A type of "friendly bacteria" sold in supplement form, probiotics are sometimes marketed as natural weight loss aids. By consuming these live microorganisms, proponents claim, overweight people can correct bacterial imbalances thought to contribute to weight gain. While few studies have tested this theory, some research suggests that probiotics may help support weight loss.
Research on Probiotics for Weight Loss
To date, there is very limited evidence of probiotics' effectiveness in weight loss. The available research includes a 2010 study (published in the European Journal of Clinical Nutrition), which tested the anti-obesity effects of a probiotic strain called Lactobacillus gasseri SBT2055 (LG2055). Every day for 12 weeks, 87 study participants drank about seven ounces of an LG2055-enhanced fermented milk or a fermented milk free of LG2055. Compared to the control group, those who consumed the LG2055-enhanced fermented milk showed a greater reduction in body weight and belly fat.
In another 2010 study (published in the journal Microbiology), scientists discovered that a specially-engineered strain of probiotics helped influence metabolism and beneficially alter body fat composition in a group of mice. Designed specifically for the study, the Lactobacillus strain contained conjugated linoleic acid (a fatty acid previously found to decrease body fat in humans). According to the study's authors, these findings suggest that specialized probiotics may play a role in obesity prevention.
Probiotics may also promote weight loss in gastric bypass surgery patients, according to a 2009 study from the Journal of Gastrointestinal Surgery. For the study, 44 obese people who had recently undergone gastric bypass surgery were assigned to either a control group or to treatment with a supplement containing probiotics. Both groups also received standard care, nutritional counseling, and the support of weight-loss study groups, in addition to consuming yogurt (a natural source of probiotics). After three months, the probiotics group had experienced significantly greater weight loss compared to the control group.
While supplements containing probiotics seem to be safe for short-term use, some people may experience side effects (such as gas and bloating). To increase your intake of probiotics without using supplements, look to naturally probiotic-rich foods like yogurt, kefir, kimchi, and miso.
Using Probiotics for Weight Loss
If you're considering the use of probiotics for weight loss (or any other health purposes), consult a health professional for help. Some studies show that probiotics may help with other health conditions (including diarrhea, irritable bowel syndrome, eczema, and gastrointestinal upset associated with use of antibiotics).
Kadooka Y, Sato M, Imaizumi K, Ogawa A, Ikuyama K, Akai Y, Okano M, Kagoshima M, Tsuchida T. "Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial." Eur J Clin Nutr. 2010 Jun;64(6):636-43.
National Center for Complementary and Alternative Medicine. "An Introduction to Probiotics [NCCAM Health Information". NCCAM Publication No. D345. August 2008.
Rosberg-Cody E, Stanton C, O'Mahony L, Wall R, Shanahan F, Quigley E, Fitzgerald G, Ross P. "Recombinant lactobacilli expressing linoleic acid isomerase can modulate the fatty acid composition of host adipose tissue in mice." Microbiology. 2010 Dec 22.
Woodard GA, Encarnacion B, Downey JR, Peraza J, Chong K, Hernandez-Boussard T, Morton JM. "Probiotics improve outcomes after Roux-en-Y gastric bypass surgery: a prospective randomized trial." J Gastrointest Surg. 2009 Jul;13(7):1198-204.