Probiotics 101: a Beginner’s Guide

What are probiotics?

Probiotics are microorganisms that provide health benefits when consumed or used in adequate amounts. While commercial probiotic products are mainly made up of bacteria, probiotics can include fungi like yeasts, molds like penicillium, and even some viruses, like bacteriophages.

Common probiotic strains include:

• Lactobacillus (bacteria)
• Bifidobacterium (bacteria)
• Saccharomyces boulardii (yeast)

In their earliest forms, probiotics were limited to dietary supplements, certain foods, and food additives targeting your gut microbiome, the natural ecosystem of microorganisms in your digestive tract. Your gut microbiome helps with the breakdown and absorption of nutrients and plays several important roles in immune system regulation and neurotransmitter production.

When you take a probiotic supplement or consume foods rich in probiotics, you help increase the population of beneficial microorganisms in your gut. More beneficial microorganisms in your gut microbiome support your gut health by:

• allowing less room for harmful, disease-causing microorganisms (pathogens) to grow
• promoting the secretion of substances that inhibit harmful microorganism growth
• teaching immune cells to differentiate between harmful and beneficial microbes
• balancing neurotransmitter production
• regulating energy breakdown, use, and storage in the body
• strengthening the intestinal lining to prevent pathogens and harmful substances from crossing into the bloodstream
• promoting mucous production in the gut to reinforce the protective intestinal lining

Your gut microbiome isn’t the only place in your body that can benefit from probiotics. As knowledge about the whole-body microbiome and probiotics has increased, so has our understanding of how probiotics benefit other areas, such as the skin and mouth microbiome.

In addition to ingested probiotics, topical probiotics are now available to help target these other microorganism ecosystems.

Probiotic sources

Probiotics occur naturally in foods or can be added to your diet through supplements or probiotic-enriched products.

Foods naturally rich in probiotics include fermented dairy products such as:

• yogurt
• kefir
• unpasteurized cheese
• traditional buttermilk

And nondairy fermented products, such as:

• sauerkraut
• kimchi
• miso
• tempeh
• kombucha
• pickles (fermented, not vinegar-pickled)
• natto
• kvass
• certain salamis and fermented sausages

You can also add probiotics to your regular nonfermented diet by using dietary supplements. Probiotics are available in powders, capsules, tablets, chews, and liquids. When selecting a probiotic, quality is important. Many products are labeled with “live and active cultures” with a colony-forming unit (CFU) of 1 billion or higherTrusted Source. CFU counts indicate the number of live microorganisms in a probiotic supplement.

For additional quality assurance, aim for products that carry a safety seal, such as:

• Good Manufacturing Practices (GMP) Seal
• Non-GMO Project Verified
• United States Pharmacopeia (USP) Verified

Side effects and considerations

Probiotics have a long historyTrusted Source of safe use in healthy people but may cause mild but temporary gastrointestinal side effects such as gas, bloating, diarrhea, or upset stomach.

Despite their broad safety profile, probiotics aren’t for everyone. Certain populations, like infants, older adults, or people who are immunocompromised, can experience serious side effects. Although rare, probiotics for these groups may contribute to:

• increased infections
• sepsis
• medication interactions
• difficulties with blood sugar management
• autoimmune flare-ups

Because probiotics can affect your health positively and negatively under different circumstances, talking with your doctor before you add probiotics to your diet can help reduce the chances of experiencing side effects, especially if you live with underlying health conditions.

How to add probiotics to your diet

Different brands of probiotic products come with their own recommended use instructions. While some older evidenceTrusted Source suggests taking your probiotics 30 minutes before a meal can help protect them against digestive acids, many probiotics are now formulated with protective coatings that allow them to be taken even on an empty stomach.

To ensure the effectiveness of your probiotic, it’s always best to follow the instructions on the label. Overall, the timing of your probiotic may be less important than your consistency of use.

Probiotics do not typically remain in your system long-term or create long-term microorganism colonization. This means your microbiome will return to its baseline state if you stop taking your supplement or take it sporadically. By taking your probiotic at the same time each day or as otherwise directed by the product label, you can keep the level of beneficial microorganisms from the probiotic at its peak.

Whether you eat probiotic-rich foods or take a probiotic supplement, making it a habit will support your long-term health goals.

The takeaway

Probiotics are microorganisms that provide health benefits when used or consumed in adequate amounts. You can add probiotics to your diet through probiotic-rich foods or dietary supplements.

While probiotics aren’t for everyone, consistently adding probiotics to your healthcare routine can support long-term microbiome health and overall well-being. Before starting any probiotic routine, check with your doctor to ensure it’s the right choice for you.