Lactic acid bacteria isolated from poultry protect the intestinal epithelial cells of chickens from in vitro wheat germ agglutinin-induced cytotoxicity.

Poultry fed on wheat-based diets regularly ingest wheat germ agglutinin (WGA) that has toxic effects in vitro on intestinal epithelial cells (IEC) obtained from 14-d-old broilers. Cytotoxicity and the potential role of 14 intestinal bacterial strains in the removal of bound lectins in epithelial cell cultures were investigated. Cytotoxicity was dependent on time and lectin concentration; the lethal dose (LD50) was 8.36 µg/ml for IEC exposed for 2 h to WGA. Complementary sugars to WGA were detected on the surface of one Enterococcus and 9 Lactobacillus strains isolated from poultry. These strains were evaluated as a lectin removal tool for cytotoxicity prevention. Incubation of lactic acid bacteria with WGA before IEC-lectin interaction caused a substantial reduction in the percentage of cell deaths. The protection was attributed to the amount of lectin bound to the bacterial surfaces and was strain-dependent. L. salivarius LET 201 and L. reuteri LET 210 were more efficient than the other lactic acid bacteria assayed. These results provide a basis for the development of probiotic supplements or cell-wall preparations of selected lactic acid bacteria intended to avoid harmful effects of a natural constituent of the grain in wheat-based diets.

Feed supplementation with avian Propionibacterium acidipropionici contributes to mucosa development in early stages of rearing broiler chickens.

Different studies in animal rearing claim the probiotic potential of species of the genus Propionibacterium. The effects of strains of Propionibacterium acidipropionici isolated from poultry intestine on microbiota activity and intestinal mucosa development were investigated in the early stage of rearing chicks and the safety of the dose used was investigated. The strains P. acidipropionici LET105 and LET107, administered as monoculture to chicks from the 1st to 14th day of life in a daily dose of 106 cfu/ml administered in the drinking water resulted harmless. The animals arrived at the expected weight for age and no differences were observed with respect to the food intake and water consumption related to control without bacteria administration. The analysis of microbiota composition revealed the presence of propionibacteria at the middle and end of the trial only in treated groups. Normal development of lactic acid bacteria and bifidobacteria, and slow colonisation by Bacteroides at the 7th day of the study was observed in the same groups. Analysis of the organic acids concentrations in the caecal content of birds revealed higher lactic acid and lower butyric acid production. Lower short chain fatty acids total concentration than expected during treatment was related to a better development of the gut mucosa. Increase in length of villus-crypt units, goblet cells counts and neutral mucins production were evidenced. Higher mucus secretion produced by dietary supplementation with propionibacteria could provide increased protection against pathogens.

Propionibacterium acidipropionici CRL1198 influences the production of acids and the growth of bacterial genera stimulated by inulin in a murine model of cecal slurries.

Different attempts have been made to improve the health status of humans and animals by increasing the intestinal production of short-chain fatty acids (SCFA) derived from non-digestible carbohydrates fermentation. In this paper we investigate the in vitro production of short-chain fatty acids (SCFA) after addition of inulin, propionibacteria or a combination of both in an experimental model of mice cecal slurries. The development of bacterial genera which are usually stimulated by inulin addition was also investigated. According to our experimental data, acetic acid and butyric acids concentrations increased after incubation in slurries that had no supplements. By contrast, butyric acid concentrations remained in the basal value when supplements were used. Fermentation of only inulin did not increase the concentration of total SCFA. Propionibacterium acidipropionici CRL1198 improved the production of propionic acid in cecal slurries when it was added alone, but the effect was more noticeable in the combination with inulin. A modulation of the global fermentative activity of the cecal microbiota was evidenced by the increase on the ratio propionic acid/SCFA in supplementations with propionibacteria. Statistical analysis of data demonstrated that samples from homogenates with propionibacteria alone or combined with inulin belong to the same cluster. The presence of propionibacteria limited the growth of Bacteroides fragilis and Clostridium hystoliticum groups in slurries with and without inulin. The growth of Bifidobacterium was not modified and the stimulating effect of inulin on lactobacilli disappeared in the presence of propionibacteria. In conclusion, dairy propionibacteria are potential candidates to develop new functional foods helpful to ensure the intestinal production of SCFA during inulin supplementation and to control the overgrowth of bacteria belonging to Bacteroides and Clostridium genera.