Postprandial leucine and insulin responses and toxicological effects of a novel whey protein hydrolysate-based supplement in rats

The purpose of this study was: aim 1) compare insulin and leucine serum responses after feeding a novel hydrolyzed whey protein (wph)-based supplement versus a whey protein isolate (wpi) in rats during the post-absorptive state,and aim 2) to perform a thorough toxicological analysis on rats that consume different doses of the novel wph-based supplement over a 30-day period. in male wistar rats (~250 g,n = 40),serum insulin and leucine concentrations were quantified up to 120 min after one human equivalent dose of a wpi or the wph-based supplement. in a second cohort of rats (~250 g,n = 20),we examined serum/blood and liver/kidney histopathological markers after 30 days of feeding low (1human equivalent dose),medium (3 doses) and high (6 doses) amounts of the wph-based supplement. in aim 1,higher leucine levels existed at 15 min after wph vs. wpi ingestion (p = 0.04) followed by higher insulin concentrations at 60 min (p = 0.002). in aim 2,liver and kidney histopathology/toxicology markers were not different 30 days after feeding with low,medium,high dose wph-based supplementation or water only. there were no between-condition differences in body fat or lean mass or circulating clinical chemistry markers following the 30-day feeding intervention in aim 2. in comparison to wpi,acute ingestion of a novel wph-based supplement resulted in a higher transient leucine response with a sequential increase in insulin. furthermore,chronic ingestion of the tested whey protein hydrolysate supplement appears safe. © 2012 toedebusch et al.; licensee biomed central ltd.