What are the different types of probiotics? A guide to understanding gut health

According to the World Health Organization (WHO), probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Beyond just yogurt, these beneficial microbes come in many forms, each with unique functions that can support your digestive system and overall wellness.

Quick Summary

An in-depth guide covering the major types of probiotics, including Lactobacillus, Bifidobacterium, and Saccharomyces boulardii, explaining their unique functions and best sources.

Key Points

• Strain Matters: The health effects of probiotics are strain-specific, so the letters and numbers after the species name are the most important part of the label.

• Main Types: The most common probiotic families include the bacteria Lactobacillus, Bifidobacterium, the yeast Saccharomyces boulardii, and spore-forming Bacillus.

• Diverse Sources: Probiotics are found in supplements and a wide array of fermented foods like yogurt, kefir, kimchi, and sauerkraut.

• Targeted Benefits: Different probiotic types offer unique benefits, from alleviating diarrhea with S. boulardii to easing IBS symptoms with specific Bifidobacterium strains.

• Shelf-Stable Spores: Spore-based probiotics from the Bacillus genus are highly resistant to heat and stomach acid, ensuring they reach the gut intact.

• Multi-Strain Advantages: Using a multi-strain probiotic formulation can offer a broader spectrum of benefits compared to a single-strain product.

Understanding Probiotic Classification: Genus, Species, and Strain

To effectively choose a probiotic, it is essential to understand the hierarchy of their classification, which includes genus, species, and strain. The genus is the broad category, like Lactobacillus or Bifidobacterium. The species is a more specific grouping within that genus, such as rhamnosus within Lactobacillus. The strain, denoted by letters and numbers (e.g., GG), is the most specific level and is what ultimately determines the health benefits. For example, two different strains from the same species may offer completely different benefits. This is why looking for a specific strain name on a product label is crucial for targeted health goals.

The Main Bacterial Types of Probiotics

The most well-known probiotics are bacteria, primarily from the Lactobacillus and Bifidobacterium families. These two groups are the most studied and frequently used in supplements and fermented foods.

Lactobacillus: The Multitaskers

Found in the mouth, digestive tract, and vagina, Lactobacillus bacteria are known for their ability to produce lactic acid, which helps regulate pH levels and inhibit the growth of harmful bacteria. They are naturally present in many fermented foods like yogurt, kefir, and sauerkraut.

Common Lactobacillus strains and their benefits include:

• Lactobacillus acidophilus (NCFM): May improve digestion, aid lactose digestion, and potentially help lower cholesterol levels.
• Lacticaseibacillus rhamnosus (GG): One of the most researched strains, it is known for surviving the harsh stomach environment and may help prevent antibiotic-associated diarrhea and support immune balance.
• Lactiplantibacillus plantarum (299v): Studied for its effects on irritable bowel syndrome (IBS) symptoms and increasing iron absorption.

Bifidobacterium: The Gut Residents

Bifidobacteria are prominent residents of the large intestine, where they ferment dietary fiber into short-chain fatty acids (SCFAs), providing fuel for the gut lining and reducing inflammation. They are commonly found in dairy products and are especially important for infants.

Notable Bifidobacterium strains and their functions:

• Bifidobacterium animalis (subsp. lactis HN019): Has been shown to support the intestinal barrier and may improve constipation and immune function.
• Bifidobacterium infantis (35624): Has been researched for improving symptoms of IBS and plays a crucial role in establishing a healthy infant microbiome.
• Bifidobacterium longum (BB536): Often studied for its ability to keep the digestive system regular and may also support the immune system.

Beyond Bacteria: Probiotic Yeasts and Spore-Formers

While bacteria dominate the probiotic world, other microorganisms also offer significant health benefits. Beneficial yeasts and spore-forming bacteria represent unique categories with distinct properties.

Saccharomyces Boulardii: A Beneficial Yeast

This is a beneficial, non-pathogenic yeast that is naturally resistant to antibiotics, making it particularly useful for preventing and treating antibiotic-associated diarrhea. It is also known for its effectiveness against other forms of infectious diarrhea and may alleviate symptoms of IBS. Unlike bacterial probiotics, it is not harmed by most antibiotic treatments and can be taken concurrently.

Bacillus: The Hardworking Spore-Formers

Found in soil, Bacillus species are a unique type of probiotic because they can form a protective spore that allows them to survive extreme conditions like stomach acid and heat. This makes them incredibly hardy and shelf-stable. Once they reach the intestines, they revert to their active form and can help restore gut microflora. Strains like Bacillus coagulans and Bacillus subtilis are commonly used in supplements.

