Weight loss from caloric restriction vs Roux-en-Y gastric bypass surgery differentially regulates systemic and portal vein GDF15 levels in obese Zucker fatty rats

Gastric bypass surgery weight loss-independently induces gut Il-22 release in association with improved glycemic control in obese Zucker fatty rats

“…Experiments on Il-22 deficient mice are needed to prove that Il-22 mediates the weight loss-independent improvements in glycemic control after RYGB. Notably, we previously found that portal vein and systemic plasma levels of the anorexigenic cytokine growth differentiation factor 15 (GDF15) is increased in the same RYGB rats analyzed in the present study, and in a manner that correlates with their body weight and food intake [ 20 ]. This raises the possibility that different cytokines may account for distinct metabolic benefits of RYGB.…”

“…Rats were individually housed under ambient humidity and a temperature of 22 °C in a 12-h light/dark cycle with free access to tap water and Purina 5008 Lab diet (Purina Mills, USA, 4.15 kcal/g, 16.7% of kcal from fat) unless otherwise stated. Part of the phenotypic data from these animals has previously been reported [ 19 , 20 ]. All experiments were reviewed and approved by the Animal Care Committee of the local government of Unterfranken, Bavaria, Germany (License 55.2–2531.01–72/12).…”

“…Further, the potential source of Il-22 was not addressed in these studies, nor was its relationship with improvements in metabolic health after RYGB. To address this gap in knowledge, we re-analyzed portal vein plasma and systemic plasma samples taken from genetically obese and glucose intolerant RYGB-operated Zucker fatty rats compared with sham-operated obese and body weight-matched (BWM) controls [ 19 , 20 ].…”

Multiple micronutrient deficiencies as a long-term complication of bariatric surgery

“…However, one of the consequences of bariatric surgeries is that it causes or exacerbates nutritional deficiencies 2. Mechanisms that explain why bariatric surgery leads to nutritional deficiencies include alteration to the intestinal anatomy and gut microbial environment as well as dysregulation of enzymes and hormones 3…”