Effect of flavophospholipol on fecal microbiota in weaned pigs challenged with Typhimurium.

Background: The heightened prevalence of Typhimurium remains a public health and food safety concern. Studies have reported antibiotic, flavophospholipol, may have the ability to reduce in swine, as well as alter the gut microbiota in favour of beneficial bacteria by inhibiting pathogenic bacteria. Thus, the objective of this study was to investigate the fecal microbiota of weaned pigs receiving in-feed flavophospholipol and challenged with Typhimurium.

Results: Twenty-one weaned pigs were fed either a diet containing 4 ppm of flavophospholipol (treatment group) or a non-medicated feed (control group) for 36 days post-weaning (Day 1 to Day 36). The pigs were orally challenged with a 2 mL dose of 10 CFU/mL of Typhimurium at Day 7 and Day 8. Community bacterial DNA extracted from fecal samples collected at Day 6 (before challenge) and Day 36 (28 days after challenge) were used to assess the fecal microbiota using the V4 region of the 16S rRNA gene with Illumina MiSeq next-generation sequencing. Sequencing data were visualized using mothur and analyzed in JMP and R software. The fecal microbiota of pigs in the treatment group had differences in abundance of phyla (Firmicutes, Proteobacteria) and genera (, unclassified Ruminococcaceae, , , , , , , unclassified Firmicutes, IV and when compared to pigs that were controls, 28 days after challenge with ( < 0.05). Specifically, results demonstrated a significant increase in phylum Proteobacteria ( 0.001) and decrease in Firmicutes ( = 0.012) and genus ( = 0.003) in the treated pigs suggestive of possible microbial dysbiosis. An increased abundance of genera ( = 0.012) was also noted in the treated group in comparison to the control.

Conclusion: Based on these findings, it is difficult to conclude whether treatment with 4 ppm of flavophospholipol is promoting favorable indigenous bacteria in the pig microbiota as previous literature has suggested.