Understanding antral contraction in human stomach through comparison with soft elastic reactor
Résumé
Introduction
Human digestion, a major concern due to the rapid development of nutrition-related chronic diseases,
rely apart from enzymatic reactions on homogenization of the gastric content by antral contractions.
Although recent CFD studies made it possible to explore the influence of the rheological
properties of the gastric content on the efficiency of gastric mixing, this key step is yet far from being
fully understood.
Objective
This work aims at discussing the influences of contraction frequency and viscosity of the digesta
in human gastric mixing by comparison with the mixing efficiency of an innovative soft elastic reactor
(SER), that induces mixing by vibration of its wall in a similar way as antral contraction waves
(ACWs) promote stomach motility.
Methodology
In this view, the SER mixing curve, recently established by Delaplace et al. (2018) using a dimensional
analysis approach, was considered in order to determine the flow regime under which the
gastric mixing of foods (viscosity ranging from 10-3 to 1 Pa.s) was performed
Main findings
It was shown that depending on the viscosity of the SER/stomach content and the amplitude of penetration/
ACWs, the number of strikes/contractions required to achieve homogenization was largely
different. Moreover, the operating points of SER and ACWs mixing were close, justifying the comparison
between both reactors.
Conclusion
Based on this, the level of mechanical solicitation provided by human peristalsis was shown to be
not as high as expected, and the mixing performance of distal region, confined in laminar regime,
was found limited and not only due to mechanical solicitations. Further efforts are needed to investigate
the role of other physiological processes such as gastric secretions and gastric emptying in
mixing performance of intragastric fluid homogenized by the antral contraction.
Format : Poster