BACKGROUND: Today the use of natural substances plays a major role in improving the growth and immunity of aquatic organisms. OBJECTIVES: The purpose of the present study was to evaluate the effects of Iron nanoparticles with Lactobacillus casei as a probiotic on growth parameters and probiotic counts in rainbow trout intestine. METHODS: Seven hundred and twenty fish with 12±0.49 g initial weight were prepared and after acclimatized to the laboratory conditions divided randomly into six groups. First group was selected as control, other groups were fed with a commercial diet supplemented with 108 CFU/g Lactobacillus casei (group 2), 50 µg/kg Iron nanoparticles (group 3), 100 µg/kg Iron nanoparticles (group 4), 50 µg/kg Iron nanoparticles with 108 CFU/g Lactobacillus casei (group 5) and 100 µg/kg Iron nanoparticles with 108 CFU/g Lactobacillus casei (group 6), respectively. Biometry and intestine bacteriologic examination were carried out at days 0 and 60. RESULTS: Results showed that growth parameters (weight gain, body weight gain, specific growth rate, daily growth rate, and condition factor and food conversion rate) were significantly higher in group 5 compared with the other groups. Also, intestine bacterial counts increased by using Iron nanoparticles in combination with Lactobacillus casei. The fish that received 100 µg/kg Iron nanoparticles and probiotic had significantly higher bacterial counts in their intestine compared with the other groups. CONCLUSSIONS: Based on the obtained results we conclude that diet supplementation with Iron nanoparticles and Lactobacillus casei as a probiotic could significantly improve growth parameters in rainbow trout. However, these results would warrant further study on the clinical application of these agents.

BACKGROUND: Cheese is a dairy product that is popular in the world. Prebiotics and probiotics are increasingly being used to produce potentially symbiotic foods, particularly through dairy products as vehicle. It is well known that both ingredients may offer benefits to improve host health. OBJECTIVES: In this study prebiotic effect of Olive leaf extract or survival of Lactobacillus casei in UF cheese production during 10 weeks storage in cold condition was researched. METHODS: After provision of aqueous extract of olive leaf, probiotic bacteria and starter culture were prepared for inoculation. This extract was added to UF cheese in the presence of the bacteria then, counting of L.Casei on MRS-bile agar with pour plate was done during 10 weeks of storage and sensory evaluation was performed after 10 weeks of cheese storage at 4 °C. RESULTS: The number of L. Casei was affected significantly by the addition of OLE (P<0.05). The bacterial growth had a significant relationship with the increase in OLE concentrations (P< 0.05). After 10 weeks, in all probiotic cheese, the concentration of L. Casei was at the level of 106 - 108 cfu/g. Also, sensory quality was positively affected by the presence of OLE in cheese samples. Cheese sample produced with the addition of 0.5% of OLE was the most desirable. CONCLUSIONS: The number of Lactobacillus casei was significantly increased during the storage weeks due to the addition of different concentrations of olive leaf extract. The number of probiotic was increased with increasing concentrations of the extract (P<0.05). Also, positive effects on the sensory properties of cheese samples affected by olive leaf extract were observed and the most common cheese sample was 0.5% of this extract.

BACKGROUND: Lactic acid bacteria are the most common class of bacteria used in aquaculture as probiotic. ObjectiveS: In this study the effects of various levels of Lactobacillus casei on the growth performance and digestive enzymes activity of juvenile Shirbot were evaluated. Methods: Four hundred-eighty juvenile Shirbot weighing 40 g were divided randomly in four treatments (in triplicate). Treatments of A, B and C were fed with 5×106 CFU g-1, 5×107 CFU g-1, 5×108 CFU g-1, respectively for 60 days. Control group was fed with free-probiotic diet. After the period, treatments were fed with free-probiotic diet for 15 days. Growth indices and digestive enzymes were examined on days 0, 30, 60 and 75. Results: In the Treatment B, Specific Growth  Ratio, Daily Weight Growth and Relative Growth Rate, after 30 days from the beginning of experiment improved considerably which, compared to control group had significant difference (p<0.05). Activity of chymotrypsin enzyme in treatment of group B after 30 days and similarly, trypsine in treatment of group C after 30 and 60 days, were increased significantly compared to control group (p<0.05). In the other points of sampling and enzymes, considerable difference was not seen (p>0.05). Conclusions: Results showed that 5×107 CFUg-1 of Lactobacillus casei for 30 days and 5×108 CFUg-1 for 60 days, are the best doses of probiotic.

