Under normal circumstances, the human digestive tract is home to a diverse community of microbes (AKA bacteria) that work together to support physical and mental well-being. We refer to this as intestinal microflora or, the microbiome. Probiotics are the “good” guys, specifically bacteria and/or yeast, that work to keep the peace among this population of microorganisms. Promising research supports the benefits of probiotics, specifically in regard to digestive regularity, immunity, and even mental health (here’s another reference!).
Probiotics come in a variety of forms, from supplemental pills and powders to naturally occurring sources like yogurt, sauerkraut, and beverages like kombucha. According to Consumer Lab, the various types of probiotics supported in research include:
- Bacillus
- Bifidobacteria
- Lactobacillus
- Streptococcus
- Saccharomyces (yeast)
How Do They Work?
Once thought to inhabit and recolonize the bad bacteria in our gut, probiotics are now shown to work in different ways. These microorganisms aid in the production of disease-fighting substances that help to boost immunity and even compete with harmful bacteria for access to nutrients. This indirectly helps to evict those bad guys from your body. Probiotics are also shown to promote digestive regularity by reducing antibiotic-related diarrhea and speeding the passage of food to alleviate symptoms of constipation, gas, and bloat.
Best Sources
A food-first approach is always the goal and since a variety of foods are naturally occurring in probiotics, it’s easy to boost your intake. Top sources include:
- Yogurt*
- Kefir (cultured milk drink)
- Tempeh
- Tofu
- Kimchi
- Kombucha
- Saurkraut
- Pickles
What About Prebiotics?
That’s no typo. Remember, probiotics are organisms and like all organisms, they require food! Prebiotics are plant-based fibers that promote the growth of probiotics. These fibers resist digestion, allowing them t0 be used in the production of short-chain fatty acids, which provide the nourishment needed for a healthy microbiome.
Top Sources
- Apples
- Bananas
- Garlic
- Onions
- Leafy greens
- Barley
- Oats
The Pointe: Prebiotics and probiotics work together to symbiotically nourish a flourishing microbiome!
What About Supplements?
Though it’s ideal to receive your probiotics from naturally occurring sources, supplements may be beneficial for some and are even considered safe for the general public. When scoping the aisles, remember: diversity is key. Research suggests that a probiotic supplement that contains a mixture of bacterial strains is optimal. This is because a diverse microbiome makes it less likely for a single bacterium to become dominant enough to make you sick. Benefits have been shown from probiotics containing 50 million to more than 1 trillion CFUs per day. But remember: higher CFUs don’t necessarily equal better quality or effectiveness. Make sure your supplement is third-party tested. If you’re allergic to milk, be aware that some supplements contain lactose-fermenting bacteria (ie. Lactobacilli and Bifidobacterium).
So what’s the point(e)? The *pros* of probiotics are worth the hype but choose a food first approach to letting these good guys into your system. And if you’re curious about a supplement, be sure to consult with a medical professional beforehand.
P.S. To get the probiotic benefits from your yogurt and other dairy foods, choose a product that lists “contains live cultures” or “active cultures” rather than “made with live/active cultures.” According to Consumer Lab, the latter may signal a significantly reduced number of cultures, which results from the heat of pasteurization.

