A low abundance of genus Bacteroides in gut microbiota is negatively correlated with blood phenylalanine levels in Uygur patients with phenylketonuria

Yajie Su; Qiaolibang Shadike; Mingbang Wang; Haili Jiang; Wanying Liu; Jingfang Liu; Rena Tuerdi; Wenhao Zhou; Long Li

doi:10.21037/tp-21-426

A low abundance of genus Bacteroides in gut microbiota is negatively correlated with blood phenylalanine levels in Uygur patients with phenylketonuria

Transl Pediatr. 2021 Oct;10(10):2521-2532. doi: 10.21037/tp-21-426.

Authors

Yajie Su^{1

2}, Qiaolibang Shadike², Mingbang Wang³, Haili Jiang², Wanying Liu², Jingfang Liu², Rena Tuerdi², Wenhao Zhou^{1

4}, Long Li^{2

5}

Affiliations

¹ Department of Neonatology, Children's Hospital of Fudan University, and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
² Department of Neonatology, Children's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China.
³ Centre for Molecular Medicine, Children's Hospital of Fudan University, Shanghai, China.
⁴ Shanghai Key Laboratory of Birth Defects, Pediatrics Research Institute, Shanghai, China.
⁵ Department of Neonatology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China.

Abstract

Background: A low-phenylalanine (Phe) diet affects the metabolism and diversity of gut microbial communities in children with phenylketonuria (PKU). Our study examined gut microbiota characteristics and metabolic pathways, and their correlations with clinical phenotypes in a high-incidence population.

Methods: We assessed clinical phenotypes and gut microbiota by 16S ribosomal RNA (rRNA) sequencing, and performed a correlation analysis between phenotype and gut microbiota in a PKU group (n=11) and a healthy group (n=11).

Results: The PKU group had significantly lower microbiota diversity than the healthy group (P_shannon=0.014). Phylum-level composition differed significantly between the PKU and healthy groups (Firmicutes: 44.3% vs. 43.1%; Actinobacteria: 25.9% vs. 3.3%; Bacteroidetes: 16.6% vs. 53.2%; and Proteobacteria: 10.9% vs. 0.12%, respectively). Further, a significantly decreased level of genus Bacteroidetes (P<0.0001) in the PKU group was negatively correlated with blood Phe level (P=0.014). The microbial function prediction of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways exhibited a decreased ability of glycan degradation and glutamate metabolism in the PKU group.

Conclusions: Our findings revealed that genus Bacteroide was not only in extremely low abundance in the PKU group, but was also negatively correlated with blood Phe level. The remarkable capability of genus Bacteroides to use complex recalcitrant glycans may be the main reason for the decreased ability of glycan degradation in the PKU group.

Keywords: 16S ribosomal RNA sequencing (16S rRNA sequencing); Phenylketonuria (PKU); Uygur; clinical phenotype; gut microbiota.