Objective  To evaluate the effect of liver transplantation on intestinal microflora in children with biliary atresia.

  Methods  The fecal samples and liver function indexes of 16 children with biliary atresia before and 6 months after liver transplantation were collected, and 10 healthy children were selected as the healthy controls. DNA extraction and metagenome sequencing were carried out in the fecal samples. Statistical analysis was performed by software packages, such as R language. The changes of species structure and functional composition of intestinal microflora after liver transplantation were analyzed. The recovery of intestinal microflora in children with biliary atresia after liver transplantation was assessed. The relationship between intestinal microflora and liver function indexes was investigated.

  Results  Following liver transplantation, the number of species of intestinal microflora in children with biliary atresia was increased. The opportunistic pathogens were the dominant species of intestinal microflora in children with biliary atresia before liver transplantation. The abundance of opportunistic pathogens was decreased and the abundance of short-chain fatty acid-producing bacteria was increased after liver transplantation (all P < 0.05). Following liver transplantation, lipid metabolism, amino acid metabolism, carbohydrate metabolism, energy metabolism, metabolism of cofactors and vitamins were enhanced, whereas infectious diseases of bacterial, immune diseases and drug resistance were weakened. Compared with the healthy control group, there were no statistically significant differences in the diversity and structure of intestinal microflora in the post-liver transplant group, but different species were observed between two groups. The liver function indexes of children with biliary atresia after liver transplantation tended to decline (all P < 0.000 1). The abundance of beneficial intestinal microflora was negatively correlated with liver function indexes, whereas the abundance of opportunistic pathogens was positively correlated with liver function indexes (all P < 0.05).

  Conclusions  Liver transplantation may significantly improve the structure and functional composition of intestinal microflora in children with biliary atresia.