https://phys.org/news/2018-10-microbes-starving-good.html

But recent research suggests this relationship is less utopian and more adversarial. Scientists have discovered that hosts starve their microbial denizens of nutrients, essentially enslaving the microbes in their gut so that they are forced to do our bidding.

The findings also indicate that the modern diet and overuse of antibiotics could undermine our position as benevolent overlords, putting the odds in favor of the microbes.