Objective To investigate the differences of intestinal microflora between children suffered with Phenylketonuria (PKU) and healthy children by high-throughput sequencing of 16S ribosomal ribonucleic acid (16S rRNA) gene.

Methods Children managed by Yunnan Neonatal Disease Screening Center were recruited as research objects in 2020. Children with PKU (all children in this group received special diet treatment)were matched with 1 - 2 normal children for similar age, the same place of residence and household registration. A total of 11 children in the PKU group and 16 healthy children in the control group were recruited. Fecal DNA was extracted from all children's fresh stools for high-throughput sequencing of the V3 - V4 region of 16S rRNA gene. Sequencing data were analyzed by the BGI microbial amplicon analysis platform for gut microbiota analysis, and intestinal microflora were compared between 2 groups.

Results There was no difference in α diversity between the PKU group and the healthy control group(P > 0.05), but there was significant difference in β diversity between 2 the groups(R = 0.084, P < 0.05). At the phylum level, Bacteroidetes and firmicutes were the dominant phyla in the intestinal microflora of both the PKU group and the healthy control group. While at the genus level, Bacteroides, Faecalibacterium and Lachnospiracea incertae sedis were the dominant genera. The relative abundance of Bacteroides and Bifidobacteria in the control group was higher than that in the PKU group (P = 0.011, P = 0.007), while the relative abundance of Prevotella in the PKU group was higher than that in the control group(P = 0.012).

Conclusion There are differences in intestinal microflora between PKU and healthy children in terms of diversity and relative abundance, which could be ascribed to the special diet treatment for PKU children and may affect their growth and development.