Most people do not “eat” Urolithin B directly. Your gut microbes manufacture it after you consume foods that contain ellagitannins and ellagic acid, most prominently from pomegranate, walnuts, pecans, and certain berries. The tricky part is that the amount of Urolithin B your body makes from the same meal varies widely from person to person. Researchers have described distinct urolithin “metabotypes” in humans, including people who mainly generate Urolithin A, others who generate more Urolithin B, and non-producers who make little to none, even with identical diets. This variability has been documented across multiple human feeding studies in the clinical nutrition literature led by groups in Spain and Europe during the 2010s. So how much food do you need to make Urolithin B? The honest answer is a range, not a single serving, and it depends on your microbiome, food choices, and consistency.

Why the “right amount” of food depends on your microbiome

Ellagitannins are large polyphenols that your digestive enzymes barely touch. They move down the gut where specific bacteria break them into smaller molecules, including Urolithin B. If you host the right converters, a standard serving of pomegranate or walnuts can produce measurable urolithin metabolites in blood and urine. If you do not, you could eat the same foods for weeks and produce very little. Human studies that mapped metabotypes A, B, and 0 found these patterns can be fairly stable over time, although diet quality and fiber diversity may nudge production. In practical terms, this means food quantity is only half the story. The other half is the health and composition of your microbial community.

Foods that supply the raw material for Urolithin B

Pomegranate sits at the top of the list. Analytical chemistry comparisons repeatedly show that the peel contains the highest concentration of ellagitannins such as punicalagins, with meaningful but lower amounts in the arils and fresh juice. You do not eat the peel, so in daily life you rely on arils and minimally processed juice for precursors. Walnuts and pecans are next. Their polyphenols, particularly in the skin, provide ellagitannins and free ellagic acid in a fiber-rich matrix that suits microbial fermentation. Among berries, red raspberries stand out for sanguiin H-6 and lambertianin C, while blackberries and strawberries contribute smaller but still helpful amounts. Regional fruits like cloudberries are strong sources where available.

What human feeding studies suggest about servings

Controlled trials give us ballpark ranges rather than exact thresholds. In studies of pomegranate juice and arils, producers often excreted urolithin conjugates after daily servings that looked like typical household portions, for example one small glass of minimally processed juice or a generous cup of arils, taken consistently for days to weeks. Walnut interventions commonly used about 30 to 60 grams per day, roughly a handful to two, and detected downstream urolithins in many participants. Raspberry servings around one to two cups have also produced measurable metabolites in producers. Across these papers, the theme is consistent. Regular intake over several weeks matters more than a single large dose, and individual response varies dramatically because of metabotypes.

A practical food framework that covers most people

If your goal is to give your microbes repeated chances to make Urolithin B, build a simple weekly rhythm that rotates the richest precursors.

• Pomegranate: target 1 to 1.5 cups of arils on two or three days per week, or one small glass of minimally processed juice on a few days. Choose low-heat products with little added sugar to preserve polyphenols.

• Walnuts or pecans: aim for 30 to 60 grams per day, three to five days per week. Favor lighter roasts and fresher nuts because the polyphenols concentrate in the skin and can degrade with heat and storage.

• Berries: include 1 to 2 cups of red raspberries on two days per week, and add blackberries or strawberries on at least two other days. Frozen fruit works well because freezing preserves polyphenols.

• Fiber and diversity: keep a Mediterranean-style base of legumes, whole grains, vegetables, and olive oil to feed the very microbes that perform ellagitannin conversions. Fermented foods can help round out diversity.

This rotation is not a rigid plan. It is a realistic cadence most active adults can maintain while covering seasonal gaps.

Why the same servings do not work for everyone

In the same trial, one participant can show robust Urolithin B signatures after a week of walnuts and pomegranate, while another shows very little. Papers from polyphenol metabolism groups highlight that antibiotic use, habitual diet, age, and even oral hygiene can shift the presence of key converters. That is why you should judge success over months, not days. Give your microbiome time to adapt to the new pattern, then decide whether food is enough for your goals.

How long it takes to see a difference

Microbial communities adapt slowly compared with your taste buds. In feeding studies, urolithin conjugates often rise within one to two weeks in producers. For real-world effects such as steadier energy or recovery, the timeline is longer because those outcomes depend on downstream cellular processes, including mitophagy and improved fuel handling. Early human supplementation work reported mitochondrial gene activation in about four weeks and endurance or strength gains after roughly four months in older or sedentary adults, published in journals like Nature Metabolism in 2019 and JAMA Network Open and Cell Reports Medicine in 2022. Food-based strategies use the same pathways, so expect a similar cadence when your diet is consistent.

How to tell whether food is “working” for you

There is no at-home strip that reads “Urolithin B.” Researchers confirm production by measuring conjugated urolithins in urine or plasma, which requires a lab. For most people, a practical approach is to track simple functional markers while you maintain the food pattern. Keep one repeatable cardio session and note time to fatigue or average heart rate, add one fixed resistance circuit and record total work, then rate soreness at 24 and 48 hours. Review trends every four weeks. If training repeatability improves and next-day heaviness fades over two to three months, your overall mitochondrial environment is likely moving in the right direction, regardless of the exact mix of Urolithin A or B you produce.

When food alone may not be enough

Two scenarios come up often. First, you follow the plan for two to three months and still feel like a low producer, which is consistent with the metabotype 0 pattern described in the nutrition literature. Second, your schedule makes it difficult to maintain the rotation of arils, nuts, and berries week after week. In both cases, a standardized urolithin supplement provides a direct route to the downstream molecules every day while you continue to improve your diet. This is the logic behind formulas that provide both Urolithin A and Urolithin B in defined amounts.

Where BioLithin fits if you want guaranteed exposure

BioLithin delivers Urolithin A and Urolithin B that are derived from pomegranate peel, the most ellagitannin-dense part of the plant, and pairs them with taurine for mitochondrial support. Food first remains a smart foundation because it supports microbiome diversity and overall cardiometabolic health. BioLithin simply removes the conversion bottleneck created by metabotypes so you can count on daily exposure while your nutrition continues to build long-term resilience.

Common pitfalls that reduce your odds

Heavy processing lowers polyphenol content, so choose minimally heated juices and avoid sugar-loaded pomegranate drinks that taste good but do little. Do not assume any nut will do. Walnuts and pecans carry the ellagitannins, while almonds and cashews contribute other benefits but not much toward urolithin precursors. Long gaps in your rotation, for example eating berries once a month, rarely support stable production. Broad-spectrum antibiotics can temporarily reduce converter populations. If you require them for medical reasons, rebuild with fiber-rich meals and fermented foods once your clinician approves.

Key takeaways you can use this week

You do not need an extreme amount of food to make Urolithin B if you are a producer, you need consistent servings of the right sources. Plan on several cups of pomegranate arils or a few small glasses of minimally processed juice per week, 30 to 60 grams of walnuts or pecans on most days, and multiple cups of raspberries or related berries spread across the week. Pair that with a microbiome-friendly base diet and give it eight to twelve weeks before you judge results. If you want guaranteed, day-to-day exposure regardless of your microbiome, layer in a standardized urolithin supplement while you keep the whole-food pattern for the broader health benefits it delivers.

This content is for informational purposes only and is not a substitute for medical advice. Always consult a qualified healthcare professional before making significant dietary changes or starting supplements, especially if you manage medical conditions or take prescription medications.