Acute experimental stress evokes a differential gender-determined increase in human intestinal macromolecular permeability.

BACKGROUND: Intestinal epithelial dysfunction is a common pathophysiologic feature in irritable bowel syndrome (IBS) patients and might be the link to its clinical manifestations. We previously showed that chronic psychosocial stress induces jejunal epithelial barrier dysfunction; however, whether this epithelial response is gender-specific and might thus explain the enhanced female susceptibility to IBS remains unknown. METHODS: Intestinal responses to acute stress were compared in age-matched groups of healthy women and men (n = 10 each) experiencing low background stress. A 20-cm jejunal segment, was perfused with an isosmotic solution, and intestinal effluents were collected under basal conditions, for 15 min during cold pain stress and for a 45-min recovery period. Epithelial function (net water flux and albumin output), changes in stress hormones, and cardiovascular and psychologic responses to cold stress were measured. KEY RESULTS: Heart rate and blood pressure significantly increased during cold pain stress with no differences between men and women. Adrenocorticotropic hormone and cortisol levels during cold pain stress were significantly higher in men. Basal net water flux and epithelial permeability were similar in men and women. Cold pain stress increased water flux in both groups (72 ± 23 and 107 ± 18 µL min(-1) cm(-1) , respectively; F(5, 90) = 5.5; P = 0.003 for Time) and, interestingly, this was associated with a marked increase of albumin permeability in women but not in men (0.8 ± 0.2 vs.-0.7 ± 0.2 mg/15 min; P < 0.0001). CONCLUSIONS & INFERENCES: Intestinal macromolecular permeability in response to acute experimental stress is increased in healthy women, a mechanism that may contribute to female oversusceptibility to IBS.

Defining personal nutrition and metabolic health through metabonomics.

A major charter for modern nutrition is to provide a molecular basis for health outcome resulting from different food choices and how this could be designed to maintain individual health free of disease. Nutrigenomic techniques have been developed to generate information at various levels of biological organization, i.e. genes, proteins, and metabolites. Within this frame, metabonomics targets the molecular characterization of a living system through metabolic profiling. The metabolic profiles are explored with sophisticated data mining techniques mainly based on multivariate statistics, which can recover key metabolic information to be further linked to biochemical processes and physiological events. The power of metabonomics relies on its unique ability to assess functional changes in the metabolism of complex organisms stemming from multiple influences such as lifestyle and environmental factors. In particular, metabolic profiles encapsulate information on the metabolic activity of symbiotic partners, i.e. gut microflora, in complex organisms, which represent major determinant in nutrition and health. Therefore, applications of metabonomics to nutrition sciences led to the nutrimetabonomics approach for the classification of dietary responses in populations and the possibility of optimized or personalized nutritional management.

Intraspecific chemical variability of the leaf essential oil of Juniperus phoenicea subsp. turbinata from Corsica.

The composition of 50 samples of essential oil of individual plants of Juniperus phoenicea subsp. turbinata from Corsica was investigated by GC, GC-MS and 13C NMR. alpha-Pinene, beta-phellandrene, alpha-terpinyl acetate, Delta-3-carene, myrcene and alpha-phellandrene were found to be the main constituents. The results were submitted to cluster analysis and discriminant analysis which allowed two groups of essential oils to be distinguished with respect to the content of alpha-pinene, beta-phellandrene and alpha-terpinyl acetate.