Su1999 – the Effect of Dietary Fiber Intake on Short Chain Fatty Acidproducing Bacteria During Critical Illness: A Prospective Cohort Study

that have the potential to cause diseases.In contrast, the relative abundance of Ruminococcaceae and Christensenellaceae increased more than 2-fold (p<0.01).Members of these two families produce the protective metabolite butyrate.In agreement with this finding, butyrate concentration increased 12-fold after solid food ingestion (p<0.001)together with the two other main short chain fatty acids, acetate and propionate (5 and 2-fold increase, respectively, p<0.01).Additionally, the concentration of 3-phenylpropionate, a bacterial catabolite of phenylalanine, was increased 6-fold after solid food ingestion (p<0.001) while the concentration of trimethylamine, a choline-derived bacterial metabolite, was higher in exclusively suckling rabbits (p=0.003).Conclusion: The onset of solid food ingestion deeply remodeled the gut ecosystem at taxonomic and functional levels despite milk ingestion was still predominant.Modification of bacterial composition and metabolites after solid food ingestion might directly contribute to the postnatal maturation of the gut mucosa.Our results will pave the way for optimization of solid food introduction pattern in early life to promote gut health.