Influence of supplementation with iron and probiotic bacteria Lactobacillus plantarum and Lactobacillus curvatus on selected parameters of inflammatory state in rats on a high-fat iron-deficient diet.

BACKGROUND: A high-fat (HF) diet, diet iron deficiency and iron supplementation may affect inflammatory parameters. Probiotics influence both iron metabolism and inflammation. We compared the inflammatory state in rats on a HF iron-deficient diet receiving oral iron, Lactobacillus plantarum and Lactobacillus curvatus in different combinations. METHODS: This was a two-stage experiment. In groups C (n = 8) and HF (n = 8), rats ate a control or HF diet, respectively, for 16 weeks. In the group HFDEF (n = 48), rats ate a HF iron-deficient diet for 8 weeks (first stage) and were subsequently divided into 6 groups (n = 8 each) receiving the following for a further 8 weeks (second stage): HFDEF - a HF iron-deficient diet; HFDEFFe - a HF iron-deficient diet with iron; HFDEFLp and HFDEFLc - a HF iron-deficient diet with L. plantarum or L. curvatus, respectively; and HFDEFFeLp and HFDEFFeLc - a HF iron-deficient diet with iron and L. plantarum or L. curvatus, respectively. Body composition analysis and blood sampling was performed. Markers of iron status and levels of total antioxidant status (TAS), C-reactive protein (CRP), tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were measured in the blood. RESULTS: TAS was higher in the HFDEF group (756.57 ± 489.53 ng mL-1) versus the HFDEFLc group (187.04 ± 47.84 ng mL-1; P = 0.022). No more differences were found between groups, or in TAS, CRP, TNF-α and IL-6 concentrations. Also, no differences were found between groups for alanine and aspartate aminotransferases, glucose, total cholesterol, low- and high-density lipoproteins and triglycerides. TAS level was positively correlated with ferritin concentration, IL-6 with TAS and TNF-α with hepcidin level. CONCLUSIONS: Supplementation with L. plantarum, L. curvatus and iron in combinations exerts no influence on inflammatory status, lipid profile, hepatic function and serum fasting glucose in rats on a HF iron-deficient diet. © 2024 Society of Chemical Industry.

Gut Mycobiota Dysbiosis Is Associated with Melanoma and Response to Anti-PD-1 Therapy.

Recent research indicates that gut microbiota may be vital in the advancement of melanoma. In this study, we found that melanoma patients exhibited a distinct gut mycobiota structure compared with healthy participants. Candida albicans, Candida dubliniensis, and Neurospora crassa were more abundant in samples from patients with melanoma, whereas Saccharomyces cerevisiae and Debaryomyces hansenii were less abundant. During anti-PD-1 treatment, the relative amount of Malassezia restricta and C. albicans increased. A higher level of Saccharomyces paradoxus was associated with a positive response to anti-PD-1 treatment, whereas a higher level of Tetrapisispora blattae was associated with a lack of clinical benefits. High levels of M. restricta and C. albicans, elevated serum lactate dehydrogenase, and being overweight were linked to increased risk of melanoma progression and poorer response to anti-PD-1 treatment. Thus, this study has revealed melanoma-associated mycobiome dysbiosis, characterized by altered fungal composition and fungi species associated with a higher risk of melanoma progression, identifying a role for the gut mycobiome in melanoma progression.

Influence of Isoflavones and Probiotics on Magnesium Status in Healthy Female Rats.

Isoflavones and probiotics are promising nutrients for bone health, and magnesium (Mg) is essential for bone metabolism. This study aimed to determine the effects of daidzein, genistein and Lactobacillus acidophilus on the Mg status of healthy female rats. Forty-eight rats were randomly assigned to six groups, with the control group receiving a standard diet (AIN 93M). The remaining groups were fed the same diet with added ingredients such as tempeh flour; soy flour; pure daidzein and genistein; L. acidophilus or a combination of daidzein, genistein, and L. acidophilus. Tissue samples were collected after the eight-week intervention, and Mg concentrations were analysed using flame atomic absorption spectrometry. Myeloid and erythroid cells were determined using the haematoxylin and eosin bone staining method. Statistical analyses were conducted using one-way ANOVA with Tukey's post hoc test and Pearson's correlation coefficient. The threshold for significance was p < 0.05. Compared with the control group, adding tempeh to the diet of rats resulted in significant changes in Mg concentrations in various tissues, with a decrease in the kidneys and an increase in the fur. Although not statistically significant compared to the control group, the tempeh group showed increased Mg concentrations in the femur and spleen. The myeloid-to-erythroid cell ratio did not differ significantly among groups, but all intervention groups showed higher ratios than the control group. A strong negative correlation was observed between Mg concentrations in the kidneys and fur. Conversely, a positive correlation was identified between Mg concentrations in the pancreas and fur. Daily consumption of tempeh may improve Mg status in the organism. Intake of pure daidzein, genistein, or probiotic seems to have no effect on Mg concentrations in healthy rats.

