Bovine milk derived exosomes affect gut microbiota of DSS-induced colitis mouse

Abstract We hypothesized that oral administration of bovine milk derived exosomes (MDEs) can positively regulate the gut microbiota thus may alleviate the Dextran sodium sulfate (DSS)-induced colitis in mice. Total of 42 specific pathogen free (SPF) male BALB/c mice (3 weeks old) were randomly assigned to three groups including control/blank group (Blnk), DSS group (DSS) and Exosome group (Exo), with 7 replicates/cages per treatment and two mice in one cage. 16S rRNA gene sequencing of cecal digesta samples was conducted. DSS significantly decreased the average daily feed intake of mice in DSS and Exo groups (P = 0.03). Shannon index of the DSS group was significantly lower than the Blnk group (P < 0.05) whereas no difference between the Blnk group and Exo group were observed. Administration of MDEs tended to increase the relative abundance of Campylobaterota. The relative abundance of Roseburia was significantly decreased in the DSS group compared to the Blnk group (P < 0.05) whereas no difference was observed between the Exo group and Blnk group. Oral gavage of MDEs also tended to increase the relative abundance of Lachnospiraceae_UCG_006. In conclusion, oral gavage of 10 µL MDEs (1 mg/ml) affected gut microbiota of DSS-induced colitis mouse but the effects were limited.