Changes in Intestinal Flora and Metabolites in Neonates With Breast Milk Jaundice

Abstract

<b>Background:</b> Breast milk jaundice (BMJ) is the first cause of neonatal jaundice; however, its underlying mechanism is yet to be deciphered. We conducted a study to investigate intestinal flora in neonates with BMJ and used metabolomics to decipher the possible mechanisms by which intestinal flora induces jaundice. <b>Methods:</b> Microbiota collected from the feces of BMJ patients and jaundice-free breastfeeding newborns was used for 16S rRNA sequencing. In addition, differences in fecal metabolites were analyzed using gas chromatography mass spectrometry (GC/MS). The relationship between intestinal microbiota and the differences in fecal metabolites was then analyzed. <b>Results:</b> There was no significant difference in the richness and diversity of intestinal flora between BMJ and the control group; however, there were differences in the structure. At the phylum level, the relative abundance of <i>Firmicutes</i> was higher in the control group compared to the BMJ group, whereas <i>Proteobacteria</i> was higher in the infants with BMJ. Additionally, at the genus level, the relative abundance of <i>Haemophilus</i> was higher in the control group, whereas the relative abundances of <i>Escherichia, Morganella</i>, and <i>Rothia</i> were lower. More remarkably, the major differences in metabolites between the two groups were glyceric acid, succinic acid, and phenylalanine. Additionally, the abundance of <i>Escherichia</i> was positively correlated with succinic acid and cadaverine levels. <b>Conclusions:</b> The intestinal flora colonization status in BMJ patients is immature. This study reports for the first time that the study of intestinal flora, especially <i>Escherichia</i>, plays an important role in BMJ, and found that it may be associated with the regulation of succinic acid metabolic pathways.