Risk of Infection Associated With Administration of Intravenous Iron: A Systematic Review and Meta-analysis.

Importance: Intravenous iron is recommended by many clinical guidelines based largely on its effectiveness in reducing anemia. However, the association with important safety outcomes, such as infection, remains uncertain. Objective: To examine the risk of infection associated with intravenous iron compared with oral iron or no iron. Data Sources: Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials (RCTs) from 1966 to January 31, 2021. Ongoing trials were sought from ClinicalTrials.gov, CENTRAL, and the World Health Organization International Clinical Trials Search Registry Platform. Study Selection: Pairs of reviewers identified RCTs that compared intravenous iron with oral iron or no iron across all patient populations, excluding healthy volunteers. Nonrandomized studies published since January 1, 2007, were also included. A total of 312 full-text articles were assessed for eligibility. Data Extraction and Synthesis: Data extraction and risk of bias assessments were performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) and Cochrane recommendations, and the quality of evidence was assessed using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach. Two reviewers extracted data independently. A random-effects model was used to synthesize data from RCTs. A narrative synthesis was performed to characterize the reporting of infection. Main Outcomes and Measures: The primary outcome was risk of infection. Secondary outcomes included mortality, hospital length of stay, and changes in hemoglobin and red blood cell transfusion requirements. Measures of association were reported as risk ratios (RRs) or mean differences. Results: A total of 154 RCTs (32 920 participants) were included in the main analysis. Intravenous iron was associated with an increased risk of infection when compared with oral iron or no iron (RR, 1.17; 95% CI, 1.04-1.31; I2 = 37%; moderate certainty of evidence). Intravenous iron also was associated with an increase in hemoglobin (mean difference, 0.57 g/dL; 95% CI, 0.50-0.64 g/dL; I2 = 94%) and a reduction in the risk of requiring a red blood cell transfusion (RR, 0.93; 95% CI, 0.76-0.89; I2 = 15%) when compared with oral iron or no iron. There was no evidence of an effect on mortality or hospital length of stay. Conclusions and Relevance: In this large systematic review and meta-analysis, intravenous iron was associated with an increased risk of infection. Well-designed studies, using standardized definitions of infection, are required to understand the balance between this risk and the potential benefits.

Multi-Nutrient Fortified Dairy-Based Drink Reduces Anaemia without Observed Adverse Effects on Gut Microbiota in Anaemic Malnourished Nigerian Toddlers: A Randomised Dose-Response Study.

Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant morbidity, affects brain development and function, and results in weakness and fatigue. Although, iron fortification can reduce anaemia, yet the effect on gut microbiota is unclear. This open-label randomised study in anaemic malnourished Nigerian toddlers aimed to decrease anaemia without affecting pathogenic gut bacteria using a multi-nutrient fortified dairy-based drink. The test product was provided daily in different amounts (200, 400 or 600 mL, supplying 2.24, 4.48 and 6.72 mg of elemental iron, respectively) for 6 months. Haemoglobin, ferritin, and C-reactive protein concentrations were measured to determine anaemia, iron deficiency (ID) and iron deficiency anaemia (IDA) prevalence. Faecal samples were collected to analyse gut microbiota composition. All three dosages reduced anaemia prevalence, to 47%, 27% and 18%, respectively. ID and IDA prevalence was low and did not significantly decrease over time. Regarding gut microbiota, Enterobacteriaceae decreased over time without differences between groups, whereas Bifidobacteriaceae and pathogenic E. coli were not affected. In conclusion, the multi-nutrient fortified dairy-based drink reduced anaemia in a dose-dependent way, without stimulating intestinal potential pathogenic bacteria, and thus appears to be safe and effective in treating anaemia in Nigerian toddlers.

Relationship between duodenal microbiota composition, clinical features at diagnosis, and persistent symptoms in adult Coeliac disease.

