Yeast from fermented milk: vesicles and immune cell activity
What it found
In lab tests, tiny particles released by two yeast strains from fermented milk reduced the ability of human immune cells to activate T cells.
The effect was stronger for these strains than for a wine yeast strain.
What they found
Animal and lab studies
Particle size and charge
The particles from all three yeast strains were similar in size (under 100 nm), concentration, and negative charge.
Uptake by immune cells
Human dendritic cells took in the yeast particles at 37°C but much less at 4°C, suggesting an active process.
T cell activation reduced
When human dendritic cells were treated with particles from the fermented milk yeasts, they caused less T cell growth than untreated cells. The wine yeast particles had a weaker effect.
RNA content
The particles contained mainly pieces of yeast mRNA. Some RNA sequences were enriched only in the fermented milk strains, not in the wine strain.
No clear human RNA targets
The yeast RNA did not consistently match human RNA targets across replicates, so the authors think the immune effect is probably not from direct RNA interference.
What the authors conclude
- They suggest that one way probiotic foods might reduce inflammation is through yeast particles interacting with human immune cells.
- They propose that the anti-inflammatory properties of yeast particles are strain-specific, not species-specific.
- They say their findings point to specific yeast strains as a possible source of particles for delivering anti-inflammatory molecules in clinical applications.
How it was done
Most studies on fungal particles have looked at infections. The authors wanted to see if yeasts from food, not infections, could affect human immune cells.
They isolated tiny particles from three yeast strains: two from fermented goat milk (Saccharomyces cerevisiae CL4 and Pichia fermentans CL1) and one from a vineyard (Saccharomyces cerevisiae ts9). They then tested how these particles affected human immune cells (dendritic cells) in lab dishes, including their ability to trigger T cell growth.
What it can’t tell you
- These are lab tests with human cells grown in dishes. They cannot show what happens in a person eating yeast or fermented foods.
- The study did not test whether eating these yeasts would change immune responses in the body.
Who paid
- Funding
- Funded by Regione Toscana (from the PubMed record).
- Conflicts
- The authors declare no competing interests.
- Authors work at
- University of Florence, Italy
The paper
- Title
- Yeast strains isolated from fermented beverage produce extracellular vesicles with anti-inflammatory effects
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY.
- Cite
- Nenciarini S, Amoriello R, Bacci G, et al (2024). Yeast strains isolated from fermented beverage produce extracellular vesicles with anti-inflammatory effects. Scientific reports. doi:10.1038/s41598-024-51370-7Free full textPubMed 38184708DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error