Effect of in vitro cultivation on human gut microbiota composition using 16S rDNA amplicon sequencing and metabolomics approach.

Gut microbiota (GM) plays many key functions and helps maintain the host's health. Consequently, the development of GM cultivation under in vitro stimulating physiological conditions has gained extreme interest in different fields. In this study, we evaluated the impact of four culture media: Gut Microbiota Medium (GMM), Schaedler Broth (SM), Fermentation Medium (FM), and Carbohydrate Free Basal Medium (CFBM) on preserving the biodiversity and metabolic activity of human GM in batch in vitro cultures using PMA treatment coupled with 16S rDNA sequencing (PMA-seq) and LC-HR-MS/MS untargeted metabolomics supplemented with GC-MS SCFA profiling. Before the experiments, we determined the possibility of using the pooled faecal samples (MIX) from healthy donors (n = 15) as inoculum to reduce the number of variables and ensure the reproducibility of in vitro cultivation tests. Results showed the suitability of pooling faecal samples for in vitro cultivation study. Non-cultured MIX inoculum was characterized by higher α-diversity (Shannon effective count, and Effective microbial richness) compared to inocula from individual donors. After 24 h of cultivation, a significant effect of culture media composition on GM taxonomic and metabolomic profiles was observed. The SM and GMM had the highest α-diversity (Shannon effective count). The highest number of core ASVs (125) shared with non-cultured MIX inoculum and total SCFAs production was observed in the SM. These results might contribute to the development of standardized protocols for human GM in vitro cultivation by preventing methodological bias in the data.

Time Evolution of Microbial Composition and Metabolic Profile for Biogenic Amines and Free Amino Acids in a Model Cucumber Fermentation System Brined with 0.5% to 5.0% Sodium Chloride.

Salt concentrations in brine and temperature are the major environmental factors that affect activity of microorganisms and, thus may affect formation of biogenic amines (BAs) during the fermentation process. A model system to ferment cucumbers with low salt (0.5%, 1.5% or 5.0% NaCl) at two temperatures (11 or 23 °C) was used to study the ability of indigenous microbiota to produce biogenic amines and metabolize amino acid precursors. Colony counts for presumptive Enterococcus and Enterobacteriaceae increased by 4 and up to 2 log of CFU∙mL-1, respectively, and remained viable for more than 10 days. 16S rRNA sequencing showed that Lactobacillus and Enterobacter were dominant in fermented cucumbers with 0.5% and 1.5% salt concentrations after storage. The initial content of BAs in raw material of 25.44 ± 4.03 mg∙kg-1 fluctuated throughout experiment, but after 6 months there were no significant differences between tested variants. The most abundant BA was putrescine, that reached a maximum concentration of 158.02 ± 25.11 mg∙kg-1. The Biogenic Amines Index (BAI) calculated for all samples was significantly below that needed to induce undesirable effects upon consumption. The highest value was calculated for the 23 °C/5.0% NaCl brine variant after 192 h of fermentation (223.93 ± 54.40). Results presented in this work indicate that possibilities to control spontaneous fermentation by changing salt concentration and temperature to inhibit the formation of BAs are very limited.

Background levels of polycyclic aromatic hydrocarbons and legacy organochlorine pesticides in wheat sampled in 2017 and 2018 in Poland.

Both polycyclic aromatic hydrocarbons (PAHs) and legacy organochlorine insecticides (OCPs), including DDT, are dangerous chemical contaminants. The aims of this study were to (i) determine background levels of PAHs and legacy OCPs for wheat samples collected in 2017 and 2018 in Poland, (ii) identify differences between levels in wheat harvested in various regions of Poland, (iii) evaluate differences in contamination sources manifested by the profiles of the identified chemicals, (iv) identify possible correlations between different classes of chemicals present in wheat, and (v) assess the health risks associated with the presence of PAHs and OCPs in Polish wheat. Average concentrations found in the samples were 0.09 ± 0.03 µg kg-1 for benzo[a]pyrene (BaP) (formerly used as a single PAH marker), 0.43 ± 0.16 for the more recently introduced collective PAH 4 marker (benzo[a]anthracene + benzo[a]pyrene + chrysene + benzo[b]fluoranthene), and 1.07 ± 0.68 µg kg-1 for DDT and its metabolites. The PAH profiles indicated contamination from combustion-related emission sources (liquid fossil fuels, coal, biomass). Health risks associated with the presence of PAHs and OCPs in cereals were assessed using the margin of exposure (MOE) approach. The MOE values calculated based on the highest concentrations found in this study exceeded 50,000 for both BaP and PAH 4. The calculated worst-case scenario value for DDT and metabolites was as low as 0.3% of the respective tolerable daily intake (TDI) value. Assessment of dietary risk has shown that the presence of the two contaminant classes in Polish wheat grains is of low concern.

Dietary risk evaluation of acrylamide intake with bread in Poland, determined by two comparable cleanup procedures.

