Ultrasound assessment of gastric content dynamics induced by viscous soluble dietary fibers in vitro and in vivo

Viscous soluble dietary fibers (VSDFs) such as sodium alginate (SA) and konjac glucomannan (KGM) undergo structural changes during digestion that may influence satiety, but non-invasive methods to monitor these structural dynamics in real time remain limited. This study assessed whether ultrasonography can detect structural changes in gastric content over 60 minutes of digestion, in vitro and in vivo, following ingestion of SA or KGM. An in vitro gastric ultrasound model (GUSMO) combined each fiber with water or milk, with structural change assessed via a qualitative structure score and GLCM texture analysis at five timepoints. In vivo, a randomized crossover study in healthy volunteers assessed structural change within the gastric antrum using cross-sectional area, structure score, and texture analysis, alongside appetite and comfort ratings.