Digestive health is important for overall well-being, but gut health problems are common in the Chinese population. The objective of this study was to investigate the effects of oat β-glucan-based prebiotic blended formulas in humans on digestive health by assessing defecation frequency, defecation symptoms, stool quality, self-reported digestive feelings, defecation satisfaction, and gut bacteria. A parallel, randomized, double-blind, controlled trial was conducted in 168 eligible adults randomized to 3 groups for 14 days: Intervention groups A and B received 2 different doses of oat β-glucan-based prebiotic blended formulas and a Control group received oat β-glucan mixed with hydroxypropylmethyl-cellulose and microcrystalline cellulose. Participants completed a defecation diary and Bristol stool chart daily and digestive system questionnaires weekly. Fecal samples were collected on day 0 and day 14 to evaluate gut bacteria using 16S rDNA analysis. Both formulas improved defecation frequency, stool quality, defecation symptoms, defecation satisfaction, and on digestive health of human, compared with baseline (P < 0.05). Both formulas led to increased quantities of Bifidobacterium and Akkermansia bacteria, compared to control, on day 14. This study therefore demonstrated the beneficial effects of oat β-glucan-based prebiotic blended formulas on gut health in generally healthy Chinese adults. These formulas are a feasible nutritional strategy for digestive health.