Pediocin A modulates intestinal microflora metabolism in swine in vitro intestinal fermentations

The aim of this study was to investigatein vitro the effects of pediocin A [a bacteriocinproduced by lactic acid bacteria (LAB) Pediococcuspentosaceus FBB61] on microbial metabolism inthe small and large intestine of pigs. Pediocin A waspartially purified by ion exchange chromatography andadded to an in vitro fermentation system. The intestinalinoculum was collected from pigs immediately afterslaughter, diluted with a buffer, and dispensed intofermentation syringes and vessels of the 2 experimentalgroups: 1) Bac+ = cecal liquor + predigested diet +pediocin A (final concentration 160 activity units/mL);2) Bac− = cecal liquor + predigested diet + partiallypurified supernatant of P. pentosaceus FBB61–2. Intestinalmicrobial growth was monitored using the cumulativegas production technique; the kinetics of fermentation,bacterial counts, VFA, ammonia, polyamines,and p-cresol production were analyzed. Pediocin A hadalmost no effects on small intestine fermentation parameters,whereas in the cecum pediocin A decreasedgas production (−16%; P < 0.05), ammonia, and VFAproduction (−52 and −21%, respectively, after 24 h;P < 0.001) compared with the control group. Significantinhibition of clostridia and LAB occurred in cecalfermentations: the Bac+ group yielded a decreasednumber of clostridia and LAB in cecal fermentations(8.19 and 7.80 cfu/mL, respectively) compared withBac− (9.32 and 8.95 cfu/mL, respectively; P < 0.001).The low clostridia counts in the pediocin-treated groupmay also explain the reduced concentration of the carcinogeniccompound p-cresol (−88%; P < 0.01). Ourresults suggest that pediocin A could be an alternativeto replace antibiotic growth promoters for the prophylaxisof enteric diseases and to improve production offarm animals.[...]