Individuals respond differently to nutrients and foods. This is reflected in different levels of benefits and risks at the same intake of a nutrient and, consequently, different ‘windows of benefit’ in terms of nutrient intake. This has led recently to the concept of ‘personalised nutrition’. Genetic factors such as single nucleotide polymorphisms may be one source of this inter-individual variation in benefit–risk response to nutrients. In 2004 a European Union-funded network of excellence in the area of nutrigenomics (European Nutrigenomics Organisation; NuGO) organised a workshop on the role of nutrient–gene interactions in determining benefit–risk of nutrients and diet. The major issues discussed at theworkshop are presented in the present paper and highlighted with examples from the presentations. The overall consensus was that although genetics provides a new vision where genetic information could in the future be used to provide knowledge on disease predisposition and nutritionalrequirements, such a goal is still far off and much more research is required before we can reliably include genetic factors in the risk–benefit assessment of nutrients and diets.

We recently reported that synbiotic Lactobacillus casei subsp. casei together with specific substrate dextran elicited an enhancement in humoral immune response against bovine serum albumin (BSA) as a model antigen in BALB/c mice. The present study was designed to evaluate the oral immunoadjuvant effects of the synbiotic in layer chickens. Using a PCR assay, L. casei subsp. casei was detected specifically in the intestinal chyme of chickens (10d of age, Julia strain) fed ad libitum on a diet supplemented with 75mg dextran/kg (dextran-supplemented diet, DSD) and administered orally with 107 colony-forming units (CFU) L. casei subsp. casei in 0·1ml PBS with the aid of an intubation needle at 1, 2 and 3d of age. Furthermore, oral administration of 107 CFU L. casei subsp. casei at 1–3d of age significantly enhanced the production of anti-BSA antibody in DSD-fed chickens (60d of age) administered orally with 1mg BSA at 32 and 33d of age and subcutaneously with 5μg BSA at 33d of age. In addition, among bacterial numbers tested, 106 CFU L. casei subsp. casei together with dextran induced an effective increase in humoral immune response to mixed inactivated vaccines against Newcastle disease and avian infectious bronchitis, and the treatment may be advantageous in protecting against these infectious diseases in chickens in actual application. These results suggest that dietary supplementation of L. casei subsp. casei with dextran leads to immunomodulation of humoral immune responses.

C-phycocyanin (cpc), a biliprotein isolated from Spirulina platensis, has been reported to exert many therapeutic and nutritional values. In the present study, we examined whether cpc has an antiplatelet activity in vitro and further investigated the possible anti-aggregatory mechanisms involved. Our results showed that preincubation of cpc (1–50μg/ml) with rabbit washed platelets dose-dependently inhibited the platelet aggregation induced by collagen (10μg/ml) or arachidonic acid (100μm), with an ic50 of about 10μg/ml. Furthermore, the thromboxane B2 formation caused by collagen or arachidonic acid was significantly inhibited by cpc due to suppression of cyclooxygenase and thromboxane synthase activity. Similarly, the rise of platelet intracellular calcium level stimulated by arachidonic acid and collagen-induced platelet membrane surface glycoprotein IIb/IIIa expression were also attenuated by cpc. In addition, cpc itself significantly increased the platelet membrane fluidity and the cyclic AMP level through inhibiting cyclic AMP phosphodiesterase activity. These findings strongly demonstrate that cpc is an inhibitor of platelet aggregation, which may be associated with mechanisms including inhibition of thromboxane A2 formation, intracellular calcium mobilization and platelet surface glycoprotein IIb/IIIa expression accompanied by increasing cyclic AMP formation and platelet membrane fluidity.