DrFeb
Health Guide

Propionibacterium freudenreichii ssp. Shermanii

Have you ever heard of a probiotic that actually *feeds* your cells, not just your gut? Meet *Propionibacterium freudenreichii ssp. shermanii*. This specific strain of beneficial bacteria is a powerhouse found in Swiss cheese (think Emmental with the holes!). Its superpower is producing Vitamin B12 and a unique short-chain fatty acid called Propionic Acid. Think of it as a cellular mechanic: it helps fuel your gut lining and may play a vital role in keeping your brain and nervous system in tip-top shape.
Evidence BasedDietary Supplement
VERIFIED SOURCE

Bio-Activity Analysis

Propionic Acid Production

SCIENTIFIC DATA VISUALIZATION

Y-Axis
Acid Yield (g/L)
Bacterial Strain →

Health Benefits & Sources

Why You Need It

  • Vitamin B12 Production: It synthesizes B12, which is crucial for nerve health and energy.
  • Gut Barrier Support: It produces propionic acid, which feeds the cells lining your colon.
  • Metabolic Health: Early research suggests it may help regulate blood sugar and lower cholesterol.

Deep Dive

This bacterium is unique because it doesn't just live in your gut; it works there. When P. freudenreichii ferments food, it creates Vitamin B12. While we can't absorb all of it from the bacteria itself, it contributes to your overall B12 pool. More importantly, it produces Propionic Acid (PA). PA is a "superfuel" for the cells in your colon (colonocytes). By keeping these cells healthy, it strengthens your gut barrier, preventing unwanted toxins from leaking into your bloodstream. This is the 'Gut-Brain Connection' in action—keeping the gut healthy supports cognitive function.

Natural Food Sources

Since this is a specific bacterial strain, you won't find it in standard fruits or veggies. You find it where fermentation happens!

FoodAmountNote
Swiss CheeseHighThe authentic source (Emmental, Gruyère).
YogurtMediumOften added as a starter culture.
KefirMediumA fermented milk drink.

Supplementation

Because this specific strain is sensitive to stomach acid, food sources are great for general health, but supplementation is usually required for therapeutic doses. Look for "Probiotic B12" blends or specific "Propionibacterium" supplements. Dosage varies, but typically ranges from 1-10 billion CFUs daily. Always take with a meal to help the bacteria survive the journey to your intestines.

Top Food Sources

Emmental Cheese
Natural fermentation source
Gruyère Cheese
Natural fermentation source
Fortified Supplements
Best for specific health goals

Frequently Asked Questions

While it produces B12, the amount absorbed from cheese alone is usually not enough to correct a deficiency, but it is a great dietary booster.
No. It is a completely different bacterial species with unique benefits, specifically regarding B12 and Propionic Acid.
Yes, heat kills the live bacteria. To get the probiotic benefit, you must consume it in raw cheese or supplement form.
It was named after the scientist, Dr. H.J. Sherman, who helped identify its nutritional importance.

Safety & Side Effects

Generally recognized as safe (GRAS). Since it is a bacteria, those with severely compromised immune systems (e.g., undergoing chemotherapy) should consult a doctor before taking live probiotics. There are no known toxicity issues associated with this specific strain.

Scientific References

  • [1]Bacterial Vitamin B12: Pathways, Applications, and Challenges (Critical Reviews in Biotechnology, 2021)
  • [2]Propionibacterium freudenreichii: A Stress Tolerant Dairy Probiotic (Frontiers in Microbiology, 2018)
  • [3]Propionic Acid and Gut Health (Nutrients, 2020)