Comparative analysis of prebiotic effects of seaweed polysaccharides laminaran, porphyran, and ulvan using in vitro human fecal fermentation

•Laminaran stimulated the growth of Bifidobacteria and Bacteroides.•Ulvan stimulated the growth of Bifidobacteria and Lactobacilli.•Porphyran showed lower prebiotic effect than laminaran and ulvan.•Laminaran was fermented slowly to give prebiotic effect in the distal colon.