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The effect of pre-resection obesity on post-resection body composition after 75% small bowel resection in rats. Sci Rep 2021; 11:13009. [PMID: 34155300 PMCID: PMC8217239 DOI: 10.1038/s41598-021-92510-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 06/03/2021] [Indexed: 11/08/2022] Open
Abstract
In patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. Rats (CD IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. Preoperative body weight was 884 ± 95 versus 741 ± 75 g, and preoperative percent body fat was 35.8 ± 3.9 versus 24.9 ± 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% versus 5% decrease in high-fat versus low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. The high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.
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Li M, Liu Z, Qian B, Liu W, Horimoto K, Xia J, Shi M, Wang B, Zhou H, Chen L. "Dysfunctions" induced by Roux-en-Y gastric bypass surgery are concomitant with metabolic improvement independent of weight loss. Cell Discov 2020; 6:4. [PMID: 32025334 PMCID: PMC6985254 DOI: 10.1038/s41421-019-0138-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 12/03/2019] [Indexed: 12/19/2022] Open
Abstract
Metabolic surgery has been increasingly recommended for obese diabetic patients, but questions remain as to its molecular mechanism that leads to improved metabolic parameters independently of weight loss from a network viewpoint. We evaluated the role of the Roux limb (RL) in Roux-en-Y gastric bypass (RYGB) surgery in nonobese diabetic rat models. Improvements in metabolic parameters were greater in the long-RL RYGB group. Transcriptome profiles reveal that amelioration of diabetes state following RYGB differs remarkably from both normal and diabetic states. According to functional analysis, RYGB surgery significantly affected a major gene group, i.e., the newly changed group, which represented diabetes-irrelevant genes abnormally expressed after RYGB. We hypothesize that novel "dysfunctions" carried by this newly changed gene group induced by RYGB rebalance diabetic states and contribute to amelioration of metabolic parameters. An unusual increase in cholesterol (CHOL) biosynthesis in RL enriched by the newly changed group was concomitant with ameliorated metabolic parameters, as demonstrated by measurements of physiological parameters and biodistribution analysis using [14C]-labeled glucose. Our findings demonstrate RYGB-induced "dysfunctions" in the newly changed group as a compensatory role contributes to amelioration of diabetes. Rather than attempting to normalize "abnormal" molecules, we suggest a new disease treatment strategy of turning "normal" molecules "abnormal" in order to achieve a new "normal" physiological balance. It further implies a novel strategy for drug discovery, i.e. targeting also on "normal" molecules, which are traditionally ignored in pharmaceutical development.
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Affiliation(s)
- Meiyi Li
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
- Institute of Fudan-Minhang Academic Health System, Minhang Hospital, Fudan University, Shanghai, 201199 China
| | - Zhiyuan Liu
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
| | - Bangguo Qian
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
| | - Weixin Liu
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
| | - Katsuhisa Horimoto
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Jie Xia
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
| | - Meilong Shi
- Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011 China
| | - Bing Wang
- Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011 China
| | - Huarong Zhou
- Sherman College of Chiropractic, Boiling Springs, SC 29316 USA
| | - Luonan Chen
- Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy Sciences, Shanghai, 200031 China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223 China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 200031 China
- Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai, 201210 China
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Celiker H. A new proposed mechanism of action for gastric bypass surgery: Air hypothesis. Med Hypotheses 2017; 107:81-89. [PMID: 28915970 DOI: 10.1016/j.mehy.2017.08.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/02/2017] [Accepted: 08/08/2017] [Indexed: 02/07/2023]
Abstract
Roux-en-Y gastric bypass (RYGB) surgery is one of the most effective treatments for obesity and type II diabetes. RYGB was originally believed to work by mechanically restricting caloric intake or causing macronutrient malabsorption. However, such mechanical effects play no role in the remarkable efficacy of gastric bypass. Instead, mounting evidence shows that altered neuroendocrine signaling is responsible for the weight reducing effects of RYGB. The exact mechanism of this surgical response is still a mystery. Here, we propose that RYGB leads to weight loss primarily by inducing a functional shift in the gut microbiome, manifested by a relative expansion of aerobic bacteria numbers in the colon. We point to compelling evidence that gastric bypass changes the function of the microbiome by disrupting intestinal gas homeostasis, causing excessive transit of swallowed air (oxygen) into the colon.
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Affiliation(s)
- Hasan Celiker
- Xeno Biosciences Inc., 12 Mt Auburn St #7, Cambridge, MA, USA.
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