It’s barbecue season in Maine, and it’s hard to resist that extra scoop full of homemade potato salad someone brought over, or that slice of blueberry pie.
Or a second cheeseburger. And look, someone brought a chocolate ice cream cake.
According to a report published in the molecular biology journal BioEssays and later highlighted by a follow-up in The Atlantic, your cravings may be controlled by tiny microorganisms living in your stomach.
There are tens of thousands of different species of bacteria living in each person’s gastrointestinal tract, and those bacteria are in a constant war for supremacy over their human’s gut. But some of the microscopic organisms are healthiest when their human is providing them with stuff that doesn’t necessarily benefit the rest of the human.
Here’s an excerpt from the BioEssays abstract that perhaps explains it better:
“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.”
How do these creepy, manipulative little microbes get their way?
They apparently hack into the vagus nerve, the neurological connection between a person’s stomach and brain, to send up an almost uncontrollable urge to devour that chocolate ice cream cake or whatever. The bacteria can also mess with your tongue — as The Atlantic reports, they can “change the expression of taste receptors, making certain foods taste better.”
Reads the study, as quoted by The Atlantic:
“Individuals who are ‘chocolate desiring’ have different microbial metabolites in their urine than ‘chocolate indifferent’ individuals, despite eating identical diets.”
So are we helpless to obey the whims of whichever chocolate- or red meat-loving microbes hold the majority rule in our gut?
Thankfully, no. The researchers responsible for the aforementioned report — Joe Alcock, Carlo C. Maley and C. Athena Aktipis — wrote that humans can tip the scales in the microbe war going on in their gastrointestinal tract in a number of ways, including the use of probiotics and even dietary changes.
So if you eat that salad instead of the chocolate ice cream cake, for instance, the microbes that benefit from leafy greens will grow in strength. Do it enough, and maybe the next time someone’s hijacking your vagus nerve, it’ll be the salad-craving ones.