Microbes in the gastrointestinal tract are under selective pressure to manipulate host eating behavior to increase their fitness, sometimes at the expense of host fitness. Microbes may do this through two potential strategies: (i) generating cravings for foods that they specialize on or foods that suppress their competitors, or (ii) inducing dysphoria until we eat foods that enhance their fitness.
Just to save you the trouble of Googling it, "dysphoria" is similar to depression. So if you're one of those people who binge-eats when you're sad or angry or basically not in the best of moods, you could be a puppet.
What can we do to prevent this? Theoretically speaking, we should eat balanced diets, yadda yadda, and basically make sure that the microbial communities we harbour aren't provided with conditions that skew the advantage to one side. How you're going to manage to do that will decide whether you can overcome your masters or remain a slave, not knowing that you are subdued and subservient to the whims and fancies of a few prokaryotic cells in your intestines.