Abstract: Objective　To explore the changes of gastrointestinal microbiota in late preterm infants with feeding intolerance. Methods　Premature infants admitted within 24 hours of birth to the neonatal intensive care unit from January to December 2018 were selected as the study subjects. Their gestational age was 34~36+6 weeks and their mothers had no history of prenatal infection or premature rupture of membranes. Fecal samples were collected from 30 patients with feeding intolerance (intolerance group), from 30 patients without feeding intolerance (control group), and from 30 remission patients in intolerance group (remission group). The differences of fecal microbiota were compared. Results　The relative abundances of bacteroidetes and actinobacteria in the intolerance group and the remission group were lower than those in the control group, and the relative abundances of proteobacteria in the intolerance group were higher than those in the control group and the remission group, and the differences were statistically significant (all P<0.05). The relative abundance of enterococcus and bacteroides in the intolerance group was significantly lower than those in the control group and the remission group (P<0.05). The relative abundance of streptococcus and staphylococcus in the intolerance group was significantly higher than those in the control group and the remission group (P<0.05). The relative abundance of clostridium in the intolerant group and the control group was significantly lower than that in the remission group (P<0.05). The relative abundance of bifidobacterium in the intolerance group and the remission group was significantly lower than that in the control group (P<0.05). The Observed_otus number, Chao1 index and Shannon index of the intolerance group were lower than those in the control group and the remission group, and the differences were statistically significant (all P<0.05). Conclusions　The relative abundance and diversity of intestinal microbiota decreased in feeding intolerant preterm infants. With the remission of feeding intolerance, the relative abundance and diversity of intestinal microbiota was gradually recovered.

Key words: late preterm infants;　feeding intolerance;　gastrointestinal microbiota;　relative abundance;　diversity