Oral administration of heparin or heparosan increases the Lactobacillus population in gut microbiota of rats

► Heparin and heparosan increased Lactobacillus spp. in rat gut microbiota. ► Heparin and heparosan decreased Enterococcus sp. in rat gut microbiota. ► Heparin or heparosan can be an effective gut microbiota modulator.