Corrigendum to "Isoflavones and probiotics effect on bone calcium and bone cells in rats" [Heliyon 9(6) (June 2023) e16801].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e16801.].

Effects of isoflavone and probiotic intake on calcium transport and bone metabolism biomarkers in female rats.

Calcium is essential for maintaining bone health as it contributes to bone formation, remodeling, strength, and density. This study investigated the effect of isoflavones and probiotics on calcium transporters' gene expression, serum calcium levels, and bone metabolism biomarkers in healthy female rats. Forty-eight female Wistar rats were classified into six groups. Bone metabolism biomarkers (pyridinoline, deoxypyridinoline, parathyroid hormone, and osteocalcin) and serum calcium levels were measured by enzyme-linked immunosorbent assay (ELISA) and atomic absorption spectroscopy (AAS), respectively. Gene expression of calcium transporters (Trpv5 and Trpv6) was evaluated in duodenum and jejunum tissue samples using quantitative polymerase chain reaction (qPCR). Trpv5 and Trpv6, epithelial calcium channels, play a crucial role in calcium transport and homeostasis in the body. The study consisted of a1-week adaptation period for the rats to adjust to the controlled conditions, followed by an 8-week intervention phase. The daidzein and genistein group showed a significant increase in the gene expression of the Trpv6 transporter in the duodenum and a marked decrease in serum pyridinoline levels compared to the control group. The tempeh and soybean groups showed a significant decrease in the gene expression of the Trpv5 calcium transporter in the jejunum. However, no significant influence of the Lactobacillus acidophilus diet on calcium transport and bone metabolism biomarkers was observed in the L. acidophilus group. The correlation analysis showed a significant positive relationship between serum calcium, bone metabolism biomarkers, and calcium transporters. In conclusion, our study demonstrates that the daidzein and genistein diet improves calcium transport in the duodenum and reduces pyridinoline serum concentrations, while tempeh and soybean diets reduce calcium transport in the jejunum. However, the combination of daidzein, genistein, and L. acidophilus did not demonstrate a synergistic effect on calcium transport and bone metabolism, suggesting that further investigations are needed to elucidate their potential interactions.

Experimental Capacity of Human Fecal Microbiota to Degrade Fiber and Produce Short-Chain Fatty Acids Is Associated with Diet Quality and Anthropometric Parameters.

BACKGROUND: Short-chain fatty acids (SCFAs) are considered beneficial to human health. The associations between bacterial capacity to produce SCFAs, diet, and health are not fully understood. OBJECTIVE: We aimed to evaluate the capacity of human fecal microbiota to produce SCFAs and to metabolize soluble and insoluble fiber and to study its associations with human diet, anthropometric parameters, and carbohydrate and lipid metabolism. METHODS: A cross-sectional study was carried out with 200 adult participants. Diet was evaluated using food records. Capacity to produce acetate, butyrate, and propionate and to degrade soluble fiber were assessed in an ex vivo experiment where fecal samples were inoculated in a pectin-containing broth. Fecal ß-glucosidase activity was measured to assess potential to degrade insoluble fiber. RESULTS: The main dietary determinants of high capacity to metabolize fiber were high intake of vegetables, fruits, nuts, and seeds. After adjusting analyses for confounders, glucose and lipid parameters were not significantly associated with any of the studied microbial capacities, but the capacity to produce propionic acid was significantly associated with hip circumference (ß = -0.018, P = 0.044), which was seen especially in people eating healthy. CONCLUSIONS: We confirmed that high intake of fiber-rich products is positively associated with the capacity of fecal microbiota to degrade soluble and insoluble dietary fiber and that people eating healthy food might benefit from enhanced microbial capacity to produce propionic acid.