In order to study the ability of Lactobacillus casei to ameliorate murine enteritis, 18 mice were randomly divided into 3 groups: the enteritis group, intervention group, and control group. The interleukin (IL)-6 and transforming growth factor-β (TGF)-β content in mouse peripheral blood and duodenum was detected using an enzyme-linked immunosorbent assay (ELISA). The number of CD4+CD25+Foxp3+ T-regulatory cells (Tregs) and CD4+IL-17A+ Th17 cells in the mesenteric lymph nodes (MLN) and spleen were detected using flow cytometry, and quantitative reverse transcription polymerase chain reaction (PCR) and western blot analysis were used to measure Foxp3 and retinoid-related orphan receptor-γ (RORγt) mRNA and protein expression in the MLN. Histological changes in the duodenum were observed. Results indicate that in the intervention group, IL-6 content in mouse peripheral blood and duodenum was significantly lower than in the enteritis group (P < 0.05), while TGF-β content was significantly increased compared to the enteritis group (P < 0.05). For the intervention group, the percentages of CD4+CD25+Foxp3+ Tregs in spleen and MLN were increased (P < 0.05), while the percentages of CD4+IL-17A+ Th17 cells were decreased compared to the enteritis group (P < 0.05). The expression of Foxp3 mRNA and protein in the intervention group was higher than in the enteritis group, while RORγt mRNA and protein were significantly lower (P < 0.05). After mice in the enteritis group were treated with L. casei, duodenal inflammation was relieved. This study demonstrated that L. casei could have possible implications for the enterotoxigenic Escherichia coli (ETEC) induced intestinal inflammation by regulating the ratio imbalance of Th17/Treg cells.

OBJECTIVE To culture Lactobacillus spp from veterinary probiotics and measure their in vitro oxalate-degrading capacity. SAMPLE 2 commercial veterinary probiotics containing Lactobacillus spp. PROCEDURES Lactobacillus spp were cultured anaerobically on selective deMan, Rogosa, Sharpe agar medium and subcultured for speciation by 16S rDNA gene sequencing. Isolates were inoculated into broth containing sodium oxalate (5 mg/L) and incubated anaerobically for 72 hours. An oxalate-degrading isolate of Lactobacillus acidophilus (American Type Culture Collection [ATCC] 53544) was the positive control sample; sterile broth containing a known quantity of sodium oxalate was the negative control sample. Oxalate concentrations were detected with ion chromatography. Oxalate degradation was assessed with Dunnett tests to detect differences in mean oxalate concentration for each isolate, compared with results for the negative control. RESULTS Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus casei or Lactobacillus zeae (too closely related to differentiate) were isolated from probiotic 1, and L plantarum was isolated from probiotic 2. Sequencing of the 16S rDNA gene confirmed 100% homology to type species. Lactobacillus acidophilus (ATCC 53544) and L acidophilus from probiotic 1 significantly decreased oxalate concentrations by 85.3 and 161.9 mg/L, respectively. Lactobacillus plantarum from probiotics 1 and 2 significantly increased oxalate concentrations by 56.1 and 36.1 mg/L, respectively. Lactobacillus casei did not alter oxalate concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Lactobacillus acidophilus isolates significantly reduced oxalate concentrations. In vivo studies are needed to determine whether probiotics containing L acidophilus decrease urine oxalate concentrations and reduce risk of urolith recurrence in dogs with a history of calcium oxalate urolithiasis.