RESUMO
This study's objective was to evaluate the effect of the fermented soybean meal (FSBM) on Salmonella typhimurium (ST) to turkey poults using two models of infection. In the prophylactic model, one-day-old turkeys were randomly allocated to one of four different groups (n = 30 turkeys/group): (1) Control group, (2) FSBM group, (3) Control group challenged with ST (Control + ST), and (4) FSBM group challenged with ST (FSBM + ST). On day 9 of age, all poults were orally challenged with 106 colony forming units (CFU) ST and 24 h post-inoculation, intestinal samples were collected to determine ST recovery and morphometric analysis. Blood samples were collected to evaluate serum fluorescein isothiocyanate-dextran (FITC-d). In the therapeutic model, a similar experimental design was used, but turkeys were orally gavaged 104 CFU ST on day 1, and samples were collected at day 7. FSBM improved performance and reduced leaky gut in both experimental infective models. In the prophylactic model, FSBB induced morphology changes in the mucosa. Although the strains (Lactobacillus salivarius and Bacillus licheniformis) used for the fermentation process showed in vitro activity against ST, no significant effect was observed in vivo. The fermentation with different beneficial bacteria and different inclusion rates of FSBM requires further investigation.
RESUMO
The main goal of the present study was to address the effect of feeding fermented soybean meal-based diet to Atlantic salmon on gut microbiota. Further, expression of genes of interest, including cathelicidin antimicrobial peptide (cath), mucin 2 (muc2), aquaporin (aqp8ab), and proliferating cell nuclear antigen (pcna), in proximal intestine of fish fed either experimental diet was analyzed. Three experimental diets, including a control fishmeal (30% FM), soybean meal (30% SBM), or fermented soybean meal diet (30% FSBM) were randomly assigned to triplicate tanks during a 50-day trial. The PCR-TTGE showed microbiota composition was influenced by experimental diets. Bands corresponding to genus Lactobacillus and Pediococcus were characteristic in fish fed the FSBM-based diet. On the other hand, bands corresponding to Isoptericola, Cellulomonas, and Clostridium sensu stricto were only observed in fish FM-based diet, while Acinetobacter and Altererythrobacter were detected in fish fed SBM-based diet. The expression of muc2 and aqp8ab were significantly greater in fish fed the FSBM-based diet compared with the control group. Our results suggest feeding FSBM to Atlantic salmon may (1) boost health and growth physiology in fish by promoting intestinal lactic acid bacteria growth, having a prebiotic-like effect, (2) promote proximal intestine health by increasing mucin production, and (3) boost intestinal trans-cellular uptake of water. Further research to better understands the effects of bioactive compounds derived from the fermentation process of plant feedstuff on gut microbiota and the effects on health and growth in fish is required.