What Food Has the Most Lactobacillus Reuteri? Maximizing Your Probiotic Intake

October 4, 2025 •

5 min read

Based on recent research, homemade fermented products, specifically yogurt made with targeted starter cultures, often contain a significantly higher concentration of Lactobacillus reuteri than commercial alternatives. This critical distinction helps those aiming to understand what food has the most Lactobacillus reuteri to effectively increase their intake.

Quick Summary

An exploration of the dietary sources for maximizing Lactobacillus reuteri levels, comparing specialized fermented products with other food items and supplements to support gut health.

Key Points

Homemade Ferments: Homemade yogurt using a specific L. reuteri starter culture and a long fermentation period offers the highest and most reliable concentration of this probiotic.
Limited Food Sources: Common fermented foods like kefir, kimchi, and certain cheeses may contain L. reuteri, but the concentrations are often lower and less consistent than in homemade versions or supplements.
Supplements for Targeted Doses: For a guaranteed, high-potency dose of a specific L. reuteri strain, probiotic supplements are the most reliable option and have been used in targeted clinical studies.
Check Product Labels: When choosing commercial yogurt or other fermented foods, look for labels that state specific L. reuteri strains or confirm the presence of live and active cultures.
Prebiotics Support Growth: To maximize the effectiveness of L. reuteri, consume prebiotic fiber from foods like garlic, onions, bananas, and whole grains, which serve as nourishment for beneficial gut bacteria.
Gut Health Matters: Maintaining a diverse diet rich in various fermented foods is key to creating a supportive environment where a range of beneficial microbes can thrive.
Reclassification: Lactobacillus reuteri has been scientifically reclassified as Limosilactobacillus reuteri, so you may see either name on older or new product labels.

The Science Behind Lactobacillus reuteri

Lactobacillus reuteri, now reclassified as Limosilactobacillus reuteri, is a type of probiotic bacterium that plays a crucial role in maintaining a healthy gut microbiome. It is naturally found in the gastrointestinal tracts of humans and other animals, and its presence has been linked to numerous health benefits. A key characteristic of this beneficial microbe is its ability to produce antimicrobial compounds, such as reuterin, which help suppress the growth of harmful bacteria and pathogens.

Beyond its antimicrobial properties, research suggests that L. reuteri can also help regulate the immune system and support overall digestive function. It has been studied for its potential effects on conditions ranging from infantile colic to constipation and is believed to modulate the gut-brain axis. However, the levels of L. reuteri can be depleted by modern lifestyles, diets high in processed foods, and the overuse of antibiotics, making it important to find effective ways to restore and maintain its presence.

Searching for the Most Potent Food Sources

Determining exactly what food has the most Lactobacillus reuteri is complex, as concentrations vary widely based on production methods. While a variety of fermented foods may contain this probiotic, some methods and products offer a much higher and more reliable count.

Homemade Fermented Yogurt

For those seeking the highest, most consistent dose of L. reuteri from a food source, homemade yogurt is the clear winner. By using a specific starter culture that contains potent strains, such as ATCC 6475 or DSM 17938, and fermenting the yogurt for an extended period (typically 24–36 hours), you can achieve bacterial counts far exceeding those in typical commercial products. This longer fermentation time allows the probiotic cultures to proliferate, creating a highly concentrated and bioavailable product. The precise control over the strains and process makes this a highly effective method for therapeutic intake.

Commercial Fermented Foods and Dairy

While homemade yogurt is potent, other fermented foods may contain L. reuteri or other beneficial lactobacilli, though in lower, less reliable amounts.

Yogurt and Kefir: Many conventional yogurts contain some strains of Lactobacillus, but not necessarily L. reuteri. Kefir, a fermented milk drink made with kefir grains, typically contains a diverse range of bacteria and yeasts, and Lactobacillus is always present, but the specific strains and quantities can vary. For either product, it is essential to check the label for specific probiotic strain information and ensure it contains live and active cultures.
Cheeses: Certain types of cheese, particularly well-aged varieties like Parmigiano Reggiano, Cheddar, and Gruyère, may contain L. reuteri as part of their non-starter lactic acid bacteria population. However, the amounts are generally low, and it is not a primary dietary source for boosting levels.
Fermented Vegetables and Sourdough: Fermented vegetables like sauerkraut and kimchi, as well as sourdough bread, are rich in various Lactobacillus species. L. reuteri has been isolated from these foods, but again, the exact concentration depends on the specific fermentation process. Pasteurization and heat-treatment destroy probiotics, so look for raw or unpasteurized products.

Targeted Probiotic Supplements

For those who need a concentrated and consistent dose of specific L. reuteri strains, such as those used in clinical studies for targeted health benefits (e.g., DSM 17938 for colic or H. pylori management), supplements are often the most reliable option. Unlike food products, supplements offer a standardized dose of specific strains, ensuring a therapeutic quantity is delivered consistently.

