Serum Bilirubin Level Predicts Phototherapy-Associated Gut Microbiome Disruption in Neonates with Hyperbilirubinemia

Abstract

Background: Neonatal jaundice is a frequent condition that may require phototherapy to prevent bilirubin-induced neurotoxicity. Objective: To investigate the effects of phototherapy on intestinal probiotics in neonates with jaundice, and to identify clinical predictors of microbiota alterations following treatment Subjects and Methods: This prospective observational research involved 33 full-term newborns who had jaundice requiring phototherapy and 35 healthy controls. Stool samples have been gathered from cases twice; prior to exposure to phototherapy and after weaning from it. Samples were withdrawn from controls on the third day of life. Gut microbiota was analyzed using metagenomic co-sequencing with quantitative PCR of Lactobacillus and Bifidobacterium. Results: Before phototherapy, jaundiced neonates exhibited significantly lower Lactobacillus and Bifidobacterium counts compared with healthy controls (P < 0.001). Phototherapy has been related to a marked diminution in both probiotics (Lactobacillus: 9.00 ± 0.16 to 5.86 ± 3.15 log₁₀ CFU/g; Bifidobacterium: 9.17 ± 0.14 to 6.44 ± 3.40 log₁₀ CFU/g; P < 0.001). Higher total serum bilirubin and longer phototherapy duration were negatively correlated with probiotic counts, while gestational age and birth weight were protective. Multivariable regression identified total serum bilirubin as the strongest independent predictor of post-phototherapy microbiota reduction. Conclusion: Phototherapy in newborns who had jaundice is related to significant disruption of beneficial gut microbiota. Elevated bilirubin levels and lower gestational age play a central role in post-treatment microbial depletion, highlighting potential implications for neonatal intestinal and metabolic health.