A Beginner’s Guide to Probiotics: Types, Benefits, and Best Sources

Probiotics have become popular for gut health, yet with so many strains and types available, it can be challenging to know where to start. Preventive Medicine physician, Dr. Dan Angerbauer, explains that there are three main types of probiotics commonly used, each with unique benefits. Here’s a guide to understanding the different types of probiotics, how they support your health, and how to choose the best sources.

The Three Main Types of Probiotics

When choosing a probiotic, it helps to understand the differences between the major types. Dr. Angerbauer categorizes the most commonly used probiotics into three primary groups.

1. Lacto and Bifido Species

• This is the most common group, including species like Lactobacillus and Bifidobacterium, which are widely available in supplement form. Dr. Angerbauer explains these strains are typically taken in doses ranging from “1 to 50 billion per day, sometimes even more in some specific conditions.” These probiotics are often used to support digestive health and are usually well-tolerated.

2. Soil-Based and Spore-Forming Probiotics

• These newer types of probiotics, often called “soil-based” or “spore-forming” strains, are adapted to survive in various conditions, making them resilient in the gut environment. “The dose for those is anywhere from two to six billion,” notes Dr. Angerbauer. These strains occupy a unique niche in the gut, providing a different approach to balancing the microbiome.

3. Probiotic Yeast (Saccharomyces)

• The third category includes a probiotic yeast called Saccharomyces boulardii, which is especially useful for managing certain digestive issues. Dr. Angerbauer advises a typical dose for this group to be “more in the 10 to 15 billion range.”

These three categories encompass the most widely used probiotics. While there are other specialized strains, such as Akkermansia, Dr. Angerbauer emphasizes that these are the main types of probiotics currently available and commonly taken.

Who Should Take a Probiotic?

While probiotics are generally safe and available over the counter, they aren’t necessarily right for everyone. Dr. Angerbauer suggests, “If someone is having some GI symptoms, and could be as simple as constipation, which is a very common one, I think it’s generally a low-risk thing to take.” Probiotics can offer symptom relief for people experiencing digestive discomfort, but he advises caution for certain conditions: “Be aware that in some patients, a probiotic can actually make them worse, especially if they’re more in the small intestinal bacterial overgrowth camp.”

For those who do decide to try a probiotic, it’s essential to give it time to work. Dr. Angerbauer points out, “Probiotics, generally, their effects peak at around two or even three months,” stressing the importance of patience. While some may experience initial improvements in the first month, he recommends continuing for three months if there’s any improvement to allow the probiotics to establish fully in the gut.

Probiotics in Food vs. Supplements

While probiotic supplements are widely available, Dr. Angerbauer advocates for a “food first” approach, recommending fermented foods as a natural source of beneficial bacteria. “We have consumed fermented foods as humans for a long, long time,” he explains, “and there’s lots of research showing that, fermented foods are beneficial for the gut microbiome.”

Recent research also supports the benefits of fermented foods. Dr. Angerbauer references the Han et al. (2024) study, published in the Journal of Alzheimer’s Disease, examining the relationship between fermented dairy consumption with cognitive function in the National Health and Examination Survey dataset. He explains:

“In this context, they actually did cognitive testing, at different intervals. They also collected blood and so it's just a really rich data set. It is observational, so there's limitations there…They looked specifically at dairy products, but no surprise those people that had a low to moderate consumption of fermented dairy, so basically yogurt or kefir, they had improved cognitive scores. So again, it's an association, but the data on that around GI health is, I think, quite strong. And in general, even if you look at randomized clinical trials for early Alzheimer's or mild cognitive impairment, whether that's a supplementing with a food or a probiotic supplement, I would say in general, the results lean positive.”

Best Food Sources of Probiotics

For those looking to add more probiotics to their diet naturally, Dr. Angerbauer offers a “hierarchy” of probiotic-rich foods:

1. Fermented Vegetables and Soy Products

• “I think the fermented veggies are probably the most beneficial,” says Dr. Angerbauer. Foods like kimchi, sauerkraut, and pickles (without vinegar, as vinegar kills beneficial bacteria) are rich in probiotics. These vegetables should be pickled in water or brine and found in the refrigerated section for the best results.
• Tempeh and miso, two common fermented soy foods, offer another plant-based option for adding probiotics to your diet. These are particularly useful for those on vegan or vegetarian diets.

2. Yogurt and Kefir

• These dairy-based options provide a diverse mix of beneficial bacteria. “Grass-fed is probably slightly better,” Dr. Angerbauer suggests, and recommends choosing low sugar options, ideally plain yogurt with added fresh fruit.

3. Kombucha

• While kombucha can be beneficial, Dr. Angerbauer points out that it often contains added sugar. For a more gut-friendly version, look for low-sugar or unsweetened varieties.

Dr. Angerbauer recommends aiming for one serving a day of these probiotic-rich foods for general health but notes that individuals with digestive issues may benefit from gradually increasing their intake to two or three servings daily.

Probiotics can be a powerful tool for supporting gut health, but choosing the right type and dose can be key to maximizing benefits. As Dr. Angerbauer emphasizes, “Food always seems to be better,” making fermented foods a great starting point for anyone looking to improve their microbiome. By taking a gradual, patient approach to probiotic intake—whether through foods or supplements—you can support your gut’s balance and contribute to your overall health.

To learn more about probiotics you can find at the drug store or the grocery store, watch our conversation with Dr. Dan Angerbauer in the video above.

By Alicia J. Barber, PhD