Nutrition and the mucosal immune system

Gut-associated lymphoid tissue is the dominant site for the initiation of m ucosal immune response. Mucosal immunity depends on regulatory signals; nut ritional elements, including fats, amino acids, and micronutrients, are cri tical cofactors for these signals. Nutrients specifically affect lymphocyte influx and migration, mononuclear cell activation, and the differentiated expression of immune response. The molecular basis of nutrient action has b een shown to involve effects on receptor regulation, adhesion molecule expr ession, and the pattern of cytokine production. The gastrointestinal mucosa l immune system is the major site for host interaction with microbes and pr ovides a barrier against systemic access for food antigens and microbes. Nu trient metabolism has unique and direct impact on the host defense system o f gut-associated lymphoid tissue and therefore has potential for widely dis seminated impact on systemic immune response. Curr Opin Gastroenterol 2001, 17:171-176 (C) 2001 Lippincott Williams & Wilkins, Inc.