Comparison of the fecal bacterial microbiota in mice, rats, and pigs after alpha-glycosyl isoquercitrin treatment

Alpha-glycosyl isoquercitrin (AGIQ) is composed of isoquercitrin and its glucosylated derivatives and has many biological activities, including anti-inflammatory, antioxidant, and anti-cancer properties. However, the effect of AGIQ administered orally on gut microbiota composition remains unclear. The objective of this study was to evaluate the safety of AGIQ by comparing the gut microbiota of animals in different dose groups after AGIQ treatment. Male rats and mice received different doses of AGIQ (1.5%, 3%, or 5% w/v) in diet for carcinogenic or chronic toxicity studies (rasH2 mice: six months; Sprague-Dawley rats: 12 months). Male minipigs received 100, 300, or 1000 mg/kg/day for 28 days. Following the treatment, fecal samples were collected from the different animal species and analyzed using 16S-rRNA gene sequencing. No significant changes were observed in alpha and beta diversity of the gut microbiota. Characteristic bacteria that responded to AGIQ were identified in each animal species, and, interestingly, Kineothrix alysoides was commonly detected in all three species. Furthermore, AGIQ treatment significantly increased the fecal content of Kineothrix alysoides, a butyrate-producing bacterium, suggesting that it may be related to the biological activities of AGIQ. AGIQ selectively modulated the number of beneficial bacteria without changing the diversity of gut microbiota in rasH2 mice, SD rats, and minipigs