The effect of iron therapy on oxidative stress and intestinal microbiota in inflammatory bowel diseases: A review on the conundrum

Iron Deficiency in Adults: A Review

Importance

Absolute iron deficiency, defined as low iron stores with or without anemia, affects approximately 2 billion people worldwide and 14% of adults in the US. Iron-deficiency anemia, defined as low hemoglobin due to low iron stores, affects approximately 1.2 billion people worldwide, including 10 million in the US.

Observations

Absolute iron deficiency progresses from low iron stores to iron-deficiency anemia. Individuals with nonanemic iron deficiency or iron-deficiency anemia may be asymptomatic or experience fatigue, irritability, depression, difficulty concentrating, restless legs syndrome (32%-40%), pica (40%-50%), dyspnea, lightheadedness, exercise intolerance, and worsening heart failure (HF). Symptom prevalences vary depending on age, comorbidities (eg, chronic kidney disease [CKD], HF), and severity and rate of development of iron deficiency. The most common causes of iron deficiency are bleeding (menstrual, gastrointestinal), impaired iron absorption (atrophic gastritis, celiac disease, bariatric surgical procedures), inadequate dietary iron intake, and pregnancy. In high-income countries, approximately 38% of nonpregnant, reproductive-age women have iron deficiency without anemia and about 13% have iron-deficiency anemia. During the third trimester of pregnancy, iron deficiency affects up to 84% of pregnant women, based on data from high-income countries. Additional risk factors include use of nonsteroidal anti-inflammatory drugs, inflammatory bowel disease (IBD [13%-90%]), and other chronic inflammatory conditions, such as CKD (24%-85%), HF (37%-61%), and cancer (18%-82%). Testing for iron deficiency is indicated for patients with anemia and/or symptoms of iron deficiency (fatigue, pica, or restless legs syndrome) and should be considered for those with risk factors such as heavy menstrual bleeding, pregnancy, or IBD. Iron deficiency is diagnosed by low serum ferritin (typically <30 ng/mL) in individuals without inflammatory conditions or by transferrin saturation (iron/total iron binding capacity × 100) less than 20%. Causes of iron deficiency should be identified and treated. Oral iron (ferrous sulfate 325 mg/d or on alternate days) is typically first-line therapy. Intravenous iron is indicated for patients with oral iron intolerance, poor absorption (celiac disease, post-bariatric surgical procedure), chronic inflammatory conditions (CKD, HF, IBD, cancer), ongoing blood loss, and during the second and third trimesters of pregnancy.

Conclusions and Relevance

Iron deficiency and iron-deficiency anemia are common conditions that may cause symptoms such as fatigue, exercise intolerance, and difficulty concentrating. Ferritin and/or transferrin saturation are required for diagnosis and screening. Oral iron is first-line therapy for most patients. Intravenous iron is used for individuals who do not tolerate or have impaired absorption of oral iron, those with ongoing blood loss, certain chronic inflammatory conditions (IBD, CKD, HF, cancer), and during the second and third trimesters of pregnancy.

Two Birds with One Stone: Empowering Probiotic with Nanoenzyme for the Treatment of Inflammatory and Anemia through Oral Administration

In the context of ulcerative colitis (UC), iron deficiency anemia (IDA) is often presented as a prevalent systemic manifestation. However, there is an absence of an effective strategy for the specific case of UC with IDA. Herein, mendelian randomization (MR) analysis is applied to confirm the causal association between UC and iron-related conditions. Accordingly, we have developed a probiotic-based therapeutic approach that synergistically alleviates inflammation and IDA. Probiotic Escherichia coli Nissle 1917 (EcN) is functionalized by the Fe3O4 nanoenzyme and hyaluronan (HA) through electrostatic layer-by-layer (LBL) adsorption. As expected, the obtained EcN@Fe3O4/HA exhibits excellent properties in vitro, such as gastric acid resistance and ROS-scavenging capability. Upon oral administration, EcN@Fe3O4/HA shows remarkable adhesion in vivo, particularly in inflamed mice. Moreover, EcN@Fe3O4/HA shows a "two birds with one stone" effect in dextran sulfate sodium (DSS)-induced mice. First, it exerts anti-inflammatory effects through promoting the expression of tight junction proteins and regulating the gut microbiota. Second, it addresses the issue of IDA. EcN@Fe3O4/HA effectively ameliorates IDA in DSS-induced mice through iron supplementation, EPO upregulation, and iron homeostasis modulation, resulting in enhanced RBC morphology and elevated cell counts. Therefore, the proposed strategy provides inspiration for future management of diseases and related complications.

