Abstract: The aim of this study was to investigate the effect of microencapsulated cinnamon oil on antioxidant capacity and gut microbiota in mice. Six-week-old male C57 BL/6 mice were randomly divided into control, free cinnamon oil, and microcapsuled cinnamon oil groups (100 mg/(kg mb·d)). Antioxidant capacity in liver, duodenum, and colon tissues were measured after 4 weeks of continuous gavage. The 16S rDNA gene in mouse feces was detected by Illumina MiSeq high-throughput sequencing to explore the changes of gut microbiota, and the contents of short chain fatty acids in mouse feces were detected by gas chromatography-mass spectrometry. The results showed that compared with free cinnamon oil, the microcapsules could significantly increase the total antioxidant capacity in the liver, and significantly decrease the MDA content in the duodenum (P < 0.05). At the phylum level, the increase in the abundance of Bacteroidetes and the decrease in the abundance of Fimicutes in mouse feces after supplementation of cinnamon oil microcapsules were more pronounced than after supplement of cinnamon oil. At the genus level, microcapsulated cinnamon oil supplementation significantly increased the abundance of beneficial bacteria such as Bacteroides, Lactobacillus, Family_XIII_AD3011_group, unclassified_f__Lachnospiraceae, Blautia, and Ruminiclostridium, and significantly inhibited the abundance of opportunistic pathogenic bacteria including norank_f__Muribaculacea, Ruminococcaceae_UCG-014, and Gordonibacter (P < 0.05). The contents of propionic acid, butyric acid, and total acid in the feces of mice given the microcapsules were significantly increased (P < 0.05). To sum up, cinnamon oil microcapsules can continuously release bioactive ingredients in a sustained manner to inhibit opportunistic pathogenic bacteria and promote the proliferation of beneficial microflora and the production of short-chain fatty acids in the gut, thereby having a more obvious regulatory effect on the gut microbiota structure and redox state.

Key words: cinnamon oil; microcapsules; antioxidant capacity; gut microbiota