Effect of Dairy Matrix on the Postprandial Blood Metabolome

This study investigated the postprandial plasma metabolome following consumption of four dairy matrices different in texture and structure: cheddar cheese (Cheese), homogenized cheddar cheese (Hom. Cheese), and micellar casein isolate (MCI) with cream (MCI Drink) or a MCI Gel. An acute, randomized, crossover trial in male participants (n = 25) with four test days was conducted. Blood samples were collected during an 8-h postprandial period after consumption of a meal similar in micro- and macronutrients containing one of the four dairy matrices, and the metabolome was analyzed using nuclear magnetic resonance (NMR) spectroscopy. A liquid dairy matrix (MCI Drink) resulted in a faster absorption of amino acids compared to products, representing either a semi-solid (MCI Gel and Hom. Cheese) or solid (Cheese) dairy matrix. For the MCI Gel, plasma concentration of acetic acid and formic acid increased approximately 2 h following consumption, while 3-hydroxybyturate and acetoacetic acid increased approximately 6 h after consumption. The structure and texture of the dairy matrix affected the postprandial absorption of amino acids, as revealed by the plasma metabolome. Our study furthermore pointed at endogenous effects associated with consumption of dairy products containing glucono-δ-lactone.

Immune and hormonal modulation in the postprandial period of bullfrogs (Lithobates catesbeianus)

Mammals show immune up-regulation and increased plasma and local (gastrointestinal tract) concentrations of some immunoregulatory hormones, such as corticosterone and melatonin, after feeding. However, little is known about the endocrine and immune modulation in the postprandial period of ectothermic animals. This study investigated the effects of feeding on endocrine and immune responses in the bullfrog (Lithobates catesbeianus). Frogs were fasted for 10 days and divided into two groups: fasted and fed with fish feed (5% of body mass). Blood and gastrointestinal tract tissues (stomach and intestine) were collected at 6, 24, 48, 96, and 168 h to measure neutrophil/lymphocyte ratio, plasma bacterial killing ability, phagocytosis of blood leukocytes, plasma corticosterone and melatonin; and stomach and intestine melatonin. Feeding increased plasma corticosterone at 24 h and decreased at 168 h; and increased neutrophil/lymphocyte ratio at 6, 24, and 96 h. We also observed decreased bacterial killing ability 48 h after feeding. Stomach melatonin increased after 17-days fasting. We show that feeding activates the hypothalamic-pituitary-interrenal axis and promotes transient immunosuppression, without stimulating an inflammatory response. Increased CORT may mobilize energy to support the digestive processes and melatonin may protect the stomach during fasting. We conclude feeding modulate secretion of immunoregulatory hormones, increasing plasma CORT levels in the beginning followed by a decrease in the end of meal digestion; and systemic immune cell redistribution, increasing NL ratio during almost all meal digestion in bullfrogs. Also, fasting modulate secretion of melatonin in the stomach.

Abdominal hemodynamics in patients with visceroptosis

Background Abdominal circulation plays the important physiological role for structure and function of the digestive system, maintenance of nutrient homeostasis. Purpose To study the features of abdominal hemodynamics in patients with visceroptosis. Methods We studied 69 patients (mean age 22.28±3.7 years) with splanchnoptosis (visceroptosis) and 52 age- and sex- matched patients without splanchnoptosis (controls). Exclusion criteria: a history of digestive system surgery of taking blood circulation activating drugs. Doppler ultrasonography of the common hepatic artery, splenic artery, superior mesenteric artery, portal vein was performed on an empty stomach and 30 minutes after a food sample (standardized for proteins (14 g), fats (10 g) and carbohydrates (45 g)) using the Sonoace-8000 ultrasound scanner (Medison, South Korea). The data were analyzed using the Statistica-6 packages. Results There were no differences in hemodynamic parameters of fasting abdominal blood flow (ABF). After a food testing, in the postprandial period the ABF in all vessels in patients with splanchnoptosis was lower than in controls: the portal vein blood flow (BF) 1124,0 [1030,0–1419,0] ml/min vs 1373,0 [1136,0–1567,5] ml/min respectively (U=433,5; Z=−2,1; p=0,0342); the common hepatic artery BF 341,0 [295,0–394,0] ml/min vs 412,0 [331,0–521,0] ml/min respectively (U=335,0; Z=−2,3; p=0,0218); the splenic artery BF 396,0 [292,0–538,0] ml/min vs 502,0 [394,0–594,0] ml/min respectively (U=328,0; Z=−2,1; p=0,0399); the superior mesenteric artery BF 988,0 [837,0–1272,0] ml/min vs 1136,5 [992,0–1465,0] ml/min respectively (U=1625,5; Z=−2,2; p=0,0314). Changes in ABF were correlated with splanchnoptosis: the portal vein BF with any ptosis (rs=−0,21; p<0.05), the common hepatic artery BF with gastroptosis (rs=−0,38; p<0.05), the superior mesenteric artery BF with colonoptosis (rs=−0,86; p<0.05). The peripheral vascular resistance was correlated with the common hepatic artery BF (rs=−0,46; p<0.05), with the splenic artery BF (rs=−0,33; p<0.05) and with the superior mesenteric artery BF (rs=−0.79; p<0.05). Conclusions Patients with splanchnoptosis in the postprandial period have low volumetric BF in abdominal aorta vessels. This can be associated with the length of the mesenteric vessels, which undergoes the greatest changes in splanchnoptosis. Food testing reveals latent BF deficit in patients with splanchnoptosis. FUNDunding Acknowledgement Type of funding sources: None.