Isoflavones and probiotics effect on bone calcium and bone cells in rats.

Isoflavones and probiotics have shown the therapeutic potential to alter calcium absorption and bone cell metabolism. This study sought to ascertain the effect of isoflavones and probiotics on calcium status and bone health in healthy female rats. Forty-eight adult female Wistar rats were grouped and fed: a standard diet (control); and standard diets with tempeh; soy; daidzein and genistein; Lactobacillus acidophilus; and a combination of daidzein, genistein, and L. acidophilus. The biochemical serum parameters, such as alanine transaminase, aspartate transaminase, glucose, and triacylglycerol concentrations, were measured, and calcium contents in tissues were determined. After staining the bone with hematoxylin and eosin, the number of osteoblasts, osteocytes, and the percentage of bone marrow adipocytes were counted. Compared with the control group, the soy group showed a significantly lower triacylglycerol concentration. The L. acidophilus group considerably increased the calcium content in the femoral bone. The daidzein and genistein, L. acidophilus, and a combination of daidzein, genistein, and L. acidophilus groups showed significantly lower calcium contents in the heart and kidneys. The daidzein and genistein group significantly enhanced the number of osteoblasts and osteocytes. A substantial inverse correlation was observed between calcium contents in kidneys and osteoblasts. In conclusion, the combination of daidzein, genistein, and L. acidophilus may improve bone calcium concentrations and bone cells. However, no synergistic effect between isoflavones and probiotics was detected in this study.

The impact of soy products, isoflavones, and Lactobacillus acidophilus on iron status and morphological parameters in healthy female rats.

BACKGROUND: Isoflavones and probiotics are two major factors involved in bone health. Osteoporosis and disturbances in iron (Fe) levels are common health problems in aging women. This study aimed to analyze how soybean products, daidzein, genistein, and Lactobacillus acidophilus (LA) affect Fe status and blood morphological parameters in healthy female rats. METHODS: A total of 48 Wistar rats aged 3 months were randomly divided into six groups. The control group (K) received a standard diet (AIN 93 M). The remaining five groups received a standard diet supplemented with the following: tempeh flour (TP); soy flour (RS); daidzein and genistein (DG); Lactobacillus acidophilus DSM20079 (LA); as well as a combination of daidzein, genistein, and L. acidophilus DSM20079 (DGLA). After 8 weeks of intervention, blood samples of the rats were collected for morphological analysis, whereas tissue samples were collected and kept at -80 °C until Fe analysis. Red blood cells, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets (PLTs), red cell distribution width, white blood cells, neutrophils (NEUT), lymphocytes (LYM), monocytes, eosinophils (EOS), and basophils were measured for blood morphological analysis. Fe concentrations were determined using flame atomic spectrometry. For statistical analysis, an ANOVA test for significance at the 5 % level was used. The relationship between tissue Fe levels and blood morphological parameters was determined using Pearson's correlation. RESULTS: Although no significant differences were observed in the Fe content between all diets, the TP group showed significantly higher levels of NEUT and lower levels of LYM than the control group. Compared with the DG and DGLA groups, the TP group showed a dramatically higher PLT level. In addition, the RS group showed significantly higher Fe concentrations in the spleen compared with the standard diet. Compared with the DG, LA, and DGLA groups, the RS group also showed significantly higher Fe concentrations in the liver. Compared with the TP, DG, LA, and DGLA groups, the RS group showed dramatically higher Fe concentrations in the femur. Pearson's correlations between blood morphological parameters and Fe levels in tissues were observed, especially a negative correlation between the Fe level in the femur and the NEUT concentration (-0.465) and a strong positive correlation between the Fe level in the femur and the LYM concentration (0.533). CONCLUSION: Soybean flour was found to increase Fe levels in rats, whereas tempeh may alter anti-inflammatory blood parameters. Isoflavones and probiotics did not affect Fe status in healthy female rats.

Listeria monocytogenes Isolates from Meat Products and Processing Environment in Poland Are Sensitive to Commonly Used Antibiotics, with Rare Cases of Reduced Sensitivity to Ciprofloxacin.

