Lactobacillus fermentum and colds
What 2 graded rows on lactobacillus fermentum agree on for colds, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Lactobacillus fermentum page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Lactobacillus fermentum page, with its PubMed record.
Your question
Lactobacillus fermentum and colds
2 rows · 119 peopleSplit. 1 row found an improvement and 1 had mixed results.
- CGrade C× 1
- DGrade D× 1
- Rows
- 2
- Trials
- 2
- People
- 119
What the rows share
From the rowsThe best-graded row, grade C, is a randomized trial of 99 people (2011) and reported mixed results.
The rows run from 20 to 99 people, published from 2010 to 2011: 2 single studies.
The rows
1 improved · 1 mixed- DGrade DRespiratory illness in elite distance runners · Improved
Crossover RCT · n 20 · 2010 · Healthy elite male distance runners in winter training
12.6 billion CFU a day · 4 months (crossover)
Respiratory symptom days were 30 on PCC vs 72 on placebo (p < 0.001), with a trend to milder illness; salivary IgA and running performance did not change.
Row on the Lactobacillus fermentum page · PubMed 18272539 (opens PubMed)
- CGrade CGut and respiratory illness in competitive cyclists · Mixed
RCT · n 99 · 2011 · Competitive cyclists (64 men, 35 women)
At least 1 billion CFU a day · 11 weeks
Men had less severe gut illness and a lower lower-respiratory symptom load, but mild gut symptoms were about twice as common on the probiotic, and in women respiratory load rose; effects on colds were too uncertain to call.
Row on the Lactobacillus fermentum page · PubMed 21477383 (opens PubMed)