Which probiotics have Lactobacillus?

December 18, 2025 •

4 min read

The genus Lactobacillus is one of the largest and most diverse groups of lactic acid bacteria, comprising over 261 species, many of which are commonly used in fermented foods and probiotic supplements for their health-promoting properties. This wide variety means that not all Lactobacillus are the same, and their benefits can differ significantly depending on the specific strain.

Quick Summary

Many probiotics, both in supplements and fermented foods, contain various strains of Lactobacillus, such as acidophilus, rhamnosus, and casei. Understanding these specific strains and their proven benefits is key to choosing the right probiotic source for your individual health goals.

Key Points

Diverse Sources: Lactobacillus is found in many probiotic products, including both supplements and fermented foods like yogurt, kefir, sauerkraut, and kimchi.
Strain Specificity: Different Lactobacillus strains offer unique health benefits, so choosing a product that lists the full genus, species, and strain is important for targeted effects.
Common Strains: Popular and well-researched strains include L. acidophilus for digestive health and lactose intolerance, L. rhamnosus for diarrhea and IBS, and L. casei for immune support.
Live & Active Cultures: When buying fermented foods, check for labels that indicate “live and active cultures,” as pasteurization can eliminate beneficial bacteria.
Guaranteed Potency: Reputable supplements guarantee a minimum number of live Colony Forming Units (CFUs) through the expiration date, ensuring you get an effective dose.
Informed Choices: For targeted health benefits, consulting a healthcare professional and carefully reading labels to ensure a clinically-proven strain is present is recommended.
Delivery Matters: Probiotic supplements may use technology like delayed-release capsules to protect bacteria from stomach acid and ensure they reach the intestines intact.

Understanding Lactobacillus

Lactobacillus is a genus of lactic acid bacteria (LAB) that plays a critical role in human health and food fermentation. As friendly bacteria, they inhabit various parts of the body, including the gut and vagina, contributing to a balanced microbial ecosystem. Their primary function involves converting carbohydrates into lactic acid, which not only gives many fermented foods their signature sour taste but also helps create an acidic environment that inhibits the growth of harmful bacteria. While the term Lactobacillus was historically used broadly, recent taxonomic reclassification has divided the genus into 25 new genera, including Lactiplantibacillus and Lacticaseibacillus. However, the bacteria are still widely known and marketed under the familiar Lactobacillus name.

Common Lactobacillus Strains

Many probiotic products contain specific, scientifically studied strains of Lactobacillus, which are often denoted by a strain identifier (e.g., GG, LA-5). Some of the most researched and commercially available strains include:

L. acidophilus: One of the most common and well-known species, found in many dairy products like yogurt and kefir. It produces lactase, which helps break down lactose, and is often studied for its benefits related to digestive health, immune support, and vaginal health.
L. rhamnosus: A highly researched species, with the strain GG being particularly well-documented. It is known for its ability to survive stomach acids and colonize the intestinal walls, making it effective for preventing and treating various types of diarrhea, relieving IBS symptoms, and supporting immune function.
L. casei: Often used in fermented milks and cheeses, with strains like Shirota having numerous studies supporting their immune-modulating effects. It is also known for its ability to suppress the growth of certain pathogens.
L. plantarum: A versatile species found in fermented foods like kimchi and sauerkraut. It is known to produce antimicrobial substances and has shown potential benefits for gut health and immune function.

Food Sources of Lactobacillus

For those who prefer a dietary approach to probiotics, numerous fermented foods are rich in various Lactobacillus strains. It is important to note, however, that the CFU count can vary and some commercial processes, like pasteurization, can kill off beneficial bacteria.

Yogurt: A classic source, especially those labeled with a “Live and Active Cultures” seal. Many brands add specific strains like L. acidophilus and L. rhamnosus.
Kefir: A fermented milk drink that is often richer in diverse bacterial strains than yogurt. It is made by fermenting milk with kefir grains, which are cultures of bacteria and yeast.
Sauerkraut: Fermented shredded cabbage, traditionally made by natural lactic acid fermentation. Unpasteurized versions are the best source of live probiotics.
Kimchi: A spicy Korean side dish, primarily made from fermented cabbage and seasonings. It contains lactic acid bacteria, including L. kimchii.
Tempeh: An Indonesian fermented soybean product. Fermentation lowers phytic acid levels and produces vitamin B12. Unpasteurized versions are the best probiotic source.
Pickles: Pickled cucumbers fermented in salt and water can contain live bacteria. Vinegar-based pickles, however, do not contain probiotics.
Some Cheeses: Certain cheeses, like cheddar, Gouda, and mozzarella, can contain probiotics, especially those aged for shorter periods. Look for labels indicating “live cultures”.

