Scientists discovered that certain friendly bacteria living in grass-fed cows can make vitamin A and a vitamin A precursor called beta-carotene. Researchers isolated 111 bacteria from different parts of cow digestive systems and found that five strains were especially good at producing these vitamins. The most promising bacteria, called Lactiplantibacillus plantarum, survived stomach acid and bile, suggesting it could work as a probiotic supplement. This discovery could eventually help people who don’t get enough vitamin A in their diet, particularly in developing countries where vitamin A deficiency is a serious health problem.

The Quick Take

  • What they studied: Whether friendly bacteria living in cows’ bodies can naturally produce vitamin A and beta-carotene (a substance the body converts to vitamin A)
  • Who participated: 111 different bacterial strains isolated from three parts of grass-fed cows: the liver, intestines, and rumen (the first stomach chamber)
  • Key finding: Five bacterial strains, mostly Lactiplantibacillus plantarum, produced significant amounts of beta-carotene and vitamin A. The best-performing strain from the liver produced up to 111.95 micrograms of beta-carotene per gram of dried bacteria
  • What it means for you: This research suggests that in the future, these bacteria might be developed into probiotic supplements to help people get more vitamin A naturally. However, this is still early-stage research, and human testing would be needed before any products reach consumers

The Research Details

Scientists collected bacteria from three different locations in grass-fed cattle: the liver (where vitamin A is stored), the intestines (where vitamin A is converted and absorbed), and the rumen (where vitamin A is first absorbed). They isolated 111 different bacterial strains and tested them to see which ones could make beta-carotene and vitamin A.

They used special laboratory techniques to identify the bacteria and measure how much vitamin A they produced. The most promising strains were tested more thoroughly using advanced equipment that can measure exact amounts of vitamins. The researchers also tested whether the best bacteria could survive in conditions similar to the human stomach and digestive system, which is important for probiotics to work effectively.

This type of research is called a screening study because scientists are looking through many samples to find the most promising candidates for further development.

Understanding which bacteria naturally produce vitamin A is important because it could lead to new ways to help people with vitamin A deficiency. Rather than taking synthetic supplements, people might eventually take probiotic supplements containing these bacteria, which would produce vitamin A naturally in the digestive system. This approach could be especially helpful in developing countries where vitamin A deficiency causes serious health problems, including blindness in children.

This study has several strengths: the researchers used multiple advanced laboratory techniques to identify bacteria and measure vitamin production, they tested bacteria from multiple locations in the cow, and they checked whether the best bacteria could survive stomach conditions. However, this research was conducted only in laboratory conditions with cow bacteria, not in human bodies. The study doesn’t include human testing, so we don’t yet know if these bacteria would actually work as a supplement in people. More research would be needed to confirm these findings and test safety in humans.

What the Results Show

Out of 111 bacterial strains tested, 33 showed some ability to produce vitamin A or beta-carotene. Five strains stood out as particularly good producers: four strains of Lactiplantibacillus plantarum and one strain of Escherichia coli.

The Lactiplantibacillus plantarum strains produced between 22.82 and 111.95 micrograms of beta-carotene per gram of dried bacteria. The E. coli strain produced 44.77 micrograms per gram. These amounts are significant enough to potentially be useful as a supplement.

The most impressive strain came from the cow’s liver and was labeled VLL1. This strain not only produced high amounts of beta-carotene but also survived well in laboratory conditions that mimicked stomach acid (pH 2.0) and bile salts (0.3%), which are important characteristics for a probiotic to work in the human digestive system.

The research showed that bacteria from different parts of the cow had different abilities. Bacteria from the liver, where vitamin A is stored, appeared to be the best producers. The bacteria also showed good tolerance to other conditions important for probiotics, such as surviving in acidic environments and resisting bile, which helps break down fats in the digestive system. These characteristics suggest that these bacteria could potentially survive the journey through the human stomach and reach the intestines where they could be beneficial.

This research builds on earlier studies showing that some bacteria can produce or convert vitamin A precursors. However, this study is novel because it specifically looked at bacteria from grass-fed cattle and tested their ability to survive in conditions similar to the human digestive system. The focus on bacteria from natural sources (cow organs) rather than laboratory-created strains is a new approach that could lead to more effective and natural probiotic solutions.

This study was conducted entirely in laboratory conditions using bacteria grown in test tubes and petri dishes, not in living animals or humans. The researchers tested bacteria from cows, but we don’t know if these same bacteria would work the same way in human bodies. The study doesn’t include any testing of whether these bacteria would actually improve vitamin A levels in people who take them as supplements. Additionally, the sample size of bacteria tested (111 strains) is relatively small, and the study doesn’t provide information about the long-term stability or shelf-life of these bacteria as potential supplements.

The Bottom Line

This research is promising but still in early stages. It suggests that these bacteria could potentially be developed into probiotic supplements for vitamin A deficiency, but human clinical trials would be needed first. Currently, people concerned about vitamin A deficiency should continue relying on established dietary sources (like carrots, sweet potatoes, spinach, and dairy products) or supplements that have been tested in humans. If you have vitamin A deficiency or are at risk, talk to your doctor about proven treatment options.

This research is most relevant to people in developing countries where vitamin A deficiency is common and causes serious health problems like childhood blindness. It’s also of interest to researchers and supplement companies looking for new probiotic solutions. People with normal vitamin A levels don’t need to change anything based on this research. Anyone with diagnosed vitamin A deficiency should work with their healthcare provider on proven treatments rather than waiting for future probiotic products.

This research is in the laboratory discovery phase. It typically takes 5-10 years or more to develop a laboratory discovery into a tested and approved supplement or treatment for human use. The next steps would be testing these bacteria in animal models, then human safety studies, and finally effectiveness studies. Don’t expect to see products based on this research available soon.

Want to Apply This Research?

  • Track daily vitamin A intake from food sources (measured in micrograms RAE - retinol activity equivalents). Log servings of orange vegetables, leafy greens, and dairy products, and note any vitamin A supplements taken. This creates a baseline for monitoring vitamin A status.
  • Users could set a goal to include one vitamin A-rich food at each meal (such as carrots, sweet potatoes, spinach, kale, or fortified dairy products) while monitoring their intake. This practical approach works with current food sources until future probiotic options become available.
  • Establish a weekly vitamin A intake summary showing total micrograms consumed from food and supplements. For users with vitamin A deficiency, track this alongside any medical treatments recommended by their doctor. This long-term tracking helps identify dietary patterns and ensures adequate intake.

This research describes laboratory findings about bacteria that may produce vitamin A. It is not yet proven to work in humans and should not be used to replace established vitamin A treatments or dietary recommendations. If you have vitamin A deficiency or suspect you might, consult with a healthcare provider for proper diagnosis and evidence-based treatment. Do not use any experimental probiotic products based on this research without medical supervision. This article is for educational purposes only and does not constitute medical advice.