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

Boosting nutritional value: the role of iron fortification in meat and meat products

Iron deficiency is a widespread nutritional problem affecting millions of people globally, leading to various health issues including anemia. Iron fortification of meat and meat products has emerged as an effective strategy to combat this issue. This review explores the process and benefits of iron fortification, focusing on the types of iron compounds suitable for fortification, such as ferrous sulfate and ferric pyrophosphate, their bioavailability, and their impact on the sensory and nutritional qualities of meat products. Technological challenges and solutions, including encapsulation, chelation, and microencapsulation techniques, have been examined to minimize their negative impacts on sensory qualities. This review also discusses the regulatory framework governing iron fortification and consumer acceptance. Analytical methods for determining iron content, such as spectrophotometric and colorimetric detection, are discussed. Although iron-fortified meat products offer health benefits, sensory aspects and consumer acceptance are important considerations. This review provides a comprehensive understanding of the role and significance of iron fortification in meat products as a public health intervention to address iron deficiency.

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.

Ferroptosis: A New Pathway in the Interaction between Gut Microbiota and Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disorder marked by neuroinflammation, demyelination, and neuronal damage. Recent advancements highlight a novel interaction between iron-dependent cell death, known as ferroptosis, and gut microbiota, which may significantly influences the pathophysiology of MS. Ferroptosis, driven by lipid peroxidation and tightly linked to iron metabolism, is a pivotal contributor to the oxidative stress observed in MS. Concurrently, the gut microbiota, known to affect systemic immunity and neurological health, emerges as an important regulator of iron homeostasis and inflammatory responses, thereby influencing ferroptotic pathways. This review investigates how gut microbiota dysbiosis and ferroptosis impact MS, emphasizing their potential as therapeutic targets. Through an integrated examination of mechanistic pathways and clinical evidence, we discuss how targeting these interactions could lead to novel interventions that not only modulate disease progression but also offer personalized treatment strategies based on gut microbiota profiling. This synthesis aims at deepening insights into the microbial contributions to ferroptosis and their implications in MS, setting the stage for future research and therapeutic exploration.

Effect of second iron injection on growth performance, hematological parameters, and fecal microbiome of piglets fed different dietary iron levels

This experiment was conducted to evaluate the effects of a second iron injection for suckling pigs fed diets with different dietary iron levels in the nursery period on growth performance, hematological parameters, serum and liver trace mineral content, fecal score, microbiome, and metabolites. A total of 70 newborn pigs from 7 litters were assigned to either 1 or 2 iron injections within the litter and received the first i.m. iron injection (200 mg) at 2 to 3 d of age. Pigs assigned to the second injection treatment received an additional iron injection 5 d after the first injection. At weaning (days 27 to 30 of age), pigs within iron injection treatments were divided into 2 nursery diet treatments for a 27-d growth period. Treatments were 1) no additional iron injection + nursery diets with 100 ppm iron (NC), 2) second i.m. iron injection (200 mg) + NC diets, 3) no additional iron injection + nursery diets with 200 ppm iron (PC), and 4) second i.m. iron injection (200 mg) + PC diets. The second iron injection increased liver iron content at weaning (P = 0.08, tendency), and serum iron, hemoglobin, and hematocrit levels until day 13 postweaning (P < 0.05). In the nursery period, pigs receiving the second iron injection had a greater final body weight (P = 0.08, tendency), overall growth rate (P = 0.08, tendency) and feed intake (P < 0.05), and lower fecal score (P < 0.05) indicating firmer feces compared to those receiving 1 iron injection. There was no major effect of dietary iron level or interaction with the iron injection treatment in any measurements except that the pigs fed the PC diets had greater hemoglobin and hematocrit levels (P < 0.05) at day 27 postweaning and a lower fecal score (P = 0.08, tendency) in the late nursery period than those fed the NC diets. The second iron injection reduced fecal bacterial alpha-diversity based on Faith's phylogenetic diversity at weaning (P < 0.05), while the second iron injection and dietary iron levels resulted in dissimilarity in the fecal bacterial community based on Unweighted Unifrac analysis (P < 0.05; at weaning by iron injection and day 27 postweaning by dietary iron level). In conclusion, the second iron injection for suckling pigs improved postweaning growth performance and hemoglobin levels and affected the fecal microbiome, whereas an additional 100 ppm of dietary iron supplementation increased hemoglobin levels and altered the fecal microbiome in the late nursery period but did not affect postweaning growth.

Pica practices, anemia, and oral health outcomes: a systemic review

OBJECTIVES

Pica is a non-nutritive eating behavior. The potential impact of pica on oral health and the association between pica and anemia are understudied. We examined the current evidence on the relationship between pica practices, anemia, and oral health outcomes.

