Wait, Can Probiotics Really Help With Hair Growth? Here's What We Know

At this point, we likely don't need to convince you that your gut is the center of your health. It's connected to virtually every function in your body—your mental health, immunity, sleep, metabolism...we could go on. 

In the beauty space, experts are quick to reference the gut-skin axis1 (See? Your gut is the cornerstone of well-being!) and will often recommend probiotic supplements to promote good bacteria and nurture the skin microbiome—research2 shows that what you put in your mouth indeed influences your skin3 and skin microbiome in many ways. 

"The strategies coming out with the microbiome are becoming so incredibly powerful," says Davis. "Think of it like going to a restaurant. You don't freak out and say, 'There's no way I can order all of these appetizers, main courses, and desserts.' You pick and choose the ones you want. We can do the same in the microbiome." Of course, it's not as simple as ordering dinner, but researchers are beginning to pinpoint specific species of microbes that are especially great for mental health versus skin health versus metabolic health, and so on. 

And in the case of hair growth, a 2013 animal study4 looks promising. Originally, the researchers wanted to measure the GI immune-related benefits of L. reuteri, "but they noticed that the mice who got the reuteri developed all kinds of unexpected effects," Davis recounts. "Their skin healed faster. They had more lustrous, moist hair." Not to mention, the mice had thicker skin and stronger, more lush hair after eating the probiotic-laced yogurt and after drinking L. reuteri-infused water—meaning, there was something about this specific probiotic strain that leads to what researchers call a "glow of health."

So where can you get such a stellar probiotic strain? Well, a Swedish brand called BioGaia features L. reuteri DSM 17938 in their Gastrus probiotic chewable tablets—but Davis notes it contains a low dose of microbes since it was originally intended to support babies' gut health. To get more of an adult dose, Davis makes a yogurt with the BioGaia tablets, as the fermentation process amplifies the bacterial counts. (Find his exact recipe here.) "Now, this is anecdotal, but thousands of people are eating this yogurt with super-duper high counts of reuteri, and virtually all the observations made in mice are playing out in humans," he says, including (yep) lush hair growth.

Just a slight catch: According to Davis, your overall gut health must be up to speed to take full advantage of L. reuteri. "You may get some, but you won't get full [benefits]. So the key is to provide a clean slate," he explains. That said, you want to nurture your gut health by getting your fill of fermented foods, identifying your specific diet "triggers," moving your body regularly, and perhaps taking a gut-supporting probiotic supplement.*