The potential immunomodulatory role of the gut microbiota in the pathogenesis of asthma: an in vitro study.

The aim of this study was to investigate the influence of Bacteroides vulgatus (BV), Clostridium perfringens (CP), Parabacteroides distasonis (PD) and Ruminococcus albus (RA) lysates on secretion of selected cytokines by PBMC, MDM and HT-29 cells, as well as to determine the potential mechanisms of their action in the development of asthma. Enzyme-linked immunosorbent assays were used to analyze the effect of BV, CP, PD and RA lysates on the secretion of IL-1ß, IL-6, IL-10 and TNF-α by human PBMC, MDM and HT-29 cells. BV and CP lysates significantly lowered IL-1ß secretion by MDM vs. control (p < 0.05 and p < 0.001 respectively) but only at a dose of 400 µg lysate. The secretions of IL-6 by PBMC and MDM were elevated significantly above control values (p < 0.05) after administration of CP and PD lysates. BV, CP and PD lysates (100 µg) significantly increased IL-10 secretion by PBMC vs. control (p < 0.05). CP, PD and RA lysates (400 µg) significantly increased IL-10 secretion by MDM vs. control (p < 0.001). BV lysate (400 µg) also significantly increased IL-10 secretion by MDM as compared to control (p < 0.05). In PBMC and MDM, the production levels of the anti-inflammatory cytokine were increased by all the bacterial lysates used in a dose-dependent manner.

Compositional differences between gut microbiota of adult patients with asthma and healthy controls.

Introduction: Asthma is a complex and multifactorial disorder, with severe public health implications. Over the last several years, our knowledge in the field of human gut microbiota has expanded and allowed us to understand its crucial role in the development of many diseases. Aim: To analyse the nature of human gut microbiota patterns among patients with asthma compared to healthy controls. Material and methods: Composition of the complex gut microbiota was analysed in faecal samples from 13 asthma patients and 7 healthy volunteers using Next-Generation Sequencing technology (NGS). The Kruskal-Wallis Analysis of Variance (ANOVA) and Mann-Whitney tests were used to compare the above two groups of subjects. Results: The composition of the gut microbiota of asthma patients differed from that of healthy volunteers at each of the analysed levels (p < 0.05). Compared to healthy individuals, bacterial diversity was significantly lowered among the asthma group, which is the evidence of gut microbiota depletion in asthma patients. The analysis of beta diversity showed that the gut community compositions of asthma are widely dispersed in contrast to the tight clustering observed in the control group. Finally, the similarity index was found to be lower in the inter-group comparison than in the intra-group comparison, which confirmed changes in the gut microbial composition in the asthmatic group. Conclusions: The study revealed significant differences in the human gut microbiome composition between asthma patients and the healthy control group.

Antioxidative activity of probiotics.

Probiotics are defined as live microorganisms that have a beneficial effect on health by exhibiting quantitative and qualitative effects on intestinal microflora and/or modification of the immune system. A strain is considered probiotic if it demonstrates a series of clinically proven health benefits. In recent years, the number of studies related to the antioxidant properties of probiotics has significantly increased. Antioxidants are substances that inhibit the degree of oxidation of molecules and cause the transformation of radicals into inactive derivatives. The incorrect or inefficient antioxidant mechanisms results in oxidative stress and may occur in the course of many diseases such as diabetes, atherosclerosis, inflammatory bowel disease or damage to the heart, brain or transplanted organs. Correct functioning of antioxidant mechanisms seems to be crucial for the proper functioning of our body; therefore, probiotics should be carefully investigated for potential antioxidant properties.

The Influence of Probiotic Lactobacillus casei in Combination with Prebiotic Inulin on the Antioxidant Capacity of Human Plasma.

The aim of the present study was to assess whether probiotic bacteria Lactobacillus casei (4 × 10(8) CFU) influences the antioxidant properties of human plasma when combined with prebiotic Inulin (400 mg). Experiments were carried out on healthy volunteers (n = 32). Volunteers were divided according to sex (16 male and 16 female) and randomly assigned to synbiotic and control groups. Blood samples were collected before synbiotic supplementation and after 7 weeks, at the end of the study. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, and the ferric reducing ability of plasma (FRAP) in human plasma were examined. The administration of synbiotics containing L. casei plus Inulin resulted in a significant increase in FRAP values (p = 0.00008) and CAT activity (p = 0.02) and an insignificant increase in SOD and GPx activity compared to controls. Synbiotics containing L. casei (4 × 10(8) CFU) with prebiotic Inulin (400 mg) may have a positive influence on human plasma antioxidant capacity and the activity of selected antioxidant enzymes.