How to Increase Lactobacillus reuteri for Optimal Gut Health

December 4, 2025 •

4 min read

Although L. reuteri is a naturally occurring probiotic in the human gut, many people today lack sufficient levels due to modern diets, antibiotic use, and increased sanitation. Restoring this beneficial bacterium is possible through dietary changes, targeted supplements, and lifestyle adjustments.

Quick Summary

This guide covers effective strategies for boosting your body's Lactobacillus reuteri levels, including incorporating specific fermented foods and prebiotics, considering high-quality probiotic supplements, and making supportive lifestyle choices. It provides detailed recommendations to help promote a balanced gut microbiome.

Key Points

Consume Fermented Foods: Incorporate foods like homemade L. reuteri yogurt, certain sourdough bread, sauerkraut, and kimchi to introduce beneficial bacteria into your gut.
Eat Prebiotic-Rich Foods: Nourish existing and newly introduced good bacteria by consuming prebiotic fibers found in foods like onions, garlic, bananas, and whole grains.
Consider High-Quality Supplements: Use targeted probiotic supplements containing specific, well-researchedor specific amounts of L. reuteri (e.g., DSM 17938) for a concentrated and consistent dose.
Make DIY L. reuteri Yogurt: Fermenting your own yogurt with specific starter cultures and prebiotic fiber for 36 hours can create a highly potent and active probiotic food.
Support Gut Health with Lifestyle Changes: Minimize processed foods, limit unnecessary antibiotics, and manage stress to create an optimal environment for beneficial bacteria to flourish.
Consult a Healthcare Professional: Always seek advice from a medical expert before starting new supplements, especially if you have an underlying health condition.

Understanding the Importance of Lactobacillus reuteri

Limosilactobacillus reuteri, now commonly referred to as L. reuteri, is a well-researched probiotic species known for its positive impact on human health. This beneficial bacterium can produce reuterin, a broad-spectrum antimicrobial compound that helps suppress the growth of harmful pathogens in the gut. It is also known to support immune function, reduce inflammation, strengthen the intestinal barrier, and aid in digestion. A healthy population of L. reuteri is crucial for maintaining a balanced and robust gut microbiome. However, modern lifestyles have significantly depleted these valuable strains, necessitating proactive measures to increase their numbers.

Methods for Increasing Lactobacillus reuteri

There are two primary approaches to increase your body’s L. reuteri levels: consuming specific foods and taking targeted probiotic supplements. A combination of both is often the most effective strategy for long-term gut health.

Dietary Approaches: Fermented and Prebiotic Foods

Certain foods are natural sources of L. reuteri, while others contain prebiotics that feed and nourish the existing beneficial bacteria.

Foods Containing L. reuteri (Probiotics):

Yogurt and Kefir: Some yogurts and kefirs are fortified with specific strains of L. reuteri (check the label for strains like DSM 17938). Alternatively, you can ferment your own super-potent L. reuteri yogurt at home using a specialized starter culture and a low-temperature yogurt maker.
Sourdough Bread: The traditional, long-fermentation process of sourdough naturally cultivates L. reuteri and other beneficial lactic acid bacteria.
Fermented Vegetables: Certain fermented vegetables like sauerkraut, kimchi, and traditional pickled cucumbers can contain L. reuteri, though the bacterial composition can vary. Unpasteurized versions are essential for live cultures.

Foods that Feed L. reuteri (Prebiotics):

Fibre-Rich Foods: A diverse diet rich in whole grains, fruits, and vegetables provides the prebiotic fiber that good gut bacteria, including L. reuteri, thrive on.
Onions and Garlic: These act as powerful prebiotics, stimulating the growth of beneficial bacteria.
Bananas: This fruit contains prebiotic fiber that helps nourish probiotics in the gut.
Artichokes: Artichokes are another excellent source of prebiotic fiber that promotes a healthy gut environment.

Supplemental Approaches: Targeted Probiotics

For a more concentrated and consistent amount of L. reuteri, targeted supplements are a reliable option. Reputable brands offer specific, clinically-studied strains.

Common L. reuteri Strains in Supplements:

L. reuteri DSM 17938 (BioGaia Protectis): One of the most-studied strains, documented in numerous clinical studies for its safety and effectiveness, particularly for infants and children.
L. reuteri ATCC PTA 6475 (BioGaia Osfortis): Known for its potential anti-inflammatory effects and ability to modulate the immune system.
L. reuteri RC-14: Used in women's health products to support urogenital and vaginal flora.