BACKGROUND: Duodenal dysbiosis has been suggested to possibly influence the clinical manifestations of coeliac disease (CD), both at onset and when symptoms persist despite a gluten-free diet (GFD). AIMS: To evaluate the relationship between duodenal microbiota composition and: i) clinical phenotype of untreated CD (UCD); ii) presence and type of persistent symptoms despite a satisfactory serological and histological response to a strict GFD. METHODS: Duodenal microbiota was analyzed by 16S rRNA sequencing and compared with i) clinical features in 12 adult UCD patients; ii) presence/absence and type of persistent symptoms (diarrhea-predominant vs. non-diarrhea predominant) in 25 adult treated coeliac patients (TCD) on a strict GFD. RESULTS: UCD with iron deficiency anemia (IDA) had a pro-inflammatory shift in their duodenal microbiota (reduction of Firmicutes, p = 0.03; increase of beta-Proteobacteria, p = 0.02) than those without IDA. TCD with persistent diarrhea showed a reduction of Actinobacteria (p = 0.03) and Rothia spp (p = 0.046) compared to TCD suffering from other type of persistent symptoms. CONCLUSION: A distinctive duodenal microbiota profile is associated with IDA in UCD, and diarrhea-predominant persistent symptoms in TCD. Clinical interventions may include reconsidering patients presenting with IDA as a specific disease subtype, and dietary rebalancing if diarrhea persists despite histological response to a GFD.

Gut Microbial and Metabolic Profiling Reveal the Lingering Effects of Infantile Iron Deficiency Unless Treated with Iron.

SCOPE: Iron deficiency (ID) compromises the health of infants worldwide. Although readily treated with iron, concerns remain about the persistence of some effects. Metabolic and gut microbial consequences of infantile ID were investigated in juvenile monkeys after natural recovery (pID) from iron deficiency or post-treatment with iron dextran and B vitamins (pID+Fe). METHODS AND RESULTS: Metabolomic profiling of urine and plasma is conducted with 1 H nuclear magnetic resonance (NMR) spectroscopy. Gut microbiota are characterized from rectal swabs by amplicon sequencing of the 16S rRNA gene. Urinary metabolic profiles of pID monkeys significantly differed from pID+Fe and continuously iron-sufficient controls (IS) with higher maltose and lower amounts of microbial-derived metabolites. Persistent differences in energy metabolism are apparent from the plasma metabolic phenotypes with greater reliance on anaerobic glycolysis in pID monkeys. Microbial profiling indicated higher abundances of Methanobrevibacter, Lachnobacterium, and Ruminococcus in pID monkeys and any history of ID resulted in a lower Prevotella abundance compared to the IS controls. CONCLUSIONS: Lingering metabolic and microbial effects are found after natural recovery from ID. These long-term biochemical derangements are not present in the pID+Fe animals emphasizing the importance of the early detection and treatment of early-life ID to ameliorate its chronic metabolic effects.

Global look at nutritional and functional iron deficiency in infancy.

Iron-deficiency anemia (IDA) affects many infants in low- and middle-income countries (LMICs) and may impair cognitive development and adaptive immunity. Effective interventions to improve iron intakes for infants in LMICs are urgently needed. However, absorption of oral iron fortificants and supplements is low, usually <10%, and most of the iron passes into the colon unabsorbed. In randomized controlled trials, provision of iron to infants in LMICs adversely affects their gut microbiome and increases pathogenic Escherichia coli, gut inflammation, and diarrhea. To minimize these detrimental effects of iron, it is important to provide the lowest effective dosage and maximize fractional iron absorption. Prebiotic galacto-oligosaccharides and apo-lactoferrin may prove useful in iron formulations in LMICs because they increase absorption of fortificant iron and at the same time may mitigate the adverse effects of unabsorbed iron on the infant gut. Providing well-absorbed iron early in infancy may improve immune function. Recent data from a Kenyan birth cohort suggest IDA at the time of infant vaccination impairs the response to diphtheria, pertussis, and pneumococcus vaccines. A randomized trial follow-up study reported that providing iron to Kenyan infants at the time of measles vaccination increased antimeasles immunoglobulin G (IgG), seroconversion, and IgG avidity. Because IDA is so common among infants in LMICs and because the vaccine-preventable disease burden is so high, even if IDA only modestly reduces immunogenicity of vaccines, its prevention could have major benefits.

Iron Supplementation Influence on the Gut Microbiota and Probiotic Intake Effect in Iron Deficiency-A Literature-Based Review.

