Frontiers in Microbiology | www.frontiersin.org February 2020 | Volume 11 | Article 202Rubio-Gómez et al.Transcriptomic Response to FOS Prebiotic cluster of 15 genes, encoding uncharacterized proteins, which were repressed in the presence of FOS. The analysis of isogenic mutants has shown that genes of this genomic island encode proteins involved in growth, biofilm formation and motility. These results indicate that FOS selectively modulates bacterial pathogenicity by interfering with different signaling pathways.