Asian Plantain (Plantago asiatica), like its close relative Plantago ovata (the source of psyllium), contains mucilaginous polysaccharides in its seeds and seed husks. These mucilages absorb water and form a gel-like mass in the intestines, increasing stool bulk and moisture, which stimulates peristalsis and facilitates bowel movements. The use of Plantago seed husks as a bulk-forming laxative has considerable scientific validation, with most studies focusing on Plantago ovata (psyllium), but similar fiber content and mucilage properties are found in Plantago asiatica.

Clinical studies on Plantago ovata have consistently shown efficacy in treating constipation in adults, and pharmacopoeias in several countries (including China and Japan) recognize Plantago seeds for this indication. While direct studies on Plantago asiatica are fewer, the similar phytochemical profile justifies its traditional and modern use. A few small clinical and animal studies from East Asia support its role in improving bowel movement frequency and stool consistency, though with less robust evidence compared to Plantago ovata.

In summary, there is scientific support (albeit mainly extrapolated from related Plantago species) for the use of Asian Plantain seeds/husks in the management of adult constipation, primarily through their fiber and mucilage content. The evidence is reasonably strong, though not as well-documented as for Plantago ovata.