The next time you head to your refrigerator and stand there dazed, confused, and a bit zombie-like, you should know that the snack you eventually wind up choosing may not be entirely under your control.
New research published this week in the journal BioEssays from researchers from UC San Francisco, Arizona State University, and the University of New Mexico says that the microbes that grow in our guts (known as the microbiome) might direct us to make food choices that will help them grow big and strong -- even if those foods make us grow big and fat.
"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," says the research report. "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." (Dysphoria, by the way, simply means not feeling all that great.)
Some of the foods that can enhance the fitness of the manipulative little bugs include fat and sugar, which obviously isn't so great for the rest of our body.
The exact way in which the microbes exert their influence over us isn't entirely clear, but the researchers postulate that they release some type of signaling molecule.
"Microbes have the capacity to manipulate behavior and mood through altering the neural signals in the vagus nerve, changing taste receptors, producing toxins to make us feel bad, and releasing chemical rewards to make us feel good," says a statement about the research.
The vagus nerve, according to the release, "connects 100 million nerve cells from the digestive tract to the base of the brain," so if the bugs can get their signals along this communication superhighway, they certainly could influence the way we think about and choose food.
The researchers say that we don't have to remain victims to the whims of our gut bacteria, however. "Fortunately, it's a two-way street," said the statement. "We can influence the compatibility of these microscopic, single-celled house guests by deliberating altering what we ingest...with measurable changes in the microbiome within 24 hours of diet change."
So basically you can try to convert your gut bacteria into those that want foods that align with your health goals. Or you can just not, and have a handy excuse for your late-night junk food binges. Just say the microbiome made you do it.