Breast milk jaundice (BMJ) is the main cause of neonatal hyperbilirubinemia. Excessive serum unconjugated bilirubin level will not only cause the interruption or early termination of breastfeeding, but also cause kernicterus. Which can cause long-term dysfunction in infants. But for a long time, BMJ diagnosis has relied on clinical exclusive methods, lack of objective and reliable laboratory indicators. Which leads to misdiag. This project is a single-center, prospective nested case-control study. It is planned to establish a neonatal BMJ cohort. According to the admission criteria, 100 cases of early-onset BMJ and late-onset BMJ will be completed, and 100 healthy controls collected during the same period. , Compare the detection results of fecal miRNA and intestinal flora of the two groups of BMJ children and healthy controls, draw the ROC curve of the joint diagnosis, conduct research on the combined diagnostic value of fecal miRNA and intestinal flora analysis, and try to find the feasibility and practical value of diagnostic markers for feces in infants with BMJ.

This project is a single-center, prospective nested case-control study to investigate feasibility and practical value of diagnostic markers in infants with BMJ.

According to the admission criteria, 100 cases of early-onset BMJ, 100 late-onset BMJ and 100 healthy controls will be selected. Their feces, peripheral venous blood and mothers' breast milk were collected for further testing. Compare the detection results of fecal miRNA and intestinal flora of the two groups of BMJ children and healthy controls, draw the ROC curve of the joint diagnosis, conduct research on the combined diagnostic value of fecal miRNA and intestinal flora analysis.

This study is to find the objective and reliable laboratory indicators to diagnose BMJ.

Inclusion Criteria:

• All the following conditions must be met

  1. Term newborns admitted to hospital with "neonatal hyperbilirubinemia"
  2. Exclusive breastfeeding or mainly breastfeeding
  3. Exclude perinatal infection, G-6P-D deficiency, homoimmune hemolysis, polycythemia, scalp hematoma, intracranial hemorrhage, cholestasis, hypoglycemia, hypothyroidism, hypothermia, neonatal asphyxia, fetus Pathological jaundice factors such as delayed stool excretion.

Exclusion Criteria:

• As long as any one of the following conditions should be excluded

  1. During the follow-up period, breastfeeding was terminated or the daily milk powder intake exceeded 200 ml.
  2. Other pathological jaundice was diagnosed during the follow-up period.
  3. Take probiotics during the sampling period.
  4. The guardian asked to withdraw from the study halfway.

Newborn babies born from research start who diagnosed neonatal hyperbilirubinemia and healthy newborns