Responsive carbon dot-embedded hybrid microgels for dual sensing of iron(III) and ciprofloxacin

A novel hybrid material was synthesized through the integration of nitrogen-doped carbon quantum dots (NCQDs) within a cationic poly(N-isopropylacrylamide-co-N-3-aminopropyl methacrylamide) (PNIPAM-co-APMH) microgel to create a highly sensitive, selective and multi-responsive system (NCQDs@PNIPAM-co-APMH) with an impressive quantum yield of 42%. The resultant hybrid microgel was shown to be an exceptional dual-functional sensor for detecting ferric ions (Fe3+) and ciprofloxacin (CIP). The detection of Fe3+ was marked by a "turn-off" fluorescence response, facilitated by dynamic quenching mechanisms. In contrast, upon the introduction of CIP into the Fe3+-quenched system (Fe3+-NCQDs@PNIPAM-co-APMH), a "turn-on" fluorescence response was observed, with a corresponding LOD of 0.41 μM. A logic gate framework was employed to achieve sequential sensing of Fe3+ and CIP in an "off-on" manner. Furthermore, the material exhibited excellent recovery rates, ranging from 86% to 108%, when applied to the analysis of real samples containing CIP. In addition to its sensing capabilities, the hybrid system was effectively utilized as a fluorescent ink, offering advanced anti-counterfeiting solutions and bolstering information security. This study highlights the substantial potential of NCQD-based hybrid materials in diverse sensing applications and their implications for practical innovations.

Harnessing food-derived bioactive peptides for iron chelation: an alternative solution to iron deficiency anemia

Iron deficiency anemia (IDA) is a global public health issue. In recent years, food-derived peptide-iron chelates have attracted attention as a potential solution. This review centers on the sources of food-derived peptides for iron chelation, covering marine organisms, terrestrial animals, and plant sources. The formation mechanisms and properties of peptide-iron chelates are discussed. Moreover, the potential applications of these chelates in ameliorating IDA are explored. The review also highlights the challenges and future research directions in the development and utilization of food-derived peptide-iron chelates.

Initial gut microbiota composition is a determining factor in the promotion of colorectal cancer by oral iron supplementation: evidence from a murine model

BACKGROUND

Colorectal cancer (CRC) development is influenced by both iron and gut microbiota composition. While iron supplementation is routinely used to manage anemia in CRC patients, it may also impact gut microbiota and promote tumorigenesis. In this study, we investigated the impact of initial gut microbiota composition on iron-promoted tumorigenesis. We performed fecal microbiota transplantation (FMT) in ApcMin/+ mice using samples from healthy controls, CRC patients, and mice, followed by exposure to iron sufficient or iron excess diets.

RESULTS

We found that iron supplementation promoted CRC and resulted in distinct gut microbiota changes in ApcMin/+ mice receiving FMT from CRC patients (FMT-CRC), but not from healthy controls or mice. Oral treatment with identified bacterial strains, namely Faecalibaculum rodentium, Holdemanella biformis, Bifidobacterium pseudolongum, and Alistipes inops, protected FMT-CRC mice against iron-promoted tumorigenesis.

CONCLUSIONS

Our findings suggest that microbiota-targeted interventions may mitigate tumorigenic effects of iron supplementation in anemic patients with CRC.

Low-dose ferric carboxymaltose vs. oral iron for improving hemoglobin levels in postpartum East Asian women: A randomized controlled trial

