Each gut microbiome is unique, so the response to Saccharomyces boulardii will vary. Optibac Probiotics S. Boulardii supplement contains 5 billion live cultures per capsule. Try 1-2 capsules initially (or 3-4 capsules together if a stronger dose is required) and increase up to a maximum of 6 capsules (30 billion live cultures) spread over the day. Within these guidelines, then take as much or as little as you need, on an ad hoc or ongoing basis to support gut health and occasional diarrhoea(1,2).*