Digestion of mucin polysaccharides in vitro by bacteria isolated from the rabbit cecum

The chemical composition of mucin prepared from rabbit small intestines was compared with that of commercial pig gastric mucin. Changes in carbohydrate structure of both mucins after degradation by rabbit cecal bacteria were monitored with the periodic acid-Schiff's reaction (PAS), gas-liquid chromatography, and blood group serology. Out of 220 bacterial isolates from the rabbit cecal microflora, 37 were able to remove more than 25% of PAS-reactive mucin material from pig gastric mucin, which was more easily digested than the rabbit preparation.Bacteroides spp. were most active in mucin digestion, but nonmucinolytic cecal isolates could also use the oligosaccharides likely to be released by this activity.