Where Do I Get L. Reuteri: A Complete Guide to Sources

October 21, 2025 •

4 min read

L. reuteri, a probiotic bacterium, was originally isolated from human intestinal and fecal samples in 1962. If you're wondering "where do I get L. reuteri?", the answer lies in both concentrated supplements and specific fermented foods, which are crucial for maintaining a healthy and balanced gut microbiome.

Quick Summary

L. reuteri can be obtained from targeted probiotic supplements and specific fermented foods. Homemade reuteri yogurt is a highly concentrated source, while certain cheeses, sourdough, and pickled products also contain it. Dietary choices, prebiotic intake, and supplements all influence gut health.

Key Points

Supplements offer a high dose: Probiotic supplements are the most reliable and potent source of L. reuteri, often containing specific, clinically studied strains like DSM 17938 and ATCC PTA 6475.
Fermented foods contain L. reuteri: While variable in concentration, sources include homemade L. reuteri yogurt, certain sourdough breads, aged cheeses, and specific pickled vegetables.
Homemade yogurt is a potent source: Extended fermentation of milk with an L. reuteri starter culture and prebiotic fiber creates a highly concentrated yogurt with a therapeutic dose of probiotics.
Prebiotics support growth: Feeding your gut with prebiotic fibers from foods like garlic, onions, and bananas helps nourish L. reuteri and other beneficial bacteria.
Avoid gut-damaging habits: Reducing consumption of processed foods and unnecessary antibiotics is crucial for creating and maintaining a healthy gut microbiome where L. reuteri can thrive.
Concentration varies widely: The amount of L. reuteri in commercial fermented foods is often not guaranteed, making supplements and dedicated homemade products more reliable for targeted intake.
Infants receive L. reuteri from breastmilk: A natural source for infants, breastmilk contains L. reuteri and helps establish a healthy gut microbiome early in life.

Supplements: A Reliable and Concentrated Source

For those seeking a high and consistent dosage of L. reuteri, particularly a specific strain, supplements are the most effective method. The concentration of bacteria in supplements can be significantly higher and more controlled than in food sources. Many supplements also use protective capsule technology to ensure the bacteria survive stomach acid and reach the intestines.

Targeted Strains: Supplements often contain well-researched strains such as L. reuteri DSM 17938 (found in products like BioGaia) and ATCC PTA 6475 (often used for specific effects like influencing oxytocin).
High Potency: Products are available with billions of Colony-Forming Units (CFUs) per serving, offering a potent dose to help re-colonize the gut.
Availability: Probiotic supplements containing L. reuteri are widely available online through retailers like iHerb and in health food stores.

Fermented Foods: Traditional Sources with Variable Potency

While many people associate probiotics with all fermented foods, not all fermented products contain L. reuteri. The presence of this specific strain depends on the starter culture used in the fermentation process. For natural food sources, artisanal preparation methods are often key.

Reuteri Yogurt: A potent homemade source, L. reuteri yogurt is made by fermenting milk with a special starter culture for an extended period, typically 36 hours at a consistent temperature of around 100°F (38°C). This process can yield a very high concentration of L. reuteri.
Specific Fermented Products: Some sourdough breads, specific types of kefir, and certain naturally fermented pickled vegetables (like sauerkraut and pickles) may contain L. reuteri, though concentrations are highly variable.
Traditional Cheeses: Historically, L. reuteri has been isolated from various dairy products, including traditional cheeses like Cheddar and Parmigiano Reggiano, where it exists as a non-starter lactic acid bacterium. However, it is not consistently present in modern mass-produced versions.

Comparison Table: Supplements vs. Food Sources for L. reuteri


Feature	Probiotic Supplements	L. Reuteri Yogurt (Homemade)	General Fermented Foods
L. reuteri concentration	High, guaranteed by CFU count.	Very high with proper technique.	Variable and often low.
Strain specificity	Easily select specific strains (e.g., DSM 17938, ATCC PTA 6475).	Determined by the starter culture used.	Dependent on the natural environment and starter.
Preparation effort	Minimal; simply take a pill or powder.	Moderate; requires specific temperature and time.	Varies widely, but generally low for consumption.
Cost	Can be more expensive per serving.	Cost-effective for large batches.	Highly affordable.
Convenience	Easy to integrate into a daily routine.	Requires planning and incubation time.	Readily available at most grocery stores.
Consistency	Highly consistent dose in every serving.	Consistent between batches if technique is followed.	Inconsistent; depends on brand and batch.

