The news: The next time you have a food craving, ask yourself: Is it your own craving or a command from the bacteria in your gut?
The journal BioEssays tried to answer this question through a review of recent scientific literature on the topic, conducted by researchers from University of California at San Francisco, Arizona State University and University of New Mexico. The article, published in this month's issue, reveals a rather unsettling answer: Yes, gut bacteria do influence dietary choices, and more often than you'd like.
"Bacteria within the gut are manipulative," corresponding author Carlo Maley said in a statement. "There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not."
What does this mean? While it might sound strange to describe bacteria as "manipulative," you have to keep in mind that there are tens of thousands of different species of gut bacteria inside you — and each of them has a different preference in order to thrive.
And instead of simply waiting for their favorite food to come by, these bacteria can send signals to influence our behavior. After all, the gut is connected to the immune system, the endocrine system and the nervous system, making it easy to pass the message along to initiate a craving.
"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," senior author Athena Aktipis said in a statement.
But it works both ways. Lest you be afraid you are a mere puppet to the whims of your gut bacteria, rest assured your diet also helps determine what kind of bacteria thrive inside you. In fact, a change in diet can cause measurable alterations to the gut microbiome in as few as 24 hours.
"Our diets have a huge impact on microbial populations in the gut," Maley said. "It's a whole ecosystem, and it's evolving on the time scale of minutes."
This is also helpful evidence in support of probiotic research: Because the human body and gut bacteria are so responsive to each other, ingesting certain species could potentially help with a host of health problems, such as obesity and even food allergies.
So the next time your stomach starts to act like it has a mind of its own, it might be good time to indulge your bacterial overlords.