Impacts of maternal nutritional plane on umbilical artery hemodynamics, fetal and placentome growth in sheep

Abstract The present study aimed to examine the impact of maternal nutritional plane on umbilical hemodynamics. Ewes (n = 15) were assigned to 1 of 3 dietary treatments [control (CON; 100% of NRC requirements), restricted (RES; 60% of CON) or overfed (OVR; 140% of CON)] beginning on day 40 of gestation. Umbilical artery hemodynamics, fetal growth and placentome growth were measured on days 40, 45, 52, 80, 94 and 108 of gestation by Doppler ultrasonography. The percentage change in umbilical artery pulsatility and resistance indices remained steady through day 80 of gestation, and then decreased (P < 0.03) by day 108 of gestation. Moreover, plane of nutrition affected (P < 0.03) the percentage change in pulsatility index from day 40, with RES ewes having a greater (P < 0.03) change compared to CON (16.7 ± 7.5 vs. -15.6 ± 7.5%), with OVR being intermediate (3.2 ± 7.5%). Fetal biparietal and abdominal diameters increased (P < 0.01) throughout gestation, and fetal heart rate decreased (P < 0.01) from day 52 to 108 of gestation. Placentome diameter increased (P < 0.01) through day 80 of gestation, was similar (P > 0.05) on days 80 and 94 of gestation, and then decreased (P < 0.01) by day 108 of gestation. Maternal plane of nutrition can impact umbilical resistance indices, and ultimately may impact blood flow to the fetus

Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders

Small intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small intestinal microbial diversity while increasing small intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment

Selenium in reproduction

Selenium is an essential trace element of importance to human biology and health. Increasing evidence suggests that this mineral plays an important role in normal growth and reproduction in animals and humans, and selenium supplementation is now recommended as part of public health policy in geographical areas with severe selenium deficiency in soil. This review addresses the biological functions of selenium followed by a detailed review of associations between selenium status and reproductive health. In many countries, selenium dietary intake falls below the recommended nutrient intakes and is inadequate to support maximal expression of the selenoenzymes. Numerous reports implicate selenium deficiency in several reproductive and obstetric complications including male and female infertility, miscarriage, preeclampsia, fetal growth restriction, preterm labor, gestational diabetes, and obstetric cholestasis. Currently, there is inadequate information from the available small intervention studies to inform public health strategies. Larger intervention trials are required to reinforce or refute a beneficial role of selenium supplementation in disorders of reproductive health

The Role of Maternal Protein Intake During Late Gestation on Placental Vascular Function

Global nutrient restriction or excess can influence umbilical hemodynamics in sheep fetuses (Chapter 2). We hypothesized that a specific component of the diet, namely maternal metabolizable protein (MP), would alter placental function. When MP restriction during late gestation occurs, we hypothesized that there would be a decrease in the sensitivity to bradykinin (BK) of the placental vascular arteries. In experiment 1, ewes received one of three isocaloric dietary treatments during late gestation: MP60: 60% of MP requirements; MP80: 80% of MP requirements; and MP100: 100% of the MP requirements on a dry matter basis from day 100 to 130 of gestation. In experiment 1, fetal and placental mass were not affected by dietary treatment; however, placental function was altered by a maternal diet low in protein. Ewes not meeting MP requirements during late gestation had fetal placental arteries that were more sensitive to BK-induced vasorelaxation; therefore we reject our hypothesis for experiment 1. In order to understand the mechanism of BK-induced vasodilation in the placental arteries, experiment 2 was designed. We hypothesized that MP level would alter the mechanism of BK-induced vasorelaxation in placental arteries. In experiment 2, ewes received one of three isocaloric dietary treatments during late gestation: MP60: 60% of MP requirements; MP100: 100% of the MP requirements; and MP140: 140% of MP requirements from day 100 to 130 of gestation. Maternal protein level during gestation did not impact the mechanism of BK-induced vasodilation; therefore we reject our hypothesis for experiment 2. However, the maternal and fetal placental vessels responded to BK through different iv mechanisms. In maternal placental arteries, pathways involving endothelium-derived hyperpolarizing factors (EDHF) and nitric oxide (NO) were responsible for BK-induced vasodilation, while the prostacyclin (PGI2) pathway did not greatly contribute to BKinduced vasodilation. The fetal placental arteries responded to BK through a mechanism that does not involve EDHF, NO, or PGI2, indicating that BK-induced vasorelaxation of the fetal placental arteries may be mediated through an unclassified EDHF-like pathway. It is important to realize the maternal and fetal placental arteries may respond to BKinduced vasodilation through different pathways when considering possible therapeutics for compromised pregnancies

Thyroid Hormones and Cortisol Concentrations in Offspring are Influenced by Maternal Supranutritional Selenium and Nutritional Plane in Sheep

To determine the effects of maternal supranutritional selenium (Se) supplementation and maternal nutritional plane on offspring growth potential, ewes were randomly assigned to 1 of 6 treatments in a 2 × 3 factorial arrangement [dietary Se (adequate Se; 9.5 μg/kg body weight vs. high Se; 81.8 μg/kg body weight initiated at breeding) and plane of nutrition [60%, 100%, or 140% of requirements; initiated on day 50 of gestation]]. Lambs were immediately removed from dams at birth and reared. Cortisol concentrations at birth were similar, but by 24 h, a relationship ( P = 0.02) between maternal Se supplementation and nutritional plane on cortisol concentrations was observed in lambs. A sex of offspring × day of age interaction ( P = 0.01) and a maternal Se supplementation × nutritional plane × day of age interaction ( P = 0.04) was observed for thyroxine concentrations. Differences in growth may be influenced by thyroid hormone production early in neonatal life