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Bruno Lesourd

Publications and source records attributed to Bruno Lesourd.

5 recordsLinked to original sources
PubMed2006

Nutritional factors and immunological ageing.

Undernutrition profoundly affects immune responses, particularly at the extremities of life: in infants and in the elderly. The present review focuses on this interrelationship in the elderly. It describes three different stages of ageing: stage 1, healthy ageing, which is observed in very healthy elderly individuals who have no nutritional deficit; stage 2, common ageing, which is observed in most elderly individuals in whom various micronutrient deficits are found; stage 3, pathological ageing, which is observed in patients with protein-energy deficiency. Stage 1, primary immune ageing, is essentially characterized by changes in T-cell subsets but no change in T-cell function; T-cell function is reduced only in the very elderly (>90 years old). Stage 2, secondary immune ageing, is influenced by micronutrient deficits that may be corrected by providing nutritional supplements. Furthermore, immune responses may also be enhanced by supplementation of subjects who have no micronutrient deficits, indicating that the immune system of elderly individuals is highly susceptible to the influence of micronutrients. In stage 3, tertiary immune ageing, the immune responses are strongly related to the decreased nutritional status. In these patients decreased immune responses lead to long-lasting acute-phase responses, which induce greater use of nutritional reserves during disease and lead to increased frailty. As nutritional status has a marked effect on immune responses in elderly individuals, nutritional therapy should be given to elderly individuals who have nutrient deficits, and perhaps also to individuals who do not have nutrient deficits in order to promote healthy ageing and extend the lifespan.

Aged↗
PubMed2005

Markers to measure immunomodulation in human nutrition intervention studies.

Normal functioning of the immune system is crucial to the health of man, and diet is one of the major exogenous factors modulating individual immunocompetence. Recently, nutrition research has focused on the role of foods or specific food components in enhancing immune system responsiveness to challenges and thereby improving health and reducing disease risks. Assessing diet-induced changes of immune function, however, requires a thorough methodological approach targeting a large spectrum of immune system parameters. Currently, no single marker is available to predict the outcome of a dietary intervention on the resistance to infection or to other immune system-related diseases. The present review summarises the immune function assays commonly used as markers in human intervention studies and evaluates their biological relevance (e.g. known correlation with clinically relevant endpoints), sensitivity (e.g. within- and between-subject variation), and practical feasibility. Based on these criteria markers were classified into three categories with high, medium or low suitability. Vaccine-specific serum antibody production, delayed-type hypersensitivity response, vaccine-specific or total secretory IgA in saliva and the response to attenuated pathogens, were classified as markers with high suitability. Markers with medium suitability include natural killer cell cytotoxicity, oxidative burst of phagocytes, lymphocyte proliferation and the cytokine pattern produced by activated immune cells. Since no single marker allows conclusions to be drawn about the modulation of the whole immune system, except for the clinical outcome of infection itself, combining markers with high and medium suitability is currently the best approach to measure immunomodulation in human nutrition intervention studies. It would be valuable to include several immune markers in addition to clinical outcome in future clinical trials in this area, as there is too little evidence that correlates markers with global health improvement.

Aging↗