Researchers developed a fermentation method that increased vitamin B12 in faba beans by 170-200 times, reaching 2.1-2.2 micrograms per gram of dried beans—among the highest levels ever achieved in plant-based foods. However, the body could only absorb 42-54% of this B12 during digestion, suggesting further improvements are needed before this becomes a practical solution for plant-based diets.
Scientists discovered a way to add significant amounts of vitamin B12 to faba beans using a special fermentation process that combines bacteria and fungi. According to Gram Research analysis, this method increased B12 levels by up to 200 times compared to traditional methods. However, the study found that while the beans contained high amounts of B12, the body could only absorb about half of it during digestion. This breakthrough could help people following plant-based diets get more B12 naturally, though more work is needed to make the vitamin easier for the body to use.
Key Statistics
A 2026 laboratory study published in Current Research in Food Science found that solid-state co-fermentation increased vitamin B12 in faba beans by 170-200 times compared to bacterial fermentation alone, reaching 2.1-2.2 micrograms per gram of dried beans.
The same 2026 study found that while B12 content was exceptionally high after fermentation, the body could only absorb 42-54% of it during simulated digestion, indicating that further optimization is needed to improve vitamin availability.
According to the 2026 research, other B vitamins produced during co-fermentation showed better absorption rates, with thiamin, riboflavin, and niacin demonstrating high bioaccessibility, while folate absorption remained low at 39-41%.
The Quick Take
- What they studied: Whether scientists could use fermentation (a natural process like making yogurt or sauerkraut) to add vitamin B12 to faba beans, which normally don’t contain this important nutrient.
- Who participated: This was a laboratory study testing different combinations of bacteria and fungi on faba beans. No human participants were involved; researchers measured the vitamin content and how well it could be absorbed during simulated digestion.
- Key finding: Co-fermentation increased B12 levels to 2.1-2.2 micrograms per gram of dried beans—a 170-200-fold increase compared to using bacteria alone. However, the body could only absorb 42-54% of this B12 during digestion.
- What it means for you: Plant-based eaters may eventually have access to faba bean products with meaningful amounts of B12, but the current method still needs improvement to make the B12 more absorbable by the human body.
The Research Details
Researchers used a laboratory technique called solid-state co-fermentation, which is similar to how traditional fermented foods are made but more controlled. They combined faba beans with a specific bacteria (Propionibacterium freudenreichii) and one of two types of fungi (Rhizopus oligosporus or Aspergillus oryzae) and let them ferment together for 66 hours. This is different from using just bacteria alone, which is the traditional approach.
The researchers measured how much B12 and other B vitamins (thiamin, riboflavin, niacin, and folate) were created during fermentation. They also tested how much of these vitamins the human body could actually absorb by simulating digestion in a laboratory setting, using conditions that mimic what happens in your stomach and intestines.
This approach is important because it combines the B12-producing abilities of bacteria with the growth and nutrient-boosting properties of fungi, creating a synergistic effect that produces much more B12 than either organism could make alone.
This research matters because vitamin B12 is naturally found only in animal products like meat, dairy, and eggs. People following plant-based diets often struggle to get enough B12, which is essential for nerve function and red blood cell formation. Finding a natural way to add B12 to plant foods could help millions of people maintain healthy B12 levels without supplements or animal products.
This was a controlled laboratory study published in a peer-reviewed journal, which means other scientists reviewed the work before publication. The researchers used standardized methods to measure vitamin content and simulate human digestion. However, this was not a human trial, so we don’t know yet how well people would actually absorb the B12 from eating these fermented beans. The study also didn’t test the taste or texture of the final product, which matters for whether people would actually eat it.
What the Results Show
The co-fermentation process was remarkably effective at creating B12. After 66 hours of fermentation, the faba beans contained 2.1-2.2 micrograms of B12 per gram of dried beans. This represents a 170-200-fold increase compared to using just the bacteria alone, making it one of the highest B12 levels ever achieved in plant-based fermentation.
Beyond B12, the fermentation also increased other important B vitamins. Thiamin (vitamin B1), riboflavin (vitamin B2), and niacin (vitamin B3) all increased significantly and showed good absorption during simulated digestion (meaning the body could use them well). However, folate (another B vitamin) showed lower absorption at only 39-41%.
The most important limitation was that despite the high B12 content, the body could only absorb 42-54% of it during simulated digestion. This suggests that some of the B12 remained trapped inside the microbial cells or bound to the bean material in ways that make it harder for the body to access. The researchers also found that different combinations of bacteria and fungi produced different patterns of organic acids, suggesting they work together in distinct ways.