Dietary Fat Chain Length, Saturation, and PUFA Source Acutely Affect Diet-Induced Thermogenesis but Not Satiety in Adults in a Randomized, Crossover Trial

Structural differences in dietary fatty acids modify their rate of oxidation and effect on satiety, endpoints that may influence the development of obesity. This study tests the hypothesis that meals containing fat sources with elevated unsaturated fats will result in greater postprandial energy expenditure, fat oxidation, and satiety than meals containing fats with greater saturation. In a randomized, 5-way crossover design, healthy men and women (n = 23; age: 25.7 ± 6.6 years; BMI: 27.7 ± 3.8 kg/m2) consumed liquid meals containing 30 g of fat from heavy cream (HC), olive oil (OO), sunflower oil (SFO), flaxseed oil (FSO), and fish oil (FO). Energy expenditure and diet-induced thermogenesis (DIT) were determined by metabolic rate over a 240 min postprandial period. Serum concentrations of ghrelin, glucose, insulin, and triacylglycerol (TAG) were assessed. DIT induced by SFO was 5% lower than HC and FO (p = 0.04). Energy expenditure and substrate oxidation did not differ between fat sources. Postprandial TAG concentrations were significantly affected by fat source (p = 0.0001). Varying fat sources by the degree of saturation and PUFA type modified DIT but not satiety responses in normal to obese adult men and women.

The influence of nutritional state on the fatty acid composition of circulating lipid fractions: implications for their use as biomarkers of dietary fat intake

Background: The fatty acid (FA) composition of blood can be used as an objective biomarker of dietary FA intake. It remains unclear how the nutritional state influences the FA composition of plasma lipid fractions, and thus their usefulness as biomarkers in a non-fasted state. Objectives: To investigate the associations between palmitate, oleate and linoleate in plasma lipid fractions and self-reported dietary FA intake, and assess the influence of meal consumption on the relative abundance of these FA in plasma lipid fractions (i.e. triglyceride [TG], phospholipids [PLs] and cholesterol esters [CEs]). Design: Analysis was performed in plasma samples collected from 49 (34 males and 15 females) participants aged 26–57 years with a body mass index (BMI) between 21.6 and 34.2 kg/m2, all of whom had participated in multiple study visits, thus a pooled cohort of 98 data sets was available for analysis. A subset (n = 25) had undergone nutritional interventions and was therefore used to investigate the relationship between the FA composition of plasma lipid fractions and dietary fat intake. Results: Significant (P < 0.05) positive associations were observed between dietary polyunsaturated fat and linoleate abundance in plasma CE. When investigating the influence of meal consumption on postprandial FA composition, we found plasma TG palmitate significantly (P < 0.05) decreased across the postprandial period, whereas oleate and linoleate increased. A similar pattern was observed in plasma PL, whereas linoleate abundance decreased in the plasma CE. Conclusion: Our data demonstrate that the FA composition of plasma CE may be the lipid fraction to utilise as an objective biomarker when investigating recent (i.e. previous weeks-months) dietary FA intakes. In addition, we show that the consumption of a high-fat meal influences the FA composition of plasma TG, PL and CE over the course of the postprandial period, and therefore, suggest that fasting blood samples should be utilised when using FA composition as a biomarker of dietary FA intake.

Dietary Patterns During Lactation and Human Milk Composition and Quantity: A NESR Systematic Review