Creating a Gut Environment to Promote L. Reuteri Growth

Beyond consuming L. reuteri directly, you can also support its growth and colonization by fostering a healthy overall gut microbiome. This indirect approach complements direct intake and helps the bacteria thrive.

Nourishing the Existing Gut Microbiome

Prebiotic Fiber: Provide food for beneficial bacteria with prebiotic fibers found in foods like garlic, onions, bananas, and asparagus. These fibers selectively feed probiotics, helping them flourish.
Dietary Diversity: A diet rich in a variety of high-fiber foods, fruits, and vegetables promotes a diverse microbiome, which is essential for a balanced and resilient gut.
Limit Processed Foods: Overconsumption of highly processed foods, sugar, and alcohol can negatively impact gut health and disrupt the balance of your microbiome.

Lifestyle Factors and Natural Sources

Avoid Unnecessary Antibiotics: Overuse of antibiotics can significantly harm beneficial gut bacteria, including L. reuteri. Only use them when necessary to protect your microbiome.
Consider Breastmilk for Infants: For infants, breast milk is a natural and traditional source of L. reuteri, playing a crucial role in establishing their gut health from the start.
L. reuteri yogurt recipe: A popular method for obtaining a high dose is making yogurt. You will need a specific starter culture (containing L. reuteri), prebiotic fiber (like inulin or potato starch), and milk. Fermenting for 36 hours at a low, consistent temperature will yield a thick, probiotic-dense product. This can be easily made with an appliance designed for yogurt making or sous vide.

Conclusion

Obtaining L. reuteri is possible through a combination of intentional dietary choices, strategic supplementation, and even homemade preparations. Supplements offer a reliable and potent dose of specific strains, making them ideal for therapeutic use or for those who need consistency. Homemade L. reuteri yogurt is a highly concentrated and cost-effective food-based alternative. For a more general approach, supporting a diverse and healthy gut environment with prebiotic foods and a balanced diet can help any beneficial bacteria, including L. reuteri, to thrive. Ultimately, a multi-faceted approach addressing diet, lifestyle, and supplementation provides the most comprehensive strategy for getting and maintaining L. reuteri in your system. This proactive engagement with your gut health can have wide-ranging benefits for your overall well-being.

Frequently Asked Questions

Most commercial yogurts do not contain L. reuteri unless it is specifically added and listed on the label. Standard yogurts are made with different bacterial strains. The highest concentrations of L. reuteri are found in specialized homemade versions.

To make L. reuteri yogurt, you need an L. reuteri starter culture, milk, and prebiotic fiber (like inulin or potato starch). You ferment the mixture at a low, consistent temperature (around 100°F or 38°C) for 24 to 36 hours using a yogurt maker.

Look for supplements that specify the strain, such as DSM 17938 or ATCC PTA 6475, and list a high number of Colony-Forming Units (CFUs). Products like BioGaia or Swanson L. Reuteri Plus are common examples.

Some artisanal or specially prepared kefirs may contain L. reuteri, but it is not a guaranteed ingredient in all kefir products. Like yogurt, the presence of the strain depends on the starter cultures used in fermentation.

While often associated with dairy, L. reuteri can be found in some fermented plant-based products, such as certain sourdough breads and naturally fermented sauerkraut. However, concentrations vary widely.

L. reuteri is a specific probiotic species known for producing antimicrobial compounds like reuterin and influencing the immune system. Its effects and colonization patterns differ from other probiotics, so its source and strain are important for targeted benefits.

Colonization can begin within days of consistent intake, but levels will decrease within a few months if supplementation or consumption is stopped. Some benefits may be noticeable sooner, but long-term consistency is key for sustained effects.