Modeling the effects of inner-lining geometry and motility patterns on transport in the intestinal tract

Pulsatile flow in the intestinal tract is governed by coordinated wall contractions and complex anatomical geometries, including crypts, villi, and folds. By altering local flow characteristics, such as velocity distribution, hydraulic resistance, and concentrations of nutrient and bacterial species, these features influence transport, mixing, and absorption.

To explore this relationship, we design a series of geometrically inspired intestinal domains that incorporate realistic deformation patterns. Using numerical simulations, we evaluate how different geometric and contractile configurations impact fluid flow and transport dynamics across a range of physiological conditions.

We model fluid flow using the Navier–Stokes equations with both idealized Womersley inlet conditions and fluid–structure interaction simulations. The transport dynamics of bacterial and nutrient species is modeled using coupled reaction–advection–diffusion equations. Our model incorporates nutrient absorption, nutrient quality, and bacterial colonization of the crypts.

Our results highlight how the morphological and mechanical complexity in the gut modulates flow resistance and transport dynamics, offering valuable insights into the design principles of biological transport systems.