Iron deficiency in the human body is a global issue with an impact on more than two billion individuals worldwide. The most important functions ensured by adequate amounts of iron in the body are related to transport and storage of oxygen, electron transfer, mediation of oxidation-reduction reactions, synthesis of hormones, the replication of DNA, cell cycle restoration and control, fixation of nitrogen, and antioxidant effects. In the case of iron deficiency, even marginal insufficiencies may impair the proper functionality of the human body. On the other hand, an excess in iron concentration has a major impact on the gut microbiota composition. There are several non-genetic causes that lead to iron deficiencies, and thus, several approaches in their treatment. The most common methods are related to food fortifications and supplements. In this review, following a summary of iron metabolism and its health implications, we analyzed the scientific literature for the influence of iron fortification and supplementation on the gut microbiome and the effect of probiotics, prebiotics, and/or synbiotics in iron absorption and availability for the organism.

Salmonella effector SpvB interferes with intracellular iron homeostasis via regulation of transcription factor NRF2.

Iron is a necessary nutrient for humans and nearly all bacterial species. During Salmonella infection, macrophages limit the availability of iron to intracellular pathogens in one of the central components of nutritional immunity. However, Salmonella also have mechanisms to interfere with the antimicrobial effect of host iron withdrawal and meet their own nutrient requirements by scavenging iron from the host. Here, we provide what is, to our knowledge, the first report that SpvB, a pSLT-encoded cytotoxic protein whose function is associated with the intracellular stage of salmonellosis, perturbs macrophage iron metabolism, thereby facilitating Salmonella survival and intracellular replication. In investigating the underlying mechanism, we observed that the Salmonella effector SpvB down-regulated nuclear factor erythroid-derived 2-related factor 2 (NRF2), and its C-terminal domain was necessary and sufficient for NRF2 degradation via the proteasome pathway. Decreased NRF2 expression in the nucleus resulted in a decrease in its transcriptional target ferroportin, encoding the sole macrophage iron exporter, thus ultimately decreasing iron efflux and increasing the intracellular iron content. Additionally, SpvB contributes to the pathogenesis of Salmonella including severe serum hypoferremia, increased splenic and hepatic bacterial burden, and inflammatory injury in vivo. Together, our observations uncovered a novel contribution of SpvB to Salmonella pathology via interference with host intracellular iron metabolism.-Yang, S., Deng, Q., Sun, L., Dong, K., Li, Y., Wu, S., Huang, R. Salmonella effector SpvB interferes with intracellular iron homeostasis via regulation of transcription factor NRF2.

Association between Active H. pylori Infection and Iron Deficiency Assessed by Serum Hepcidin Levels in School-Age Children.

Hepcidin regulates iron metabolism. Its synthesis increases in infection and decreases in iron deficiency. The aim of this study was to evaluate the relationship between H. pylori infection and iron deficiency by levels of hepcidin in children. A total of 350 school-age children participated in this cross-sectional study. Determinations of serum ferritin, hemoglobin, hepcidin, C-reactive protein, and α-1-acid-glycoprotein were done. Active H. pylori infection was performed with a 13C-urea breath test. In schoolchildren without H. pylori infection, hepcidin was lower in those with iron deficiency compared to children with normal iron status (5.5 ng/mL vs. 8.2 ng/mL, p = 0.017); while in schoolchildren with H. pylori infection the levels of hepcidin tended to be higher, regardless of the iron nutritional status. Using multivariate analysis, the association between H. pylori infection and iron deficiency was different by hepcidin levels. The association between H. pylori and iron deficiency was not significant for lower values of hepcidin (Odds Ratio = 0.17; 95% Confidence Interval [CI] 0.02-1.44), while the same association was significant for higher values of hepcidin (OR = 2.84; CI 95% 1.32-6.09). This joint effect is reflected in the adjusted probabilities for iron deficiency: Individuals with H. pylori infection and higher levels of hepcidin had a probability of 0.24 (CI 95% 0.14-0.34) for iron deficiency, and this probability was 0.24 (CI 95% 0.14-0.33) in children without H. pylori infection and lower levels of hepcidin. In children with H. pylori infection and iron deficiency, the hepcidin synthesis is upregulated. The stimulus to the synthesis of hepcidin due to H. pylori infection is greater than the iron deficiency stimulus.

Helicobacter pylori and hematological disorders.

