Maturation of Intestinal Oxygenation: A Review of Mechanisms and Clinical Implications for Preterm Neonates

Abstract

Nutrient requirements of preterm neonates may be substantial, to support growth and maturation processes in the presence of challenging post-natal circumstances. This may be accompanied by substantial intestinal oxygen requirements. Preterm neonates may not be able to meet these oxygen requirements, due to a developmental delay in intestinal oxygenation regulation mechanisms. This review summarizes the available literature on post-natal maturation of intestinal oxygenation mechanisms and translates these changes into clinical observations and potential implications for preterm neonates. The different mechanisms that may be involved in regulation of intestinal oxygenation, regardless of post-natal age, are first discussed. The contribution of these mechanisms to intestinal oxygenation regulation is then evaluated in newborn and mature intestine. Finally, the course of clinical observations is used to translate these findings to potential implications for preterm neonates.

A Multiscale Spatiotemporal Model Including a Switch from Aerobic to Anaerobic Metabolism Reproduces Succession in the Early Infant Gut Microbiota

“…is depletion of a hypothesized initial amount of oxygen ( 4 , 5 ). Oxygen diffuses into the gut lumen from the body and is taken up by bacteria, by colonocytes, and by nonbiological chemical processes in the cecal contents ( 6 – 8 ), leading to oxygen depletion. The relative importance of these processes is still under debate ( 7 , 8 ).…”

Disrupted establishment of anaerobe and facultative anaerobe balance in preterm infants with extrauterine growth restriction

“…However, only meconium and feces on day 28 were collected with no follow-up in that study, which could not reflect the dynamic maturation process of gut microbiota ( 22 ). Generally, the high level of oxygen in the newborn gastrointestinal tract facilitates the colonization of facultative anaerobes, many of which are potential pathogens ( 23 ). As the early colonizers gradually consume oxygen in the gastrointestinal tract, obligate anaerobes consequently colonize in the new environment.…”

A multiscale spatiotemporal model including a switch from aerobic to anaerobic metabolism reproduces succession in the early infant gut microbiota

“…A possible trigger for the replacement of the Enterobacteriacea by Bifidobacterium spp., is depletion of a hypothesized initial amount of oxygen (4, 5). Oxygen diffuses into the gut lumen from the body and is taken up by bacteria, by colonocytes, and by non-biological chemical processes in the cecal contents (6, 7, 8) leading to oxygen depletion. The relative importance of these processes is still under debate (7, 8).…”