According to a study published in Food Hydrocolloids, researchers at the University of Nottingham and University of East Anglia examined the implications of changing the physical state of psyllium and its effect on gas production, an issue with some fibers that can cause discomfort. They determined through in vitro work that viscosity was a factor in gas production, independent of sugar composition and linkage. The research suggests that seed processing or selective breeding may be strategies to alter the ingredient.

Original Study: https://www.sciencedirect.com/science/article/pii/S0268005X23000899?via%3Dihub