Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study

doi:10.1016/j.cjche.2024.12.014

Chinese Journal of Chemical Engineering ›› 2025, Vol. 81 ›› Issue (5): 76-86.DOI: 10.1016/j.cjche.2024.12.014

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Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study

Yulan Zhao¹, Yifan Qin², Xiao Dong Chen¹, Jie Xiao¹

1. School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China;
2. Department of Chemical Engineering and Biological Engineering, Monash University, Melbourne 3800, Australia

Received:2024-08-20 Revised:2024-12-08 Accepted:2024-12-19 Online:2025-03-07 Published:2025-05-28
Contact: Jie Xiao,E-mail:jie.xiao@suda.edu.cn
Supported by:
We are grateful for the financial support from the National Natural Science Foundation of China (21978184), the “Jiangsu Innovation and Entrepreneurship (Shuang Chuang) Program”, the “Jiangsu Specially-Appointed Professors Program”, and the “Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions”.

Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study

Yulan Zhao¹, Yifan Qin², Xiao Dong Chen¹, Jie Xiao¹

1. School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China;
2. Department of Chemical Engineering and Biological Engineering, Monash University, Melbourne 3800, Australia

通讯作者: Jie Xiao,E-mail:jie.xiao@suda.edu.cn
基金资助:
We are grateful for the financial support from the National Natural Science Foundation of China (21978184), the “Jiangsu Innovation and Entrepreneurship (Shuang Chuang) Program”, the “Jiangsu Specially-Appointed Professors Program”, and the “Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions”.

Abstract

Abstract: Up to now, how the secretion modes of intestinal fluid (i.e., pancreaticobiliary secretion and wall secretion) can regulate intestinal acid-base environment has not been fully understood. Understanding the regulation mechanism is not only of great significance for intestinal health but may also lead to optimized designs for bio-inspired soft elastic reactors (SERs). In this work, the mixing and reaction of acidic gastric juice and alkaline intestinal fluid in a 3D duodenum with moving walls were modelled. A unique feature of this model is the implementation of both pancreaticobiliary and wall secretion of intestinal fluid as boundary conditions. This model allowed us to quantitatively explore the influence of secretion modes on pH regulation. The results demonstrated that coexistence of both pancreaticobiliary and wall secretions is the key to maintain the average pH in the duodenum at about 7.4. Their coexistence synergistically promotes the mixing and reaction of acid-base digestion liquids and provides a suitable catalytic environment for lipase in the intestine.

Key words: Mixing, Bioreactor, Computational fluid dynamics (CFD), Acid-base environment, Intestinal physiology

摘要： Up to now, how the secretion modes of intestinal fluid (i.e., pancreaticobiliary secretion and wall secretion) can regulate intestinal acid-base environment has not been fully understood. Understanding the regulation mechanism is not only of great significance for intestinal health but may also lead to optimized designs for bio-inspired soft elastic reactors (SERs). In this work, the mixing and reaction of acidic gastric juice and alkaline intestinal fluid in a 3D duodenum with moving walls were modelled. A unique feature of this model is the implementation of both pancreaticobiliary and wall secretion of intestinal fluid as boundary conditions. This model allowed us to quantitatively explore the influence of secretion modes on pH regulation. The results demonstrated that coexistence of both pancreaticobiliary and wall secretions is the key to maintain the average pH in the duodenum at about 7.4. Their coexistence synergistically promotes the mixing and reaction of acid-base digestion liquids and provides a suitable catalytic environment for lipase in the intestine.

关键词: Mixing, Bioreactor, Computational fluid dynamics (CFD), Acid-base environment, Intestinal physiology

Yulan Zhao, Yifan Qin, Xiao Dong Chen, Jie Xiao. Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study[J]. Chinese Journal of Chemical Engineering, 2025, 81(5): 76-86.

Yulan Zhao, Yifan Qin, Xiao Dong Chen, Jie Xiao. Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study[J]. 中国化学工程学报, 2025, 81(5): 76-86.

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Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study

Acid-base regulation in duodenum by intestinal fluid secretion: A simulation study

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