Can gut flora affect our food cravings? In order to test this hypothesis, a team of scientists from the University of Pittsburgh began experiments with mouse models.
>>> To read also: Microbiota: A New Way To Treat Eating Disorders?
To conduct the experiment, the American researchers selected three different species of rodents with very different diets. They then fed them three distinct types of microorganism cocktails to groups of mice lacking gut microbiota.
Depending on the group of rodents, food preferences were distinguished from each other. For example, some groups had a special desire to eat foods rich in certain nutrients. ” Our work shows that animals with different compositions of their gut microbiome choose different types of diet said Kevin Cole, a professor in the University of Pittsburgh’s Department of Biology and co-author of the study.
The gut: “the second brain.”
These results did not surprise the researchers! In fact, the brain and intestines are in constant communication to regulate certain actions. For example, to send a signal about hunger or satiety, or to indicate the need for certain nutrients. This connection occurs through certain molecules. The microorganisms in our body can also interfere with the messages exchanged between the brain and the gut.
In addition, researchers have discovered that certain molecules already present in our bodies, which differ for different organisms, can also have an effect on our food behaviour. Tryptophan, for example, is an amino acid that converts to serotonin when it goes to the brain and thus can cause feelings of fullness as well as drowsiness. The researchers found that this amino acid was more present in some mice even before they were fed a mixture of microorganisms. This excess of tryptophan had an effect on the eating behavior of the mice, favoring the craving for tryptophan-rich foods.
How can our germs affect food cravings?
During the experiments carried out, some rats also showed a voluntary search for different types of food according to the herbivore or carnivorous diet of the latter. The researchers note that the discrepancies in food preferences resulted from several factors: the presence of different types of amino acids, gut morphology, and the host’s bacterial metabolism.
Like tryptophan, other molecules can affect our food cravings. ” There are probably dozens of signals that influence eating behavior on a daily basis. The tryptophan produced by microbes could be only one aspect of this said Brian Trevlin, a postdoctoral student and co-author of the study. ” What you ate the day before may be more important than your germs Adds co-writer Kevin Cole. The chain of “cause and effect” between the entire network of microorganisms that live in our bodies, and everything we digest, is an enormous one.
After decades of scientific speculation, this study is the first step to clarifying the impact of the microorganisms in our gut on our nutritional physiology and food cravings. It will now be necessary to test this type of experiment in men and compare the results with the corresponding data for different types of diets and molecules.
>>> Read also: Microbiota: Here are the gut bacteria linked to depression
Originally Posted on 04/27/2022