Do Probiotics Have Vitamin B in Them? A Look at Bacterial Synthesis

December 26, 2025 •

4 min read

Certain species of bacteria, including common probiotic strains like Lactobacillus and Bifidobacterium, can produce B-group vitamins, including folate and B12. However, this does not mean that probiotics have vitamin B in them in the same way that a vitamin supplement does.

Quick Summary

Probiotic supplements themselves do not contain B vitamins, but some strains of probiotic bacteria can synthesize B vitamins within the gut microbiome. The true benefit comes from the improved gut health, which helps the body better absorb nutrients from food and supplements.

Key Points

Not a Direct Source: Probiotic supplements and foods do not contain measured quantities of B vitamins like a standard vitamin pill.
Some Strains Produce Vitamins: Specific probiotic bacterial strains, including certain Lactobacillus and Bifidobacterium species, are capable of synthesizing B vitamins.
B Vitamins Produced: Key B vitamins synthesized by these bacteria include folate (B9), riboflavin (B2), and vitamin B12.
Improved Absorption: Probiotics enhance overall gut health, creating a better environment for the body to absorb nutrients from food and supplements.
Synergistic Effect: Combining B vitamins and probiotics can lead to better absorption and overall gut health than taking either one alone.
Not a Replacement for Supplements: For a diagnosed deficiency, relying solely on probiotics for B vitamins is not recommended due to variable production levels.
Look for Specific Strains: If you want to benefit from bacterial vitamin production, seek out products containing strains known for this capability, such as specific Lactobacillus plantarum or Bifidobacterium longum strains.

Understanding the Relationship Between Probiotics and B Vitamins

For many, the link between probiotics and B vitamins is a point of confusion. While a bottle of probiotic supplements or a container of yogurt isn't a direct source of B vitamins in the same way as a multivitamin, the connection is far more complex and fascinating. The key lies in the metabolic capabilities of certain bacterial strains and the overall impact of a healthy gut on nutrient absorption.

Some probiotic bacteria possess the genetic pathways to produce certain B vitamins as part of their natural life cycle. These vitamins are often released into the gut where they can potentially be used by the host body. This process is distinct from simply consuming a vitamin that has been added to a supplement or food product.

Which Probiotic Strains Produce B Vitamins?

Not all probiotic strains are created equal when it comes to vitamin synthesis. Research has identified several key species and strains that are proficient at producing specific B vitamins. The ability to synthesize these vitamins depends on the bacteria's genetics and the environment in which it grows.

Here are some well-documented examples of vitamin-producing probiotic strains:

Bifidobacterium longum and other Bifidobacteria: Known for synthesizing folate (B9) and vitamin B12.
Lactobacillus plantarum and other Lactobacilli: Capable of producing various B vitamins, including folate, riboflavin (B2), and B12. Specific strains like Lactobacillus rossiae are known producers of B12.
Lactococcus lactis: A species used in food fermentation that has been genetically engineered to overproduce folate and riboflavin for fortification purposes.
Propionibacterium freudenreichii: A bacterium commonly found in Swiss cheese that can produce B12.

The Role of Probiotics in Vitamin Absorption

Beyond internal production, probiotics play a crucial role in enhancing the body's overall ability to absorb vitamins. A healthy, balanced gut microbiome is more efficient at digesting food and extracting nutrients. Recent studies have shown that combining probiotics with B vitamins can significantly improve their absorption rates.

Promoting a Healthy Gut Environment: Probiotics can influence the gut's pH levels, which can affect the bioavailability of certain B vitamins. Lactic acid bacteria, for instance, can lower the pH in the intestinal tract, potentially aiding the absorption of some nutrients.
Supporting the Intestinal Lining: A well-maintained gut lining is crucial for efficient nutrient transfer into the bloodstream. By supporting the integrity of this lining, probiotics help ensure that the vitamins and minerals consumed are effectively utilized by the body.
Synergistic Effects: Recent animal studies have shown that administering probiotics and B vitamins together has a synergistic effect, leading to better vitamin absorption and improved gut health markers than either one alone.

