Abstract: The abundance of Akkermansia muciniphila in the intestine was negatively correlated to a series of metabolic diseases such as obesity and type II diabetes. In order to observe the effects of Lactobacillus casei SY13, SY13 and fructo-oligosaccharide, SY13 and lactulose on Akkermansia muciniphila in mice, 8-week-old mice and 9-month-old mice were studied. The mice were randomly divided into 5 groups:AP group (8-week-old mice, gavaged for 1 day, once a day), AO group (9-months-old mice, gavage for 1 day, once a day), BP group (8-week-old mice, gavage 28 days, once a day), BO group (9-month-old mice, gavage 28 days, once a day), 48 in each group.Each experimental group was divided into control group (sterile PBS, 0.3 mL), Lactobacillus casei SY13 group (SY13, 10⁹ cfu, 0.3 mL), SY13 fructo-oligosaccharide group (10⁹ cfu;Fructooligosaccharides, 15 mg;0.3 mL) and SY13 lactulose group (SY13:10⁹ cfu, lactulose:15 mg, 0.3 mL), 12 ineach group.The abundance of Akkermansia muciniphila in jejunum, ileum, cecum and colon of mice were detected by real-time fluorescence quantitative PCR. The abundance of Akkermansia muciniphila indirectly reflectedby CT values.The results showed that the CT value of SY13 lactulose group was significantly lower than that of the other groups (p<0.05), the CT value of young mice was significantly lower than that of the aged group (p<0.05). Compared with single gavage, CT value was lower in long-term gavage (p<0.05).The research showed that, SY13-lactulose group had the best effect on increasing the abundance of Akkermansia muciniphila in the intestine ofmice, and the lower the mice age, the longer the gavage time, the higher abundance of Akkermansia muciniphila.At the same time, the longer the gavage, the longer the retention time of Akkermansia muciniphila, which was not related to the age of mice and gavage.