Targeting Immune Aging: New Findings from the MitoImmune Study on Urolithin A (Mitopure®)

Can Mitopure^®, and its active ingredient Urolithin A, support an aging immune system? As we recognize immune aging as a primary driver of age-related disease, this question has taken on new clinical importance.

The newly published MitoImmune study in Nature Aging provides the first rigorous clinical evidence to address this question. Conducted by researchers from Timeline, the Buck Institute for Research on Aging, and the lab of Professor. Florian Greten at the Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, the trial examined whether 1,000 mg/day of Mitopure^® could improve markers of immune fitness, immune cell metabolism, and mitochondrial function.

Let’s take a closer look at this landmark study and how these findings may translate into practical clinical applications.

 

Why Immune Aging Accelerates Biological Aging and Why It Matters

Immune health has long been recognized as a key pillar of overall well-being and also as a key driver of aging if out of balance. As we get older, the body’s baseline level of inflammation tends to rise, a process known as “inflammaging.” The immune system not only loses efficiency but can also actively contribute to age-related diseases.

Immune health has long been recognized as a key pillar of overall well-being and also as a key driver of aging if out of balance. As we get older, the body’s baseline level of inflammation tends to rise, a process known as “inflammaging.” The immune system not only loses efficiency but can also actively contribute to age-related diseases.

When the immune system begins to age, the downstream effects ripple across nearly every organ system.

The hallmarks of immune aging include:

1. Inflammaging. As we age, immune cells produce higher levels of pro-inflammatory cytokines (IL-6, TNF-α, CRP).
2. Loss of Naïve T Cells. The thymus shrinks dramatically after puberty, which means adults produce very few new naïve T cells, making targeting immune responses more challenging.
3. Accumulation of Senescent Cells. Senescent T cells and macrophages secrete SASP (senescence-associated secretory phenotype) molecules that amplify inflammation.
4. Metabolic Inflexibility in Immune Cells. Healthy immune cells switch between glycolysis and oxidative phosphorylation depending on their task. Aging immune cells become locked into inefficient glycolytic metabolism.
5. Reduced Autophagy and Mitophagy. Aging cells fail to clear damaged proteins and dysfunctional mitochondria, leading to a buildup of toxic metabolic byproducts.

Research has started to connect many of the mechanisms behind immune aging to mitochondrial health. Since immune cells rely heavily on mitochondria to power their rapid responses, maintaining healthy mitochondrial function may be key to preserving immune resilience across our lifespan.

 

Why Mitophagy Matters for Mitochondrial Health and Healthy Aging

Mitochondria are central to immune function. T cells and macrophages rely on mitochondria to generate the ATP needed for activation, proliferation, cytokine production, and pathogen killing. When mitochondrial health declines with age, the immune system begins to decline as well.

As damaged mitochondria accumulate, their efficiency declines. This reduces the metabolic flexibility of several immune cells, leading to heavier reliance on less efficient processes (i.e., glycolysis). Immune cells locked into glycolysis behave differently: they become more inflammatory, less capable of forming durable memory responses, and more prone to exhaustion.

This mechanistic link makes the mitochondria an interesting focus area for immune health.

 

How Urolithin A Activates Mitophagy to Support Mitochondrial Health

Urolithin A is a postbiotic compound that promotes mitophagy in the cell. Typically, Urolithin A should be naturally synthesized by the gut from dietary polyphenols, which are found in foods like pomegranates, walnuts, and certain berries. However, research has shown that only about 30–40% of individuals have the right gut microbiome composition to make meaningful levels of UA from diet alone.

This is why Mitopure®, a pure, bioactive form of Urolithin A, was developed to deliver a consistent, clinically validated dose independent of microbiome variability.

 

Across several clinical trials, Mitopure^® has been shown to activate mitophagy and support healthy mitochondrial function in human muscle tissue. Studies have demonstrated measurable effects on biomarkers of mitochondrial health, improved muscle strength, and enhanced cellular energy production in middle-aged and older adults.

 

Clinical Results from the MitoImmune Study on Urolithin A and Immune Aging

The MitoImmune study was a single-center, randomized, double-blind, placebo-controlled trial in healthy middle-aged adults (45–70 years; 60% women, 40% men; mean age 53). Participants were randomized 1:1 to receive either 1,000 mg of Urolithin A (Mitopure®) or a matching placebo daily for 28 days.

The study was done by Timeline in partnership with Dr. Dominic Denk and Professor Florian Greten at the Georg-Speyer-Haus Institute for Tumor Biology and Experimental Therapy, as well as the team at Dr. Eric Verdin’s lab at the Buck Institute for Research on Aging.

Here’s what was found:

• Supports immune fitness: Urolithin A increased the number of naïve CD8+ T cells. These are the fresh, immune response cells that gradually decline with age. These cells also showed less “exhaustion,” suggesting they were better equipped to support immune health. By preserving the pool of metabolically healthy, responsive T cells, Urolithin A may help maintain a balanced immune response that is associated with healthy aging.
• Healthier energy metabolism : Immune cells from the Urolithin A group shifted toward cleaner fuel sources like fatty acids and amino acids, rather than relying on glucose. This shift supports a more efficient and less .
• Stronger mitochondria: The intervention triggered mitochondrial biogenesis, the creation of new and healthy mitochondria.
• Supports healthy immune cell activity: When challenged ex vivo (using human cells in a lab setting), immune cells from participants taking Urolithin A cleared E.coli particles more effectively, supporting a more youthful immune cell profile associated with healthy aging.
• Safe and well-tolerated: The supplement was well-tolerated and with no difference in adverse events between groups. One placebo participant discontinued due to an unrelated event, and no significant changes were observed in kidney or liver function. Additionally, Urolithin A showed good bioavailability, confirming its safety in healthy older adults.

Figure 1: Urolithin A Alters the CD8+ T Cell Phenotype

Figure 2: Urolithin A Induces Metabolic Reprogramming of Human Immune Cells

 

What the MitoImmune Findings Mean for Immune Aging and Mitochondrial Health

The MitoImmune study underscores a powerful concept: the health of our mitochondria may directly shape the health of our immune system. This trial provides good evidence that mitochondrial quality and mitophagy are potential levers for immune support.

Daily supplementation with Urolithin A may help support immune fitness by promoting mitochondrial health. While further research is needed to fully understand the long-term benefits, this study provides compelling evidence on the close connection between mitochondrial and immune health.