A Dietary Comparison: Homemade vs. Commercial vs. Supplements

To help you decide the best approach, here is a comparison of different ways to get L. reuteri.


Feature	Homemade L. reuteri Yogurt	Commercial Fermented Foods	Probiotic Supplements
Concentration	Very high, especially with specific starter cultures and long fermentation.	Variable and often low; dependent on the product and brand.	High, consistent, and standardized dosage of specific strains.
Strain Specificity	You control the strains by selecting your starter culture.	Unpredictable; labels may list general bacteria, not specific strains.	You know exactly which strains and quantities you are getting.
Cost	Relatively low upfront cost, economical over time.	Varies widely by product; can be inexpensive (e.g., yogurt) or expensive (specialty cheese).	Higher cost per dose, but potentially more effective for targeted therapy.
Convenience	Requires time and effort for preparation and fermentation.	Highly convenient; widely available in grocery stores.	Very convenient; easy to take in capsule or powder form.
Live Cultures	Guaranteed live and active cultures if made correctly.	Guaranteed only if marked "live and active cultures" and unpasteurized.	Guaranteed potency and stability through expiration date.

Promoting Native Lactobacillus reuteri with Prebiotics

Increasing your L. reuteri intake isn't only about adding fermented foods; it's also about creating a supportive environment for them to flourish. Prebiotic fiber is the food source for probiotics. By incorporating prebiotic-rich foods into your diet, you can promote the growth of beneficial bacteria, including L. reuteri, that may already reside in your gut. Excellent prebiotic sources include:

Garlic and Onions: Rich in fructans that nourish gut flora.
Bananas: Especially unripe ones, provide resistant starch.
Asparagus: Contains inulin, a type of prebiotic fiber.
Whole Grains: Provide complex carbohydrates that feed beneficial bacteria.
Legumes: A great source of fiber and prebiotics.
Artichokes: Contain inulin and are high in fiber.

A balanced diet rich in both probiotics and prebiotics creates a synergistic effect that promotes a diverse and thriving gut microbiome.

Integrating L. reuteri-Rich Foods into Your Diet

For maximum potency: Make your own L. reuteri yogurt using a reliable starter culture and a temperature-controlled fermentation device. Follow the manufacturer's instructions for the specific strains you use.
For convenience: Consider using a high-quality probiotic supplement that contains the specific L. reuteri strain you are targeting. This ensures consistency and therapeutic dosage.
For a general boost: Incorporate a variety of raw fermented foods, like unpasteurized sauerkraut, kimchi, and kefir, into your regular meals. Read labels carefully to confirm they contain live cultures.
For a supportive gut environment: Pair your probiotic sources with a diverse range of prebiotic foods to nurture both the introduced bacteria and your existing gut flora. For more information on enhancing your microbiome, explore diet recommendations.

Conclusion: Making the Right Choice for Your Gut

While Lactobacillus reuteri can be found in some fermented foods, it is generally not present in sufficiently high, consistent concentrations to provide targeted therapeutic benefits. For those who want to maximize their intake, the best food source is homemade yogurt prepared with a specific L. reuteri starter culture and a long fermentation time. Supplements offer the most reliable and highest dose for targeted health goals. However, supporting your overall gut health with a diverse, fiber-rich diet that includes various fermented and prebiotic foods is a solid strategy for cultivating a thriving microbiome. By combining these strategies, you can take control of your digestive health and effectively boost your L. reuteri levels.

Optimize your gut health with science-backed insights on diet and supplements.

Frequently Asked Questions

To ensure a commercial product contains L. reuteri, check the ingredient list on the label for specific strain information, such as DSM 17938 or ATCC 6475. For fermented foods, look for confirmation that they contain live and active cultures and are unpasteurized.

Yes, homemade L. reuteri yogurt is generally considered more potent because it allows for a high concentration of specific strains through a controlled, extended fermentation process. Commercial versions often have lower, less consistent quantities.

No, not all fermented foods contain L. reuteri, and the quantity varies significantly. While many contain other beneficial Lactobacillus species, the presence of L. reuteri is not guaranteed without using a specific starter culture.

Prebiotics are non-digestible fibers that feed and stimulate the growth of beneficial gut bacteria, including L. reuteri. They are essential for creating a healthy gut environment that allows these probiotics to flourish.

Yes, it is possible for individuals to have naturally low levels or a deficiency of L. reuteri, especially due to modern dietary and environmental factors. Supplements or targeted dietary strategies can help sustain higher levels.

Consumption of L. reuteri has been associated with benefits for digestive health, immune function, and oral health. It may help with conditions like infantile colic, constipation, and managing H. pylori infections.

The best choice depends on your goal. For a general gut health boost, a varied diet of fermented foods is beneficial. For targeted, high-concentration intake for a specific health issue, a supplement is more reliable and consistent.