exaggerated inflammatory response and gut microbial dysbiosis play a crucial role in necrotizing enterocolitis (nec). The probiotic Saccharomyces boulardii (SB) is a yeast that has a beneficial effect on NEC; however, the association between its protective effects and the regulation of the inflammation-related sirtuin 1 (SirT1)/nuclear factor-κB (nF-κB) signaling pathway and gut microbiota in NEC is unknown. In the present study, the NEC model was established by artificial feeding and lipopolysaccharide (LPS), hypoxia and hypothermia stimulation. Mice were divided into normal, control (artificial feeding), NEC and NEC + SB groups. Hematoxylin and eosin staining demonstrated that SB improved the pathological damage of the intestine caused by NEC in neonatal mice. Furthermore, downregulation of SirT1 and upregulation of nF-κB expression were confirmed by immunofluorescence staining, western blotting and reverse transcription-quantitative PCR (RT-qPCR) in NEC mice. SB treatment concurrently inhibited the nec roles on the SirT1 and nF-κB pathway at both the protein and mRNA levels. deletion of SirT1 [SirT1 knockout (Ko)] in the intestine abolished all the effects of SB in nec mice, including protection of pathological damage and inhibition of the SirT1/nF-κB pathway activation. The abundance of gut microbial composition, as determined by RT-qPCR, was significantly decreased in the control group compared with the normal group. A further decrease in microbiota abundance was observed in the NEC group, and SB administration significantly improved the enrichment of gut microbiota in neonatal mice with NEC. As anticipated, the increased abundance of gut microbiota modulated by SB was markedly reduced in SIRT1KO NEC mice. The present study revealed that the protective role of SB on NEC was associated with the SIRT1/nF-κB pathway and gut microbiota regulation.

BackgroundIn clinical practice, oral probiotics are often given to children with hyperbilirubinaemia who receive phototherapy, but the exact mechanism of the action of the probiotics on hyperbilirubinaemia remains unclear. It is unclear how the effects of phototherapy on the probiotic flora in the neonatal gut, in particular.Materials and methodsFifty newborns who needed phototherapy from June 2018 to June 2020 were selected as the study subjects, and five healthy newborns in the same period were used as controls to analyse the changes in probiotic bacteria in their faeces.Results1. In the intestinal tracts of newborns, Bifidobacterium is the main probiotic strain, with a small amount of Lactobacillus. There were probiotic species changes in the neonatal intestinal microbiota after phototherapy for 24 and 48 h. The amount of Bifidobacterium and Lactobacillus decreased significantly (P < 0.05). 2. A correlation analysis of probiotic species and bile acid metabolism indexes showed that Bifidobacterium was positively correlated with many metabolites (P < 0.05), such as chenodeoxycholic acid, hyodeoxycholic acid, cholic acid, allocholic acid, and β-cholic acid. It was also negatively correlated with many metabolites (P < 0.05), such as glycocholic acid, sodium, sodium tudca, and chenodeoxycholic acid. Lactobacillus was negatively correlated with metabolites (P < 0.05) such as α-sodium cholate and β-cholic acid. 3. A correlation analysis between the changes in probiotics and intestinal short-chain fatty acid metabolites after phototherapy showed that acetic acid, butyric acid, caproic acid, and propionic acid decreased and were significantly correlated with Bifidobacterium (P < 0.05). 4. After phototherapy, 17 metabolites changed significantly (P < 0.05). This correlated with many probiotics (P < 0.05). The significantly changed probiotics in this study showed a significant correlation with some intestinal metabolites (P < 0.05).ConclusionIt was found that phototherapy can significantly affect the intestinal probiotic flora and the metabolic indicators of newborns, which may be an important reason for the side effects of phototherapy, and also provides the theoretical basis for the provision of probiotics to newborns with jaundice.

IntroductionInfant jaundice is a common condition which results from a high concentration of serum bilirubin. Phototherapy is a widely-used treatment for bilirubin clearance.We analyzed the effect of phototherapy on intestinal flora and metabolism of newborns. The aim was to assess the benefit of treatment for hyperbilirubinemia with phototherapy.Material and methodsFifty-three jaundiced infants hospitalized at our neonatal intensive care unit were treated with phototherapy. Of them, 29 were prescribed antibiotics during the hospitalization. Fecal samples were collected before and 24 h and 48 h after phototherapy. The bacterial species and relative abundance were identified with Macrogene sequencing. The bile acids in feces were identified using liquid chromatography-mass spectroscopy (LC-MS).ResultsDifferential microbial species/genera and secondary bile acids were found after phototherapy. There are significant differences in the changes of the microbial species/genera between infants who did not receive antibiotic treatment and those who were given antibiotic treatment. Secondary bile acids were also significantly altered. At the same time, the differential microbial species/genera and the differential secondary bile acids interacted with each other.ConclusionsThis study identified several differential intestinal microbial species and secondary bile acids in fecal samples from infants with jaundice before and after phototherapy.Phototherapy can change the flora and its metabolism and Its long-term impact needs further observation.