Photo by Blaine Moats
| Credit: Blaine Moats

What are probiotics anyway?

By Marge Perry

We've been battling bacteria for years. We use antibacterial soap to wash our hands, antibacterial ointment for wounds, and antibacterial kitchen and bathroom cleaners. So why on earth would we want to encourage bacterial growth — and in our guts, no less? Probiotics are bacteria — but they are friendly bacteria that do us good.

Read on to learn more about probiotics and prebiotics, and how they affect your overall health.

Feed your health

Your gut is home to trillions of live bacteria called a microbiome. It does important work: It helps you digest and absorb nutrients and synthesize certain vitamins. To keep your gut happy, you need plenty of good bacteria. That's where probiotics come in.

Probiotics are found in certain foods and supplements. The most well-studied are Lactobacillus and Bifidobacterium, which you've likely seen listed on yogurt containers.

But you can't have probiotics without prebiotics. Prebiotics — indigestible fiber, such as inulin and beta-glucan — are food for probiotics. Here's how to add prebiotics and probiotics to your diet.

Probiotics: Yogurt, kefir, unpasteurized sauerkraut, kimchi, apple cider vinegar, miso, pickles, kombucha, and soft fermented cheeses, such as Swiss, cheddar, mozzarella, Gouda, and cottage cheese

Prebiotics: Garlic, onion, chickory root, leeks, bananas, oats, apples, jicama

Fermented Doesn't Equal Probiotic

Just because a food is fermented doesn't mean it's probiotic. Some fermented foods have health benefits, but not all. Case in point: Beer and wine are fermented, but the microbes used to make them are filtered out before you take a sip. Sourdough bread is fermented — but all the probiotic benefits are baked out.

Heat is a probiotic's kryptonite. Live probiotic cultures die at 115°F, so don't boil them. Pasteurization is a heat process developed to kill "bad" bacteria. But in the process, it kills the good ones, too. That's why canned (and therefore pasteurized) sauerkraut doesn't have a probiotic benefit.

Outnumber the Bad Guys

Consuming probiotics while you're on antibiotics can counteract negative side effects that one in three people experience with antibiotics.

And some research shows that probiotics may also help treat diarrhea and constipation. It's because your gut is full of all kinds of bacteria, some of which keep you healthy, and others that can make you sick. As with any turf war, the good guys need to outnumber the bad. When you take antibiotics, have certain infections, or suffer from irritable bowel syndrome, the bad guys grow, your balance gets out of whack, and then your gut suffers the unpleasant consequences. That's where probiotics can help by increasing the number of good bacteria.

While there's no specific daily probiotic recommendation yet, most research says to aim for 1 billion to 10 billion live bacteria cultures per day (about 1 cup of yogurt or kefir) to keep your gut healthy.

Yogurt: a ticket to better skin?

It looks like probiotics could be good for your skin as well as your gut. In one study, when people applied a cream with a probiotic common in yogurt, their ceramides — the key to healthy, moisturized skin—increased significantly. Other studies have found that imbalances in the gut microbiome are common in people with skin disorders (think acne or eczema). In one study, when participants drank probiotics such as kefir, their acne improved over 12 weeks. More research is needed to determine how much and what specific probiotics are beneficial to skin, though.

Photo by Blaine Moats

Happy Gut, Happy Brain

Researchers believe that changes in your gut bacteria may play a role in anxiety and depression. The intestine has its own nervous system and even its own serotonin.

Your gut and brain communicate (it's called the brain-gut axis, or cross talk), which may be why your stomach flutters when you have to speak in public, or why you get stomach aches when you're upset.

A recent review of 10 studies on using probiotics to treat depression and anxiety had mixed results, but there was enough there to encourage further research. Who knows — maybe someday we'll be drowning our sorrows in a (probiotic) drink.

This article originally appeared in Allrecipes Magazine.