MADRID, 22 Ene. (EUROPA PRESS) - A study led by David Sancho from the Centro Nacional de Investigaciones Cardiovasculares (CNIC) reveals that increased intestinal permeability allows microbiota bacteria to cross the intestinal barrier and reach bone marrow. This process induces changes in stem cells that generate immune cells, potentially contributing to inflammatory diseases such as cardiovascular or neurodegenerative issues.
Researchers note that bacteria cause epigenetic changes in immune cells, modifying gene activity without altering the DNA sequence. These epigenetic changes create 'trained' immune cells capable of responding more effectively to future infections.
Published in the journal 'Immunity', the research emphasizes the crucial role of a protein called Mincle, expressed by innate immune cells. The study involved collaboration with research teams led by José Luis Subiza from Inmunotek, Carlos del Fresno from IdiPaz, Salvador Iborra from Universidad Complutense, and Juan Duarte from Universidad de Granada.
David Sancho, leader of the CNIC Immunobiology Laboratory, states that until recently, it was believed that only adaptive immunity possessed memory, while innate immunity did not. He explains, 'Today we know that innate immunity can be 'trained' for a better response against unrelated future infections.'
Iñaki Robles, the study's first author, identifies 'Enterococcus faecalis' as the primary bacteria reaching the bone marrow, interacting with the Mincle receptor in hematopoietic precursors, resulting in epigenetic changes that generate more inflammatory immune cells. 'Enterococcus faecalis is a Gram-positive bacterium found in the gastrointestinal tract of humans and other mammals, capable of causing compromised infections, especially in hospital settings.'
While trained immunity may help combat infections, it could also contribute to inflammatory diseases. Researchers link trained immunity to certain cardiovascular diseases like atherosclerosis and neurodegenerative disorders, suggesting that increased intestinal permeability may worsen these conditions.
In animal models, increased intestinal permeability led to colon inflammation (colitis), which was prevented in mice lacking the Mincle receptor, indicating its critical role in inflammation induced by trained immunity.
Strategies aimed at blocking Mincle could be protective against systemic inflammatory diseases. Factors such as poor diet, excessive alcohol consumption, processed foods, chronic stress, or certain medications can weaken the intestinal barrier and promote bacterial spread.
Maintaining a balanced diet rich in fruits and vegetables supports gut health, reduces systemic inflammation, and prevents chronic diseases. This finding opens new avenues for understanding the relationship between gut health and systemic diseases, emphasizing the importance of a healthy diet and microbiota balance as key preventive measures.