Objectives To inform the Dietary Guidelines for Americans, 2020–2025, the USDA and HHS identified important public health questions to be examined by the 2020 Dietary Guidelines Advisory Committee. The Committee conducted a systematic review with support from the USDA's Nutrition Evidence Systematic Review (NESR) team to answer the question: What is the relationship between dietary patterns consumed during lactation and human milk composition and quantity? Methods The Committee developed protocols to describe how they would use NESR's SR methodology to examine the evidence related to dietary patterns (DP) during lactation and human milk (HM). NESR librarians conducted a literature search and NESR analysts dual-screened the results using pre-defined inclusion and exclusion criteria to identify articles published between 2000 and 2019. NESR analysts extracted data from and assessed the risk of bias of included studies. The Committee synthesized the evidence, developed conclusion statements, and graded the strength of the evidence. Results This systematic review included 7 articles. Three articles from 2 cross-sectional studies examined DP and HM, while 4 articles from 3 randomized controlled trials examined diets based on macronutrient distributions and HM. The body of evidence was limited by small sample sizes, risk of bias concerns, heterogeneous methods, and study populations with limited racial/ethnic and socioeconomic diversity. Conclusions Limited evidence suggests that maternal consumption of diets higher in fat (&gt;35% fat) and lower in carbohydrate during lactation is related to higher total fat in HM collected in the maternal postprandial period. Limited evidence suggests that certain maternal DP during lactation, including diets based on macronutrient distributions, are related to the relative proportions of saturated fat and monounsaturated fatty acids in HM, and of polyunsaturated fatty acids in HM collected in the maternal postprandial period. Insufficient or no evidence was available to assess the association between DP during lactation and HM quantity, as well as total protein, water- and fat-soluble vitamins, minerals, human milk oligosaccharides, and bioactive proteins in HM. Funding Sources USDA, Food and Nutrition Service, Center for Nutrition Policy and Promotion.

In Vivo Digestion of Egg Products Enriched with DHA: Effect of the Food Matrix on DHA Bioavailability

The aim of the present study was to determine to what extent the food matrix could affect the release of docosahexaenoic acid (DHA) during digestion and its incorporation into systemic circulation. In this aim, three DHA-enriched egg products having the same composition but different structure were developed: omelet, hard-boiled egg, and mousse. Then, nine pigs fitted with T-shape cannulas at duodenal level and a jugular venous catheter were fed with the DHA-enriched egg products, and duodenal effluents and plasma were collected throughout the postprandial period. Results highlighted an undeniable effect of the food matrix on digestion parameters and DHA bioavailability. The transit of DHA and protein through the duodenum was faster after the ingestion of the mousse than after the ingestion of the omelet and hard-boiled egg. While most of the DHA and protein ingested under the form of mousse had already passed through the duodenum 4.5 h after its ingestion, significantly higher quantities were still present in the case of the omelet and hard-boiled egg. In terms of bioavailability, the omelet was the most efficient vector for delivering DHA into systemic circulation. It supplied 56% and 120% more DHA than the hard-boiled egg and the mousse, respectively.

Lkb1 suppresses amino acid-driven gluconeogenesis in the liver

Excessive glucose production by the liver is a key factor in the hyperglycemia observed in type 2 diabetes mellitus (T2DM). Here, we highlight a novel role of liver kinase B1 (Lkb1) in this regulation. We show that mice with a hepatocyte-specific deletion of Lkb1 have higher levels of hepatic amino acid catabolism, driving gluconeogenesis. This effect is observed during both fasting and the postprandial period, identifying Lkb1 as a critical suppressor of postprandial hepatic gluconeogenesis. Hepatic Lkb1 deletion is associated with major changes in whole-body metabolism, leading to a lower lean body mass and, in the longer term, sarcopenia and cachexia, as a consequence of the diversion of amino acids to liver metabolism at the expense of muscle. Using genetic, proteomic and pharmacological approaches, we identify the aminotransferases and specifically Agxt as effectors of the suppressor function of Lkb1 in amino acid-driven gluconeogenesis.

Effect of Acute Sprint Exercise on Myokines and Food Intake Hormones in Young Healthy Men

Physical exercise is known to influence hormonal mediators of appetite, but the effect of short-term maximal intensity exercise on plasma levels of appetite hormones and cytokines has been little studied. We investigated the effect of a 30 s Wingate Test, followed by a postprandial period, on appetite sensations, food intake, and appetite hormones. Twenty-six physically active young males rated their subjective feelings of hunger, prospective food consumption, and fatigue on visual analogue scales at baseline, after exercise was completed, and during the postprandial period. Blood samples were obtained for the measurement of nesfatin-1, ghrelin, leptin, insulin, pancreatic polypeptide (PP), human growth factor (hGH) and cytokine interleukin-6 (IL-6), irisin and plasma lactate concentrations, at 30 min before exercise, immediately (210 s) after exercise, and 30 min following a meal and at corresponding times in control sedentary males without ad libitum meal intake, respectively. Appetite perceptions and food intake were decreased in response to exercise. Plasma levels of irisin, IL-6, lactate, nesfatin-1 and ghrelin was increased after exercise and then it was returned to postprandial/control period in both groups. A significant rise in plasma insulin, hGH and PP levels after exercise was observed while meal intake potentiated this response. In conclusion, an acute short-term fatiguing exercise can transiently suppress hunger sensations and food intake in humans. We postulate that this physiological response involves exercise-induced alterations in plasma hormones and the release of myokines such as irisin and IL-6, and supports the notion of existence of the skeletal muscle–brain–gut axis. Nevertheless, the detailed relationship between acute exercise releasing myokines, appetite sensations and impairment of this axis leading to several diseases should be further examined.