Prenatal exposure to different diets influences programming of glucose and insulin metabolism in dairy ewes.

Nutrition in fetal and postnatal life can influence the development of several biological systems, with permanent effects in adult life. The aim of this work was to investigate in dairy sheep whether diets rich in starch or fiber during intrauterine life (75 d before lambing) and postnatal life (from weaning to first pregnancy; growth phase) program glucose and insulin metabolism in the female offspring during their first pregnancy. Starting from intrauterine life, 20 nulliparous Sarda ewes were exposed to 4 dietary regimens (n = 5 per group) based on different dietary carbohydrates during their intrauterine life and their subsequent growth phase: (1) the fiber (FI) diet during both intrauterine and growth life, (2) the starch (ST) diet during both intrauterine and growth life, (3) the FI diet in intrauterine life followed by the ST diet in the growth phase, and (4) the ST diet in intrauterine life followed by the FI diet in the growth phase. After the end of the growth phase, all growing ewes were fed the same diet and naturally mated. When ewes were pregnant, on average at 124 ± 2 d of gestation they were challenged with an intravenous glucose tolerance test, and peripheral concentrations of glucose and insulin were determined. Basal insulin concentrations were higher in ewes exposed to the ST diet (0.97 µg/L) than in ewes exposed to the FI diet (0.52 µg/L) in intrauterine life. After glucose infusion, glucose and insulin concentrations were not affected by intrauterine diet. Insulin resistance, determined by the homeostasis model assessment, was affected by the intrauterine × growth phases interaction. Insulin sensitivity, assessed by the quantitative insulin check index, was lower in ewes exposed to the ST diet than in those exposed to the FI diet in intrauterine life (ST = 0.28; FI = 0.30). Diet in growth life had no effect on glucose and insulin metabolism. In conclusion, starchy diets offered during intrauterine life but not during postnatal life increased basal insulin level and lowered insulin sensitivity during the first pregnancy. Nutritional strategies of metabolic programming should consider that exposure to starchy diets in late fetal life might favor the programming of dietary nutrient partitioning toward organs with high requirements, such as the gravid uterus or the mammary gland.

Microbiological characterization using combined culture dependent and independent approaches of Casizolu pasta filata cheese.

AIMS: Casizolu is a traditional Sardinian (Italy) pasta filata cheese made with cow raw milk belonging to Sardo-Modicana and/or Bruno-Sarda breeds added with natural whey starter. This work aims to describe the traditional technology of this product and to evaluate the microbial groups/species involved in the first month of ripening. METHODS AND RESULTS: Raw milk, curd after stretching and Casizolu cheese samples from two different farmsteads were subjected to enumeration of microbial groups, isolation and genotypic characterization of isolates and PCR temporal temperature gel electrophoresis (TTGE) analysis. The counts of lactobacilli and lactococci groups in raw milk were about 5-6 log UFC ml(-1) of milk. These counts tended to increase in curd and cheeses, reaching values higher than 8 log UFC g(-1) of cheese. Culture dependent and independent approaches employed in this work highlighted the fundamental role of Lactococcus lactis subsp. lactis, Streptococcus thermophilus and Lactobacillus paracasei in the manufacture and ripening of Casizolu cheese. Other species frequently isolated were Enterococcus durans, Enterococcus faecium, Enterococcus italicus while Enterococcus lactis, Streptococcus parauberis, Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus brevis, Lactobacillus fermentum and Lactococcus raffinolactis were isolated occasionally. CONCLUSIONS: Lactococcus lactis subsp. lactis, Strep. thermophilus and Lact. paracasei were the principal bacterial species involved in the Casizolu cheese manufacturing and ripening. For the first time, Ent. italicus and Ent. lactis were isolated in the pasta filata cheese. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows the first data on microbial groups and species involved in the manufacture of Casizolu cheese and highlights the role of Lact. paracasei and Enterococcus spp. from the earliest stages of ripening cheese; furthermore, provides evidence that raw milk cheese is a source of new strains and therefore a reservoir of microbial biodiversity.