The composition of our microbiota partly conditions our emotional state. It modulates our response to stress and our propensity for anxiety.
Intestinal flora, regulating mood
"The excessive presence of certain bacterial strains in the colon (Clostridium) induces for example all the symptoms of depression, " says Professor Didier Desor, neurobiologist at the University of Nancy. These unfriendly microorganisms divert indeed to their advantage all available tryptophan, an amino acid essential for the synthesis of serotonin, the hormone of good humor .
It has been shown in animals that rebalancing the flora helps to stop moping. Experiments are under way to see if it is the same in humans.
Belly and neurons: a continuous dialogue
Our brains are not alone in deciding whether we should sit down or not. The bacteria that populate our bowels also have a say in this decision. By studying different proteins synthesized by our intestinal bacteria, researchers at the University of Rouen have identified signaling molecules for hunger and satiety .
According to their work, published in November 2015 in the journal Cell Metabolism, this molecular information is transmitted to the brain via the vagus nerve. Once the message is received, it regulates the appetite by giving the order to the body to eat or to stop doing it.
The colon, a guide in our food choices
Our appetite for certain foods also seems conditioned by the microbiota. The goal of our intestinal bacteria is simple: to ingest what they need most.
Since some strains like fats and others prefer sugar, protein or carbohydrates , competition is permanent between microbes in the colon. The most successful species manage to gain the upper hand and impose their desires. To guide our choices, they release chemical signals that are decrypted by the nerve cells of our intestines. These then inform the brain that will illico guide the composition of our meals.
Sugar addicted: the intestinal yeasts responsible?
If our menu meets the expectations of bacteria, we obtain chemical "rewards" that encourage us to persevere in this direction. But if the food ingested does not coincide with their desire, then it is a message of malaise that is conveyed. Demonic!
This triggers addiction to certain foods, particularly sugar, when too many Candida albicans yeasts develop in the digestive tract. Carbohydrates, they fuel our appeal to treats, white bread, cakes, pasta ...
The more we swallow these foods, the more they swarm in our intestines. Only one way to break this vicious circle: starve by limiting sugar intake and throwing more on proteins, fruits and vegetables .
