Effect of Macronutrient Type and Gastrointestinal Release Site on PYY Response in Normal Healthy Subjects

Laxative Properties of Microencapsulated Oleic Acid Delivered to the Distal Small Intestine in Patients with Constipation after Bariatric Surgery or Treatment with Glucagon-Like- Peptide 1 Analogues

BACKGROUND

Constipation is prevalent after bariatric surgery and glucagon-like-peptide 1 (GLP-1) analogues. Increasing fat content in the distal small intestine and colon can enhance colonic peristalsis, potentially alleviating symptoms of constipation.

AIM

We investigated whether oleic acid can ameliorate constipation in patients undergoing bariatric surgery or receiving GLP-1 analogues.

METHODOLOGY

Fourteen adults with chronic constipation according to Rome IV criteria following bariatric surgery or GLP-1 analogues were on stable treatment for constipation for more than 4 weeks. This randomized double-blind crossover trial compared microcapsules containing 21.25 g of oleic acid delivered in the distal small intestine or the stomach. The primary outcome was changed in the number of bowel motions over 24 h. Exploratory endpoints included alterations in straining, diarrhoea, faecal leakage over 24 h and hunger, fullness, nausea and calorie intake for the 3 h after ingesting the microcapsules.

FINDINGS

Receiving oleic acid into the distal small intestine increased number of bowel movements per day (2.5 vs 1.1, p = 0.009) and caused softer stool consistency (p = 0.03). 9/14 of the control group passed motions and 13/14 of the intervention group passed motions in 24 h (p = 0.059). No significant differences were observed in straining (p = 0.65), rapid bowel movements (p = 0.08), accidental leakage (p = 0.32), hunger, fullness, nausea or food intake between the groups (all p > 0.05). There were no disparities in safety profile between groups.

CONCLUSION

Microcapsules containing oleic acid delivered to the distal small intestine appear to be a safe and effective relief from chronic constipation in patients undergoing bariatric surgery and/or receiving GLP-1 analogues.

The impacts and mechanisms of dietary proteins on glucose homeostasis and food intake: a pivotal role of gut hormones

Glucose and energy metabolism disorders are the main reasons induced type 2 diabetes (T2D) and obesity. Besides providing energy, dietary nutrients could regulate glucose homeostasis and food intake via intestinal nutrient sensing induced gut hormone secretion. However, reviews regarding intestinal protein sensing are very limited, and no accurate information is available on their underlying mechanisms. Through intestinal protein sensing, dietary proteins regulate glucose homeostasis and food intake by secreting gut hormones, such as glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY) and glucose-dependent insulinotropic polypeptide (GIP). After activating the sensory receptors, such as calcium-sensing receptor (CaSR), peptide transporter-1 (PepT1), and taste 1 receptors (T1Rs), protein digests induced Ca2+ influx and thus triggered gut hormone release. Additionally, research models used to study intestinal protein sensing have been emphasized, especially several innovative models with excellent physiological relevance, such as co-culture cell models, intestinal organoids, and gut-on-a-chips. Lastly, protein-based dietary strategies that stimulate gut hormone secretion and inhibit gut hormone degradation are proposed for regulating glucose homeostasis and food intake.

The effect of slow-release milk replacer feeding on health and behaviour parameters in dairy breed calves

The aim of this research paper was to evaluate the effect of a slow-release milk replacer on health and behaviour of neonatal dairy calves. This was done with the potential benefits to welfare during transport in mind. A total of 15 calves were randomly divided into three groups of 5, namely, a control group fed twice in 24 h with 3 l of a conventional milk replacer, a slow-release group fed once in 24 h with 2 l of conventional milk replacer and 1 litre of a specialised micro-encapsulated feed and an enriched-replacer group fed once in 24 h with 3 l of milk replacer enriched with micellar casein. Blood samples were taken before feeding and 6, 12, 18 and 24 h after and analysed for acid-base parameters, electrolytes, glucose, haemoglobin, cortisol, insulin, cholecystokinin and adiponectin. Calf behaviour was recorded between 6 and 14 h after feeding. There was a significant increase in blood pH 6 h after feeding in all groups, but the glucose, HCO3 - and base excess increased significantly in the slow-release group only, whereas sodium increased significantly in the enriched group only. Glucose levels remained significantly higher in the slow-release group, relative to the control, at 6, 12, and 18 h after feeding. Insulin levels changed significantly over time in the enriched and control group but remained constant in the slow-release group. Insulin levels were significantly higher in the control group when compared to the slow-release group after feeding. Adiponectin changed significantly over time after feeding in the control group only, but no significant changes were observed between the feeding groups. Behavioural patterns were similar in control and slow release groups but less favourable (less lying time, more vocalisations) in the enriched group. In conclusion, once-daily feeding of slow-release milk replacer demonstrated favourable patterns of blood variables related to satiety and hunger as well as behavioural patterns that did not differ from conventional twice-daily feeding.