Helicobacter pylori (H. pylori) is one of the most common worldwide infections, which can affect both adults and children. The prevalence of this bacterium is variable in different countries, depending on various hygienic and socioeconomic conditions and living customs. The major damaged tissues of the infection are in the upper gastrointestinal tract, causing gastritis, gastric and duodenal ulcer and gastrointestinal malignancy. Nevertheless, other disorders are associated with this pathogen, including several hematological diseases, such as iron deficiency anemia, immune thrombocytopenia and vitamin B12 deficiency. A huge of data in literature support these associations, enough to recognize them in the last Maastricht V/Florence Consensus Report by European Study Group. The pathogenic mechanisms underlying the linkage between H. pylori and these hematological disorders are not clearly identified, but certainly the good hematological response reaches after eradication therapy confirm a central role of the bacterium in this scenario. Instead, the pathogenic mechanisms of H. pylori infection, which lead to the occurrence of mucosa-associated lymphoid tissue (MALT) lymphoma are clearer and more consolidated; so much that nowadays eradication therapy alone represents the only treatment in this disorder, when localized and with a concomitant H. pylori infection. This review focuses on the hematologic diseases related to H. pylori, particularly on iron deficiency anemia, vitamin B12 deficiency, immune thrombocytopenia and gastric MALT lymphoma.

Anemia in infancy is associated with alterations in systemic metabolism and microbial structure and function in a sex-specific manner: an observational study.

Background: Anemia is a term that describes low hemoglobin concentrations and can result from micronutrient deficiencies, infection, or low birth weight. Early-life anemia, particularly iron-deficiency anemia (IDA) is associated with several negative metabolic, developmental, and cognitive outcomes, some of which persist into adulthood. Objective: The aim of this study was to investigate alterations in systemic metabolism and fecal microbial diversity and functionality associated with anemia and IDA in male and female infants from Iquitos, Peru. Design: Cross-sectional stool and serum samples were collected from 95 infants (53 boys and 42 girls) at 12 mo of age. The fecal microbiome was assessed by using 16S ribosomal RNA gene sequencing, and the fecal and serum metabolomes were quantified using 1H-nuclear magnetic resonance. Results: The prevalence of anemia was 64%, with a greater proportion of anemia in male infants attributed to iron deficiency. Metabolically, anemia was associated with decreased concentrations of tricarboxylic acid cycle metabolites in both sexes (males: succinate, P = 0.031; females: fumarate, P = 0.028). In addition, anemic male infants exhibited significantly lower serum concentrations of several amino acids compared with nonanemic male infants. Although no specific structural or functional differences in the microbiota were observed with anemia in general, likely due the heterogeneity of its etiology, IDA affected the microbiome both structurally and functionally. Specifically, the abundance of butyrate-producing bacteria was lower in IDA subjects of both sexes than in nonanemic, non-iron-deficient subjects of the same sex (females: Butyricicoccus, P = 0.041; males: Coprococcus, P = 0.010; Roseburia, P = 0.027). IDA male infants had higher concentrations of 4-hydroxyphenyllactate (P < 0.001) and putrescine (P = 0.042) than those without IDA, whereas IDA female infants exhibited higher concentrations of leucine (P = 0.011) and valine (P = 0.003). Conclusions: Sexually dimorphic differences associated with anemia and IDA are suggestive of greater mitochondrial dysfunction and oxidative stress in male infants compared with female infants, and alterations in microbial structure and function may further contribute. Differences in metabolic pathways associated with anemia and IDA in each sex point to potential mechanisms for the associated lasting cognitive deficits. This trial is registered at clinicaltrials.gov as NCT03377777.

Helicobacter pylori and extragastric diseases.

Many studies have been performed in the last year concerning the potential role of Helicobacter pylori in different extragastric diseases, reinforcing the idea that specific microorganisms may cause diseases even far from the primary site of infection. While the role of H. pylori on idiopathic thrombocytopenic purpura, sideropenic anemia, and vitamin B12 deficiency has been well established, there is a growing interest in other conditions, such as cardiovascular, neurologic, dermatologic, obstetric, immunologic, and metabolic diseases. Concerning neurologic diseases, there is a great interest in cognitive impairment and neurodegeneration. The aim of this review was to summarize the results of the most relevant studies published over the last year on this fascinating topic.

Development of Probiotic Formulation for the Treatment of Iron Deficiency Anemia.

