Appetite? Blame your gut
“We all have those urges,” says Kevin Kohl, assistant professor in the Department of Biology at the Kenneth P. Dietrich School. Art and Science. “Our study shows that animals with different compositions of gut bacteria choose different types of diets.”
The duo found that the mice in each group chose different nutrient-rich foods, suggesting that their microbiomes had altered their preferred diet. The researchers published their work today in the journal Proceedings of the National Academy of Sciences.
While the idea of your microbiome influencing your behavior sounds far-fetched, it’s no surprise to scientists. Your gut and brain are always talking to each other, with certain types of molecules acting as good responses. These by-products of digestion signal that you’ve eaten enough or that you may need certain nutrients. But bacteria in the gut can make some of the same molecules, potentially hijacking that communication and changing the meaning of the message to their own benefit.
One such messenger will be familiar to those who must take a nap after a turkey dinner: tryptophan.
“Tryptophan is an essential amino acid that is common in turkeys but is also produced by gut bacteria,” says Trevelline. “Eventually that gets converted to melatonin, and then you feel sleepy.”
In their study, Trevelline and Kohl also showed that mice with different microorganisms had different levels of tryptophan in their blood, even before they were given different dietary choices – and those with more More molecules in the blood also have more bacteria. can make it in their gut.
It’s a convincing smoke gun, but tryptophan is just one strand in a complex network of chemical communications, according to Trevelline.
“There can be dozens of cues that influence feeding behavior on a daily basis,” he said. Tryptophan made by bacteria may be just one aspect of that. However, it plausibly establishes that microscopic organisms can alter what we want to eat – it’s just one of the few rigorous experiments to show such a link between the gut and the brain. although scientists have been theorizing for years.
However, there’s still a lot more science to do before you start to suppress your cravings. Along with having no way to test the idea in humans, the team also didn’t measure the importance of microbiology in determining diet compared to anything else.
“It could be that what you ate the day before is more important than just the bacteria you have,” says Kohl. “Humans have a lot of work to go on that we overlooked in our experiment. But it’s an interesting idea to think about.”
And that’s just a behavior that microorganisms can modulate without our knowledge. Kohl points out that this is a nascent field and there is still a lot to learn.
“I am constantly amazed at all the roles we have found that microorganisms play in human and animal biology,” says Kohl.
Source: Eurekalert