Can Probiotics Replace a B Vitamin Supplement?

Despite the vitamin-producing capabilities of some probiotic strains, it is generally not recommended to rely on them as your sole source of B vitamins. The amount of vitamins produced can be highly variable and may not be sufficient to meet daily requirements, especially for individuals with deficiencies. Dietary intake and supplementation remain the most reliable ways to ensure adequate vitamin levels.


Feature	Probiotic-Mediated Vitamin Support	Direct B Vitamin Supplementation
Mechanism	Production by specific bacterial strains within the gut and enhanced absorption.	Directly provides a specific, measured dose of B vitamins.
Quantity	Highly variable and strain-dependent. Amount produced may be insufficient to meet full daily needs.	Precise, guaranteed dosage is listed on the product label.
Absorption	Enhanced due to a healthier gut microbiome, which improves the body's natural absorption processes.	Absorption depends on the body's existing digestive health. May require probiotics for optimal uptake.
Best For	Supporting overall gut health and providing a complementary, natural source of some B vitamins.	Correcting a diagnosed vitamin deficiency or ensuring daily intake requirements are consistently met.
Form	Live bacteria found in fermented foods or dietary supplements.	Non-living capsules, tablets, or liquid drops.

The Importance of a Balanced Approach

For optimal B vitamin levels, a combination of strategies is often best. A diet rich in natural B vitamin sources, such as leafy greens, meat, and dairy, provides the necessary raw materials. Incorporating probiotic-rich foods like yogurt or kefir, or a high-quality probiotic supplement, can support the gut environment and potentially add to your body's B vitamin pool through bacterial synthesis. For those with diagnosed deficiencies or specific dietary restrictions (like vegans who need B12), supplementation is often a necessary and reliable component of their health plan.

Conclusion: The Final Word on Probiotics and Vitamin B

So, do probiotics have vitamin B in them? The answer is nuanced: while the probiotic supplements or fermented foods themselves do not contain B vitamins in a significant, measured quantity, certain bacterial strains within them can produce these essential nutrients. More importantly, maintaining a healthy gut through probiotics can significantly improve your body's ability to absorb B vitamins from your regular diet. For the most effective approach, consider combining a nutrient-rich diet with targeted supplementation when necessary, while also supporting your gut with probiotics to maximize absorption and overall health. A healthy microbiome is an invaluable ally in maintaining optimal nutrient status.

Potential of Probiotic-Based Fortification

Scientists are actively researching ways to harness the vitamin-producing power of probiotics. By using specific strains of bacteria that overproduce certain B vitamins, food manufacturers could fortify products like yogurt or bread more naturally. This could offer a new, more effective way to prevent nutrient deficiencies on a larger scale. For more information, read the study on using probiotics for micronutrient enrichment from the NIH.

Authoritative Source: IntechOpen. "Biosynthesis of Vitamins by Probiotic Bacteria". https://www.intechopen.com/chapters/50488

Frequently Asked Questions

While some fermented foods contain probiotic bacteria that produce B vitamins, the amount is highly variable and unlikely to be enough to meet your daily needs, especially if you have a deficiency.

Certain strains of Lactobacillus and Bifidobacterium are well-known producers of B vitamins. Examples include Lactobacillus plantarum (B12, folate) and Bifidobacterium longum (folate, B12).

For optimal health, it is best to consider both. A B vitamin supplement provides a reliable dose, while probiotics support overall gut health and may enhance the absorption of those vitamins.

No, probiotic supplements and products do not contain B vitamins as an ingredient. The vitamin content depends on the specific bacterial strains present and their metabolic activity.

Probiotics improve gut health by promoting a balanced microbiome and a healthy intestinal lining. This better environment is more efficient at extracting and absorbing nutrients from your diet and supplements.

Yes, antibiotics can disrupt your gut microbiota. A healthy microbiome contributes to B vitamin synthesis and absorption, so this disruption can potentially affect your vitamin status.

Some probiotic strains, like Lactobacillus plantarum, produce B12, but the amount is not sufficient to rely on as a primary source. Vegans should continue to use fortified foods or B12 supplements.