The latest to join the is-it-bad-or-is-it-good debate are probiotics. On Reddit skin-care message boards, the benefits and detriments of probiotics are hot topics, with some claiming that they are an acne miracle cure and others blaming them for cystic acne. The Cut’s senior editor Isabel Wilkinson added them to her diet at the suggestion of her dermatologist and saw a noticeable difference in clarity and tone. To understand some of the science behind them, I called Dr. Frank Lipman, Gwyneth Paltrow‘s holistic doctor, who told me that probiotics can benefit skin by hosting “friendly” bacteria. Unlike a reality-show contestant, these bacteria are here to make friends. Read on to learn about whether probiotics are right for you and about the importance of a “diverse” gut flora (which has no relation to botany).

Most people know of probiotics via Jamie Lee Curtis yogurt commercials. What is a probiotic? 
Probiotics are the naturally occurring “good” bacteria that live in your gut and play a significant role in your total wellness.

When you’re healthy, your intestinal tract hosts over 100 trillion friendly bacteria (that’s 10 times more than the number of cells in your body), which spend their days aiding digestion, boosting the immune system, and consuming bad bacteria. They manufacture key nutrients and limit the growth of yeast and unhealthy bacteria — and, in their spare time, probiotics help inhibit bouts of lactose intolerance, poor digestion, and diarrhea.

Where can you find probiotics?
To boost your levels of good bacteria, you can take a probiotic supplement, and you can also eat foods like miso, tempeh, kimchi, sauerkraut, and Kefir.

Many people eat yogurt because they have been told that it’s a good source of friendly bacteria. However, this is not necessarily true. The bacteria used to make most yogurt (L. bulgaricus and S. thermophilus) are not the key beneficial bacteria. Some brands add a small amount of acidophilus just so they can say so on the label. Plus, much of the yogurt you buy in the store is pasteurized after it is made. This is done to increase the shelf life, but pasteurization destroys all the benefits of the yogurt. If you do choose yogurt in the store, make sure the label says “live, active cultures.” And of course you want to make sure your dairy products have not been produced with antibiotics or hormones.

What are the benefits to including a probiotic in your diet?
Probiotics can help prevent and correct debilitating digestive problems, such as constipation, diarrhea, colitis, and irritable bowel syndrome. They also produce immunity-boosting chemicals and kill off invading pathogens. They help protect against stomach ulcers, food poisoning, lactose intolerance, yeast overgrowth, yeast infections, harmful bacteria, viruses, and fungi. They even help improve your skin’s health and appearance.

What is the connection between your stomach/gut and your skin?
The GI tract and skin are both organs of detoxification. We need a healthy microbiome in the gut to break down food, absorb nutrients, and eliminate toxins. When our gut flora is not healthy, and there are more bad bacteria than good bacteria, a lot of problems can arise — including chronic inflammation, which is a cause of acne and other skin problems. Some bad bacteria, fungus, and yeast can even cause inflammation in and of themselves. So, if you are looking to clear up your skin, you have to start with your gut.

How can you tell if your stomach is affecting the condition of your skin?
Experiment with cleaning up your diet and taking key supplements. Cut out wheat, sugar, and dairy from your diet for two weeks, and take probiotics to help reduce inflammation in the gut that may be linked to acne. You can also take a fish-oil supplement to reduce inflammation.

How can you tell if a probiotic will benefit you?
Try it and see if your symptoms improve. You may notice improved digestion, clearer skin, and better immunity (being less susceptible to catching colds, for example).

How often should you take probiotics?
Look for probiotics that deliver 20 to 50 billion live organisms per dose and contain a combination of different strains of lactobacillus and bifidobacteria. Be Well Probiotics contain the five best-researched, most viable, and stable strains of bacteria known today. Take probiotics as directed, once or twice a day, preferably with meals.

Some internet lore (a.k.a. message boards) says that probiotics can cure acne, but only temporarily. Others say that on its own, it’s not enough to cure acne. What is the truth?
I would say that a clean diet that avoids sugar, gluten, and processed foods is also crucial. Probiotic supplements can help reduce inflammation and are often very helpful for improving acne, but without also changing your diet, you will likely not be able to clear up your skin for the long term.

What is the difference between a probiotic and an antibiotic? 
Antibiotics are used to kill “bad” bacteria, both as medication and in our food supply. The trouble is that antibiotics kill not only the bad bacteria, but the good bacteria, too! If you have to take an antibiotic, take probiotics as well, and take them away from each antibiotic dose to help maintain the diversity of your gut flora.

Originally published on The Cut