LearnIngredient 01
Tributyrin, explained
A fat molecule made of three butyrate units on a glycerol backbone. What it is, how it differs from butyrate salts, and what the one published study on the branded form actually tested.
Tributyrin is a triglyceride: one glycerol backbone carrying three butyrate molecules. It occurs naturally in small amounts in butter and milk fat. As a supplement ingredient it is valued for a simple reason: it is a way to carry butyrate through the stomach as a fat, rather than as a salt.
That distinction matters more than it sounds. Butyrate on its own is a short-chain fatty acid with a strong, persistent odor, and the common supplement forms bind it to sodium or calcium. Tributyrin ties the butyrate up inside a fat molecule instead, which is why it is handled and dosed differently.
How it becomes butyrate
Fats are digested by enzymes called lipases, which clip fatty acids off the glycerol backbone. When tributyrin meets lipase in the small intestine, butyrate is released. The 2025 laboratory study on the branded ingredient estimated that roughly 41 to 49 percent of the tributyrin was broken down in a simulation of the small intestine, leaving about half intact to travel further along the digestive tract before releasing its butyrate.
Those numbers come from a laboratory model, not from people. They are useful for understanding the mechanism and for comparing forms. They are not a measurement of what happens in any particular person, and they say nothing about a finished product until that product is tested.
Net active amount versus carrier weight
By weight, butyrate makes up a little under 90 percent of a tributyrin molecule; the rest is the glycerol backbone. Ingredient suppliers also sell tributyrin on carriers, powders that make a liquid fat easier to encapsulate, and those carriers can account for a large share of the milligrams on a label.
This is why the amount printed on a label deserves a second look. "500 mg tributyrin powder" and "500 mg tributyrin" can describe very different amounts of the active molecule. Open Origin will print the net active amount of tributyrin on the Formula 01 label, and the lot certificate will show the assay that confirms it.
Tributyrin compared with butyrate salts
Sodium butyrate and calcium butyrate are salts of butyric acid. They deliver butyrate directly, they are inexpensive, and they have been studied in people. Their drawbacks are practical: the odor is difficult to mask, each dose adds sodium or calcium, and the butyrate is available immediately in the stomach rather than being released along the way.
A 2011 review of butyrate research described the poor palatability of available oral butyrate products as a real obstacle to their use and called for better-tolerated formulations. Tributyrin is one answer to that problem, though it is not free of odor either; the finished capsule still has to be specified and tested for it.
The branded form selected for development
CoreBiome® is a branded, patented tributyrin ingredient from Compound Solutions. It is the tributyrin selected for Formula 01 development. The description of it linked below is the supplier's own; the laboratory study above was funded by the supplier, carried out by a contract research laboratory, and published in a peer-reviewed journal with that disclosure. Both facts are worth knowing when reading either.
The studies, one at a time
What was done, what was found, what it can’t tell you.
Laboratory digestion and microbiome model, 2025
- Design
- In vitro. Simulated stomach and small intestine, then a multi-compartment colon model seeded with stool from three donors.
- Who
- No human participants. Three stool donors for the colon model.
- Amount and duration
- Capsule (300 mg) and softgel (450 mg) forms in the digestion model; 300 mg per day equivalent in the colon model for three weeks.
- What was measured
- How much tributyrin was broken down in the upper digestive tract, butyrate levels in the colon model, changes in bacterial groups, and barrier and immune markers in a cell co-culture.
- What was found
- About 41 to 49 percent of tributyrin was hydrolyzed in the small-intestine simulation. Butyrate levels in the colon model rose over three weeks. The authors reported shifts in several bacterial groups and changes in barrier and immune markers in the cell model.
- Limits
- The authors state that findings from these simulations do not translate directly to effects in people and that three donors limits statistical power. Funded by Compound Solutions, the ingredient supplier, as disclosed in the paper.
Read this part too
What this doesn’t show.
- No published human trial of tributyrin at supplement doses reports a consumer-relevant outcome. What people feel, if anything, has not been measured.
- No study has tested Formula 01 or any finished Open Origin product.
- How much butyrate reaches the colon in a person taking a given capsule is not known from the studies above.
References
Sources, labeled.
A published study reports its own data. A review summarizes other people’s. A supplier description is marketing, and we link it so you can see the difference.
- 1Published study
Duysburgh C, Verstrepen L, Van Meulebroek L, Marzorati M. Tributyrin (CoreBiome®) enhances butyrate levels and modulates the gut microbiota, barrier function, and immune response in vitro. Frontiers in Nutrition. 2025.
frontiersin.org - 2Published review
Canani RB, Costanzo MD, Leone L, Pedata M, Meli R, Calignano A. Potential beneficial effects of butyrate in intestinal and extraintestinal diseases. World Journal of Gastroenterology. 2011;17(12):1519-1528.
pmc.ncbi.nlm.nih.gov - 3
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Content on this page is general education about ingredients, not advice about you. Ask a qualified clinician about your own situation.