Probiotics are increasingly more present both as functional foods, and in pharmaceutical preparations with multiple levels of action that contribute to human health. Probiotics realize their positive effects with a proper dose, and by maintaining a declared number of probiotics cells by the expiration date. Important precondition for developing a probiotic product is the right choice of clinically proven probiotic strain, the choice of other active components, as well as, the optimization of the quantity of active component of probiotic per product dose. This scientific paper describes the optimization of the number of probiotics cells in the formulation of dietary supplement that contains probiotic culture Lactobacillus plantarum 299v, iron and vitamin C. Variations of the quantity of active component were analyzed in development batches of the encapsulated probiotic product categorized as dietary supplement with the following ingredients: probiotic culture, sucrosomal form of iron and vitamin C. Optimal quantity of active component L. plantarum of 50 mg, was selected. The purpose of this scientific paper is to select the optimal formulation of probiotic culture in a dietary supplement that contains iron and vitamin C, and to also determine its expiration date by the analysis of the number of viable probiotic cells.

Fatal gastrointestinal histoplasmosis 15 years after orthotopic liver transplantation.

We report a case of ileo-colonic Histoplasmosis without apparent respiratory involvement in a patient who had previously undergone an orthotopic liver transplant (OLT) for primary biliary cholangitis 15 years earlier. The recipient lived in the United Kingdom, a non-endemic region for Histoplasmosis. However, she had previously lived in rural southern Africa prior to her OLT. The patient presented with iron deficiency anaemia, diarrhoea, abdominal pain and progressive weight loss. She reported no previous foreign travel, however, it later became known that following her OLT she had been on holiday to rural southern Africa. On investigation, a mild granulomatous colitis primarily affecting the right colon was identified, that initially improved with mesalazine. Her symptoms worsened after 18 mo with progressive ulceration of her distal small bowel and right colon. Mycobacterial, Yersinia, cytomegalovirus and human immunodeficiency virus infections were excluded and the patient was treated with prednisolone for a working diagnosis of Crohn's disease. Despite some early symptom improvement following steroids, there was subsequent deterioration with the patient developing gram-negative sepsis and multi-organ failure, leading to her death. Post-mortem examination revealed that her ileo-colonic inflammation was caused by Histoplasmosis.

Systematic gastric biopsy in iron deficiency anaemia.

BACKGROUND AND STUDY AIMS: Gastric biopsies are recommended in patients with iron deficiency anaemia to identify atrophic gastritis. However, in practice, only duodenal biopsies are routinely performed. The aim of our study was to determine the value of gastric biopsies in iron deficiency anaemia. PATIENTS AND METHODS: A prospective study including all patients referred for gastrointestinal endoscopy for iron deficiency anaemia from May 2008 to September 2014 was performed. All patients having endoscopic lesions which may explain occult bleeding were excluded, as well as patients using non-steroidal anti-inflammatory drugs or anticoagulation treatment. Two fundic biopsies, two antral biopsies, and one biopsy from the lesser curve were taken in all patients. Following entities were particularly looked for: chronic gastritis, Helicobacter pylori infection, intestinal metaplasia, endocrine hyperplasia and villous atrophy. In cases where intestinal metaplasia was present in the fundus and associated with endocrine hyperplasia and glandular atrophy, immunohistochemical study was performed to confirm autoimmune gastritis. RESULTS: One hundred seventy-seven patients (mean age 50 years, range: 15-90) were included. Chronic gastritis was found in 149 cases (84%). Infection by Helicobacter pylori was found in 107 cases (60%). Fundic intestinal metaplasia was observed in 25 patients (14%) and was associated with Helicobacter pylori infection in 52% of cases. Atrophic gastritis was observed in 14 cases (8%) and autoimmune gastritis was confirmed in 5 cases by immunohistochemical study. One patient had on gastric biopsy a carcinoma with signet ring cells. CONCLUSION: Intestinal metaplasia was frequently observed and was mostly related to Helicobacter pylori infection. These patients require monitoring, especially if they are young because it represents a pre neoplastic condition. However, in our study autoimmune gastritis often described in the literature in case of iron deficiency anaemia was rarely seen raising the question of relative cost-efficiency of fundic biopsies during iron deficiency anaemia.

Helicobacter pylori sabA gene is associated with iron deficiency anemia in childhood and adolescence.

