Mapping the gut microbiome to preterm neonatal outcomes

The development of the gut microbiome in preterm infants can have a substantial impact on health, such as the development of the common preterm disease Necrotizing Enterocolitis (NEC). This thesis aimed to identify further areas in which the gut microbiome could be contributing to the development of disease in preterm infants. Experimental methodology included, 16S rRNA gene metataxonomics, to map the preterm gut microbiome. In addition, protease activity and inhibition assays were implemented to assess total faecal protease activity and identify families of proteases present. Moreover, ELISAs were used to investigate inflammatory content of preterm infant stool. Finally, data from a project, by Dr David Gallacher, into the lung microbiome of preterm infants was analysed with the data from this project to establish links between the development of the gut and lung microbiomes of preterm infants. The results of this thesis found that the preterm gut microbiome shifts from a Firmicute dominated community to a Proteobacteria one, during the first 30 days of life. In addition, associations between gender, mode of delivery, antibiotics and sampling site were found. Secondly, no significant changes in protease activity were found over time, however, protease activity during the first 30 days of life varied between individuals. Thirdly, no inflammatory response was detected in the stool of preterm infants. Finally,no significant associations between the bacterial communities of the gut and the lung of preterm infants. In conclusion, novel findings of this thesis have shown that gender, antibiotics and sampling site have a significant effect of the development of the gut microbiome during the first 30 days of life. Moreover, protease and inflammatory activity of preterm infant stool was not significant. Lastly, development of the gut and lung microbiomes of preterm ventilated infants progress along very different courses