Probiotics: Everything You Need to Know

Jamie Lee Curtis is probably best known for her star-making 1978 debut in the original Halloween, or her turn as Lindsay Lohan’s mom in the 2003 reboot of Freaky Friday (for which she was nominated for a Golden Globe). But it’s wouldn’t be too far of a stretch to claim that her finest onscreen moment arrived in 2008, as a spokesperson in over a dozen commercials for the yogurt Activia.

In each of these 30-second performances, Curtis made cultural taboos like constipation and diarrhea totally approachable. And in the midst of shilling expensive yogurt to Americans, she schooled us on the benefits of probiotics, too.

Even though Activia is no longer allowed to claim that it’s “scientifically proven” to help digestion (turns out it’s just as beneficial as normal yogurt), probiotics have only grown in popularity. Research continues to prove that swallowing a pill filled with bacteria can be a powerful way to improve overall health.

What do probiotics do?

Your body is covered in microbes, inside and out—in fact, bacteria outnumber the body’s cells  10 to 1. Gross. But before you douse your entire body in hand sanitizer, realize that most of them are actually good for you, and live in the stomach and intestines.

Otherwise known as gut bacteria, microbes play a huge role in digestion, immunity, energy levels, and our bodies’ ability to break down and use nutrients. A healthy gut microbiome has also been linked to mental wellness—studies show that there is a deep connection between gut and brain health, sometimes called the gut-brain axis. Most recently, researchers found that having normal levels of beneficial stomach bacteria decreased patients’ likelihood of developing depression.

And although probiotic bacteria is pretty resilient, there are plenty of reasons that your digestive bacteria levels could use a little boost. A round of antibiotics from your doctor will help you kick that infection, but could also deplete healthy levels of good bugs. Probiotics are foods or supplements that can help fix that problem by contributing healthy microorganisms to the body.

Potential benefits

Taking a probiotic directly affects gut health—and your gut is responsible for a lot more than just digestion. When something’s off in there, either due to a bacterial imbalance or trauma like ulcers and inflammation, it affects the rest of the body dramatically.

Researchers have found that patients with irritable bowel syndrome (who often have bacterial imbalances throughout their digestive systems) are more likely to develop anxiety or depression. Imbalanced gut flora has been linked to obesity, type 2 diabetes, metabolic syndrome, heart disease, colorectal cancer, and Alzheimer’s disease, too. And as mentioned above, we know that supporting the gut with probiotics can decrease the likelihood of developing depression, but they also prevent these other serious chronic diseases.

A healthy gut protects you from serious diseases, but can also improve mood. In fact, there are more serotonin-producing cells lining the colon than in the brain. Scientists have even tried transplanting the stomach bacteria of more adventurous mice into “shy” mice—and found the formerly introverted specimens became more outgoing and exploratory after the procedure.

Probiotics support immunity, too. Several strains of bacteria have been linked to better immune function, and can even prevent risk of infection from viruses like the common cold.

And last but not least, a probiotic supplement can improve digestive health and regularity. Activia got famous for helping the 63 million Americans a year who deal with chronic constipation find relief—but pretty much any probiotic source is going to improve digestive issues like diarrhea, constipation, indigestion, gas, and even heartburn.

Forms of probiotics

Found in both food and supplements, probiotics are measured in colony forming units (CFUs). While there’s not currently a recommended daily value to follow, a supplement with 5 billion CFUs per pill is usually a dose that works well. Regularly enjoying foods probiotic-rich like yogurt, kefir, kimchi, and kombucha can be great for gut health, but the problem is that number of CFUs in them is totally unknown and varies per serving and brand.

Supplements always have the CFUs and specific strains of bacteria listed on the bottle. Not all contain the same bacteria and fungi, so it’s possible to select a specific formulation depending on what you’d like to treat.

When looking for a supplement, choose one that has at least three varied types of bacteria. And experiment with different formulas to see what feels right for you—you’ll know it’s working if symptoms like bloating, fatigue, and poor digestion diminish.

Lactobacillus acidophilus

One of the most popular strains used in probiotics. Good for ulcerative colitis, irritable bowel syndrome, canker sores, eczema, lactose intolerance, and the prevention of respiratory infections, acidophilus can also help rebuild the gut flora after a round of antibiotic treatments. This bacteria is often also found in kimchi, kefir, and miso.

B. bifidum

Predominately used for digestive issues like IBS and ulcerative colitis, but it’s also known for supporting the mouth bacteria that prevents cavities and tooth decay.

Saccharomyces boulardii

Recommended by cardiologists for those with heart issues, it’s also good for treating acne and helping restore gut health in those that suffer from diarrhea. Other than in a supplement, you’ll find strains of this bacteria in kombucha tea and kefir.

Bacillus coagulans

Particularly beneficial for helping the body to digest lactose and improving absorption of calcium, phosphorus, and iron. It’s also an excellent strain to help maintain vaginal health. A study of women who took B. coagulans daily found that 91 percent experienced relief from vaginal discomfort.

Bifidobacterium longum

This is a common type of bacteria found in the digestive tract, but its production declines as we age. However, b. longum is famous for its digestive benefits: It breaks down carbohydrates and protects cells from free-radical damage, making it ideal for detoxification purposes. Want to finally see those abs again? Try supplementing with this strain to ease bloating and absorb nutrients even better.

To get even more specific about how you can support your gut health, head to Clinical Guide to Probiotic Products, published by by the Alliance for Education on Probiotics. Though designed as a clinical tool for healthcare professionals, the guide is searchable by health issue—and you can find appropriate probiotic strains that have been proven effective.

Probiotics can get pricey, but remember you can shop hundreds of different formulations at Thrive Market for 25-50 percent off retail price.

Do you need a probiotic supplement?

Maybe, maybe not—but it couldn’t hurt. Even if your microbiome is in perfect condition, adding a probiotic into your regular routine can only boost your immune system, and potentially have a greater effect on overall mood and mental health. Check with your doctor to see if they have a specific recommendation for you before you go all in.

Wanna know more? Check out the rest of our vitamin primers here:

• Vitamin A
• Vitamin B
• Vitamin C
• Vitamin D
• Vitamin E
• Magnesium
• Calcium

Illustration by Foley Wu