Effects of Chicken Protein Hydrolysate (CPH) Supplementation in People With High Waist Circumference (CHICKPEP)

Randomized, Double Blind, Placebo Controlled Study to Investigate the Effect of Chicken Protein Hydrolysates (CPH) in Persons With High Waist Circumference

In this randomized, placebo controlled, double blind trial, effects of relatively high doses of chicken protein hydrolysate (CPH) or casein hydrolysate (placebo) supplementation will be investigate in healthy persons with abdominal obesity. The 12-week study examines potential effects on body weight, abdominal obesity, body composition, plasma parameters of metabolic health including lipids, inflammatory parameters, redox state and microbiota biomarkers.

Small peptides in the range of 2 - 12 amino acids are believed to cross the intestinal wall undigested and enter the circulation where they can have a range of activities based on their amino acid composition and structure. Natural peptides isolated from a number of food proteins, including plants and marine organisms, are shown to have antioxidant effects in in vitro tests, and anti-hypertensive effects in mice through inhibition of the angiotensin-converting-enzyme (ACE). Protein hydrolysates from both animal- and plant-based sources will consist of a mixture of potentially bioactive peptides that can have specific effects based on their composition. Studies have shown that egg- and soy-derived hydrolysates have anti-diabetic and anti-obesity properties in rodents. Pre-clinical studies in mice have demonstrated potent plasma cytokine lowering abilities and atherosclerosis-prevention by chicken protein hydrolysate (CPH) diets, as well as effects on plasma cholesterol level, cytokines and lipid metabolism, including mitochondrial function. In addition, an isolated peptide fraction from chicken inhibits the dipeptyl peptidase IV, and thus has the potential to restore glucose homeostasis in type 2 diabetics. The hydrolysate supplements used in this study are obtained from rest raw materials (RRM) from mechanical deboning of chicken meat (Food Grade, Nortura AS Hærland, Norway). Freshly minced chicken RRM has been treated with enzymes optimized to generate bioactive hydrolysates. The supplement is given in a dose of 18 g protein per day, corresponding to the protein content of a standard meal, and similar to doses recommended in protein shake supplements. Around 60 males and females age >20 years with abdominal obesity participate, recruited primarily through social media advertisements (Facebook) limited to a 12 km radius around the city center of Bergen. Participants provided written informed consent, and were screened via self-reporting in an online form in EasyTrial hosted by the Research Unit for Clinical Trials at the University of Bergen. Data collection by the study staff at baseline verifies inclusion and exclusion criteria and participant eligibility prior to randomization. The potential participants are informed about practical details at a digital or physical meeting 1-2 weeks prior to baseline. Groups of participants (40-60% males/females) are block randomized to the two treatments (CPH or placebo casein supplementation) using randomly selected block sizes, and stratified according to sex. The participants are given a container with the powder sufficient for the entire 12-week study period, and a spoon to measure the intake at breakfast (6 g), lunch (6 g) and supper (6 g), or morning (9 g) and evening (9 g) according to individual preference. The patients will mix the powder products in water or mineral water.

Daily oral self-administration of 18 g of supplement dissolved in water/mineral water, spread over 2-3 occasions

Daily oral self-administration of 18 g of supplement dissolved in water/mineral water, spread over 2-3 occasions

Changes from baseline in waist circumference in the CPH group as compared to placebo/casein at week 12

Waist circumference will be measured using anthropometric tape over light clothing. For waist circumference, the minimum circumference between the iliac crest and the rib cage will be used.

Changes from baseline in glucagon-like peptide 1 (GLP-1, hormone involved in appetite and metabolism regulation) in the CPH group as compared to placebo/casein

Measured in plasma using immunological methods (ELISA). All plasma samples will be kept on ice directly after collection, and relevant inhibitors will be added.

Changes from baseline in gastric inhibitory polypeptide (GIP, hormone involved in metabolism regulation) in the CPH group as compared to placebo/casein

Measured in plasma using immunological methods (ELISA). All plasma samples will be kept on ice directly after collection, and relevant inhibitors will be added.

Changes from baseline in ghrelin (hormone involved in appetite regulation) in the CPH group as compared to placebo/casein

Measured in plasma using immunological methods (ELISA). All plasma samples will be kept on ice directly after collection, and relevant inhibitors will be added.

Waist and hip circumference will be measured using anthropometric tape over light clothing. For waist circumference, the minimum circumference between the iliac crest and the rib cage will be used. For hip circumference, the maximum measurement over the great trochanters will be used.

Height will be measured with a wall-mounted stadiometer. Waist circumference will be measured using anthropometric tape over light clothing. The minimum circumference between the iliac crest and the rib cage will be used.

Changes from baseline in the Quick1 surrogate marker forinsulin sensitivity in the CPH group as compared to placebo/casein

Glucose and insulin will be measured in serum by routine laboratories. Quick1 will be calculated by 1 / (log(fasting insulin μU/mL) + log(fasting glucose mg/dL)

Change from baseline in serum non-esterified fatty acids (NEFA) in the CPH group as compared to placebo/casein

Change from baseline in serum HDL cholesterol/LDL cholesterol size ratio in the CPH group as compared to placebo/casein

Changes in serum acetylcarnitine/palmitoylcarnitine ratio in the CPH group as compared to placebo/casein at week 12

Plasma choline, betaine, free carnitine and its precursors: trimethyllysine and γ-butyrobetaine, as well as short-, medium-, and long-chain acylcarnitines, will be analysed in serum using LC/MS/MS. Stable isotope dilution LC/MS/MS will be used for quantification of trimethylamine oxide (TMAO), dimethylglycine (DMG), choline and betaine. Plasma metabolites of the TCA cycle and amino acids-kynurenine-nicotinamide pathway will be measured by LC-MS.

Changes in serum TMAO (trimethylamine N-oxide) in the CPH group as compared to placebo/casein at week 12

Changes from baseline in the serum anti-inflammatory fatty acid index in the CPH group as compared to placebo at Week 12.

Fatty acid composition will be analysed using GC/MS. The anti-inflammatory fatty acid index is calculated as ((C22:5n-3 + C22:6n-3 + C20:3n-6 + C20:5n-3)/C20:4n-6)*100

Inclusion Criteria: Female and male subjects at least 20 years old understanding Norwegian oral and written information Waist circumference of: Men > 95 cm Women > 81 cm Exclusion Criteria: Pregnancy Having used high-dose omega-3 PUFA supplements (>2 g/day) 28 days' prior to randomization Alcohol or drug abuse or any conditions associated with poor compliance Scheduled hospitalization during the course of the study that could compromise the study Major diseases or infections including chronic diseases Known or suspected sensitivity or allergic reactions to the IMP or excipients Presence of other major medical or psychiatric illness that would affect the ability to participate in the study or put the subject at increased risk Intake of statins. If needed to obtain the recruitment goals, we will accept people using a low dose of statin. Simvastatin 10 mg or Pravastatin 10-20 mg will be accepted, but not higher doses or the drugs Lipitor/Atorvastatin and Crestor/Rosuvastatin.