Gut Microbiota Dysbiosis Associated with Bile Acid Metabolism in Neonatal Cholestasis Disease

Abstract

Neonatal cholestasis disease (NCD) is a complex and easily mis-diagnosed condition. We analyzed microbiota community structure in feces and measured short-chain fatty acids, bile acids (BAs) and liver function of 12 healthy, 13 NCD, and 13 treated infants after diagnosis. Based on 16S rRNA gene amplicon sequencing and gas-chromatographic-mass-spectrometric analysis of secondary BAs, we identified microbial genera and metabolites that associate with abnormal bile secretion. Streptococcus gallolyticus and Parabacteroides distasonis, and Lactobacillus gasseri had higher relative abundance in healthy and NCD infants respectively. Compared to NCD patients, healthy infants had higher LCA, CDCA and GCDCA fecal concentrations. The three microbial species and three secondary bile acids were selected as potential non-invasive combined biomarkers to diagnose NCD. We propose that microbiota-metabolite combined biomarkers could be used for diagnosis of NCD, and this may contribute to improved early clinical diagnosis of NCD in the future.

Figure 1

Fecal BAs concentration in healthy control (HC) group and non-treated neonatal cholestasis (NNC) group. * and ** represent p-value lower than 0.05 and 0.01 respectively.

Figure 2

The variation of microbiota component in four groups (healthy controls (HC), non-treated neonatal cholestasis participants (NNC), non-remission neonatal cholestasis participants after treated (TNCN) and remission neonatal cholestasis participants after treated (TNCR)) and samples distribution of age and gender. (A) Relative abundance of microbiota in genus level (top 20 genera); (B) Age and gender distribution of participants (black point and blank point represent female and male neonates); (C–E) Microbiota alpha diversity (chao1, Shannon index, and Simpson’s index) of four groups; (F) Distance-based redundancy analysis (DB-RDA) of four groups microbiota constrained by metabolites. Colors of points, violins, and diamonds represent different groups, maroon, navy, grey, and orange represent HC, NNC, TNCN, TNCR respectively.

Figure 3

Selected important features and the differences of features in the genus level. (A) The top 50 important features of participation were shown according to the Mean Decrease Gini. (B) the relative abundance of microbiota (green), the concentration of BAs in the feces (deep blue), and microbiota diversity indexes (purple) were shown after a logarithmic transformation.

Figure 4

Significant correlative relation between BAs and microbiota. Colorful and various shapes points in the network mean OTUs or BAs, the color of points means genus of OTUs (numbers in the bracket present OTU numbers). The colorful panes under the genus names mean different phyla (phylum name own the same color with the panes’). The red and blue lines mean positive and negative correlation respectively. The width of lines and letters on the line represents the r-value and the p-value of the correlative relation respectively.

Figure 5

Potential Biomarkers action mechanism. Pale yellow and laurel-green panes present secondary BAs biosynthesis in the intestinal environment and selected features of microbiota respectively. The yellow line means enterohepatic circulation, and vesicles mean gut microbiota. Green texts in the laurel-green panes represent selected by both feature selection analysis and correlation statistical analysis, and the black texts found by a single analysis.