Antibiotic resistance is a global health problem, causing not only an increased mortality rate of bacterial infections but also economic losses due to, among other reasons, the need for longer hospital stays. Listeria monocytogenes is one of the foodborne pathogens with the ability to induce a serious illness called listeriosis, with approximately 20-30% fatal outcomes. The treatment regimen of listeriosis in humans includes the administration of antibiotics (in most cases, ampicillin or trimethoprim with sulfamethoxazole in case of allergies to ß-lactams), so the resistance of this pathogen to antibiotics can potentially lead to increased mortality. The antibiotic sensitivity status of n = 153 L. monocytogenes isolates originating from meat food samples (raw and processed) and meat-processing environment (both contacting and non-contacting with food) collected between October 2020 and November 2021 in Poland was examined in this study. Susceptibility to antibiotics was determined using the disc diffusion method on Mueller-Hinton agar plates. All collected samples were susceptible to 9 antibiotics: ampicillin (10 µg), chloramphenicol (30 µg), erythromycin (15 µg), gentamicin (10 µg), penicillin (10 IU), streptomycin (10 µg), sulfamethoxazole/trimethoprim (1.25/23.75 µg), tetracycline (30 µg) and vancomycin (30 µg). Some of the isolates (n = 10; 6.5%) showed reduced susceptibility to ciprofloxacin (5 µg), which was classified as an intermediate response. All these ten isolates were collected from surfaces contacting with food in food-processing facilities.

Myeloid-Derived Suppressor Cells (MDSC) in Melanoma Patients Treated with Anti-PD-1 Immunotherapy.

Myeloid-derived suppressor cells (MDSC) are a subset of immature myeloid cells with suppressive activity well described in the context of cancer. They inhibit anti-tumour immunity, promote metastasis formation and can lead to immune therapy resistance. In a retrospective study, blood probes of 46 advanced melanoma patients were analysed before the first administration of anti-PD-1 immunotherapy and in the third month of treatment for MDSC, immature monocytic (ImMC), monocytic MDSC (MoMDSC) and granulocytic MDSC (GrMDSC) by multi-channel flow cytometry. Cell frequencies were correlated with response to immunotherapy, progression-free survival (PFS) and lactate dehydrogenase (LDH) serum level. Responders to anti-PD-1 therapy had higher MoMDSC levels (4.1 ± 1.2%) compared to non-responders (3.0 ± 1.2%) (p = 0.0333) before the first administration of anti-PD-1. No significant changes in MDSCs frequencies were observed in the groups of patients before and in the third month of therapy. The cut-off values of MDSCs, MoMDSCs, GrMDSCs and ImMCs for favourable 2- and 3-year PFS were established. Elevated LDH level is a negative prognostic factor of response to the treatment and is related to an elevated ratio of GrMDSCs and ImMCs level compared to patients' LDH level below the cut-off. Our data may provide a new perspective for more careful consideration of MDSCs, and specially MoMDSCs, as a tool for monitoring the immune status of melanoma patients. Changes in MDSC levels may have a potential prognostic value, however a correlation with other parameters must be established.

Circulating Microbial Cell-Free DNA in Health and Disease.

Human blood contains low biomass of circulating microbial cell-free DNA (cfmDNA) that predominantly originates from bacteria. Numerous studies have detected circulating cfmDNA in patients with infectious and non-infectious diseases, and in healthy individuals. Remarkable differences were found in the microbial composition of healthy subjects and patients compared to cohorts with various diseases or even patients with diversified prognoses, implying that these alterations may be associated with disease development. Although the function of circulating cfmDNA needs to be elucidated (whether it acts as a bystander of dysbiosis or a key player in disease development), several studies have demonstrated its potential as a non-invasive biomarker that may improve diagnosis and treatment efficacy. The origin of circulating cfmDNA is still the subject of much deliberation, but studies have identified members of various microbiome niches, including the gut, oral cavity, airways, and skin. Further studies investigating the origin and function of circulating cfmDNA are needed. Moreover, low-biomass microbiome studies are prone to contamination, therefore stringent negative experimental control reactions and decontamination frameworks are advised in order to detect genuine circulating cfmDNA.

Host Factors Associated with Gut Mycobiome Structure.

