Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression

Abstract

.2016.-We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2, and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated reduced energy absorption through the intestine. We propose that this mobilized energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adiposehypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway. whey proteins; gut microbiota MAMMALS ACHIEVE energy homeostasis by matching energy supply (from food consumed) with the summed energy demand of body tissues. This is achieved in part by sensing nutrient (energy) availability in the intestinal lumen, where their transport through a carrier-mediated mechanism in the circulatory system causes subsequent changes in the hypothalamic-and adipose-related mechanisms regulating energy balance (16,35,41). A growing body of evidence suggests that the gut microbiota also play important roles in energy balance regulation by influencing the related intestinal and hypothalamic cellular activities (10, 32) and by harvesting energy from ingested food and then providing it for host metabolism, including storage in the adipose tissue (3). Thus, in theory, manipulation of the gut microbiota, along with the intestinal nutrient-sensing and transport-related genes, has the potential to change the intestinal, hypothalamic, and adipose control of energy balance and body weight dynamics.Whey proteins, including bovine serum albumin (BSA) and lactoferrin, are constituents of milk (19), with the bovine form having been part of the human diet since at least the Bronze Age (51). Because these proteins are now increasingly being used in infant formula, and in food products to improve muscle mass in athletes and the elderly (18), there is a need to understand the impact of their ...

Dietary α-lactalbumin alters energy balance, gut microbiota composition and intestinal nutrient transporter expression in high-fat diet-fed mice

“…Cumulative energy intake, one-way ANOVA: F (2,22) =81·7 ( P <0·001 followed by Bonferroni's post hoc test). Hypothalamic gene expression, one-way ANOVA: pomc F (2,22) =9·2 ( P <0·01); npy F (2,22) =2·8 ( P =0·079); ghsR F (2,22) =9·8 ( P <0·01); all followed by Bonferroni's post hoc test except npy . (a, b) , LFD-CAS; , HFD-CAS; , HFD-LAB.…”

“…In addition, we showed that WPI reduced epididymal white adipose tissue (eWAT) weight and the overall body weight gain. Consistent with changes in the gut, WPI increased energy intake, which was reflected in the altered hypothalamic gene expression of neuropeptides, namely, proopiomelanocortin ( pomc ), neuropeptide Y ( npy ) and ghrelin ( 22 ) .…”

“…This effect might be attributed to an altered composition of the gut microbiota involved in energy harvest, since other studies have shown that dietary whey proteins can influence the composition of the gut microbiota ( 21 – 24 ) . Indeed, we showed that WPI reduced the proportion of Firmicutes in the mouse gut microbiome ( 22 ) , and this was accompanied by a reduction in the expression of intestinal nutrient transporters, specifically glut2 and fatp4 . In addition, we showed that WPI reduced epididymal white adipose tissue (eWAT) weight and the overall body weight gain.…”

The Appetite−Suppressant and GLP-1-Stimulating Effects of Whey Proteins in Obese Subjects are Associated with Increased Circulating Levels of Specific Amino Acids

“…Among different sources of proteins, whey proteins seem to be the most effective [4]. Several mechanisms have been invoked to explain the appetite-suppressant and weight-losing effects that whey proteins produce when administered to normal weight or obese subjects [5]: secretion of gastrointestinal anorexigenic peptides [6][7][8][9], stimulation of energy expenditure via an increased thermogenesis [10], and direct actions on specific hypothalamic areas involved in the regulation of food intake [11].…”

Effects of endurance training and herb supplementation on tissue nesfatin-1/nucleobindin-2 and ghrelin mRNA expression

“…In contrast to nesfatin-1, ghrelin as an orexigenic peptide increase food intake behavior during energy deficiencies status/negative energy balance situations (starvation, fasting, cachexia, malnutrition, weight reduction, calorie restriction, eating disorders) [32][33][34]. In addition, to energy regulation matter, it has been shown that different nutrients manipulation has also impact on ghrelin levels and gene expression [35,36]. A varieties of actions for ghrelin on different bodily system, energy regulation, metabolic functions, regulatory action on some appetite peptides, and some other function have been mentioned [26,37].…”