Simulation and modeling of dietary changes in the infant gut microbiome

The early gut microbiome is essential for health, and diet has a profound influence in its composition. Oligosaccharides in breast milk or formula act as prebiotics, influencing gut microbiome structure. Here we simulated the impact of a dietary switch from fructooligosaccharides (FOS) to 2-fucosyllactose (2FL) in a continuous culture containing a consortium of species of the infant gut microbiome. During growth on FOS the consortium was dominated by Lactobacillus acidophilus, characterized by high amounts of lactate. Switching to 2FL led to a decrease in total biomass, and a recovery in Bifidobacterium infantis and Escherichia coli levels. While FOS was rapidly metabolized by the consortium, 2FL was utilized only after a delay. 2FL consumption was followed by a gradual switch from lactate to acetate. The activity of these bacterial species correlated well with gene expression analysis. Mathematical modeling of a multi-species consortium in continuous culture was capable to explain in great part the behavior of the system. The model was finally used to represent the outcome of the system after 48 h after each regime. This work highlights the impact of dietary changes in the gut microbiome, and provides a modeling framework to predict this influence.