METHODS

We used Population, Intervention, Control, and Outcomes (PICO) terms to create MeSH terms to assess 1) the relationship between pica and iron deficiency anemia (IDA), 2) the relationship between IDA and oral health, and 3) the relationship between pica, anemia, and oral health outcomes. The review was registered on Prospero [CRD42022349022]. We searched databases including PubMed, Embase, Web of Science, Cochrane Library, and, clinicaltrials.gov in June 2022.

RESULTS

From 4,159 searched articles, 89 met the inclusion criteria. Studies were published between 1959 and 2022 from 33 countries. Nearly half of these studies (55.1%, n = 49) were case reports. The most common picas included geophagia (soil/dirt) (44.9%, n = 40 papers), pagophagia (ice) (22.5%, n = 20), amylophagia (starch) (15.7%, n = 14), paint/metal (5.6%, n = 5), paper (5.6%, n = 5) and others such as pica for foam and hair. Fifteen case reports and one intervention study showed the effects of pica practice on oral health, such as tooth abrasion, dental caries, and de-papillated tongue. Furthermore, 81% of the papers reported the co-occurrence of pica with anemia and 15 papers reported a significant association (p < 0.05) between pica and low hemoglobin levels ranging from < 12.0 to 2.7g/dL among all age groups, including among pregnant and postpartum women. Pica practices were strongly associated with IDA (serum ferritin < 15.0 - 4.3 mcg/ml) but showed a non-statistically significant trend of association with oral health outcomes.

CONCLUSION

Pica was strongly associated with anemia and IDA. Tooth abrasion and dental caries were observed among pica users. Future studies could define the strength of the pica-oral health association, and the potential mediators, such as anemia.

Microbiome and Hemato-immune Aging

The microbiome is a highly complex and diverse symbiotic component that undergoes dynamic changes with the organismal aging. Microbial perturbations, termed dysbiosis, exert strong influence on dysregulating the bone marrow niche and subsequently promoting the aging of hematopoietic and immune system. Accumulating studies have revealed the substantial impact of intestinal microbiome on the initiation and progression of age-related hematologic alteration and diseases, such as clonal hematopoiesis and blood cancers. Current therapeutic approaches to restore the altered microbiome diversity target specific pathobionts and are demonstrated to improve clinical outcomes of antihematologic malignancy treatments. In this review, we discuss the interplay between the microbiome and the hemato-immune system during aging process. We also shed light on the emerging therapeutic strategies to tackle the dysbiosis for amelioration of aging and disease progression.

Efficacy of probiotic, prebiotic, and synbiotics supplements in individuals with anemia: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Anemia is a common global health problem, particularly in impoverished regions, with a high incidence rate. The condition is multifactorial, with iron deficiency being one of the most prevalent causes. Current treatment for anemia often relies on iron supplements or erythropoiesis-stimulating agents, although these therapies may show limited efficacy for some patients. Recent evidence suggests that probiotics, prebiotics, and synbiotics, as microbiome modulators, hold significant potential in the treatment of anemia. These interventions may enhance iron absorption and improve overall blood health through their impact on gut microbiota, thus providing an alternative or complementary approach to conventional treatments.

METHODS

Six databases, including the Cochrane Central Register of Controlled Trials, Embase, PubMed, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), and WangFang data library, were searched up to November 20, 2024. Studies published in English and Chinese were included. We included randomized controlled trials (RCTs) evaluating the effects of probiotics, prebiotics, or synbiotics in treating anemia. The experimental groups received probiotics, prebiotics, or synbiotics, while the control groups received placebo, alternative treatments, or no treatment. The primary outcome was hemoglobin (Hb) levels. Secondary outcomes included serum iron (SI) and serum ferritin (SF). A descriptive analysis was conducted for studies where meta-analysis was not feasible. The GRADE tool was used to assess the quality of evidence, and the Cochrane guidelines were employed to evaluate the risk of bias in each study.

RESULTS

Seven studies were included comprising a total of eight RCTs, with the main types of anemia being iron deficiency anemia (IDA) and anemia of chronic kidney disease (CKD), involving 632 patients. The analysis revealed that probiotics, prebiotics, or synbiotics significantly improved Hb levels in patients with anemia (WMD = 10.760, 95% CI: 4.593 to 16.747, p = 0.001), though heterogeneity was high (I² = 96.5%). Two RCTs (n = 120 participants) reported significant increases in serum iron levels in the probiotic group (WMD = 3.835, 95% CI: 3.271 to 4.400), with moderate heterogeneity (I² = 38.7%). Two RCTs (n = 192 participants) reported no significant differences were observed between the groups in serum ferritin levels (WMD = 8.048, p = 0.115), and heterogeneity remained high (I² = 62.6%). Subgroup analyses revealed that probiotics improved Hb levels in renal and iron-deficiency anemia, as well as across different doses. The synbiotic group showed consistent efficacy (I² = 0%), while the prebiotic group did not exhibit significant effects, with extremely high heterogeneity (I² = 99.3%). This indicates that heterogeneity may stem from variations in intervention types, and the results should be interpreted with caution.

