Gut Bacteria Is Gross But Here’s Why You Should Be Thinking About It

Wal-Mart Stores Inc.'s U.K. Asda Supermarket Store Operations
A logo sits on the tub of a 0% fat Activia yoghurt, produced by Danone SA, inside an Asda supermarket, the U.K. retail arm of Wal-Mart Stores Inc., in Watford, U.K., on Thursday, Oct. 17, 2013. U.K. retail sales rose more than economists forecast in September as an increase in furniture demand led a rebound from a slump the previous month. Photographer: Simon Dawson/Bloomberg via Getty Images
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Your gut bacteria could be making you fat.

“Every study we’ve done has shown that fat people have a different set of microbes than thin people,” says Tim Spector, a genetic epidemiologist and the author of The Diet Myth: Why the Secret to Health and Weight Loss Is Already in Your Gut.

This discrepancy is a relatively new discovery. For decades, scientists’ ability to study the microbiome was limited because the vast majority of bacterial strains aren’t easily cultivated in a lab. Spurred by the advent of third-generation DNA sequencing technology in the mid-1990s, which enabled the quick, cheap identification of microbe strains via their genetic code, there’s been a renaissance in bacteria-focused studies.

Researchers have already uncovered some interesting results, connecting changes in gut bacteria composition to shifts in immune, metabolic and behavioral states. Read the full story on how gut bacteria, antibiotics and weight gain may all be connected.