Scientists create artificial stomach to understand digestion

Researchers have built a prototype of an artificial stomach to better understand how gastric juices in the stomach break down ingested food and other substances.

The scientists hope the findings could help in the effort to fight obesity and enhance drug absorption.

Not much is known about how the complex flow patterns and mechanical stresses produced in the stomach contribute to digestion.

Researchers from France, Michigan and Switzerland built a prototype of an artificial antrum, or lower stomach, to present a deeper understanding of how physical forces influence food digestion based on fluid dynamics. In Physics of Fluids, by AIP Publishing, they reveal a classifying effect based on the break-up of liquid drops combined with transport phenomena derived from complementary computer simulations.

The science

The relevant parts of the stomach are the corpus, where food is stored; the antrum, where food is ground; and the pylorus, or pyloric sphincter, the tissue valve that connects to the small intestine. Slow-wave muscle contractions begin in the corpus, with wave speed and amplitude increasing to form the antral contraction waves (ACWs) as they spread towards the pylorus.

The researchers’ antrum device consists of a cylinder, capped at one end to imitate a closed pylorus, and a hollow piston that moves inside the cylinder to replicate ACWs. As verified through computer simulations and experimental measurements, the prototype produces the characteristics of retropulsive jet flow that exist in the antrum.

Food disintegration is quantified by determining the breakup of liquid drops in flow fields produced by ACWs. The researchers studied different model fluid systems with various viscosity to account for the broad physical properties of digested food. The drop size and other parameters resemble conditions in a real stomach.

Drop break-up occurred near the surface of the hollow piston, where the flow field exhibited slower velocities but higher strain rates, thus exposing the drop to higher shear stresses during a longer period. No break-up occurred for drops near the centre of the piston, because the stresses and residence times are smaller and shorter.

“The results extracted from this simple prototype have deepened insights into the disintegration process that takes place in the stomach,” co-author Damien Dufour said. “Drops near the wall will break up as they are transported towards the pylorus. The drops in the centre return toward the corpus, without major size reduction, to disintegrate later. One may perceive this combined action of the ACWs as a classifying effect.”

How this could help

The human body is not able to synthesise all nutrients required to sustain its metabolism by itself. Food brings along essential micronutrients such as iron and iodine, which are extracted into the body through the intestine. The whole process of food from mouth to stomach is to successfully make the body function.

The study of nutritional science has progressed rapidly, and how these nutrients affect the body is relatively well understood. However, what remains unclear is the underlying mechanism of how these physical and chemical interactions occurring in the gastro-intestinal (GI) tract take place.

If scientists can understand the physical process of the stomach, they could make tailor-made foods designed to address these functional needs in addition to the nutritional ones.

This could assist with lowering obesity and make food more efficient. While the prototype is a start to these advancements, there is a long way to go.

The researchers hope to make modifications to the prototype to get further insight into the dispersing characteristics and food disintegration within the stomach.

Image credit: ©stock.adobe.com/au/Rido

Originally published here.