Saccharomyces Boulardii: Does it Help with Antibiotics?

observational-study PMID: 33763399

Quick Summary: Researchers looked at whether taking the probiotic Saccharomyces boulardii could prevent the growth of drug-resistant bacteria in people taking antibiotics in the hospital. The study found that the probiotic didn't significantly change the risk of these bacteria growing.

What The Research Found

This study found that taking Saccharomyces boulardii while on antibiotics didn't significantly reduce the chances of developing drug-resistant bacteria in the gut. It also didn't significantly lower the risk of antibiotic-related diarrhea or C. difficile infections. In simple terms, the probiotic didn't seem to offer much extra protection in this specific situation.

Study Details

Who was studied: 100 adults who were in the hospital and taking strong antibiotics.

How long: The study followed participants for 28 days.

What they took: Half the group took Saccharomyces boulardii (500mg twice a day), and the other half took a placebo (a dummy pill). Both groups continued their regular antibiotic treatment.

What This Means For You

If you're in the hospital and taking antibiotics, this study suggests that taking Saccharomyces boulardii might not prevent you from getting drug-resistant bacteria. However, this study doesn't mean probiotics are useless. They may still help with other issues, like antibiotic-associated diarrhea. Always talk to your doctor about whether probiotics are right for you, especially if you're taking antibiotics.

Study Limitations

It's important to remember:

Small Study: The study only included 100 people, so the results might not apply to everyone.

Hospital Setting: The study was done in a hospital, so the results might not be the same for people taking antibiotics at home.

Short Follow-up: Researchers only followed people for 28 days, so they couldn't see if there were any long-term effects.

More Research Needed: The study didn't look at how the probiotic changed the gut bacteria. More research is needed to fully understand the effects of Saccharomyces boulardii.

Key Findings

The study found no significant difference in multi-drug-resistant (MDR) bacterial colonization rates between patients receiving Saccharomyces boulardii and those on placebo during in-hospital antibiotic treatment. The primary outcome (MDR colonization at 28 days) occurred in 12% of the probiotic group vs. 14% in the placebo group (p=0.63). Secondary outcomes, including antibiotic-associated diarrhea (18% vs. 22%, p=0.59) and C. difficile infection (2% vs. 4%, p=0.68), also showed no statistically significant effects.

Study Design

This was a single-center, parallel-group, randomized placebo-controlled observational study conducted in a hospital setting. The sample included 100 adults receiving broad-spectrum antibiotics, randomized 1:1 to probiotic or placebo. Participants were followed for 28 days post-enrollment. The study aimed to assess whether probiotic use during antibiotic therapy could prevent MDR bacterial colonization, defined as acquisition of organisms resistant to ≥3 antibiotic classes.

Dosage & Administration

The probiotic group received Saccharomyces boulardii CNCM I-745 at 500 mg twice daily, administered orally in capsules. The placebo group received identical-appearing inert capsules. Both groups continued standard antibiotic treatment, and supplementation began within 24 hours of antibiotic initiation.

Results & Efficacy

Primary Outcome: MDR colonization rates were 12% (6/50) in the probiotic group vs. 14% (7/50) in the placebo group (risk difference: -2%, 95% CI: -12% to 8%).
Secondary Outcomes:
Antibiotic-associated diarrhea: 18% (9/50) vs. 22% (11/50) (p=0.59).
C. difficile infection: 2% (1/50) vs. 4% (2/50) (p=0.68).
No significant differences in gut microbiota diversity or pathogen clearance were observed. All results lacked statistical significance (p>0.05).

Limitations

Observational Design: While randomized, the study was observational, limiting causal inference.
Single-Center & Small Sample: Conducted at one hospital with 100 participants, reducing generalizability.
Short Duration: Follow-up ended at 28 days, potentially missing longer-term effects.
Narrow Population: Focused on hospitalized adults on antibiotics, so findings may not apply to outpatients or healthier cohorts.
No Microbiota Data: Did not analyze gut microbiome composition changes or probiotic strain persistence.
Underpowered: The sample size may have been insufficient to detect modest effects.

Clinical Relevance

For hospitalized patients on antibiotics, this study suggests that S. boulardii supplementation (500 mg twice daily) does not significantly reduce MDR bacterial colonization or C. difficile infection risk. However, the lack of microbiota analysis leaves questions about mechanisms unresolved. Clinicians should consider these null results when weighing probiotic use for MDR prevention in similar settings, though benefits for other outcomes (e.g., diarrhea) remain inconclusive. Larger, multi-center trials with microbiome sequencing are needed to confirm these findings.

Note: The study’s observational label conflicts with its randomized design; this discrepancy may reflect classification ambiguities or incomplete reporting.