Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Apr 27, 2016; 8(4): 301-307
Published online Apr 27, 2016. doi: 10.4240/wjgs.v8.i4.301
Effect of Roux-en-Y gastric bypass surgery on intestinal Akkermansia muciniphila
Ming Yan, Mao-Min Song, Ri-Xing Bai, Shi Cheng, Wen-Mao Yan
Ming Yan, Mao-Min Song, Ri-Xing Bai, Shi Cheng, Wen-Mao Yan, Department of General Surgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
Author contributions: Yan M, Song MM and Bai RX designed the research; Yan M, Bai RX and Yan WM performed the research and wrote the paper; Yan M and Yan WM contributed new reagents/analytic tools and analyzed the data.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital Affiliated to Capital Medical University.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Animal Ethical and Welfare Committee of Beijing Tiantan Hospital Affiliated to Capital Medical University (IACUC protocol number: EN-42532).
Conflict-of-interest statement: The authors declared that they have no conflicts of interest to this work.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Mao-Min Song, Professor, Department of General Surgery, Beijing Tiantan Hospital, Capital Medical University, No. 6, Tiantanxili Road, Beijing 100050, China. dryanming@hotmail.com
Telephone: +86-10-67096586
Received: November 2, 2015
Peer-review started: November 3, 2015
First decision: December 18, 2015
Revised: January 11, 2016
Accepted: January 29, 2016
Article in press: January 31, 2016
Published online: April 27, 2016
Abstract

AIM: To investigated changes in intestinal Akkermansia muciniphila (A. muciniphila) and explored the mechanism underlying the therapeutic effects of Roux-en-Y gastric bypass (RYGB) surgery on type 2 diabetes in diabetic Goto-Kakizaki (GK) rats.

METHODS: Male diabetic GK rats (n = 12) aged 8 wk were randomly assigned to the surgery group (GK-RYGB) or sham surgery group (GK-Sham) (n = 6 per group), and another 6 male Wistar rats aged 8 wk served as controls (WS-Sham). In the surgery group, RYGB surgery was conducted, and a sham operation was performed in both sham groups. Fasting blood glucose (FBG) levels before and after surgery, fasting levels of serum insulin and serum glucagon-like peptide-1 (GLP-1) and levels 30 min after intragastric injection of glucose, and the amount of A. muciniphila in the stool were determined. Insulin and GLP-1 were measured by enzyme-linked immunosorbent assay, and A. muciniphila were detected by fluorescence-based quantitative polymerase chain reaction.

RESULTS: The FBG was improved, and serum GLP-1 and insulin increased significantly (P < 0.05) in the GK-RYGB group after surgery compared to levels before surgery and to levels in the GK-Sham group. Before surgery, the amounts of A. muciniphila in the GK-RYGB and GK-Sham groups were significantly lower than in the WS-Sham group (P < 0.05). After surgery, the amount of A. muciniphila in the GK-RYGB group increased markedly compared to that before surgery and to that in the GK-Sham and WS-Sham groups (P < 0.05). In addition, the A. muciniphila amount was positively related to GLP-1 (r = 0.86, P < 0.05).

CONCLUSION: Our results demonstrated RYGB surgery may increase GLP-1 secretion, elevate serum insulin after intragastric injection of glucose, and improve insulin resistance in diabetic GK rats, thereby contributing to a significant reduction in blood glucose. The increased amount of A. muciniphila after RYGB surgery may be related to elevated GLP-1 secretion.

Keywords: Roux-en-Y gastric bypass surgery, Type 2 diabetes, Glucagon-like peptide-1, Glucose-dependent insulinotropic peptide, Akkermansia mucinipilia

Core tip: Roux-en-Y gastric bypass (RYGB) surgery can improve blood glucose with definite efficacy in obese patients with type 2 diabetes mellitus and that this effect is also long lasting. But the mechanism of RYGB is not clear. Our study demonstrated RYGB surgery may increase glucagon-like peptide-1 (GLP-1) secretion, elevate serum insulin after intragastric injection of glucose, and improve insulin resistance in diabetic Goto-Kakizaki rats, thereby contributing to a significant reduction in blood glucose. The increased amount of Akkermansia muciniphila after RYGB surgery may be related to elevated GLP-1 secretion.