Effect of different bariatric surgeries on dietary protein bioavailability in rats.

This study aims at evaluating dietary protein bioavailability after different bariatric surgeries in rats. Diet-induced, obese Wistar rats were operated for vertical sleeve gastrectomy (VSG), Roux-en-Y gastric bypass (RYGB). The control group was composed of pair-fed, sham-operated rats (Sham). Two weeks after surgery, rats were fed a 15N protein meal. Protein bioavailability was assessed by determination of 15N recovery in the gastrointestinal tract and organs 6 h after the meal. Fractional protein synthesis rate (FSR) was assessed using a flooding dose of 13C valine. Weight loss was the highest in RYGB and the lowest in Sham. Surprisingly, RYGB (95.6 ± 0.7%) improved protein digestibility (P=0.045) compared to Sham (93.5 ± 0.5%) and VSG (93.8 ± 0.6%). In contrast, 15N retained in the liver (P=0.001) and plasma protein (P=0.037) was lower than in Sham, with a similar trend in muscle (P=0.052). FSR was little altered by bariatric surgery except for a decrease in the kidney of RYGB (P = 0.02). The 15N distribution along the small intestinal tissue suggests that dietary nitrogen was considerably retained in the remodeled mucosa of RYGB compared to Sham. This study revealed that in contrast to VSG, RYGB slightly improved protein digestibility but altered peripheral protein bioavailability. This effect may be ascribed to a higher uptake of dietary amino acids by the remodeled intestine. PMID: 31460792 [PubMed - as supplied by publisher]
Source: American Journal of Physiology. Gastrointestinal and Liver Physiology - Category: Physiology Authors: Tags: Am J Physiol Gastrointest Liver Physiol Source Type: research