Isolation of bacterial consortia with probiotic potential from the rumen of tropical calves.

Probiotics are live microorganisms that confer health benefits to their animal host by balancing the composition of its gastrointestinal microbiota and modulating its immune response. In this work, we studied bacterial consortia isolated from the rumen of 28- and 42-day-old calves to select those showing probiotic capacity. Consortia were characterized and their growth dynamics were determined in several growth media. The number of viable bacteria was larger in the Man, Rogosa and Sharpe broth (MRS) than in nutritive medium A (MNA) and the largest was for A3D42. Antibiotic susceptibility of bacterial consortia in MRS was higher than in MNA and the most susceptible samples were A1D28 and A3D42. In turn, A3D42 showed the highest tolerance to bile salts in MRS and MNA. Moreover, all bacterial consortia showed optimal growth at pH 5, 5.5, 6 and 7 in both media, while their temperature tolerance was higher in MRS. The antagonistic activity of bacterial consortia in MNA was higher than in MRS with A2D42 showing the best antagonistic activity for Pseudomona aureginosa (ATCC 9027) and Staphylococcus aureus (ATCC 6538) in MNA. Additionally, A1D42 and A2D42 in MRS and A3D42 in MNA had significant adhesion to mucins, and A1D42 in MRS had the highest. Regarding their species composition, all bacterial consortia in MRS belonged to the phylum Firmicutes, and the class Bacilli and bacterial consortia in MNA belonged to three phyla; Proteobacteria, Firmicutes, and Bacteroidetes. Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus fermentum, and Lactobacillus johnsonii were identified in all bacterial consortia in MRS broth. Based on these results, A1D42 and A3D42 grown in MRS showed the best potential as probiotics for calves, which could result in health benefits and improve their production.

Improvement of physico-chemical properties and phenolic compounds bioavailability by concentrating dietary fiber of peach (Prunus persica) juice by-product.

BACKGROUND: This study aimed to concentrate dietary fiber (DF) from peach (Prunus persica) juice by-product (PJBP), to improve its functional properties, and its polyphenols bioavailability. The dietary fiber concentrates (DFCs) were obtained from PJBP using water/ethanol treatments (100:0, 20:80, 50:50, 80:20, and 0:100, v/v) at 1:5 ratio (wet weight/solvent, w/v) for 5 and 20 min at 21 °C. RESULTS: All treatments concentrated condensed tannins, total and insoluble DF, with the highest content found with 100% H2 O treatment. The major polyphenols of DFC were 4-O-caffeoylquinic, chlorogenic, and 1,5-di-O-caffeoylquinic acids. Water and oil retention capacity and maximum glucose diffusion rate were improved mainly with 100% H2 O treatment. Healthy rats were fed with a standard diet supplemented with 8% of PJBP, DFC obtained with 100% H2 O for 5 min, or DFC obtained with 20% EtOH for 5 min. Gastrointestinal digesta weight and viscosity were increased in animals supplemented with 100% H2 O DFC. Moreover, the urinary excretion of polyphenol metabolites, mainly glucuronide and sulfate conjugates, was increased with this treatment, indicating a greater bioavailability of PJBP polyphenols, which was associated with an increased dietary fiber porosity. CONCLUSION: Water treatment could be used to potentiate PJBP functional properties and polyphenols bioavailability. © 2017 Society of Chemical Industry.

Chitosan Nanoparticles Containing Lipoic Acid with Antioxidant Properties as a Potential Nutritional Supplement.

The addition of the antioxidant α-lipoic acid (ALA) to a balanced diet might be crucial for the prevention of comorbidities such as cardiovascular diseases, diabetes, and obesity. Due to its low half-life and instability under stomach-like conditions, α-lipoic acid was encapsulated into chitosan nanoparticles (Ch-NPs). The resulting chitosan nanoparticles containing 20% w/w ALA (Ch-ALA-NPs) with an average diameter of 44 nm demonstrated antioxidant activity and stability under stomach-like conditions for up to 3 h. Furthermore, fluorescent Ch-ALA-NPs were effectively internalized into 3T3-L1 fibroblasts and were able to cross the intestinal barrier, as evidenced by everted intestine in vitro experiments. Thus, chitosan-based nanoparticles seem to be an attractive administration method for antioxidants, or other sensible additives, in food.