What is Urolithin B?
Urolithin B is a phenolic compound and a major metabolite of ellagitannins and ellagic acid, polyphenols abundant in certain fruits and nuts. Unlike their precursors, urolithins are produced by specific gut microbiota and are more readily absorbed. When consuming foods rich in ellagitannins, such as pomegranates, raspberries, and walnuts, gut bacteria metabolize these compounds into urolithins, including urolithin B. The health benefits associated with these foods are largely attributed to the activity of these metabolites. However, urolithin production depends on an individual's unique gut microbiota, leading to interest in supplementation for consistent benefits.
Powerful Anti-inflammatory Effects
Chronic inflammation is a major contributor to numerous chronic diseases. Research indicates urolithin B has significant anti-inflammatory capabilities by suppressing key pro-inflammatory cytokines and inhibiting inflammatory pathways.
- Reduces levels of inflammatory cytokines like IL-6, TNF-α, and IL-1β.
- Inhibits inflammatory signaling pathways, including NF-κB and MAPK.
- Alleviates neuroinflammation in animal models of Alzheimer's disease.
- Attenuates intestinal inflammatory injury in aging mice.
Strong Antioxidant Properties
Oxidative stress is implicated in a wide range of chronic diseases. Urolithin B exhibits powerful antioxidant activity, protecting cells from damage.
- Scavenges reactive oxygen species (ROS) and inhibits lipid peroxidation.
- Boosts the body's natural antioxidant defenses by enhancing enzymes like superoxide dismutase (SOD).
- Activates the Nrf2 signaling pathway, a regulator of antioxidant responses.
Supports Skeletal Muscle Health
Urolithin B shows potential for enhancing skeletal muscle function and mass, particularly relevant for age-related muscle decline (sarcopenia).
- Promotes protein synthesis in muscle cells via the mTORC1 pathway.
- Reduces muscle atrophy and enhances muscle differentiation.
- Induces muscle hypertrophy (growth) in animal studies.
Beneficial for Cardiovascular and Metabolic Health
Urolithin B offers significant protective effects against cardiovascular and metabolic dysfunction in preclinical studies.
- Decreased lipid plaque deposition and inhibited lipid uptake in mouse models of atherosclerosis.
- Improved cardiac function and protection against cell death during myocardial ischemia in animal studies.
- Helps regulate metabolic dysfunction associated with obesity and hyperglycemia by modulating gut microbiota and improving lipid metabolism.
Comparison: Urolithin B vs. Urolithin A
Both urolithins A (UA) and B (UB) are beneficial metabolites, but research suggests differences in their specific effects and potency, which can vary depending on the target tissue and metabolic process.
| Feature | Urolithin B | Urolithin A |
|---|---|---|
| Muscle Growth | Strong anabolic effects proven in preclinical studies, promoting growth and inhibiting atrophy. | Also promotes muscle endurance, with some studies showing similar or less pronounced effects compared to UB. |
| Cardiovascular Health | Has shown potent protective functions against cardiovascular disease (CVD) and is found in higher concentrations in the heart. | Also has antiatherogenic effects, but some studies indicate varying degrees of potency compared to UB for certain effects. |
| Anticancer Activity | Exhibits anti-proliferative and pro-apoptotic effects in certain cancer cell lines (prostate, breast, colorectal). | May show more prominent antiproliferative capabilities against certain cancers like leukemia in some studies. |
| Antioxidant Effect | Possesses strong antioxidant and free-radical scavenging properties, though some in vitro results vary based on testing method. | More pronounced antioxidant activity in some cell-based assays compared to urolithin B. |
| Bioavailability | Bioavailable and reaches target tissues, with studies showing higher concentrations in some organs like the heart. | Bioavailability is highly variable among individuals due to gut microbiota differences. |
Conclusion
Urolithin B is a potent metabolite derived from ellagitannins, offering a range of potential health benefits supported by preclinical research. Its anti-inflammatory and antioxidant properties contribute to protective effects on cardiovascular, metabolic, and nervous systems. Its ability to enhance skeletal muscle mass and function makes it promising for healthy aging and combating muscle wasting. While current evidence is largely from animal models and cell studies, the potential for urolithin B as a therapeutic agent is significant. Further clinical trials are needed to confirm efficacy and safety in humans. To increase urolithin precursors, include ellagitannin-rich foods like pomegranates and walnuts in your diet.
Sources
: Chen, P., et al. Recent Advances and Perspectives on the Health Benefits of Urolithin B, A Bioactive Natural Product Derived From Ellagitannins. Frontiers in Pharmacology. 2022. 917266. : Rodriguez, J., et al. Urolithin B, a newly identified regulator of skeletal muscle mass. PubMed. 2017. 28251839. : Lee, K. M., et al. Anti-inflammatory and antioxidant mechanisms of urolithin B in LPS-stimulated microglia. PubMed. 2019. 30668443. : Al-Rehany, M., et al. The Gut Microbiota Metabolite Urolithin B Mitigates Cholestatic Liver Damage in Mice via Modulation of Nrf2, NF-κB, and PPARα Signaling Pathways. PubMed Central (PMC). 2025. PMC12387986.
Disclaimer: This information is for informational purposes only and does not constitute medical advice. Consult with a healthcare professional before making any health-related decisions.
