 because my stools became formed while taking florastor but once I stopped my stools started losing its shape. Once I added florastor back in, my stool issue resolved. I really feel like it helps! Maybe not for all but it did for me. I believe I’m going through pi-ibs right now. I keep a food/stool journal and I’ve played around with different factors and I narrowed it down to florastor helping me.

  13. JC says:

    I believe I have developed C. diff after nearly 4 weeks of antibiotic use. I am being tested and one result showed >3000 mcg Calprotectin (colitis). The doctor wants to do a colonoscopy but I read these are not necessary to diagnose C. diff??? I have been taking pharmacy grade probiotics for about 2 weeks and noticed considerable improvement. I am afraid the colonoscopy will exacerbate my colitis, especially if it is not necessary. Any thoughts on this?

    1. Sharon says:

      Hi JC,
      I would consult with your gastroenterologist in coordination with others who you see for your condition.
      I felt it necessary for my patient, as did her GP & Neuro, to get a colonoscopy because the stool samples can eventually show as false negatives or false positives – even as soon as the second test if needed. Also, it was obvious to me & confirmed by her physicians that other digestive issues needed to be looked at and one colonoscopy could’ve handled all of this. She remained adamant in refusing to get one, which wasn’t uncommon behavior for her medically. That’s the only reason she didn’t have one – she refused “just because she could” and wouldn’t budge. There was no evidence that I could find nor her doctors to suggest it would exacerbate it.
      I’ve had colonoscopies for stomach ulcers and it’s a quick yet effective procedure to look internally and assess innumerable things which in turn, helps provide a much quicker and thorough analysis of what’s going on and in turn, how to handle, steps to take, etc
      Colonoscopies are excellent tools for this/C-diff and certainly colitis, and in looking into other things during the procedure.
      Again though, I’d certainly talk with your gastroenterologist and your physician(s) whose care you’re in.
      Good luck. I know it’s a tough time.

  14. Sharon says:

    Hi everyone,
    I treated a patient who had MS & contracted C-diff during a short hospital stay for a septic UTI. I researched and experimented with every aspect on top of my diverse background as well as networking with other specialists, people who had it and/or were going through their repeat bouts with it, studies on C-diff, environmental factors and much more – what I really honed in on were the probiotics, diet, diarrhea, CDC guidance for contagious diseases and sanitizing and related to help resolve it and ideally, prevent reoccurrence.
    I’ll note what I finally found to be effective regarding getting her C diff to go away in regard to antibiotics and probiotics vs all of the above.
    Vancomycin was the only antibiotic that worked but not alone -no real progress was seen and she continued to have diarrhea and continual exacerbated digestive issues along with symptoms and issues throughout her body and system as a result. I added Florastar as the probiotic. But, the key to this or trick I found effective for this to really work and be effective was administering two probiotics to every single antibiotic. The antibiotic kept killing all of the bacteria in the gut. Two (probiotics) to one (antibiotic) – and, success finally.
    Activia yogurt I found to be the best, and I made smoothies using it, fresh organic fruits, gatorade, etc (NO dairy is vital)….I got creative and taste tested all before. I ended up making them for me also they were that good. She got so bad, she was suffering from malnutrition. These smoothies were the only thing that helped while being tasty – she’s one who is extremely noncompliant medically overall but certainly with her diet, but she would drink these and they stuck whereas no other food or beverage would not. They would go straight through her system and cause more problems.
    Very long story short –
    After she was cleared (not sure how many months – the hospital discharged her much too soon so I was in charge from the time the hospital should have kept her in their care, but was once again neglectful unfortunately, and for at least five months, until I was finally able to get her clear of it… and approx her 5th test after original diagnosis).
    Before I discharged her from my private care, I made sure her regular physician and neuro had a specific probiotic on her medication chart as a daily, vital, and lifelong one. They were excellent in working with me on this.
    To keep it simple, just remember to double up on your probiotic during an episode and certainly if you’re taking an antibiotic. Otherwise, they should be taken as noted (usually once a day) when there’s no occurrence.
    I now have it and if I’m without my probiotic for a day, wow. No good.
    Yogurt that has no sugar and is dairy free is also an important addition.
    Hope this helps.
    Best wishes everyone