Ferric carboxymaltose (FCM) is widely used to correct anemia and replenish iron stores rapidly, particularly in Western populations. However, lower doses of FCM are typically used in East Asia, with limited research on their effectiveness, especially in postpartum women. This randomized controlled trial aimed to assess the efficacy of low-dose FCM compared with oral ferrous sulfate in increasing postpartum hemoglobin (Hb) levels and replenishing iron stores in East Asian women. Sixty postpartum women with Hb levels < 10 g/dL and serum ferritin ≤ 30 ng/mL were randomized to receive either intravenous FCM (500 mg at baseline and 2 weeks) or oral ferrous sulfate (210 mg daily for 4 weeks). The primary outcome was the increase in Hb levels at 2 weeks post-enrollment. Secondary outcomes included serum ferritin, transferrin saturation, the Edinburgh Postnatal Depression Scale (EPDS) score, and adverse events at 4 weeks. The FCM group demonstrated a significantly greater increase in Hb levels at 2 weeks (mean difference 0.42 g/dL; 95% CI: 0.12-0.72; P =  0.006), with markedly higher ferritin (adjusted mean difference 356.0 ng/mL; 95% CI: 321.0-403.0; P <  0.001) and transferrin saturation (adjusted mean difference 10.76%; 95% CI: 4.20-17.31; P =  0.002) at 4 weeks. Although there was no significant difference in final Hb levels at 4 weeks (mean difference 0.36 g/dL; 95% CI: -0.01-0.72; P =  0.055), the FCM group had a lower median EPDS score (median difference -3.0; 95% CI: -5.0 to -1.0; P =  0.002) and fewer gastrointestinal side effects, including constipation and nausea. Hypophosphatemia occurred asymptomatically in three patients in the FCM group. These findings suggest that low-dose FCM infusion is highly effective in increasing Hb levels at 2 weeks post-enrollment, with fewer gastrointestinal side effects and higher ferritin levels observed at 4 weeks post-enrollment compared with oral ferrous sulfate. This study was registered at the UMIN Clinical Trials Registry, which meets the requirements of the ICMJE, on December 1, 2021 (ID: UMIN000046049).

Prooxidant state in anticancer drugs and prospect use of mitochondrial cofactors and anti-inflammatory agents in cancer prevention

An extensive body of literature has associated cancer with redox imbalance and inflammatory conditions. Thus, several studies and current clinical practice have relied on the use of anticancer drugs known to be associated with prooxidant state. On the other hand, a number of studies have reported on the effects of several antioxidants, anti-inflammatory agents and of mitochondrial cofactors (also termed mitochondrial nutrients, MNs) in counteracting or slowing carcinogenesis, or in controlling cancer growth. In the available literature, a body of evidence points on the roles of anti-inflammatory agents and of individual MNs against carcinogenesis or in controlling cancer cell proliferation, but only a few reports on the combined use of two or the effect of three MNs. These combinations are proposed as potentially successful tools to counteract carcinogenesis in prospective animal model studies or in adjuvant cancer treatment strategies. A "triad" of MNs are suggested to restore redox balance, mitigate side effects of prooxidative anticancer drugs, or aid in cancer prevention and/or adjuvant therapy. By elucidating their mechanistic underpinnings and appraising their clinical efficacy, we aim to contribute with a comprehensive understanding of these therapeutic modalities.

Iron Homeostasis Dysregulation, Oro-Gastrointestinal Microbial Inflammatory Factors, and Alzheimer's Disease: A Narrative Review

Alzheimer's disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder that profoundly impacts cognitive function and the nervous system. Emerging evidence highlights the pivotal roles of iron homeostasis dysregulation and microbial inflammatory factors in the oral and gut microbiome as potential contributors to the pathogenesis of AD. Iron homeostasis disruption can result in excessive intracellular iron accumulation, promoting the generation of reactive oxygen species (ROS) and oxidative damage. Additionally, inflammatory agents produced by pathogenic bacteria may enter the body via two primary pathways: directly through the gut or indirectly via the oral cavity, entering the bloodstream and reaching the brain. This infiltration disrupts cellular homeostasis, induces neuroinflammation, and exacerbates AD-related pathology. Addressing these mechanisms through personalized treatment strategies that target the underlying causes of AD could play a critical role in preventing its onset and progression.

IL-6 signaling accelerates iron overload by upregulating DMT1 in endothelial cells to promote aortic dissection

