2'-Fucosyllactose (2'-FL) changes infants gut microbiota composition and their metabolism in a host-free human colonic model

Background: Breast milk is critical for neonates, providing the necessary energy, nutrients, and bioactive com-pounds for growth and development. Research indicated that human milk oligosaccharides (HMOs) have been shown to shape a beneficial gut microbiota, as well as their metabolism (e.g. short-chain fatty acids). 2'-Fuco-syllactose (2'-FL) is one major HMO that composed of 30% of total HMOs.Objectives: This study aimed to understand the impact of 2'-FL on the composition and metabolism of infant gut microbiota.Methods: Our study utilized an in-vitro human colonic model (HCM) to investigate the host-free interactions between 2'-FL and infant gut microbiota. To simulate the infant gut microbiota, we inoculated the HCM system with eight representative bacterial species from infant gut microbiota. The effects of 2'-FL on the gut microbial composition and their metabolism were determined through real-time quantitative PCR and liquid -chromatography mass spectrometry (LC/MS). The obtained data were analyzed using Compound Discoverer 3.1 and MetaboAnalyst 4.0.Results: Our study findings suggest that the intervention of 2'-FL in HCM resulted in a significant change in the abundance of representative bacterial species. PCR analysis showed a consistent increase in the abundance of Parabacteroides. distasonis in all three colon sections. Furthermore, analysis of free fatty acids revealed a sig-nificant increase in their levels in the ascending, transverse, and descending colons, except for caproic acid, which was significantly reduced to a non-detectable level. The identification of significant extracellular polar metabolites, such as glutathione and serotonin, enabled us to distinguish between the metabolomes before and after 2'-FL intervention. Moreover, correlation analysis revealed a significant association between the altered microbes and microbial metabolites.Conclusions: In summary, our study demonstrated the impact of 2'-FL intervention on the defined composition of infant gut microbiota and their metabolic pathways in an in vitro setting. Our findings provide valuable insights for future follow-up investigations into the role of 2'-FL in regulating the growth and development of infant gut microbiota in vivo.

Automated summary

This study investigated the impact of 2'-FL on the composition and metabolism of infant gut microbiota using an in-vitro human colonic model. The intervention of 2'-FL resulted in significant changes in the abundance of representative bacterial species and an increase in free fatty acid levels. The study also identified significant extracellular polar metabolites and revealed a significant association between altered microbes and microbial metabolites.