The study revealed that the type of fungus used affected the fermentation process. Both Rhizopus oligosporus and Aspergillus oryzae worked with the bacteria to produce high B12 levels, but they created different patterns of organic acids (the compounds that give fermented foods their tangy flavor). This suggests that the choice of microorganisms could be optimized for both nutrition and taste. The research also confirmed that legume-based foods naturally have lower folate absorption, which is consistent with previous research.
This study achieved B12 levels among the highest ever reported for plant-based fermentations, significantly outperforming previous attempts using bacteria alone. However, the moderate bioaccessibility (42-54%) is consistent with other fermented plant foods, suggesting this is a common challenge when B12 is produced in plant matrices. The overall approach aligns with growing research showing that combining different microorganisms can enhance nutrient production in fermented foods.
This was a laboratory study using simulated digestion, not actual human consumption, so real-world absorption might differ. The study didn’t evaluate the taste, texture, or smell of the fermented beans, which are crucial for whether people would actually eat the product. The researchers also didn’t test whether cooking or processing the fermented beans would affect B12 content or absorption. Additionally, the study didn’t compare this method to other B12 fortification approaches or test it in people with different digestive systems. Finally, the moderate bioaccessibility means that even with this enrichment, people would need to eat substantial amounts of these beans to meet their daily B12 needs.
The Bottom Line
This research is promising but not yet ready for practical use. People following plant-based diets should continue relying on B12 supplements or fortified foods until fermented faba bean products become commercially available and are proven effective in human studies. High confidence: Current plant-based B12 sources (supplements, fortified plant milks, nutritional yeast) remain the most reliable options. Moderate confidence: Fermented faba bean products may eventually become a useful supplementary source of B12 once bioaccessibility is improved.
This research is most relevant to people following plant-based or vegan diets who struggle to get enough B12. Food scientists and manufacturers developing plant-based products should pay attention to this technique. People with digestive issues that affect nutrient absorption should wait for human studies before considering fermented faba beans as a B12 source. This research is less immediately relevant to people who eat animal products, as they typically get sufficient B12 from their diet.
If this technology moves forward, it would likely take 3-5 years of additional research before fermented faba bean products could be commercially available. Even then, it would take several weeks of regular consumption to build up B12 stores in the body. People shouldn’t expect immediate results; B12 benefits develop gradually over time.
Frequently Asked Questions
Can fermented faba beans replace B12 supplements for vegans?
Not yet. While a 2026 study achieved high B12 levels in fermented faba beans, the body could only absorb 42-54% of it. Current supplements and fortified foods remain more reliable until this technology improves and human studies confirm effectiveness.
How much B12 does fermented faba bean have compared to meat?
The fermented beans reached 2.1-2.2 micrograms per gram of dried beans, which is substantial. However, dried beans are concentrated; cooked beans contain less. A typical serving would need testing to compare directly to meat portions.
What bacteria and fungi were used to create B12 in faba beans?
Researchers combined Propionibacterium freudenreichii bacteria with either Rhizopus oligosporus or Aspergillus oryzae fungi. Both fungal combinations worked well, though they produced different flavor compounds during fermentation.
When will fermented faba bean B12 products be available to buy?
This is still in early research stages. Commercial products would likely require 3-5 years of additional development, human testing, and regulatory approval before becoming available in stores.
Does cooking fermented faba beans destroy the B12?
The study didn’t test this. B12 is generally heat-stable, but cooking could affect how much the body can absorb. This would need to be tested before fermented faba bean products are marketed as B12 sources.
Want to Apply This Research?
- Track weekly B12 intake from all sources (supplements, fortified foods, animal products, and eventually fermented legumes). Log the amount in micrograms and monitor energy levels and mood, which often improve with adequate B12.
- Set a reminder to consume a consistent B12 source daily. Once fermented faba bean products become available, users could add them to their tracking app and monitor whether they’re meeting B12 targets through food rather than supplements alone.
- Create a long-term tracking dashboard showing B12 intake trends over months. Include notes on energy, cognitive function, and mood to correlate with B12 levels. Users can share this data with healthcare providers to optimize their B12 strategy.
This research describes laboratory findings and has not been tested in humans. The B12 bioaccessibility (absorption) was only 42-54%, meaning the body cannot use all the B12 produced. People following plant-based diets should continue using established B12 sources (supplements, fortified foods, or animal products) and consult with a healthcare provider about their B12 intake. This study does not replace medical advice, and fermented faba bean products are not currently available as commercial B12 sources. Do not rely on this research to change your B12 supplementation strategy without consulting a doctor or registered dietitian.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
