ABSTRACT
Bifi dobacteria are members of the Actinobacteria phylum, one of the main phylogenetic groups inhabiting the human intestine. Their abundance in the gut microbiota varies, depending on the population group, but it has been established that they are one of the most prevalent genera, especially in newborns and infants. The mechanisms used by bifi dobacteria to counteract the harsh conditions found in our body, as well as the molecular crosstalking dialog that they establish with human cells (i.e., enterocytes and immune cells), has been strongly hampered by the lack of molecular tools to perform functional studies (i.e., knock-out and gene expression systems). However, in recent last years, we have seen a tremendous advance of omics and molecular biology techniques that can be applied to the study of the functional aspects of bifi dobacteria (Ventura et al. 2009). This has facilitated
* Corresponding author: amargolles@ipla.csic.es
the elucidation of several mechanisms involved in survival, persistence, colonization and downstream responses induced in host cells. This chapter attempts to summarize the current knowledge on these mechanisms.
