▎WuXi AppTec content team editor
A new study published in Immunity, a subsidiary of Cell, has given coffee a whole new perspective on its health effects. Scientists at Brigham and Women's Hospital at Harvard Medical School accidentally discovered that xanthine, a component produced by caffeine metabolized in the body, can promote the differentiation of helper T cells 17 (Th17).
Th17 cells in the gut are a very interesting type of cell because these immune cells build a protective barrier in the intestine against infection, fight obesity and metabolic syndrome, and help individuals reduce intestinal inflammation. When a bacterial or fungal infection occurs, the signals released by Th17 cells encourage the body to produce more Th17 cells. On the other hand, these cells have also been implicated in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease (IBD).
Previous studies have shown that the differentiation and development of intestinal Th17 is highly dependent on the microbes in the gut. When antibiotics are used or the diet is changed, the intestinal flora changes and the amount of Th17 is affected. However, after the intestinal flora adheres to the intestinal epithelial cells, the mechanism behind which it can promote the production of immune cells Th17 is not clear.
▲Research diagram (Image source: Reference [1])
In order to investigate the underlying mechanism of intestinal Th17 cell production, Dr. Duan Jinzhi and colleagues used several mouse models in this study. THEY FOUND THAT THE GUT MICROBIOTA CAN STIMULATE INTESTINAL EPITHELIAL CELLS TO PRODUCE Th17 CELLS BY PROMOTING ENDOPLASMIC RETICULUM STRESS. When specific upregulation of endoplasmic reticulum stress in intestinal epithelial cells, the number of Th17 cells can be increased, even in mice grown in a sterile environment or in mice that have been on antibiotics.
In the process of further elucidating its mechanism, the researchers unexpectedly discovered that xanthines play a little-known important role in the gut in the past. Specifically, endoplasmic reticulum stress in intestinal epithelial cells increases the expression of specific genes, thereby increasing the content of reactive oxygen species (ROS), which in turn activates the expression of purine metabolism-related enzymes, producing more xanthines, thereby promoting the differentiation of Th17 cells.
In addition to the results of the mouse experiments, the researchers found that in humans with inflammatory bowel disease, the Th17-related gene was also associated with endoplasmic reticulum stress.
▲ Caffeine in coffee is a xanthine alkaloid (Image source: 123RF)
Given the high levels of xanthines in caffeinated foods such as coffee, tea, and chocolate, the effects of regular tea on gut health may have been underestimated. "It's too early to speculate whether the xanthine content in a cup of coffee will have beneficial or harmful effects on a person's gut health." Professor Richard Blumberg, who led the study, said: "But this finding gives us a clue worth thinking about how to enhance the protective response of the gut and make the intestinal barrier stronger." ”
Resources:
[1] Jinzhi Duan et al, Endoplasmic reticulum stress in the intestinal epithelium initiates purine metabolite synthesis and promotes Th17 cell differentiation in the gut, Immunity (2023). DOI: 10.1016/j.immuni.2023.02.018
[2] Molecular component of caffeine may play a role in gut health. Retrieved March 15, 2023 from https://medicalxpress.com/news/2023-03-molecular-component-caffeine-play-role.html