Comparison of Methods: Food vs. Supplements


Feature	Dietary Sources (Foods)	Probiotic Supplements
Bacterial Count	Varies widely, often lower. Dependent on preparation and freshness.	Consistent (Colony Forming Units or CFUs).
Strain Specificity	Not guaranteed. Fermented foods contain a mix of different bacteria strains.	Targeted, specific strains. You know exactly what you are getting (e.g., DSM 17938).
Cost	Can be more affordable over time, using regular, whole-food ingredients.	Varies by brand and potency, often higher upfront cost.
Ease of Use	Requires active food preparation (e.g., fermenting yogurt, making sourdough).	Convenient capsules, tablets, or drops that are easy to incorporate into a routine.
Prebiotic Support	Foods rich in prebiotics, like onions and bananas, are often consumed alongside fermented foods.	Some high-quality supplements include added prebiotics (a synbiotic blend) to support bacterial growth.
Key Considerations	Effectiveness depends on proper preparation and sourcing of unpasteurized products.	Some strains are more heat-sensitive; follow storage recommendations (some require refrigeration).

Lifestyle Factors that Support a Healthy Microbiome

In addition to diet and supplementation, several lifestyle changes can foster a healthier gut environment where L. reuteri can thrive:

Minimize Processed Foods: Highly processed foods and excessive sugar intake can negatively impact the delicate balance of your gut microbiome.
Limit Antibiotic Use: Unnecessary use of antibiotics can decimate beneficial gut bacteria. Only take them when necessary and with a healthcare professional’s guidance.
Manage Stress: Chronic stress can disrupt the gut microbiome. Practices like mindfulness, yoga, and meditation can help improve overall gut health.
Stay Hydrated: Drinking plenty of water daily is crucial for digestive function and supporting a healthy microbiome.
Regular Exercise: Physical activity can positively influence the diversity and composition of your gut bacteria.

Making Homemade L. reuteri Yogurt

For those who prefer a DIY approach, making homemade L. reuteri yogurt is an excellent way to get a potent and high-CFU amount. This method involves a long fermentation process (typically 24-36 hours) at a specific, low temperature (around 100°F or 37.7°C). You will need a starter culture containing a specific L. reuteri strain (like those from BioGaia or specialized starters) and a high-quality milk base, often with prebiotic fiber added to feed the bacteria during fermentation. This produces a significantly thicker, more potent product than store-bought varieties.

Conclusion

Increasing your L. reuteri levels is a powerful step toward improving digestive function, strengthening your immune system, and promoting overall wellness. Both dietary and supplemental approaches offer effective pathways to achieve this. By consciously incorporating fermented and prebiotic-rich foods while supporting your gut health with positive lifestyle changes, you can create a thriving internal environment. For a potent, consistent boost, high-quality supplements or homemade long-fermentation yogurt provide a targeted solution. As always, consult a healthcare provider for personalized advice, especially if you have pre-existing health conditions or are considering supplements.

Frequently Asked Questions

Foods naturally high in Lactobacillus reuteri can include certain fermented products like traditionally made sourdough bread, some yogurts (if the strain is added), kefir, sauerkraut, and kimchi. However, the bacterial content can be inconsistent in store-bought products due to pasteurization, so making your own or choosing specific, unpasteurized items is recommended.

Supplements offer a higher, more consistent, and strain-specific amount of L. reuteri compared to food sources. Food sources, while beneficial for overall gut diversity, have varying bacterial counts. Supplements can be a reliable option for those needing a guaranteed amount or targeting a specific health concern.

To make homemade L. reuteri yogurt, you need a specific starter culture (containing L. reuteri strains), a milk base, and prebiotic fiber (like inulin). The mixture is fermented for an extended period, typically 24-36 hours, at a low temperature around 100°F (37.7°C), which requires a dedicated yogurt maker.

Prebiotics are non-digestible dietary fibers that act as food for beneficial gut bacteria, including L. reuteri. Consuming prebiotic-rich foods like onions, garlic, bananas, and artichokes helps nourish and promote the growth and activity of these healthy microbes already present in your gut.

It is not recommended to take L. reuteri at the same time as antibiotics, as the medication can reduce the effectiveness of the probiotic. For best results, take the probiotic at least 2 to 3 hours before or after your antibiotic dose, and consult your doctor for guidance.

The time it takes to see the effects of L. reuteri varies depending on individual health and the reason for supplementation. Some people may notice improvements in digestive issues within a few days, while for others it may take several weeks. Continued, consistent use is important for long-term benefits.

The amount can vary by product and strain. Always follow the specific instructions on the supplement label or consult a healthcare provider for personalized recommendations.