Recent studies revealed a significant role of the gut fungal community in human health. Here, we investigated the content and variation of gut mycobiota among subjects from the European population. We explored the interplay between gut fungi and various host-related sociodemographic, lifestyle, health, and dietary factors. The study included 923 participants. Fecal DNA samples were analyzed by whole-metagenome high-throughput sequencing. Subsequently, fungi taxonomic profiles were determined and accompanied by computational and statistical analyses of the association with 53 host-related factors. Fungal communities were characterized by a high prevalence of Saccharomyces, Candida, and Sporisorium. Ten factors were found to correlate significantly with the overall mycobiota variation. Most were diet related, including the consumption of chips, meat, sodas, sweetening, processed food, and alcohol, followed by age and marital status. Differences in α- and/or ß-diversity were also reported for other factors such as body mass index (BMI), job type, autoimmunological diseases, and probiotics. Differential abundance analysis revealed fungal species that exhibited different patterns of changes under specific conditions. The human gut mycobiota is dominated by yeast, including Saccharomyces, Malassezia, and Candida. Although intervolunteer variability was high, several fungal species persisted across most samples, which may be evidence that a core gut mycobiota exists. Moreover, we showed that host-related factors such as diet, age, and marital status influence the variability of gut mycobiota. To our knowledge, this is the first large and comprehensive study of the European cohort in terms of gut mycobiota associations with such an extensive and differentiated host-related set of factors. IMPORTANCE The human gut is inhabited by many organisms, including bacteria and fungi, that may affect human health. However, research on human gut mycobiome is still rare. Moreover, the large European-based cohort study is missing. Here, we analyzed the first large European cohort in terms of gut mycobiota associations with a differentiated host-related set of factors. Our results showed that chips, meat, sodas, sweetening, processed food, beer, alcohol consumption, age, and marital status were associated with the variability of gut mycobiota. Moreover, our analysis revealed changes in abundances at the fungal species level for many investigated factors. Our results can suggest potentially valuable paths for further, narrowly focused research on gut mycobiome and its impact on human health. In the coming era of gut microbiome-based precision medicine, further research into the relationship between different mycobial structures and host-related factors may result in new preventive approaches or therapeutic procedures.

A Clinical Outcome of the Anti-PD-1 Therapy of Melanoma in Polish Patients Is Mediated by Population-Specific Gut Microbiome Composition.

The gut microbiota is considered a key player modulating the efficacy of immune checkpoint inhibitor therapy. The study investigated the association between the response to anti-PD-1 therapy and the baseline gut microbiome in a Polish cohort of melanoma patients, alongside selected agents modifying the microbiome. Sixty-four melanoma patients enrolled for the anti-PD-1 therapy, and ten healthy subjects were recruited. The response to the treatment was assessed according to the response evaluation criteria in solid tumors, and patients were classified as responders or non-responders. The association between selected extrinsic factors and response was investigated using questionnaire-based analysis and the metataxonomics of the microbiota. In the responders, the Bacteroidota to Firmicutes ratio was higher, and the richness was decreased. The abundance of Prevotella copri and Bacteroides uniformis was related to the response, whereas the non-responders' gut microbiota was enriched with Faecalibacterium prausnitzii and Desulfovibrio intestinalis and some unclassified Firmicutes. Dietary patterns, including plant, dairy, and fat consumption as well as gastrointestinal tract functioning were significantly associated with the therapeutic effects of the therapy. The specific gut microbiota along with diet were found to be associated with the response to the therapy in the population of melanoma patients.

Ex vivo folate production by fecal bacteria does not predict human blood folate status: Associations between dietary patterns, gut microbiota, and folate metabolism.

Although some bacteria inhabiting the human gut synthesize folates, it has not yet been established whether bacterial folate biosynthesis can impact human folate status. The main objectives of this study were to evaluate associations between different lifestyle factors and the potential of fecal microbiota to produce folates, and to investigate whether this potential is associated with circulating folate and total homocysteine (tHcy) levels in humans. To this end, we carried out an observational study of two hundred adult participants, with high variance in dietary habits. Diet was determined using three-day food records. Fecal microbiota composition was assessed by 16S rRNA gene amplicon sequencing. To establish the folate-production potential of fecal bacteria, cultures containing feces were incubated under anaerobic conditions for 24 h, and the folate concentration was measured before and after incubation. The folate concentration in cultures was 185.4 ± 228.1 pg/ml/log(CFU/g) (2125.4 ± 2454.3 pg/ml) higher after incubation. This change in concentration was not associated with the healthy eating index that measures diet quality (r = -0.11, p = 0.11), but it was positively associated with low α-diversity (r = -0.18, p < 0.01), and high relative abundance of the Bacteroides, as well as Sutterella and Parasutterella genera. The gut microbiota's folate producing potential was associated neither with serum folate nor with plasma tHcy levels. In conclusion, some taxa of the native gut microbiota have the ability to synthesize folates under culture conditions, but this bacterial folate biosynthesis capacity does not predict human folate status.

