Severe anemia in preterm infants associated with increased bacterial virulence potential and metabolic disequilibrium

Abstract

Anemia in preterm infants is associated with gut dysbiosis and necrotizing enterocolitis. Our study aimed to identify the bacterial functions and metabolites that can explain the underlying mechanisms of anemia associated disease conditions. We conducted a case control study in preterm infants with cases having a hematocrit $$\le$$ 25%. The control infants were matched by birth gestational age and weight. Fecal samples were collected before, at the onset, and after the onset of anemia in cases and with matched postnatal age in controls for metagenomics and metabolomics analyzes. 18 anemic and 20 control infants with fecal samples collected at 17 days, 5 weeks, and 7 weeks postnatal age were included. Virulence factor potential, decrease in beta diversity evolution, and larger changes in metabolome were associated with severe anemia. Metabolite abundances of N-acetylneuraminate and butyrobetaine were associated with virulence factor potential. Anemic group had decreased prostaglandin and lactic acid levels. Fecal omics data showed that severe anemia is associated with a pro-inflammatory gut microbiota with more virulent and less commensal anaerobic bacterial activities. Future studies can examine the link between anemia-associated dysbiosis and clinical outcomes and predict an infant-specific hematocrit threshold that negatively affects clinical outcomes.