Aortic dissection (AD), caused by tearing of the intima and avulsion of the aortic media, is a severe threat to patient life and organ function. Iron is closely related to dissection formation and organ injury, but the mechanism of iron ion transport disorder in endothelial cells (ECs) remains unclear. We identified the characteristic EC of dissection with iron overload by single-cell RNA sequencing data. After intersecting iron homeostasis and differentially expressed genes, it was found that hypoxia-inducible factor-1α (HIF-1α) and divalent metal transporter 1 (DMT1) are key genes for iron ion disorder. Subsequently, IL-6R was identified as an essential reason for the JAK-STAT activation, a classical iron regulation pathway, through further intersection and validation. In in vivo and in vitro, both high IL-6 receptor expression and elevated IL-6 levels promote JAK1-STAT3 phosphorylation, leading to increased HIF-1α protein levels. Elevated HIF-1α binds explicitly to the 5'-UTR sequence of the DMT1 gene and transcriptionally promotes DMT1 expression, thereby increasing Fe2+ accumulation and endoplasmic reticulum stress (ERS). Blocking IL-6R and free iron with deferoxamine and tocilizumab significantly prolonged survival and reduced aortic and organ damage in dissection mice. A comparison of perioperative data between AD patients and others revealed that high free iron, IL-6, and ERS levels are characteristics of AD patients and are correlated with prognosis. In conclusion, activated IL-6/JAK1/STAT3 signaling axis up-regulates DMT1 expression by increasing HIF-1α, thereby increasing intracellular Fe2+ accumulation and tissue injury, which suggests a potential therapeutic target for AD.

Calcium deficiency is associated with malnutrition risk in patients with inflammatory bowel disease

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) often have the condition of malnutrition, which can be presented as sarcopenia, micronutrient deficiencies, etc. Trace elements (magnesium, calcium, iron, copper, zinc, plumbum and manganese) belonging to micronutrients, are greatly vital for the assessment of nutritional status in humans. Trace element deficiencies are also the main manifestation of malnutrition. Calcium (Ca) has been proved to play an important part in maintaining body homeostasis and regulating cellular function. However, there are still a lack of studies on the association between malnutrition and Ca deficiency in IBD. This research aimed to investigate the role of Ca for malnutrition in IBD patients.

METHODS

We prospectively collected blood samples from 149 patients and utilized inductively coupled plasma mass spectrometry to examine their venous serum trace element concentrations. Logistic regression analyses were used to investigate the association between Ca and malnutrition. Receiver operating characteristic (ROC) curves were generated to calculate the cutoffs for determination of Ca deficiency.

RESULTS

Except Ca, the concentrations of the other six trace elements presented no statistical significance between non-malnutrition and malnutrition group. In comparison with the non-malnutrition group, the serum concentration of Ca decreased in the malnutrition group (89.36 vs 87.03 mg/L, p = 0.023). With regard to ROC curve, Ca < 87.21 mg/L showed the best discriminative capability with an area of 0.624 (95% CI: 0.520, 0.727, p = 0.023). Multivariate analyses demonstrated that Ca < 87.21 mg/L (OR = 3.393, 95% CI: 1.524, 7.554, p = 0.003) and age (OR = 0.958, 95% CI: 0.926, 0.990, p = 0.011) were associated with malnutrition risk. Serum Ca levels were significantly lower in the malnutrition group than those in the non-malnutrition group among UC patients, those with severe disease state or the female group.

CONCLUSIONS

In patients with IBD, Ca deficiency is an independent factor for high malnutrition risk.

Extrapulmonary Comorbidities Associated with Chronic Obstructive Pulmonary Disease: A Review

Most patients with chronic obstructive pulmonary disease (COPD) suffer from at least one additional, clinically relevant chronic disease. To a degree, the high global prevalence and mortality rate of COPD is closely related to its extrapulmonary effects. Moreover, the various of comorbidities of COPD and itself interact with each other, resulting in diverse clinical manifestations and individual differences, and thus further influencing the prognosis as well as healthcare burden of COPD patients. This is closely related to the common risk factors of chronic diseases (aging, smoking, inactivity, etc.). Additionally, some pathophysiological mechanisms caused by COPD, including the systemic inflammatory response, hypoxia, oxidative stress, and others, also have an impact on other systems. But comprehensive management and medical interventions have not yet been established. The clinicians should improve their knowledge and skills in diagnosing as well as treating the comorbidities of COPD, and then aim to develop more individualized, efficient diagnostic and therapeutic strategies for different patients to achieve greater clinical benefits. In this article, we will review the risk factors, mechanisms, and treatment strategies for extrapulmonary comorbidities in chronic obstructive pulmonary disease, including cardiovascular diseases, diabetes, anemia, osteoporosis, emotional disorders, and gastroesophageal reflux disease.

