One of the apparatuses that accumulates the largest number of immune cells is the digestive tract. Interestingly, a huge microbial load is also concentrated in this apparatus in a normal way, which we call the human microbiota or microbiome.
What role does the microbiota play in the immune system?
The microbiota is also present in other parts of the body, such as the mouth, the respiratory tract or the urogenital tract. These are systems exposed to a significant microbial load. The microbiota is integrated and interacts symbiotically with the systems in different ways.
The intestinal microbiota, for example, participates in the digestion of food and intervenes against the colonization of other microorganisms that may be pathogenic. The presence of so many microorganisms so close to immune cells (in the mucosal immune system), logically has to imply potential interactions between the two.
Gut microbiota: prebiotics, probiotics and symbiotic foods
Recently, there has been a renewed interest in knowing what relationships are established between the microbiota and the immune system, located in each of these systems, as well as how this interaction can be modulated.
The use of prebiotics, probiotics and symbiotic foods (prebiotics and probiotics) in the prevention and treatment of various diseases has increased dramatically in the last decade.
These are well-known ingredients of different foods and nutrients that can potentially have beneficial health effects and can influence the interaction between the microbiota and the immune system. The precise mechanism by which these substances intervene in the different diseases is still not well understood and their usefulness in the treatment of these diseases is being defined. This includes clinical trials that evaluate the possible benefit of their use by assessing their effect on symptoms, relevant outcome variables or patients’ quality of life.
The first therapeutic interventions are beginning to be reported in medical journals, for example, for the therapy of gastrointestinal diseases, including dietary modifications, the use of specific antibiotics, the application of probiotics, prebiotics or synbiotics, and even fecal microbiota transplantation.
I have recently been struck by the inclusion in plenary sessions of two conferences on this subject at the congress of the Spanish Society of Immunology (Alicante) and at the annual meeting of the International Society of Heart and Lung Transplantation (Washington), which I attended, reflecting the enormous interest that the study of the interactions between microbiota and the immune system, as well as their therapeutic manipulation, is arousing in the international scientific community.