CONCLUSION

There is moderate-quality evidence suggesting that probiotics, prebiotics, and synbiotics may improve anemia management, particularly by enhancing Hb levels. Further high-quality RCTs are required to explore the specific role of synbiotics in anemia management, including their comparative efficacy against probiotics and prebiotics alone, and their impact on gastrointestinal factors such as gut microbiota modulation and inflammation reduction.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024590073.

Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency anaemia patients initiating oral iron replacement: a randomised controlled trial

This study aimed to investigate gastrointestinal tolerability, treatment persistence and iron status markers in patients with iron deficiency anaemia (IDA) who received oral iron replacement therapy (IRT) with v. without concomitant Lactobacillus plantarum 299v (L. plantarum 299v) probiotic supplementation. A total of 295 patents with newly diagnosed IDA were randomly assigned to receive either IRT alone (n 157, IRT-only group) or IRT plus L. plantarum 299v (n 138, IRT-Pro group) in this prospective randomised non-placebo-controlled study (ClinicalTrials.gov Identifier: NCT06521879). Gastrointestinal intolerance symptoms (at baseline, within the first 30 d of IRT and at any time during 3-month IRT), serum Hb levels (at baseline and 3rd month of IRT) and iron status markers (at baseline and 3rd month of IRT) were recorded. IRT-Pro group, when compared with IRT-only group, experienced significantly lower rates of gastrointestinal intolerance over the course of IRT (13·0 % v. 46·5 %, P < 0·001) and treatment discontinuation within the first 30 d (3·6 % v. 15·9 %, P < 0·001). At 3rd month of therapy, IRT-Pro v. IRT-only group had significantly higher serum levels for iron (76·0 (51·0-96·0) v. 60·0(43·0-70·0) µg/dl, P < 0·001) and transferrin saturation (20·1 (12·5-28·5) v. 14·5 (10·5-19·0) %, P < 0·001) and higher change from baseline Hb (0·9 (0·3-1·3) v. 0·4 (-0·1-1·1) g/dl, P < 0·001) levels. Use of L. plantarum 299v probiotic supplementation during the first 30 d of IRT in IDA patients significantly reduces the gastrointestinal burden of IRT (particularly abdominal pain and bloating), the likelihood of intolerance development (by ∼3 times) and treatment discontinuation (by∼5 times), as accompanied by improved serum Hb levels and serum iron markers.

Current iron therapy in the light of regulation, intestinal microbiome, and toxicity: are we prescribing too much iron?

Iron deficiency is a widespread global health concern with varying prevalence rates across different regions. In developing countries, scarcity of food and chronic infections contribute to iron deficiency, while in industrialized nations, reduced food intake and dietary preferences affect iron status. Other causes that can lead to iron deficiency are conditions and diseases that result in reduced intestinal iron absorption and blood loss. In addition, iron absorption and its bioavailability are influenced by the composition of the diet. Individuals with increased iron needs, including infants, adolescents, and athletes, are particularly vulnerable to deficiency. Severe iron deficiency can lead to anemia with performance intolerance or shortness of breath. In addition, even without anemia, iron deficiency leads to mental and physical fatigue, which points to the fundamental biological importance of iron, especially in mitochondrial function and the respiratory chain. Standard oral iron supplementation often results in gastrointestinal side effects and poor compliance. Low-dose iron therapy seems to be a valid and reasonable therapeutic option due to reduced hepatic hepcidin formation, facilitating efficient iron resorption, replenishment of iron storage, and causing significantly fewer side effects. Elevated iron levels influence gut microbiota composition, favoring pathogenic bacteria and potentially disrupting metabolic and immune functions. Protective bacteria, such as bifidobacteria and lactobacilli, are particularly susceptible to increased iron levels. Dysbiosis resulting from iron supplementation may contribute to gastrointestinal disorders, inflammatory bowel disease, and metabolic disturbances. Furthermore, gut microbiota alterations have been linked to mental health issues. Future iron therapy should consider low-dose supplementation to mitigate adverse effects and the impact on the gut microbiome. A comprehensive understanding of the interplay between iron intake, gut microbiota, and human health is crucial for optimizing therapeutic approaches and minimizing potential risks associated with iron supplementation.