The standardisation of the approach to metagenomic human gut analysis: from sample collection to microbiome profiling.

In recent years, the number of metagenomic studies increased significantly. Wide range of factors, including the tremendous community complexity and variability, is contributing to the challenge in reliable microbiome community profiling. Many approaches have been proposed to overcome these problems making hardly possible to compare results of different studies. The significant differences between procedures used in metagenomic research are reflected in a variation of the obtained results. This calls for the need for standardisation of the procedure, to reduce the confounding factors originating from DNA isolation, sequencing and bioinformatics analyses in order to ensure that the differences in microbiome composition are of a true biological origin. Although the best practices for metagenomics studies have been the topic of several publications and the main aim of the International Human Microbiome Standard (IHMS) project, standardisation of the procedure for generating and analysing metagenomic data is still far from being achieved. To highlight the difficulties in the standardisation of metagenomics methods, we thoroughly examined each step of the analysis of the human gut microbiome. We tested the DNA isolation procedure, preparation of NGS libraries for next-generation sequencing, and bioinformatics analysis, aimed at identifying microbial taxa. We showed that the homogenisation time is the leading factor impacting sample diversity, with the recommendation for a shorter homogenisation time (10 min). Ten minutes of homogenisation allows for better reflection of the bacteria gram-positive/gram-negative ratio, and the obtained results are the least heterogenous in terms of beta-diversity of samples microbial composition. Besides increasing the homogenisation time, we observed further potential impact of the library preparation kit on the gut microbiome profiling. Moreover, our analysis revealed that the choice of the library preparation kit influences the reproducibility of the results, which is an important factor that has to be taken into account in every experiment. In this study, a tagmentation-based kit allowed for obtaining the most reproducible results. We also considered the choice of the computational tool for determining the composition of intestinal microbiota, with Kraken2/Bracken pipeline outperforming MetaPhlAn2 in our in silico experiments. The design of an experiment and a detailed establishment of an experimental protocol may have a serious impact on determining the taxonomic profile of the intestinal microbiome community. Results of our experiment can be helpful for a wide range of studies that aim to better understand the role of the gut microbiome, as well as for clinical purposes.

ß-glucuronidase activity is associated with carbohydrate metabolism but not with androgen status in overweight and obese women with polycystic ovary syndrome.

OBJECTIVES: The aim of this study was to evaluate the relationship between ß-glucuronidase and androgen levels in overweight and obese women with polycystic ovary syndrome (PCOS). The connection between ß-glucuronidase, the abundance of selected gut bacteria, carbohydrate metabolism, and diet quality was also determined. METHODS: This cross-sectional study was conducted with 56 women with a mean age of 29.14 ± 5.11 y and a mean body mass index (BMI) of 34.15 ± 5.72 kg/m2. Anthropometrical parameters, fecal ß-glucosidase activity, and selected food frequency intake were measured. RESULTS: Women with better quality diets, apart from lower BMI and better carbohydrate metabolism parameters, had more abundant Faecalibacterium prausnitzii and Akkermansia muciniphila. Two-hour oral glucose tolerance test (OGTT-2h-glu; mg/dL) was the main predictor of ß-glucuronidase activity and there was no relationship between ß-glucuronidase activity and androgen levels. Non-Healthy Diet Index-14 (nHDI-14) was the main predictor for A. muciniphila, Bifidobacteriu. longum, and F. prausnitzii abundance. QUICKI was a significant predictor of A. muciniphila abundance and OGTT-2h-glu was a significant predictor of F. prausnitzii abundance. CONCLUSION: There was no relationship between ß-glucuronidase activity and androgen levels in overweight and obese women with PCOS, but ß-glucuronidase activity may be an important factor in carbohydrate metabolism. Modulation of the abundances of F. prausnitzii, A. muciniphila, and B. longum using special diets should thus be considered a promising intervention.

Antioxidant Activity, Probiotic Survivability, and Sensory Properties of a Phenolic-Rich Pulse Snack Bar Enriched with Lactiplantibacillus plantarum.

