Submitted to: ASM Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2016
Publication Date: 9/11/2016
Citation: Firrman, J., Liu, L.S., Tomasula, P.M., Xiao, W. 2016. The effect of naringenin on the genetic expression of commensal gut bacteria. ASM Conference. 16(9):11.
Technical Abstract: Naringenin is a plant polyphenol consumed in the diet. However, it is estimated that 90-95% of polyphenols are not absorbed in the small intestine and reach the colon intact where they interact with the gut microbiota. Previously, the effect of naringenin on the growth of the commensal gut bacteria Ruminococcus gauvreauii, Bifidobacterium catenulatum and Enterococcus caccae was documented. However, the genotypic effect of naringenin on these bacteria was not considered. In this study, Ruminococcus gauvreauii, Bifidobacterium catenulatum and Enterococcus caccae were grown in the presence of naringenin and sent for Single Molecule RNA sequencing via the Helicos platform. The RNA reads were mapped to their corresponding genes and used to create genetic expression profiles. By comparing these profiles, the change in genetic regulation due to the addition of naringenin was determined. Genetic analysis revealed that in response to naringenin Ruminococcus gauvreauii upregulated genes involved in iron transport and molecular translocation. Bifidobacterium catenulatum responded to naringenin through upregulation of genes involved in cellular metabolism, DNA repair and molecular transport, and downregulation of genes involved in thymidine biosynthesis and metabolism. In response to naringenin, Enterococcus caccae upregulated pathways involved in transcription and protein transport and downregulated genes responsible for sugar transport and purine synthesis. For the first time, the effect of naringenin on the growth and genetic expression of three different commensal gut bacteria was documented. The pattern of gene expression was consistent with the observed phenotype, and provides insight into the interaction between genetic regulation and growth. These results clearly demonstrate that different bacterial strains may respond to external stimuli through initiation of separate genetic pathways. This is also a unique demonstration of how RNA single molecule sequencing can be used to study the gut microbiota.