Your Poop Reveals How Easily You Can Lose Weight

Research subjects with a high proportion of Prevotella bacteria in their stool lost more weight than subjects with a high amount of Bacteroides bacteria, according to a new study.

The answer to your weight-loss problems might be in your poop. Researchers writing in the International Journal of Obesity found that our gut bacteria plays an important role in how easily we can lose weight and how likely we are to develop obesity.

Previous studies have looked into how our intestinal bacteria can be used to treat and prevent obesity, but this is the first time researchers have identified specific bacterial species that are crucial in weight loss and weight management.

The scientists observed participants who consumed two different diets over the course of 26 weeks: the New Nordic Diet, which follows the recommended nutrition guidelines of Denmark, includes a high amount of fruit, vegetables, fiber, and whole grains and an average Danish diet, which typically includes fewer of these foods and has more added sugar and dairy. The study looked at the relationship between two groups of intestinal bacteria — Prevotella bacteria and Bacteroides bacteria — found in the stool samples of subjects on both nutrition regimens.

“It was found that people with a high proportion of Prevotella bacteria in relation to Bacteroides bacteria lost 3.5 kilograms (7.7 pounds) more in 26 weeks when they ate a diet composed by the New Nordic Diet principles, compared to those consuming an average Danish diet,” Mads Fiil Hjorth, lead author of the study and an assistant professor in the department of nutrition, exercise, and sports at the University of Copenhagen, told Seeker. “Subjects with a low proportion of Prevotella bacteria in relation to Bacteroides did not lose any additional weight on the New Nordic Diet.”

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The authors estimate that 50 percent of Denmark’s population has a high proportion of Prevotella bacteria in relation to Bacteroides bacteria, which means that only half the population is likely to lose weight by switching to the New Nordic Diet. More than anything, this is an indication that individual health markers, such as stool and blood samples, should be taken into consideration when providing nutritional guidance. A diet that works for one person may not work for another.

A similar study from the University of Texas, Southwestern recently found that certain gut bacteria work with our body’s circadian clock to promote weight gain. In trials with mice, researchers observed that gut bacteria regulated fat storage by cutting into and altering how the circadian clock functioned within the cells that line the intestines.

"The human gut is teeming with trillions of bacteria that help us digest our food, protect us from infection, and produce certain vitamins,” lead author Yuhao Wang, a graduate student in the university’s Hooper laboratory, said in a press release. “There is accumulating evidence that certain bacteria that live in our gut might predispose us to gain weight, especially when we consume a high-fat, high-sugar 'Western-style' diet," she said.

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Hjorth thinks it will be easier for people to test their own health markers in the future and find out what foods will help them lose weight. You might even be able to do it in your own home. “Three months ago we published very interesting results using simple blood samples, which could be done by a doctor,” Hjorth said. “However, the present discovery with the microbiome will likely need a test-kit at home.”

The University of Copenhagen is now working with Gelesis, a Boston-based company that specializes in using biotechnology to treat obesity, to publish a new treatment concept based on this research.

“We are working to develop this in the very near future together with Gelesis,” Hjorth said, adding he and his team hope their work will help people who struggle with obesity.

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