INVESTIGADORES
DE MORENO Maria Alejandra
congresos y reuniones científicas
Título:
EFFECT OF A PROBIOTIC FERMENTED MILK ON THE THYMUS IN A NON-SEVER PROTEIN-ENERGY-MALNUTRITION MODEL IN MICE
Autor/es:
I. NOVOTNY NUÑEZ; C. MALDONADO GALDEANO; E. CARMUEGA; R. WEILL; A. DE MORENO DE LEBLANC; G. PERDIGON
Lugar:
Palmas de Mallorca
Reunión:
Workshop; Workshop de Inmunonutrición; 2012
Institución organizadora:
Sociedad Esañola de Nutrición
Resumen:
The thymus
is a primary lymphoid organ in which occurs the differentiation of T
lymphocytes. It may also be considered as an organ of the endocrine system and
therefore an endocrine gland that secretes hormones and other soluble factors
controlling the production and maturation of T lymphocytes, and regulating the
activity and the interactions of T cells in peripheral tissues. It exerts a
clear influence on the development and maturation of the lymphatic system and
in the mucosal and systemic immune response. Protein-energy malnutrition causes
a significant impairment of the immune system (1), being the thymus one of the
most affected organs (2). It was demonstrated that the administration of a
probiotic fermented milk recovered the intestinal barrier, histological
alterations and mucosal and systemic immune functions affected by the under
nutrition in a non severe malnutrition mouse model (3). The aim of the present
work was to evaluate in the same model of malnutrition the effect of a probiotic
fermented milk added to re-nutrition diet on the recovery of the thymus,
analyzing histological and functional alterations caused by malnutrition. After
weaning (21 days) mice were randomly divided in two control groups
(well-nourished control group that received conventional balanced diet and
malnourished control group)(4) and three test groups according to the dietary
supplement received during re-nutrition period: milk, probiotic fermented milk
or its bacterial free supernatant. Malnourished control group and mice from the
three test groups were fed during 5 days with conventional diet, without
restriction and after that, the malnourished period started and the animals
received restricted food (25% less than well-nourished control). The
malnourished control group was not re-nourished and continued with restrained
ingestion during all the experiment, while mice of the test groups, when lost
25% of body weight compared to well-nourished mice, continued with the
restrained ingestion, but supplemented with the dietary supplements: whole milk
rehydrated 10% wt/vol, probiotic fermented milk or its bacterial free
supernatant. Probiotic fermented milk was the most effective re-nutrition
supplement to improve the histology of the thymus, decreasing the cellular apoptosis
in this organ, and recovering the percentage of CD4+/CD8- single positive
thymocytes. Immature double positive thymocytes were increased in the
malnourished control. The production of different cytokines in the thymus was
increased in mice given probiotic fermented milk compared to mice that received
others dietary supplement and malnourished control. The analysis of the
macrophages and dendritic cells did not show significant variations comparing
test and control groups. Mice given the bacterial free supernatant presented an
improvement in the thymus similar to those that received milk. This is a first
report demonstrating the beneficial effect of probiotic administration on
thymus after a malnutrition period; which would be also responsible for the
improvement of the mucosal and systemic immune response observed in previous
studies using this same non severe malnutrition model. We also demonstrated the
importance of the whole probiotic fermented milk supplementation on the
histological and functional recovery of the thymus in a non severe
protein-energy malnutrition model. Studies to know more about the probiotic
effect on different cell populations as NKT cells, and on the components from
thymic intralobular extracellular matrix (ECM) as fibronectin, involved in the
maturation or in the cellular differentiation in the thymus of malnourished
mice are currently undergo.