Probiotics and Weight Loss

Can a probiotic supplement help you lose weight? Nutrition Diva answers a reader question.

Monica Reinagel, MS, LD/N, CNS
2-minute read

Q. "Can you comment on the recent news that probiotics can help women lose weight? I'm not actively trying to lose weight, but I do have periods when work is overwhelming and I don't get much time to exercise. Would taking a daily probiotic help me fight off those pesky few pounds that creep on when work is crazy?"

A. It just might. There is a growing pile of research suggesting that the bugs that do (or don't) live in your gut can make a big difference in what you weigh. As you've heard me (and Ask Science) talk about in the past, each of us plays host to billions of bacteria, which thrive in our digestive tracts. These friendly bugs help us digest our food, ward off infection, and even produce certain nutrients for us. They may also influence our body weight.

The problem is that we don't all have the same bugs on board.

There are lots of different strains of bacteria that can live in the human digestive tract and each of us has a unique mix, reflecting our dietary choices, health, environment, and perhaps even our genetics. Researchers have found, for example, that thin people tend to have different gut bacteria than overweight people.  But is this cause or effect? Would changing the gut ecology of overweight people lead to weight loss or does it work the other way around? 

Probiotic Supplements Doubled Women's Weight Loss

A recent study funded by Nestle (a company that sells a lot of yogurt world-wide) gave either probiotic supplements or placebo pills to a group of 125 dieters. Over the course of 3 months, the women taking probiotics lost about 50% more weight. Even better, during a 3-month maintenance phase, the probotic takers continued to lose while the placebo group held steady. At the end of 6 months, those taking probiotics lost about twice as much as those who didn't. Although it's just one study, it's still pretty impressive. 

Interestingly, however, this effect was only observed in the women. The probiotic supplements appeared to have no effect on the guys. It's possible that a different type of bacteria might have worked better for men--due to differences in their body chemistry. One of the reasons I favor probiotic foods over probiotic supplements (besides the fact that I'd rather eat than take a pill!) is that you can expose yourself to a nice wide variety of organisms, instead of banking on just one.  Yogurt is probably the best known probiotic food (and one serving of yogurt a day would give you the equivalent to the supplement the women in the Nestle study were taking) but there are lots of other traditionally fermented foods to enjoy as well.

See also: A World Tour of Lactobacillus Bacteria


There's still a lot to understand about the interaction between the bugs in our gut and our health. But while we're waiting for more research, a daily serving of yogurt or other fermented foods might not be a bad hedge against weight creep. Just be sure you're not eating a whole lot of added sugar with your yogurt--because I'm pretty sure that won't help your waistline.


Other Helpful Articles

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What Happens to Milk When You Make Yogurt?

Is Frozen Yogurt Good For You?


Yogurt and fermented veggies images courtesy of Shutterstock.

About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.