Metformin Attenuates Neutrophil Recruitment through the H3K18 Lactylation/Reactive Oxygen Species Pathway in Zebrafish

Beyond its well-established role in diabetes management, metformin has gained attention as a promising therapeutic for inflammation-related diseases, largely due to its antioxidant capabilities. However, the mechanistic underpinnings of this effect remain elusive. Using in vivo zebrafish models of inflammation, we explored the impact of metformin on neutrophil recruitment and the underlying mechanisms involved. Our data indicate that metformin reduces histone (H3K18) lactylation, leading to the decreased production of reactive oxygen species (ROS) and a muted neutrophil response to both caudal fin injury and otic vesicle inflammation. To investigate the precise mechanisms through which metformin modulates neutrophil migration via ROS and H3K18 lactylation, we meticulously established the correlation between metformin-induced suppression of H3K18 lactylation and ROS levels. Through supplementary experiments involving the restoration of lactate and ROS, our findings demonstrated that elevated levels of both lactate and ROS significantly promoted the inflammatory response in zebrafish. Collectively, our study illuminates previously unexplored avenues of metformin's antioxidant and anti-inflammatory actions through the downregulation of H3K18 lactylation and ROS production, highlighting the crucial role of epigenetic regulation in inflammation and pointing to metformin's potential in treating inflammation-associated conditions.

Predicting response to iron supplementation in patients with active inflammatory bowel disease (PRIme): a randomised trial protocol

INTRODUCTION

Iron deficiency anaemia (IDA) is the most common systemic manifestation of inflammatory bowel disease (IBD) that has detrimental effects on quality of life (QoL) and disease outcomes. Iron deficiency (ID), with or without anaemia, poses a diagnostic and therapeutic challenge in patients with IBD due to the multifactorial nature of ID(A) and its frequent recurrence. Elevated hepcidin-a systemic iron regulator that modulates systemic iron availability and intestinal iron absorption-has been associated with oral iron malabsorption in IBD. Therefore, hepcidin could assist in therapeutic decision-making. In this study, we investigate whether hepcidin can predict response to oral and intravenous iron supplementation in patients with active IBD undergoing anti-inflammatory treatment.

METHODS AND ANALYSIS

PRIme is an exploratory, multicentre, open-label and randomised trial. All adult patients with active IBD and ID(A) will be assessed for eligibility. The participants (n=90) will be recruited at five academic hospitals within the Netherlands and randomised into three groups (1:1:1): oral ferrous fumarate, oral ferric maltol or intravenous iron. Clinical and biochemical data will be collected at the baseline and after 6, 14 and 24 weeks. Blood samples will be collected to measure hepcidin and other biomarkers related to iron status. In addition, patient-reported outcomes regarding QoL and disease burden will be evaluated. The primary outcome is the utility of hepcidin as a predictive biomarker for response to iron therapy, which will be assessed using receiver operating curve analysis.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Review Board at the Leiden University Medical Center (IRB No. P21.109) and other study sites. All participants will provide written informed consent to enrol in the study. The findings will be published in a peer-reviewed journal and disseminated at scientific conferences; the dataset will be available on reasonable request.

TRIAL REGISTRATION

Prospectively registered in the https://clinicaltrials.gov/ and the Eudra registries. First submitted on 10 May 2022 to the ClinicalTrials.gov (ID: NCT05456932) and on 3 March 2022 to the European Union Drug Regulating Authorities Clinical Trials Database (ID: 2022-000894-16).

Modulation of the Gut Microbiota by Nutrition and Its Relationship to Epigenetics

The intestinal microbiota is a community of microorganisms inhabiting the human intestines, potentially influencing both physiological and pathophysiological processes in the human body. Existing evidence suggests that nutrients can influence the modulation of the gut microbiota. However, there is still limited evidence regarding the effects of vitamin and mineral supplementation on the human gut microbiota through epigenetic modification. It is plausible that maintaining an adequate dietary intake of vitamin D, iron, fibre, zinc and magnesium may have a beneficial effect on alleviating inflammation in the body, reducing oxidative stress, and improving the condition of the intestinal microbiota through various epigenetic mechanisms. Moreover, epigenetics involves alterations in the phenotype of a cell without changing its fundamental DNA sequence. It appears that the modulation of the microbiota by various nutrients may lead to epigenetic regulation. The correlations between microbiota and epigenetics are potentially interdependent. Therefore, the primary objective of this review is to identify the complex relationships between diet, gut microbiota, and epigenetic regulation. These interactions could play a crucial role in systemic health.