Can I take Saccharomyces boulardii (SB) with antibiotics?

Saccharomyces cerevisiae (Boulardii), commonly known as SB, is a live yeast with probiotic-like activity that helps maintain a healthy digestive tract, supports healthy immune function and helps reduce the occurrence of symptoms of diarrhoea associated with antibiotic use and traveller’s diarrhoea.

Gastrointestinal tract and microbiota
Your gastrointestinal tract (GIT) is naturally populated by bacteria, single-celled microorganisms, yeasts and fungi, which are collectively known as the gastrointestinal microbiota. Your microbiota maintains health and wellbeing, provides you with nutrients and protects you from harmful microbes. It’s also involved in many metabolic processes, including the fermentation of undigested carbohydrates into short-chain fatty acids (main source of energy for the cells lining your colon), lipid metabolism and vitamin synthesis. The balance of your intestinal microbiota may be disturbed by environmental or physiological factors, including antibiotic use and dietary choices. The intestinal microbiota is one of the key elements in your body’s immune defence system.

SB is a non-pathogenic, transient yeast that mimics the activity of a probiotic in the GIT for a therapeutic benefit. SB achieves steady-state concentrations within 3 days and is cleared within 3 to 5 days after it is discontinued. SB is not naturally occurring in your GIT and is not affected by antibiotics.

SB helps to maintain healthy immune system function, both within the intestines and systemically, through the intestinal microbiota and supports GIT integrity by enhancing GIT mucous membrane health. SB has been investigated in numerous trials and has been shown to reduce the incidence of antibiotic-associated diarrhoea (AAD) as well as traveller’s diarrhoea. 

  • A 2010 meta-analysis encompassing 5,029 patients found that SB reduced the occurrence of antibiotic-associated diarrhoea [1].
  • Two studies using SB have demonstrated a significant reduction in the occurrence of traveller’s diarrhoea when given 5 days prior to travel and continued throughout the duration of the trip [2].

SB helps restore beneficial bowel flora and supports beneficial gut flora during antibiotic use.


Diarrhoea is defined as frequent watery stools due to impaired fluid and electrolyte absorption in the intestines. There are many causes of diarrhoea, but the following mechanisms are typically involved:

  1. Absorption of water in the intestines is dependent on adequate absorption of solutes. If excessive amounts of solutes are retained in the intestines, water will not be absorbed.
  2. A large volume of water is normally secreted into the small intestines, but most of this water is efficiently absorbed before reaching the large intestine. Diarrhoea occurs when secretion of water into the intestines exceeds absorption.
  3. Disruption to the GIT barrier due to microbial or viral pathogens leads to inefficient absorption of water.
  4. Disorders in motility that accelerate transit time can lead to decreased absorption of fluids.


[1] McFarland, L. V. (2010). Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World journal of gastroenterology: WJG, 16(18), 2202.

[2] Kollaritsch, H., et al. (1989). Prevention of traveller's diarrhea: Comparison of different non-antibiotic preparations. Travel Med Int. 9-17.

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