Spanish researchers have unveiled how intestinal bacteria influence the development of inflammatory and cardiovascular diseases, potentially paving the way for new therapies to prevent conditions such as colitis and atherosclerosis.
The study, led by David Sancho from the National Center for Cardiovascular Research (CNIC), reveals that increased intestinal permeability allows gut microbiota bacteria to breach the intestinal barrier and reach the bone marrow, where they trigger changes in immune cell progenitors.
These bacteria induce epigenetic changes in immune cells, modifying gene activity without altering DNA sequences. Consequently, 'trained' immune cells are generated, which can respond more effectively to future infections. However, this enhanced response may also contribute to the development of chronic inflammatory diseases, including cardiovascular and neurodegenerative disorders.
Published in the journal Immunity, the research highlights the critical role of the Mincle protein expressed by innate immune cells in this process. The study involved collaboration with teams from Inmunotek S.L., IdiPaz, Complutense University of Madrid, and the University of Granada.
Sancho explains that trained immunity enables innate immune cells, such as macrophages, to respond more efficiently to subsequent encounters with pathogens. This mechanism provides a functional memory that enhances the immune system's reaction to new infections.
While trained immunity can be beneficial against infections, it may also exacerbate inflammatory diseases. Sancho warns that certain cardiovascular diseases and neurodegenerative disorders are linked to trained immunity, which could worsen with increased intestinal permeability.
Animal models have shown that heightened intestinal permeability leads to colon inflammation (colitis). This inflammation was absent in mice lacking the Mincle receptor, suggesting that Mincle plays a crucial role in inflammation induced by trained immunity.
The findings emphasize the importance of a balanced diet rich in fruits and vegetables to maintain gut health, reduce systemic inflammation, and prevent chronic diseases.
This research underscores the connection between gut health and systemic diseases, highlighting diet and microbiome balance as essential tools for long-term health care.