Modeling of enzymatic processes in the duodenum to predict areas with elevated risks of functional disorders
M.R. Kamaltdinov
Federal Scientific Center for Medical and Preventive Health Risk Management Technologies, 82 Monastyrskaya Str., Perm, 614045, Russian Federation
The present work focuses on developing a model of the duodenum considering motility, biochemical reactions occurring under effects produced by secreted digestive juices, and absorption of reaction products in normal conditions and in case of functional disorders. Analysis of literature sources allowed identifying basic bile components and pancreatic and intestinal juice enzymes influencing fats, proteins and carbohydrates that enter the duodenum.
The paper provides a simplified scheme showing how food components are transformed allowing for the neural-humoral mechanism of digestion regulation. Chyme that enters the duodenum is considered a homogenous mixture, which changes its composition during chemical reactions. Mathematical tasking includes mass and momentum conservation equations for a multi-component viscous fluid. The secretion of digestive juices and absorption of components resulting from chemical reactions are described with mass effluents in a pipe in the wall layer. The peristaltic law of the duodenum wall movement was applied to describe the tract motility; the movement characteristics do not depend on the composition of the mixture.
Numeric experiments produced necessary results to describe the hydrolysis of the 5 % starch solution under exposure to pancreatic amylase. Obviously, not all the amount of starch enters a chemical reaction and this is well in line with experimental data. The paper provides data on concentration fields for the components of glucose, amylase, and starch at different moments in time and the fluid velocity field.
The next stage in the model development is expected to consider absorption of food components, functional disorders of secretion / absorption and intestinal motility as well as influence exerted by neural and humoral mechanisms. In future, the developed model can be applied to predict areas with elevated risks of developing functional disorders, ulcer formation, and other defects of the intestinal mucosa. This will help a physician to prescribe personified therapy and diet.
- Denisov S.D., Kovalenko V.V. Anatomic characteristic of human duodenum’s relief of mucosa. Meditsinskie novosti, 2013, no. 11, pp. 11–15 (in Russian).
- Sherbatykh A.V., Reut A.A., Markelov O.A., Kuznetsov S.M. Hormonal function of duodenum in norm and pathology. Sibirskii meditsinskii zhurnal (Irkutsk), 1998, vol. 14, no. 3, pp. 5–9 (in Russian).
- Litovskii I.A., Gordienko A.V. Gastroduodenal'nye yazvy i khronicheskii gastrit (gastroduodenit). Diskussionnye vo-prosy patogeneza, diagnostiki, lecheniya [Gastroduodenal ulcers and chronic gastritis (gastroduodenitis). Controversial issues of pathogenesis, diagnosis, treatment]. Saint Petersburg, OOO «Izd-vo «SpetsLit», 2017, 304 p. (in Russian).
- Lam S.K. Pathogenesis and pathophysiology of duodenal ulcer. Clin. Gastroenterol., 1984, vol. 13, no. 2, pp. 447–472.
- Mezentseva L.V., Pertsov S.S. Mathematical modeling in biomedicine. Vestnik novykh meditsinskikh tekhnologii, 2013, vol. 20, no. 1, pp. 11–13 (in Russian).
- Harrison S.M., Cleary P.W., Sinnott M.D. Investigating mixing and emptying for aqueous liquid content from the stom-ach using a coupled biomechanical-SPH model. Food Funct., 2018, vol. 9, no. 6, pp. 3202–3219. DOI: 10.1039/c7fo01226h
- Ishida S., Miyagawa T., O'Grady G., Cheng L.K., Imai Y. Quantification of gastric emptying caused by impaired co-ordination of pyloric closure with antral contraction: a simulation study. J. R. Soc. Interface, 2019, vol. 16, no. 157, pp. 20190266. DOI: 10.1098/rsif.2019.0266
- Kamaltdinov M., Zaitseva N., Trusov P. A mathematical model of the multiphase flow in the antroduodenum: consid-eration of the digestive enzymes and regulation processes. Series on Biomechanics, 2018, vol. 32, no. 3, pp. 36–42.
- Fullard L.A., Lammers W.J., Ferrua M.J. Advective mixing due to longitudinal and segmental contractions in the ileum of the rabbit. Journal of Food Engineering, 2015, vol. 160, pp. 1–10. DOI: 10.1016/j.jfoodeng.2015.03.017
- Li C., Xiao J., Chen X.D., Jin Y. Mixing and emptying of gastric contents in human-stomach: A numerical study. J. Biomech., 2021, vol. 118, pp. 110293. DOI: 10.1016/j.jbiomech.2021.110293
- Li C., Jin Y. A CFD model for investigating the dynamics of liquid gastric contents in human-stomach induced by gas-tric motility. Journal of Food Engineering, 2021, vol. 296, pp. 110461. DOI: 10.1016/j.jfoodeng.2020.110461
- Sinnott M.D., Cleary P.W., Harrison S.M. Peristaltic transport of a particulate suspension in the small intestine. Applied Mathematical Modelling, 2017, vol. 44, pp. 143–159. DOI: 10.1016/j.apm.2017.01.034
- Palmada N., Cater J.E., Cheng L.K., Suresh V. Modelling Flow and Mixing in the Proximal Small Intestine. Annu. Int. Conf. IEEE Eng. Med. Biol. Soc., 2020, pp. 2496–2499. DOI: 10.1109/EMBC44109.2020.9176688
- Zha J., Zou S., Hao J., Liu X., Delaplace G., Jeantet R., Dupont D., Wu P. [et al.]. The role of circular folds in mixing intensification in the small intestine: A numerical study. Chemical Engineering Science, 2021, vol. 229, pp. 116079. DOI: 10.1016/j.ces.2020.116079
- Hari B., Bakalis S., Fryer P. Computational modeling and simulation of the human duodenum. Excerpt from the Proceedings of the 2012 COMSOL Conference in Milan, 2012. Available at: https://www.comsol.com/paper/download/151975/hari_paper.pdf (15.03.2022).
- Boychuk I. Peristaltic transportation of a viscous liquid in cylindrical tubes. Vestnik KHNADU, 2005, no. 29, pp. 142–143 (in Russian).
- Ankudinova S.A., Novokshonova Y.Y., Toigonbekov A.K. Motorno-evakuatornye narusheniya verkhnikh otdelov kishechnika u bol'nykh, operirovannykh po povodu raka zheludka [Motor-evacuation violations of the upper sections. intestines in patients operated for gastric cancer]. Vestnik KRSU, 2012, vol. 12, no. 2, pp. 35–37 (in Russian).
- Brayer G.D., Sidhu G., Maurus R., Rydberg E.H., Braun C., Wang Y., Nguyen N.T., Overall C.M., Withers S.G. Sub-site mapping of the human pancreatic alpha-amylase active site through structural, kinetic, and mutagenesis techniques. Biochemistry, 2000, vol. 39, no. 16, pp. 4778–4791. DOI: 10.1021/bi9921182
- Stiefel D.J., Keller P.J. Preparation and some properties of human pancreatic amylase including a comparison with human parotid amylase. Biochim. Biophys. Acta, 1973, vol. 302, no. 2, pp. 345–361. DOI: 10.1016/0005-2744(73)90163-0
- Tharakan A., Norton I.T., Fryer P.J., Bakalis S. Mass transfer and nutrient absorption in a simulated model of small in-testine. J. Food Sci., 2010, vol. 75, no. 6, pp. E339–E346. DOI: 10.1111/j.1750-3841.2010.01659.x