9 Health Problems That Saccharomyces Boulardii Can Help With



Saccharomyces boulardii is a probiotic yeast that is one of most researched supplements about.

What to look out for

Not all brands containing Saccharomyces boulardii are stable at room temperature - if you travel or need one that is fairly robust then chose a brand such as Florastor which is.

S boulardii capsules are usually either lyophilized or heat-dried. Heat-dried capsules of S boulardii need to be refrigerated after opening whereas lyophilized ones (such as Florastor) are stable for over one year at room temperature, as long as they are protected from moisture (which basically means DO NOT refrigerate.)

When taken orally this probiotic yeast will reach stable levels in your body within 3 days and it will be cleared from your system 4 days after stopping it1.

Some types of fiber eg psyllium will increase S boulardii levels in your body by 22%, while fiber such as pectin has no effect1.

Evidence for the use of Saccharomyces boulardii1

Here are nine health problems that this probiotic can help with.

  • 1. Prevention of antibiotic associated diarrhea - take 500-1000mg a day throughout the antibiotic treatment plus for 3 days to 2 wk after
  • 2. Prevention of traveler’s diarrhea - take 250-1000mg a day for the duration of the trip
  • 3. Helicobacter pylori symptoms - take 1000mg a day for 2 weeks whilst undergoingStandard triple therapy
  • 4. Treatment of C difficile infections - take 1000mg a day for 4 weeks whilst undergoing Vancomycin or metronidazole treatment
  • 5. Acute adult diarrhea - take 500-750mg a day for 8-10 days
  • 6. Inflammatory bowel disease- take 750-1000 a day for 7 weeks to 6 months whilst taking Mesalamine
  • 7. Irritable bowel syndrome - take 500mg a day for 4 weeks
  • 8. Giardiasis - take 500mg a day for 4 weeks whilst taking Metronidazole
  • 9. HIV-related diarrhea - take 3000mg a day for 7 days

Probiotics containing Saccharomyces boulardii

You can read more about two of the individual brands of Saccharomyces boulardii:- Florastor and Jarrow Formulas Saccharomyces Boulardii.

Single species

There are a number of probiotics containing S boulardii. I am a big supporter of single species brands made using the original Biocodex yeast because research shows that there are differences between the yeast used in these and other brand names1.

Biocodex has over 40 brand names worldwide for this same product and these include Florastor in the USA and UK, Perenterol in Germany, Reflor in Turkey, and Ultra-Levure in Asia.

Recommended Probiotic Yeasts



Florastor contains 250 mg or 5 billion cfu in each capsule. They are freeze dried (lyophilized)and should be kept at room temperature and NOT refrigerated.

You can buy other brands and they are usually cheaper, but just understand they are not quite the same as the original.

Other brands available are SB +MOS by Jarrows (1.5 billion per capsule). Again this is a top manufacturer and I am actually a big fan of their products but this supplement is not the same as the Biocodex one.

So although they are both contain the same yeast, for whatever reason, there are differences. I'm laboring this point because so many people want to know if they are the same. Almost, but not quite.

How important is this? Only you know. If you can keep it refrigerated and are confident that it has not been exposed to heat at any point before you bought it - it might not be a big deal at all.

My advise if you want to try this probiotic yeast is to start with the Florastor and if it works for you then, then experiment with the less expensive Jarrow's one. If you still get a good result - great - but if you don't then return to Florastor.

And if you're in the UK you can get Florastor locally.

To give a rough comparison between the two, on today's prices, you are paying .14 cents a billion for the Florastor brand and .06 cents a billion for the Jarrows. So roughly twice as expensive.

Why, you ask? Simple.

Florastor's capsule is backed up with research on what is in the Florastor bottle.

Jarrows capsule is (mostly) backed up with research on what is in Florastor's bottle!!

Other single species supplements can be bought from Kirkman, Allergy Reseach Group and Klaire Labs. None of these are heat stable.

Multi probiotics

These brands have the yeast combined with other probiotics. Almost all of the studies have been done on Saccharomyces boulardii alone so know one really knows if it works the same when combined with others in a multi probiotic.

Multi-probiotic:- Protecflor in Canada, Erce Flora in Belgium, MitoMix, Garden of Life Primal Defense Ultra Ultimate Probiotics Formula (with 13 other probiotics), and Pro-Bio Defense (with 7 others).

Out of these ones only MitoMix and Primal Defense are known to be heat stable.

Where does Saccharomyces bourlardii come from?

This is the probiotic yeast found in the well known supplement Florastor and it has an interesting history.

It was discovered by a French microbiologist, Henri Boulard in 1920 when he was in IndoChina searching for new strains of yeast that could be used in fermentation. (Some other yeast such as strains of Saccharomyces cerevisiae strains have been used in baking and brewing for centuries.)

Boulard happened to visit during a cholera outbreak - brave man! - and he noticed that the people who did NOT get cholera (and the diarrhea that goes with it!) were drinking a special tea.

This tea was made by taking the outer skin from a tropical fruit (lychee and mangosteens) and cooking them down to make tea. This fascinated him and he used his skills as a microbiologist to find out why. It was all due to a then unknown strain of yeast which he named Saccharomyces boulardii.

Biocodex bought the patent to this fabulous yeast in 1947 and have been researching it ever since.

1. Lynne V McFarland. Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World J Gastroenterol. 2010 May 14; 16(18): 2202-2222.