Lactobacillus paracasei DTA81, a cholesterol-lowering strain having immunomodulatory activity, reveals gut microbiota regulation capability in BALB/c mice receiving high-fat diet.

AIMS: In-vitro/In-vivo evaluation of cholesterol-lowering probiotic strain Lactobacillus paracasei DTA81 and the possible connection with the gut microbiota modulation. METHODS AND RESULTS: In the present study, strain DTA81 has been evaluated for the possible influence on blood lipid and glucose concentrations, modulation of the immune system, gastrointestinal survivability and modulation of gut microbiota in BALB/c mice receiving a high-fat diet. After 6 weeks of treatment, a significant reduction of total cholesterol and fasting blood sugar (FBS) among animals treated with L. paracasei DTA81 has been recorded. Comparison of colon tissue levels of different cytokines revealed a significant reduction of the inflammatory cytokine interleukin-6. The comparison of gut microbiota using the 16S rRNA approach indicated that the treatment with L. paracasei DTA81 significantly increased the taxa Bacteroidetes and Coprococcus. Moreover, the genome of DTA81 was sequenced for the in-silico assessment, and the analysis indicated the presence of cholesterol assimilation-related genes as well as the absence of negative traits such as transmissible antibiotic resistance genes, plasmids and prophage regions. CONCLUSION: The outcome of this study revealed the in-vitro and in-vivo properties of L. paracasei DTA81 and the possible mechanism between consumption of this strain, the abundance of Bacteriodetes/Coprococcus taxa, immunomodulatory activity and the subsequent reduction of cholesterol/FBS in BALB/c mice. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus paracasei DTA81 as a non-pharmacological potential probiotic supplement can influence metabolic homeostasis in individuals, particularly those adopting high-fat diets, and it can contribute to reduce coronary heart disease.

Caseinate protects stallion sperm during semen cooling and freezing.

Extenders with a defined composition containing only components with clearly protective effects on sperm during storage would be an advantage. The aims of the present work were to assess whether caseinate, improves cooled and frozen equine semen quality. Semen from six stallions were suspended with four different cooling extenders C1) Kenney extender; C2) 0.6 % caseinate; C3) 2.7 % caseinate ; and C4) C1 + 2.1 % caseinate, and frozen extenders: F1) INRA 82 extender; F2) 1.35 % caseinate; and F3) 2.7 % caseinate. Although there was no significant difference between the motility rate among the cooled (C1:45.0, C2:36.7, C3:38.3 and C4:48.3) and frozen extenders (F1:16.9, F2:21.1 and F3:18.6), significant higher values of sperm velocity variables were observed with the 1.35 % caseinate extender compared to the control (VSL: 40.8 x 18.9 and VAP: 46.8 x 25.0 µm/s), respectively. Caseinate seemed to be responsible for sperm protection during preservation and showed to be as efficient as milk.

Extenders containing dimethylformamide associated or not with glycerol are ineffective for ovine sperm cryopreservation.

The study aimed at testing the effectiveness of dimethylformamide, alone or combined with glycerol, as cryoprotectant for freezing ram semen. Ejaculates from nine rams were cryopreserved in Tris-based extenders, containing 5% of glycerol, association of dimethylformamide with glycerol, in four proportions achieving 5% of cryoprotectors in the media and pure dimethylformamide (2, 3, 4 and 5%) in replacement to glycerol. The samples were diluted to 100 × 10(6) sptz/ml and stored in 0.25-ml straws in liquid nitrogen. After thawing (37 °C for 30 s), motility was preserved better by the extender containing 5% of glycerol (p < 0.05). The extenders containing pure dimethylformamide, or more than 2% in combination with glycerol, provided sperm motilities close to zero. Plasma and acrosomal membrane integrity were preserved better (p < 0.05) in the extender containing 5% glycerol. It can be concluded that dimethylformamide, alone or combined with glycerol, has no beneficial effects on ovine semen cryopreservation.