Comparison of Probiotic Types

Feature	Lactobacillus (Bacteria)	Bifidobacterium (Bacteria)	Saccharomyces Boulardii (Yeast)	Bacillus (Spore-Former)
Primary Location	Mouth, small intestine, vagina	Large intestine	Digestive tract (temporary resident)	Primarily large intestine
Key Action	Produces lactic acid, competes with pathogens	Ferments fiber into SCFAs	Fights pathogens, supports gut function	Restores gut microflora
Best For	Diarrhea, vaginal infections, eczema	IBS symptoms, constipation, infant health	Antibiotic-associated diarrhea	Gut flora restoration, shelf-stability
Sources	Yogurt, kefir, sauerkraut	Yogurt, kefir, supplements	Supplements, sometimes fermented foods	Supplements, fermented soy (natto)
Antibiotic Resistance	Generally sensitive	Generally sensitive	Naturally resistant	Highly resistant due to spores

The Power of Multi-Strain Formulations

While some specific health issues may benefit from a single strain, many studies have shown the effectiveness of multi-strain formulations. These products contain a variety of species and strains, creating a more diverse and comprehensive approach to gut health. Think of it like a sports team: each player has a different role, and the team's overall performance benefits from a variety of skills working together. For general wellness, a product with multiple, well-researched strains from different families (e.g., Lactobacillus and Bifidobacterium) can be highly beneficial.

Conclusion: Choosing the Right Probiotic

Ultimately, the best probiotic for you depends on your specific health needs and goals. The world of probiotics extends far beyond the basic idea of 'good bacteria,' encompassing distinct families like Lactobacillus, Bifidobacterium, Saccharomyces, and Bacillus, each with unique strains offering targeted benefits. For general gut health maintenance, a multi-strain supplement or a diet rich in a variety of fermented foods can be effective. However, for specific conditions like IBS or antibiotic-associated diarrhea, selecting a product with clinically-proven strains is crucial. When choosing, always look for the full strain name on the label and consider the source, whether it's a food or a supplement. For more detailed information on specific strains and their applications, you can consult authoritative resources such as the NIH Fact Sheet on Probiotics: https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/.

What to Look For in a Probiotic Supplement

When navigating the vast market of probiotic supplements, keep these points in mind:

• Strain Specificity: Look for products that list the full strain name, including the genus, species, and alphanumeric designation.
• Potency: Check the Colony Forming Units (CFUs), which indicate the number of live microorganisms. Potency should be guaranteed through the expiration date.
• Delivery Method: Some strains require special coatings or delivery systems (like enteric-coated capsules) to survive stomach acid and reach the intestines.
• Storage: Some probiotics are shelf-stable, while others require refrigeration. Always follow the manufacturer's storage instructions.
• Read the Label: Ensure there are no unnecessary additives or high amounts of added sugar, especially in food products like yogurt.

Foods with Probiotics

Incorporating probiotic-rich foods into your diet is a delicious way to support your gut microbiome. Here are some examples:

• Yogurt and Kefir: Both fermented dairy products contain Lactobacillus and Bifidobacterium. Look for 'live and active cultures' on the label.
• Sauerkraut and Kimchi: These fermented cabbages are rich in lactic acid bacteria like Lactobacillus and provide a source of fiber and vitamins.
• Miso and Tempeh: Fermented soy products popular in Asian cuisine, offering probiotics and other nutrients.
• Kombucha: A fermented tea that contains a variety of bacteria and yeasts.
• Pickles: Naturally fermented pickles (not vinegar-brined) can be a source of probiotics. Choose options from the refrigerated section.
• Some Cheeses: Certain aged cheeses like cheddar, gouda, and parmesan may contain probiotics from the fermentation process.
• Natto: A traditional Japanese fermented soybean product containing Bacillus subtilis.

The Role of Prebiotics

It is also important to consider prebiotics, which are non-digestible fibers that act as food for probiotics. By consuming foods rich in prebiotics, such as garlic, onions, and bananas, you can help the beneficial probiotics thrive in your gut. Combining probiotics and prebiotics, known as a synbiotic approach, can enhance the benefits for gut health. A balanced diet that includes both fermented foods and dietary fiber is one of the best ways to support your microbiome naturally.

Frequently Asked Questions

What is the difference between probiotics and prebiotics?

Probiotics are the live, beneficial microorganisms themselves, while prebiotics are the non-digestible fibers that serve as food for probiotics, helping them grow and thrive in your gut.

Are all fermented foods considered probiotics?

No. While many fermented foods contain live cultures, they do not automatically qualify as probiotics. True probiotics require a specific strain in adequate amounts that has a proven health benefit, which is not guaranteed in all fermented foods.

Should I take a probiotic with or without food?

The timing can depend on the specific strain. Some work better on an empty stomach, while others are best taken with food. Always follow the manufacturer's recommendations for the best results.

Is it safe to take probiotics with antibiotics?

Some strains, particularly the yeast Saccharomyces boulardii, are naturally resistant to antibiotics and can be taken concurrently. Other bacterial probiotics may be killed by the antibiotics, so taking them at a different time of day is often recommended.

How do I know if a probiotic is working for me?

If you are taking a probiotic for a specific issue, you should see an improvement in those symptoms over time, such as more regular bowel movements or less bloating. For general wellness, it can be harder to tell, but a healthier digestive system is the goal.

Can children take probiotics?

Yes, probiotics are generally safe for children and can help with issues like diarrhea, eczema, and constipation. It's always best to consult a pediatrician to determine the correct dosage and strain for a child.

Are there any side effects of taking probiotics?

Some individuals may experience mild side effects, such as gas, bloating, or digestive discomfort, especially when first starting a new probiotic. These symptoms typically resolve as the body adjusts.