Postbiotics (Butyrate / Urolithins)

The verdict

Is Postbiotics worth taking?

Postbiotics deliver the beneficial metabolites that gut bacteria produce without requiring the bacteria themselves to be present or to survive supplementation. Butyrate directly feeds colonocytes and supports gut barrier integrity; sodium butyrate or tributyrin are the most practical supplemental forms. Urolithin A is the most clinically interesting postbiotic right now, produced from ellagic acid in pomegranates and berries by specific gut bacteria, with a 2022 landmark trial showing meaningful improvements in muscle endurance and mitochondrial function at 500 mg to 1 g daily, the first postbiotic with performance-adjacent evidence.

What it does

What Postbiotics does in the body

Gut barrier integrity, colonocyte energy supply, mitochondrial health, muscle endurance, and anti-inflammatory activity, depending on the specific postbiotic. Postbiotics are defined as preparations of inanimate microorganisms or their components that confer a health benefit, and more broadly include the bioactive metabolites produced by gut bacteria including short-chain fatty acids, organic acids, and other compounds. Butyrate is the most important SCFA for colonic health specifically. Urolithin A is the standout individual postbiotic compound with the most developed human clinical evidence base of any compound in this class.

The evidence

What the research actually shows

Moderate and rapidly growing. Butyrate’s role as the primary colonocyte energy source is mechanistically established and its supplemental forms have reasonable evidence for gut barrier support and inflammatory bowel condition management. Urolithin A has a particularly impressive and growing human evidence base: a 2022 randomized trial in middle-aged adults with sedentary lifestyles found 1 g daily significantly improved muscle strength, though its primary endpoint of peak power output was not met at 4 months, alongside measurable mitochondrial biomarker improvements. A further 2025 trial confirmed benefits in older adults with sarcopenia risk.

Food first

Getting Postbiotics from food

For butyrate: butter and ghee from grass-fed dairy contain butyrate in food form, though at concentrations that contribute to overall SCFA status rather than replicating therapeutic colonocyte delivery. Fermented foods and dietary fiber that feeds butyrate-producing bacteria are the primary food-first route. For urolithin A: pomegranates, strawberries, raspberries, and walnuts are the richest ellagitannin sources, though conversion to urolithin A requires specific gut bacteria that not all individuals possess.

What the guide adds

The part that is not on this page

Everything above is the assessment. What the guide adds for Postbiotics is the protocol:

• Optimal Form
• Bioavailability
• Purity Red Flags
• Stack With / Avoid

147 entries across nine categories, every one graded against the clinical literature the same way.

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About the author

Who graded this

Daniel Edlund is a Le Cordon Bleu-trained private chef in Los Angeles, a certified personal trainer and strength coach, and an internationally licensed massage therapist. Thirty years of strength training and fifteen years cooking in private estate kitchens. He is the author of The Complete Supplement Guide, which grades 147 entries against the clinical literature, and of The EASY Way to Organic Cooking, first published in 2013.

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This page is information, not medical advice. Supplements interact with prescription medication and with each other, and the right answer depends on your own bloodwork and history. Talk to your doctor before starting anything, particularly if you are pregnant, nursing, managing a health condition, or already taking medication.

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All 147 entries, graded →