Acrylamide is regarded as a food chemical contaminant. The aims of this work included: (i) to develop sample cleanup procedures applicable for determination of AA in soft bread samples; (ii) to determine AA levels in soft bread available in retail trade in Poland and to compare them with currently standing benchmark levels; (iii) to determine dietary risk related to AA in soft bread. The procedure based on ion-exchange solid phase extraction was more suitable to obtain LOQs corresponding to AA concentrations in soft bread samples. AA levels found in bread samples were in 3.6-163 µg kg-1 range. AA levels varied greatly from sample to sample, which suggests that both food composition and manufacturing processes play a crucial role in AA generation. When considering reference point for neoplastic effects, Margin of Exposure calculated for AA taken with soft bread ranged between 543 and 3,035.

Are myelodysplastic syndromes underdiagnosed in Poland? A report by the Polish Adult Leukaemia Group.

OBJECTIVES: The epidemiology of myelodysplastic syndromes (MDS) differs among countries. Here, we present the first epidemiological indices determined for Poland. METHODS: Twenty-one haematological centres participated in the study. Patients diagnosed with MDS and acute myeloid leukaemia (AML) with 20-29% blasts were enrolled. Data collection was conducted for strictly predefined period. RESULTS: The overall crude incidence rate for all MDS subtypes was 1.95 (95% CI, 1.81-2.09) per 100 000 person-years: 2.46 (95% CI, 2.24-2.69) for males and 1.47 (95% CI, 1.31-1.65) for females; after excluding AML cases, the indices were as follows: 2.35 (95% CI, 2.08-2.66) for males and 1.27 (95% CI, 1.08-1.5) for females. Prevalence rate was 6.2 per 100 000 persons (95% CI, 5.96-6.45), that is 6.86 (95% CI, 6.49-7.24) for males and 5.58 (95% CI, 5.26-5.92) for females. Both incidence and prevalence increased with increasing age. The most frequently diagnosed MDS subtype was refractory cytopenia with multilineage dysplasia (RCMD), responsible for 30.3% of all newly diagnosed MDSs. CONCLUSIONS: RCMD is the most frequent MDS subtype in Poland. Incidence and prevalence indices are lower than those reported for other populations, which probably results from inadequate diagnosis of potential cases of this disease.

Demographic, Hematologic, and Clinical Features of Myelodysplastic Syndrome Patients: Results from the First Polish Myelodysplastic Syndrome Registry.

Epidemiological studies on myelodysplastic syndromes (MDS) in Middle-Eastern Europe are scarce. No data about the demographic, clinical, and laboratory features of Polish MDS patients have been published. The aim of this study was to assess the epidemiological data and toxic exposure of Polish MDS patients and their association with hematological parameters and clinical outcomes. For 15 months, 966 living MDS patients were enrolled at 24 centers (12 university and 12 community hospitals). Follow-up was conducted for the next 55 months. The percentage of patients older than 80 years (16%) was between the values for Eastern and Western countries. In patients younger than 55 years, a female predominance was observed (male/female ratio 0.70:1 vs. 1.29:1; p < 0.001). Female patients had higher platelet counts (160 × 109/l vs. 111 × 109/l; p < 0.001). Patients exposed to chemicals were younger than patients without such exposure; their median age at MDS diagnosis was 66 vs. 70 years (p = 0.037). Smokers had significantly lower hemoglobin concentrations (8.6 vs. 9.1 g/dl; p = 0.032) and lower platelet counts (99 × 109/l vs. 137 × 109/l; p < 0.001) than nonsmokers. We provide the first description of the characteristics of Polish MDS patients. Females predominated in the group aged <60 years and they had higher platelet counts. The course of the disease is affected by toxic exposure and smoking.

[Assessment of nitrates and nitrites contents in preschool food rations]. / Ocena zawartosci azotanów(V) i azotanów(III) w przedszkolnych racjach pokarmowych.

The aim of this study was evaluation of nitrate/nitrite contents in preschool food rations of children 4 - 6 years old. 30 food rations served in a nursery school in Warsaw within the autumn 2005 - spring 2006 period were taken into account (10 samples per season). The levels of nitrate/nitrite in the food rations were calculated using literature data on nitrate/nitrite content in food products. The amounts of nitrate/nitrite in the examined food rations varied seasonally. The recorded nitrate season means ranged from 93 mg NaNO3 in spring to 131 mg NaNO3 in winter. The values exceeded the nitrate accepted level from 22 to 72%. On the other hand, the recorded nitrite season means ranged from 0.52 mg to 0.72 mg NaNO2 and did not exceed the nitrite accepted level. Vegetables and their products were the main source of nitrates in the evaluated food rations, they contributed about 87% of the total supplied nitrate amount. On the other hand, nitrites were supplied mainly by vegetables, vegetable products (39%), and by meat products (23%).