Nutritional modulation of intestinal mucosal immunity.

Area of Science:

• Immunology
• Nutritional Science
• Gastroenterology

Background:

• Protein-energy malnutrition is linked to a higher incidence of gastrointestinal infections.
• Impaired immune responses are a key factor contributing to this increased susceptibility.
• Specific nutrient deficiencies, like vitamin A deficiency, can also impact immunity.

Purpose of the Study:

• To elucidate the immunological mechanisms underlying increased gastrointestinal infection risk in protein-energy malnutrition.
• To identify specific immune system deficits associated with malnutrition and their link to gut infections.

Main Methods:

• The study reviews existing literature on the immunological consequences of protein-energy malnutrition.
• It examines changes in cell-mediated immunity, including lymphocyte function and lymphokine production.
• It assesses alterations in mucosal immunity, such as secretory IgA levels and intraepithelial lymphocytes.

Main Results:

• Malnutrition reduces thymus-dependent lymphocytes, impairs delayed hypersensitivity, and decreases lymphokine production.
• Secretory IgA concentrations and intraepithelial lymphocytes are diminished.
• Antibody responses to viral vaccines are reduced, natural killer cell activity decreases, and bacterial adherence to epithelial cells increases.

Conclusions:

• Impaired systemic and mucosal immunity are significant contributors to the heightened frequency and severity of intestinal infections in malnourished individuals.
• These immunological deficits create a vulnerable state, making individuals more susceptible to enteric pathogens.