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Question · After antibiotics

What do people report about S. boulardii after antibiotics?

Mostly positive, going by Reddit owner reports: 39 of 43 rated comments from people who mention a recent course of antibiotics describe a good experience with S. boulardii, and 4 describe a poor one. That is self-reported experience, not proof that it works, and results vary from person to person.

S. boulardii, After antibiotics	Owner comments
Rated comments in this context	43
Positive	39 (91%)
Negative	4 (9%)
Describe an unwanted effect	1
Context rating (small samples pulled to the average)	3.9

Saccharomyces boulardii overall: 4.0 from 478 owner comments in Reddit IBS and gut communities, November 2025 to October 2026.

What the research says

S. boulardii is a yeast, so antibacterial antibiotics do not kill it.^[PubMed]
A 2010 meta-analysis pooled adult trials, many on antibiotic-associated diarrhea.^[PubMed]

Safety

The NIH notes probiotics may not be safe for people who are very ill or have a poorly functioning immune system; ask a doctor first.^[NCCIH]

Good experiences

4/5 Cost
“I've tolerated taking Florastor 3x a day during antibiotics.”

owner comment via r/SIBO · 2026-10-04 · 6 upvotes

4/5
“S Boulardii helped me after a nasty food poisoning round, kept things from going completely off the rails while my system rebuilt itself”

owner comment via r/Microbiome · 2026-10-08 · 8 upvotes

4/5
“Since you ruled that out, I would get florastor probiotic and take that 30 days.”

owner comment via r/Microbiome · 2026-01-13 · 4 upvotes

Poor experiences

2/5
“Tho this SIBO I had was because of a probitoic (florastor) I tired to take to be healthy but that was a big mistake and backfired on my gut.”

owner comment via r/SIBO · 2025-12-05 · 3 upvotes

2/5
“I am taking florastor with my cephalexin.”

owner comment via r/IBS · 2025-11-25 · 2 upvotes

How reports compare in other contexts

Context	Rated comments	Positive	Negative
SIBO	87	65	16
IBS-D & loose stools	32	28	4
Bloating & gas	26	24	1
IBS-C & constipation	21	16	3
Pain & cramping	16	13	3

More on S. boulardii

Talk to a doctor about new, severe or lasting symptoms, and to a pharmacist before combining supplements with medicines.