BACKGROUND: Gastric Helicobacter pylori colonization leads to iron deficiency anemia (IDA), especially in children and adolescents. However the pathogenesis is poorly understood. OBJECTIVE: We sought to identify specific H. pylori genes involved in IDA development, by comparing bacterial genome-wide expression profiling in patients affected or not. METHODS: H. pylori were isolated from four children with IDA and four from matched controls without IDA. Based on these isolates, cDNA microarrays under iron-replete or depleted conditions were systematically performed to compare gene expression profiles at the whole genome level. Real-time reverse-transcription (RT-) PCR and protein assays were performed for further assessing the profile differentiation of the identified H. pylori IDA-associated genes. RESULTS: We identified 29 and 11 genes with significantly higher or lower expression in the IDA isolates compared to non-IDA isolates, respectively. Especially notable were higher expression of sabA gene encoding sialic acid-binding adhesin in the IDA isolates, which was confirmed by real-time RT-PCR study. Moreover, iron-depletion in vitro led to up-regulation of fecA1 and frpB1 genes and down-regulation of pfr, as predicted. Known iron-regulated genes such as fur, pfr, fecA, and feoB did not significantly differ between both groups. The IDA isolates had significantly higher expression of vacuolating cytotoxin gene vacA than non-IDA isolates, consistent with the results of VacA protein assays. There were no significant differences in bacterial growth value between IDA and non-IDA isolates. CONCLUSIONS: It is likely that H. pylori carrying high expression of sabA causes IDA, especially in children and adolescents who have increased daily iron demand. In addition, it is possible that several host-interactive genes, including vacA, may play a synergistic role for sabA in IDA development.

Nationwide survey of Helicobacter pylori treatment for children and adolescents in Japan.

BACKGROUND: To prevent gastric cancer, a test-and-treat strategy for Helicobacter pylori has been proposed. This retrospective study assessed the clinical features, efficacy and safety of treatment for H. pylori infection in children and adolescents. METHODS: Questionnaires concerning the clinical features and treatment of H. pylori in children and adolescents were sent to doctors in 2013. It included questions on patient background, H. pylori-associated disease, first- and second-line treatment, success or failure of eradication, resistance to antibiotics, and occurrence of adverse events. In 2014, serious adverse events associated with treatment were analyzed. RESULTS: Invitation letters and questionnaires were sent to 1097 doctors, of whom 409 (37.3%) participated. Finally, 332 patients (mean age, 11.6 ± 3.4 years; male, n = 200) treated from 1997 to 2013 were analyzed. H. pylori-associated gastritis, iron deficiency anemia, and duodenal ulcer occurred most frequently. Success rates for first- and second-line treatments were 73.1% and 79.6%, respectively. Seventy-six H. pylori strains were analyzed for resistance to amoxicillin (AMPC) and clarithromycin (CAM), and 64 were analyzed for resistance to metronidazole (MNZ). CAM resistance was most frequent, occurring in 43.4% of patients; that of MNZ was 21.9%. Adverse events were observed in 13.8% of cases. In total, 587 cases of H. pylori infection were analyzed and no serious adverse events were observed. CONCLUSIONS: Treatment for H. pylori in children and adolescents is safe, but further studies on treatment regimens should be conducted to improve eradication rates and monitor increasing CAM resistance.

Modulation of urinary siderophores by the diet, gut microbiota and inflammation in mice.

Mammalian siderophores are believed to play a critical role in maintaining iron homeostasis. However, the properties and functions of mammalian siderophores have not been fully clarified. In this study, we have employed Chrome Azurol S (CAS) assay which is a well-established method for bacterial siderophores study, to detect and quantify mammalian siderophores in urine samples. Our study demonstrates that siderophores in urine can be altered by diet, gut microbiota and inflammation. C57BL/6 mice, fed on plant-based chow diets which contain numerous phytochemicals, have more siderophores in the urine compared to those fed on purified diets. Urinary siderophores were up-regulated in iron overload conditions, but not altered by other tested nutrients status. Further, germ-free mice displayed 50% reduced urinary siderophores, in comparison to conventional mice, indicating microbiota biotransformation is critical in generating or stimulating host metabolism to create more siderophores. Altered urinary siderophores levels during inflammation suggest that host health conditions influence systemic siderophores level. This is the first report to measure urinary siderophores as a whole, describing how siderophores levels are modulated under different physiological conditions. We believe that our study opens up a new field in mammalian siderophores research and the technique we used in a novel manner has the potential to be applied to clinical purpose.