Multiplexed Assay to Quantify the PP-Fold Family of Peptides in Human Plasma Using Microflow Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND

Peptide Tyr-Tyr (PYY1-36), pancreatic polypeptide (PP1-36) and neuropeptide Y (NPY1-36) constitute the PP-fold family of peptides that is involved in metabolic regulation. Very low plasma concentrations and cleavage into active 3-36 fragments challenge bioanalytical assays used for the quantification of these peptides.

METHODS

We developed a multiplexed isotopic dilution assay to quantify PYY1-36, PP1-36, and NPY1-36 and their dipeptidyl peptidase-4 (DPP4)-derived metabolites PYY3-36, PP3-36 and NPY3-36. All peptides were immunocaptured from plasma using a monoclonal antibody and quantified by micro-ultra-HPLC-MS/MS. Blood samples from healthy volunteers were collected fasting and 30 min after nutrient stimulation. Method comparison was performed with commercial immunoassays.

RESULTS

Linearity was shown in the measured intervals (r2 > 0.99). The lower limit of quantification (LLOQ) with a CV at 20% was 1.5 pM for PYY1-36 and PYY3-36, 3.0 pM for PP1-36 and PP3-36, 0.8 pM for NPY1-36 and 0.5 pM for NPY3-36. In all cases, intra- and inter-assay bias and imprecision were <21%. Pre-analytical stability required addition of a protease inhibitor cocktail. Physiological concentrations of PYY3-36, NPY3-36, PP1-36 and PP3-36 were above the LLOQ in 43% to 100% of the samples. PYY1-36 and NPY1-36 were above the LLOQ in 9% and 0% of the samples, respectively. Immunoassays showed higher concentrations of measurands and poor agreement when compared with micro-UHPLC-MS/MS.

CONCLUSIONS

The assay allowed for specific multiplexed analysis of the PP-fold family of peptides and their DPP4-cleaved fragments in a single sample, thereby offering new perspectives to study the role and therapeutic potential of these essential peptide hormones in health and metabolic disease.

[Regular consumption of a functional broth enriched with FOS increases the levels of hormones related to satiety in healthy people. A randomized, controlled clinical trial]

INTRODUCTION

excess weight represents a public health problem due to its associated risk factors. A sedentary lifestyle, an inadequate diet or a decrease in the feeling of satiety are some of the causes. Objetives: to evaluate the satiating properties of the consumption of a functional Iberian broth enriched with phospho-fructooligosaccharides (FOS) in healthy people through the plasma concentration of hormones involved in appetite.

MATERIAL AND METHOD

acute, crossover, randomized, double-blind and controlled nutritional clinical trial carried out in 18 randomized participants in two treatment sequences (functional broth (CF), composed of 5.6 g POS/100 g and control broth (CC), with 0.4 g of maltodextrin/100 g) with 14 days of washing in between. Satiety-related parameters (glucose, insulin, leptin, ghrelin, GLP-1, PYY) and visual analog scales (VAS) were measured.

RESULTS

the percentage of body fat decreased in those who took the CF (-0.15 ± 0.32 vs 0.09 ± 0.52) (p < 0.05). Leptin concentration was higher with CF (p < 0.001), which was shown at time points -30 (p < 0.001), 0 (p < 0.001), 30 (p = 0.026) and 120 (p = 0.049) when compared to CC. The areas under the curve (AUC) for GLP-1 (p = 0.0033) and PYY (p = 0.022) were higher for CF as compared to CC.

CONCLUSIONS

consumption of an Iberian broth enriched with POS improves the plasma concentration of hormones involved in the control of satiety, and reduces the amount of body fat. This result could have beneficial effects for the prevention and treatment of overweight.

Enteroendocrine Hormone Secretion and Metabolic Control: Importance of the Region of the Gut Stimulation

It is now widely appreciated that gastrointestinal function is central to the regulation of metabolic homeostasis. Following meal ingestion, the delivery of nutrients from the stomach into the small intestine (i.e., gastric emptying) is tightly controlled to optimise their subsequent digestion and absorption. The complex interaction of intraluminal nutrients (and other bioactive compounds, such as bile acids) with the small and large intestine induces the release of an array of gastrointestinal hormones from specialised enteroendocrine cells (EECs) distributed in various regions of the gut, which in turn to regulate gastric emptying, appetite and postprandial glucose metabolism. Stimulation of gastrointestinal hormone secretion, therefore, represents a promising strategy for the management of metabolic disorders, particularly obesity and type 2 diabetes mellitus (T2DM). That EECs are distributed distinctively between the proximal and distal gut suggests that the region of the gut exposed to intraluminal stimuli is of major relevance to the secretion profile of gastrointestinal hormones and associated metabolic responses. This review discusses the process of intestinal digestion and absorption and their impacts on the release of gastrointestinal hormones and the regulation of postprandial metabolism, with an emphasis on the differences between the proximal and distal gut, and implications for the management of obesity and T2DM.