Antioxidant Potential of Pediococcus Pentosaceus Strains from the Sow Milk Bacterial Collection in Weaned Piglets

Abstract

Background: In modern animal husbandry, breeders pay increasing attention to improving sow nutrition during pregnancy and lactation to favor the health of neonates. Sow milk is a main food for piglets during their first three weeks of life, which is not only a rich repository of essential nutrients and a broad range of bioactive compounds, but also an indispensable source of commensal bacteria. Maternal milk microorganisms are important sources of commensal bacteria for neonatal gut. Bacteria from maternal milk may serve as an additive to confer a health benefit on the composition of the indigenous microbiota of piglets. Methods: The sow milk microbiota was collected using the culturomics methods of Continuous Culture and Interval Sampling, following by the identification of 16S rDNA gene sequences. To screen potential probiotics, the functional evaluation was conducted to assess their antagonistic activity against pathogens in vitro and evaluate their resistance against oxidative stress in damaged Drosophila induced by paraquat. In piglet feeding trial, a total of 54 newborn suckling piglets were chosen from nine sows and randomly assigned to three treatments with different concentration of a candidate strain. Multiple approaches were carried out to verify its antioxidant function including western blotting, enzyme activity analysis, metabolomics and 16S rDNA sequencing. Results: The 1240 isolates were screened out from the sow milk microbiota and grouped into 271 bacterial taxa based on a nonredundant set of 16S rDNA gene sequences. Among 80 Pediococcus isolates, a new Pediococcus pentosaceus strain (SMM914) showed best performance in inhibition ability against swine pathogens and in Drosophila model challenged by paraquat. Pretreatment of piglets with SMM914 induces the Nrf2-Keap1 antioxidant signaling pathway and greatly affected the pathways of amino acid metabolism and lipid metabolism in plasma. In colon, Lactobacillus was significantly increased in the high dose of SMM914 group compared with the control group. Conclusion: SMM914 functions as a promising probiotic conferring antioxidant capacity by activating the Nrf2-Keap1 antioxidant signaling pathway in piglets. Our study provided useful resources for deeply understanding the relationships between the maternal microbiota and offspring.