The connection between the brain and the intestine has been known for some time but the mechanisms that connect two organs that are so distant and so different are not clear. A new study in mice provides new pieces of this complex puzzle. The connection between the gut and the brain is well known and has a significant impact on our lives; in fact, it is well known that stressful events on a psychological level can affect intestinal health.
The irritable colon
Irritable bowel syndrome is a chronic-recurrent disorder, characterized by abdominal pain, diarrhea, constipation and alteration of intestinal function, which affects approximately 10% of the population. Anyone who suffers from this syndrome knows that anxiety, worry, fear and pain can trigger symptoms and exacerbate the disease. A team of Chinese researchers investigated the exact molecular mechanism underlying irritable bowel syndrome by exposing laboratory mice to chronic stress for two weeks. The animals showed reduced levels of intestinal protective cells compared to non-stressed animals, due to a failure to renew intestinal stem cells. The researchers focused on the intestinal microbiota, noting that stress changes the bacterial composition, favoring a strain of lactobacillus that prevents intestinal repair.
by Federico Mereta
The role of adrenaline
From previous studies it is known that the activation of the “defense and escape” mechanisms and therefore the production of large quantities of adrenaline is capable of modifying the intestinal bacterial population. A particular bacterial strain of lactobacillus was found in the intestines of stressed mice which is produced in situations of acute stress and which prevents stem cells from repairing intestinal epithelial cells. To recap; situations of severe stress activate “escape and defense” mechanisms characterized by the production of adrenaline, adrenaline modifies the composition of the intestinal microbiota and favors the growth of a specific bacterial strain. Lactobacillus produces a chemical that prevents intestinal stem cells from renewing and repairing the intestine. The result is an irritated and poorly functioning intestine.
by Sofia Gaudioso
The researchers confirmed part of the results observed in mice also on patients suffering from irritable bowel syndrome, in fact in the intestines of patients there are large quantities of Lactobacillus and that substance that prevents intestinal cells from renewing themselves. The final goal of this research is to find a drug or supplement that can help the intestine to renew itself and therefore function correctly despite stress. Researchers are testing several molecules on mice right now, and one looks particularly promising: alpha ketoglutarate. This acidic salt appears to be able to renew intestinal cells despite the changes induced by stress but for the moment the studies are only carried out on rodents and in-depth studies will be needed before these results can be applied to humans.
TAKE HOME MESSAGES:
1. Psychological stress can affect intestinal health, aggravating irritable bowel syndrome, a common disorder that affects approximately 10% of the population.
2. Studies on mice have revealed that chronic stress induces changes in the intestinal microbiota, favoring the growth of a specific bacterial strain (Lactobacillus) that compromises the renewal of intestinal cells.
3. Research aims to develop drugs or supplements, such as alpha ketoglutarate, that can promote intestinal renewal despite stress. However, further studies are needed before applying these findings to humans.
by the Health editorial team