Allosteric regulation of pyruvate kinase enables efficient and robust gluconeogenesis by preventing metabolic conflicts and carbon overflow.

Gluconeogenesis, the reciprocal pathway of glycolysis, is an energy-consuming process that generates glycolytic intermediates from non-carbohydrate sources. In this study, we demonstrate that robust and efficient gluconeogenesis in bacteria relies on the allosteric inactivation of pyruvate kinase, the enzyme responsible for the irreversible final step of glycolysis. Using the model bacterium as an example, we discovered that pyruvate kinase activity is inhibited during gluconeogenesis via its extra C-terminal domain (ECTD), which is essential for autoinhibition and metabolic regulation.

Investigation of Bile Salt Hydrolase Activity in Human Gut Bacteria Reveals Production of Conjugated Secondary Bile Acids.

Through biochemical transformation of host-derived bile acids (BAs), gut bacteria mediate host-microbe crosstalk and sit at the interface of nutrition, the microbiome, and disease. BAs play a crucial role in human health by facilitating the absorption of dietary lipophilic nutrients, interacting with hormone receptors to regulate host physiology, and shaping gut microbiota composition through antimicrobial activity. Bile acid deconjugation by bacterial bile salt hydrolase (BSH) has long been recognized as the first necessary BA modification required before further transformations can occur.

Unbound bilirubin and risk of severe neurodevelopmental impairment in extremely low birthweight newborns.

Background: Unbound bilirubin (UB) was measured on day 5 ± 1 in 1101 ELBW newborns in the Aggressive vs Conservative Phototherapy randomized controlled trial. We accessed this dataset to quantify the UB-mediated risk of severe neurodevelopmental impairment (sNDI) in extremely low birthweight (ELBW) newborns.

Methods: UB levels were standardized within laboratories as z-score percentiles.

Transgenerational associations between newborn metabolic profiles and bronchopulmonary dysplasia in neonates born to mothers with an obese phenotype.

Maternal obesity increases risk for bronchopulmonary dysplasia (BPD) by up to 42%. Identifying metabolic features that may contribute to the association between maternal pre-pregnancy body mass index (BMI) and BPD is critical in defining the molecular relationship between these conditions. We investigated the association between maternal obesity and BPD using newborn screen metabolites as an explanatory variable.