Abstract: The objective of the study is to investigate the effect of procyanidins B2 on the intestinal microflora in D-galactose-induced aging mouse model. Thirty C57/BL mice were randomly and equally divided into control, aging model and procyanidins B2 treatment groups. After an experimental period of seven weeks, total antioxidant capacity, superoxide dismutase activity and catalase activity, and malondialdehyde (MDA) content as a lipid peroxidation marker were detected in the duodenum and colon. High-throughput sequencing of the 16S rDNA gene of the intestinal flora was performed using an Illumina MiSeq platform to explore the relationship between procyanidin B2 and the intestinal flora in aging mice. The contents of short-chain fatty acids (SCFAs) in mouse feces were determined by gas chromatography-mass spectrometry. The results showed that the activity of antioxidant enzymes was significantly decreased in the duodenum and colon of aging mice, and the content of MDA was significantly increased (P < 0.05). After intervention with procyanidins B2, antioxidant enzyme and MDA levels were restored to values not significantly different from normal (P > 0.05). The major differential intestinal microorganisms were norank-f-Bacteroidales-s24-7, Bacteroides, Blautia, unclassified-Lachnospiraeae, Ruminiclostridium, Lachnospiraeae-NK4A136, and Roseburia among all groups of mice. Compared with the control group, the proportion of norank-f-Bacteroidales-s24-7 in the aging group was decreased significantly, and the proportions of the other strains were increased significantly (P < 0.05). Compared with the aging group, the proportions of norank-f-Bacteroidales-s24-7, Roseburia, Lachnospiraeae-NK4A136 and Bacteroides were significantly increased in the mice treated with procyanidins B2, while the proportion of Blautia, unclassified-Lachnospiraeae, and Ruminiclostridium was significantly decreased (P < 0.05). Accordingly, procyanidins B2 could regulate the contents of SCFAs in aging mice to improve the intestinal environment, thereby delaying the aging process.

Key words: procyanidin B2, D-galactose, intestinal flora, analysis of flora