Minor effect of the dietary combination of probiotic Pediococcus acidilactici with fructooligosaccharides or polysaccharidases on beneficial changes in the cecum of rats

Effects of dietary fructooligosaccharides (FOS, 2% and 5%) and 2 polysaccharidases (glucanase and xylanase) with or without a probiotic preparation (Pediococcus acidilactici) on cecal fermentation of Wistar rats were studied. Cecal weight, pH of digesta, ammonia and protein concentrations, as well as bacterial enzymes activity and short-chain fatty acid (SCFA) production were assessed. Generally, the probiotic supplementation did not affect the cecal metabolism. Only SCFA profile showed a higher proportion of propionic acid in the probiotic-treated groups. A significant interaction was also found between probiotic and diet additives in the case of activities of β-glucuronidase (P = .00005) and α-glucosidase (P = .031). The cecal parameters of rats fed with the diet supplemented with polysaccharidases did not differ substantially from the control group; the only differences concerned a higher protein concentration as well as higher activities of β-glucosidase and β-galactosidase in the digesta. The cecum was affected, to the greatest extent, by FOS, regardless whether they were combined with probiotic or not. Rats treated with fructans (both levels) were characterized by the lowest pH value and ammonia concentration. Fructooligosaccharides applied at a higher dose enlarged the cecum (tissue and digesta) and decreased bacterial β-glucuronidase activity, compared with the control (P = .05). The fermentation of the FOS-5% diet in the cecum was associated with the highest production of total and individual SCFAs. In conclusion, contrary to expectations, the effect of the polysaccharidases and the prebiotic FOS in the cecum of rats was not enhanced by the dietary treatments combined with the probiotic.