Probiotic Supplements with Lactobacillus

Supplements offer a standardized and concentrated dose of specific probiotic strains. When choosing a supplement, it's crucial to look beyond just the CFU count. Key factors to consider are:

Strain Specificity: Look for products that list the full genus, species, and strain (e.g., Lactobacillus rhamnosus GG). Strain-specific benefits are often backed by clinical research.
Guaranteed Potency: The best products guarantee a minimum number of live Colony Forming Units (CFUs) through the expiration date, not just at the time of manufacture.
Delivery Method: Consider the form factor. Capsules, powders, and liquids can offer varying levels of protection against stomach acid. Some supplements are formulated for shelf stability, while others require refrigeration.
Reputable Manufacturer: Transparency and proper quality control are key. Look for manufacturers that provide information about their testing and sourcing.

How to Choose the Right Probiotic

Identify your needs: Different strains address different issues, such as diarrhea, IBS, or immune support. Research which strains are best for your specific health goals.
Choose your source: Decide whether you prefer fermented foods, supplements, or a combination. Foods provide a broader range of nutrients and bacteria, while supplements offer targeted, higher-dose strains.
Read labels carefully: For both foods and supplements, check for “live and active cultures,” strain names, and a guaranteed CFU count at expiration.
Consult a professional: For specific health conditions, a healthcare provider can help you select the most appropriate probiotic product.

Comparison of Common Probiotic Sources


Feature	Fermented Foods	Probiotic Supplements
Strains	Contain a wide variety of naturally occurring microbial strains, which can be inconsistent.	Provide specific, concentrated strains often backed by clinical research.
CFU Count	Highly variable and not always guaranteed; can decrease over time, especially if not refrigerated or pasteurized.	Manufacturers typically guarantee a specific CFU count through the expiration date.
Absorption	Bacteria must survive stomach acid, with inconsistent results. Provides benefits from other nutrients in the food matrix.	Designed with technology (e.g., delayed-release capsules) to protect bacteria from stomach acid for targeted delivery to the intestines.
Convenience	Integrated into diet; requires regular consumption.	Easy to take daily; no preparation needed.
Suitability	Best for general gut health maintenance and those who enjoy fermented foods.	Ideal for addressing specific health concerns with a targeted, potent strain.

Conclusion

For those seeking to incorporate Lactobacillus, numerous options are available across both the food and supplement markets. Popular fermented foods like yogurt, kefir, and kimchi provide a natural and diverse range of bacteria, though consistency can vary. Probiotic supplements, meanwhile, offer a targeted approach with specific, clinically-studied strains and guaranteed potency, which is crucial when addressing a particular health issue. By understanding the common Lactobacillus strains and reading product labels carefully, consumers can make informed decisions to support their gut health and overall well-being. For a deeper dive into the science, the NIH offers a comprehensive resource on probiotics for health professionals(https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/).

Frequently Asked Questions

Some of the most common and well-researched Lactobacillus strains found in probiotics include L. acidophilus, L. rhamnosus (especially strain GG), L. casei (including strain Shirota), and L. plantarum.

While fermented foods like yogurt, kefir, and kimchi are excellent sources of naturally occurring Lactobacillus, the amount and variety of live bacteria can vary. Supplements provide a standardized, concentrated dose of specific strains.

Look for a “Live and Active Cultures” seal on the yogurt's packaging. This seal indicates that the product contains a significant amount of live bacteria at the time of manufacture. Be aware that some yogurts are heat-treated, which kills these cultures.

Lactobacillus is a genus, a broad category of bacteria. Lactobacillus acidophilus is a specific species within that genus. There are many different species and strains of Lactobacillus, each with unique properties.

No, probiotic efficacy is strain-specific. Two products might contain the same species, but a different strain (e.g., L. rhamnosus GG vs. another L. rhamnosus strain) can have different health effects, so it's important to look for the specific strain name.

The decision depends on the specific product and its formulation. Many supplements, both refrigerated and shelf-stable, guarantee the CFU count until the expiration date. Some strains naturally require refrigeration to maintain viability, while others are stable at room temperature.

Look for a label that guarantees the CFU count through the product's expiration date, not just at the time of manufacture. Higher CFU counts aren't always better; the right strain for your needs is more important.