Effect of Vitamin E With Therapeutic Iron Supplementation on Iron Repletion and Gut Microbiome in US Iron Deficient Infants and Toddlers.

BACKGROUND: Iron therapy induces inflammation, which could decrease iron absorption. Increased exposure of iron in the gut could also alter microbiome file. Providing antioxidants such as vitamin E with iron therapy has been associated with reduced oxidative potential. OBJECTIVE: The aim of the present study was to test the efficacy of adding vitamin E to therapeutic iron therapy on iron repletion, inflammation markers, and gut microbiome in iron-deficient infants and toddlers. DESIGN: This was a randomized, double-blind, control trial in which infants and toddlers (Denver, CO metro area) who were at risk of iron deficiency were screened. Eligible participants were randomized to receive iron therapy (6 mg ·â€Škg ·â€Šday) plus placebo (n = 22) or iron (6 mg ·â€Škg ·â€Šday) and vitamin E (18 mg/day, n = 14) for 8 weeks. Iron and inflammation status, and gut microbiome (16S sequencing) were analyzed in all participants before and after the treatment. RESULTS: After 8 weeks of treatment, average serum ferritin level returned to normal for both iron + placebo and iron + vitamin E groups at 33.3 ±â€Š20.2 and 33.5 ±â€Š21.5 µg/L, respectively. Serum vitamin E concentration increased in iron + vitamin E group. No change over time was observed regarding serum interleukin-4, tumor necrosis factor-α, or fecal calprotectin. The relative abundance of the genus Roseburia (phylum Firmicutes), a butyrate producer, increased in the Fe + E group (Δ1.3%, P < 0.01). Also at the genus level, the genus Escherichia decreased by 1.2% on average among all participants (effect of time P = 0.01). CONCLUSIONS: Using a therapeutic iron dose of 6 mg ·â€Škg ·â€Šday is effective in treating iron deficiency during an 8-week period, without inducing persistent inflammatory response. Changes of the gut microbiome raised the possibility that antioxidant therapy in conjunction with therapeutic iron supplementation could potentially improve microbial community profiles in the intestinal tract.

[The increasing and expression of virulence factors of opportunistic microorganisms in blood serum under various alternatives of iron homeostasis].

Staphylococcus aureus and Pseudomonas aeruginosa are foregroundpathogens of bacteriemia and sepsis. They produce large spectrum of such factors of pathogenicity permitting them to proliferate and survive in bloodstream as hydrolytic enzymes, adenosine diphosphate-ribosylarginine toxins, plasmocoagulase, etc. The occurrence of alteration of growth and expression of virulence factors of S. aureus and P. aeruginosa at fermentation in LB-broth depending on iron concentration was demonstrated previously. The conditions in vivo significantly differ the laboratory conditions. The activity of growth and expression of pathogenicity factors of S. aureus and P. aeruginosa at fermentation in blood serum of donors with different alternative of iron homeostasis was analyzed. The study established expression of genes of hemolytic phospholipase C (plcH), alginate (algD), exotoxin A (exoA) for P. aeruginosa and genes of protein A (spA), virulence global regulator (RNAIII) for S. aureus. The iron-deficient serum and serum with normal iron homeostasis decreased activity of growth of S. aureus and P. aeruginosa. The growth rate and expression level of all analyzed genes turned out higher at fermentation of S. aureus and P. aeruginosa in serums containing excess of iron (more than 30 mkM). The fermentation of P. aeruginosa in iron-deficient serum resulted in decreasing of expression level of genes plcH, algD, exoA. The expression of RNA III and spaA S.aureus in iron-deficient serum increased towards normal content of iron in blood. The example of S. aureus and P. aeruginosa demonstrated that expression of many virulence factors of opportunistic microorganisms depends on iron homeostasis of host organism. The survival and proliferation of microorganisms in blood depend on both immune status of host organism and biological characteristics of pathogen.

Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori.

BACKGROUND: The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia. METHODS: To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA. RESULTS: Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability. CONCLUSIONS: Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration.