Synbiotics-Regulated Gene Expression Signatures Determined in Vitro reflect the Molecular Background of the Treated Host Animal

Synbiotics (combination of pre- and probiotics) comprise of bioactive formulations that promote development of beneficial microflora and stimulate digestive and immune systems of the host organism. The aim of this study was to determine synbiotics-regulated gene expression signatures in the chicken transcriptome. For this purpose, a prebiotic (RFOs – raffinose family oligosaccharides), two in-house constructed synbiotics containing RFOs and a strain of Lactococcus lactis subsp. lactis (S1) or cremoris (S2) and a commercial synbiotic (S3), were used. The effects of synbiotics in chickens were analyzed using in vitro and in vivo models. First, DT40 cell line (chicken B lymphocytes) was stimulated with pre- and synbiotics in vitro, followed by a whole-genome transcriptome analysis with NimbleGen Gene Expression Microarray (135K). This approach allowed pinpointing a panel of 13 differentially expressed genes, which served as immune-related gene expression signatures for in vivo study. In the next step, fertilized eggs were in ovo inoculated with the pre- and synbiotics at 12 day of incubation. Hatched chicks were raised for 6 weeks, followed by slaughter and sample collection (cecal tonsils, spleen). Gene expression analysis was performed in both tissues with RT-qPCR, resulting in differential expression of the target genes (e.g. CCLI8 and GPR55). This study allowed setting up a system for selection of the synbiotics-regulated gene expression signatures in vitro and further use of these target genes for in vivo monitoring of the molecular pathways activated in chickens by the synbiotics.   

Acknowledgements: Polish-American Fulbright Commission and National Science Centre in Poland (grant no: UMO-2013/11/B/NZ9/00783)