Pulse-based snack bars incorporated with probiotics were developed to provide an overview for the preparation of simple functional food concerning the antioxidant load and iron status improvement. The study focused on the application of microencapsulated probiotics in dry matrices, such as chickpeas and green lentils, in snack bars. The study aims to analyse the products' antioxidative activities, chemical and sensory properties, as well as the probiotic survivability in the dry matrices. The basic chemical composition showed that 100 g of product can fulfil up to 4.4% and 3.3% of the daily iron value from chickpeas and green lentils, respectively (assuming the iron bioavailability is 23%). Sensory evaluation and hedonic analysis of the fresh pulse snack bar showed that panelists preferred the chickpea snack bar over the green lentil snack bar. For storage analysis, snack bars were stored at 20 °C and were vacuum packaged in sealed low density polyethylene (LDPE) pouches with no light exposure for two months. Hedonic analysis during storage showed significant differences in the aroma of the snack bars (p < 0.05). Generally, the antioxidant activities decreased during the two months of storage. A strong correlation was observed between total phenolic content (TPC) and antioxidant activity assays: ORAC (Oxygen Radical Absorbance Capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), PCL (Photochemiluminescence). Moreover, after two months of storage, a 1-log decrease of probiotic viable cells was observed in both snack bars. To meet the dietary requirement of probiotics, it is suggested that people consume five portions and 9.4 portions of the chickpea and green lentil snack bars, respectively. The resulting products have promising properties with respect to probiotics and antioxidant potential in an unconventional way.

Nonhemolytic Listeria monocytogenes-Prevalence Rate, Reasons Underlying Atypical Phenotype, and Methods for Accurate Hemolysis Assessment.

Listeria monocytogenes is a foodborne pathogen that typically presents ß-hemolytic activity. However, there are literature reports indicating that L. monocytogenes strains are sometimes nonhemolytic or their zones of hemolysis are perceivable only after removal of the colonies from the agar plate. Nonhemolytic L. monocytogenes are most commonly encountered in food products, but some have also been detected in clinical samples. Usually, atypical bacteria of this species belong to serotype 1/2a. Mutations of the prfA gene sequence are the most common reason for changed phenotype, and mutations of the hly gene are the second most common cause. There are also reports that the methodology used for detecting hemolysis may influence the results. Sheep or horse blood, although most commonly used in modern studies, may not allow for the production of clear hemolytic zones on blood agar, whereas other types of blood (guinea pig, rabbit, piglet, and human) are more suitable according to some studies. Furthermore, the standard blood agar plate technique is less sensitive than its modifications such as bilayer or top-layer (overlay) techniques. The microplate technique (employing erythrocyte suspensions) is probably the most informative when assessing listerial hemolysis and is the least susceptible to subjective interpretation.

Influence of multistrain probiotic and iron supplementation on iron status in rats.

OBJECTIVE: The impact of multistrain probiotics on iron (Fe) metabolism under Fe-deficient diet conditions remains unknown. The study aimed to compare the effect of 6 weeks simultaneous and exclusive oral multistrain probiotic and iron supplementation on selected parameters of Fe metabolism in rats on an Fe-deficient diet. METHODS: Forty rats were assigned to five groups, with eight animals in each, and for 6 weeks received: the CC group- a standard diet, the DD group- an Fe-deficient diet, the DPB group- an Fe-deficient with a multispecies probiotic, the DFE group- an Fe-deficient diet supplemented with iron, the DPBFE group- an Fe-deficient diet with iron and a multispecies probiotic. The Fe content in blood and tissues; serum concentration of erythroferrone, ferritin (Ft), homocysteine, hepcidin (HEPC) and lactoferrin; liver content of divalent metal transporter 1 (DMT1), transferrin receptor protein 1 (TfR1) and 2 (TfR2) and ZRT/IRT-like protein 14 (ZIP14) and faecal microbiota were assessed. RESULTS: In DPBFE group, unlike in DPB and DFE groups, duodenal Fe content was higher compared to DD group. Similarly, serum Ft level was higher in DPBFE group, but not in DPB and DFE groups, compared to DD group. CONCLUSIONS: Six weeks simultaneous oral multistrain probiotic and Fe supplementation, but not exclusive probiotic or Fe intake, increases duodenal Fe absorption in rats and presents higher effectiveness in increasing tissue Fe stores.