A young child formula supplemented with a synbiotic mixture of scGOS/lcFOS and Bifidobacterium breve M-16V improves the gut microbiota and iron status in healthy toddlers

Early-life gut microbiota development depends on a highly synchronized microbial colonization process in which diet is a key regulator. Microbiota transition toward a more adult-like state in toddlerhood goes hand in hand with the transition from a milk-based diet to a family diet. Microbiota development during the first year of life has been extensively researched; however, studies during toddlerhood remain sparse. Young children's requirement for micronutrients, such as dietary iron, is higher than adults. However, their intake is usually sub-optimal based on regular dietary consumption. The Child Health and Residence Microbes (CHaRM) study, conducted as an adjunct to the GUMLi (Growing Up Milk "Lite") trial, was a double-blind randomized controlled trial to investigate the effects on body composition of toddler milk compared to unfortified standard cow's milk in healthy children between 1 and 2 years of age in Brisbane (Australia). In this trial, fortified milk with reduced protein content and added synbiotics [Bifidobacterium breve M-16V, short-chain galactooligosaccharides, and long-chain fructooligosaccharides (ratio 9:1)] and micronutrients were compared to standard unfortified cow's milk. In the present study, the effects of the intervention on the gut microbiota and its relationship with iron status in toddlers were investigated in a subset of 29 children (18 in the Active group and 11 in the Control group) who completed the CHaRM study. The toddler microbiota consisted mainly of members of the phyla Firmicutes, Bacteroidota, and Actinobacteriota. The abundance of the B. breve species was quantified and was found to be lower in the Control group than in the Active group. Analysis of blood iron markers showed an improved iron status in the Active group. We observed a positive correlation between Bifidobacterium abundance and blood iron status. PICRUSt, a predictive functionality algorithm based on 16S ribosomal gene sequencing, was used to correlate potential microbial functions with iron status measurements. This analysis showed that the abundance of predicted genes encoding for enterobactin, a class of siderophores specific to Enterobacteriaceae, is inversely correlated with the relative abundance of members of the genus Bifidobacterium. These findings suggest that healthy children who consume a young child formula fortified with synbiotics as part of a healthy diet have improved iron availability and absorption in the gut and an increased abundance of Bifidobacterium in their gut microbiome.

Association of Gut Microbiota Composition with Stunting Incidence in Children under Five in Jakarta Slums

BACKGROUND

Stunting can be linked to various factors, one of which is dysbiosis. This study aims to analyze the microbiota composition and related contributing factors of stunted and non-stunted children in the slum areas of Jakarta.

METHODS

The subjects in this study included 21 stunted (HAZ ≤ -2SD) and 21 non-stunted children (-2SD ≤ HAZ ≤ 3SD) aged 2-5 years. Microbiota analysis was performed by extracting DNA from the subjects' feces and then via 16S rRNA sequencing using next-generation sequencing (NGS).

RESULTS

The results of this study showed that in stunted children, the abundance of Mitsuokella (24,469 OTUs), Alloprevotella (23,952 OTUs), and Providencia alcalifaciens (861 OTUs) was higher, while in non-stunted children, that of Blautia (29,755 OTUs), Lachnospiraceae (6134 OTUs), Bilophila (12,417 OTUs), Monoglobus (484 OTUs), Akkermansia muciniphila (1116 OTUs), Odoribacter splanchnicus (42,993 OTUs), and Bacteroides clarus (8900 OTUs) was higher. Differences in microbiota composition in the two groups were influenced by nutrient intake, birth history, breastfeeding history, handwashing habits before eating, drinking water sources, and water sources for other activities.

CONCLUSIONS

This study highlights that stunted children have a significantly different gut microbiota composition compared to non-stunted children, with higher levels of pathogenic bacteria and lower levels of beneficial bacteria. Future research should focus on interventions that can improve the gut microbiota composition to prevent stunting in children.

Iron Treatment in Patients with Iron Deficiency Before and After Metabolic and Bariatric Surgery: A Narrative Review

Iron is an essential nutrient in living organisms with multiple vital functions. Iron deficiency (ID) can cause long term health consequences beyond iron deficiency anemia (IDA). The high prevalence of ID and its long-term effects in patients with obesity and after metabolic and bariatric surgery (MBS) is recognized. Nevertheless, there is limited knowledge of the optimal route or dose for treatment of patients with obesity and post-MBS, and an evidence-based universal guideline for prevention and treatment of ID in short- and long-term post-MBS (PMBS) is not yet available. ID in the general population is currently treated with oral or parenteral iron, where oral iron treatment is considered the preferred option with parenteral iron as a second-line treatment in case there is intolerance or lack of response to oral iron. In patients with obesity with chronic low-grade inflammation and PMBS patients with altered gut anatomy and function, there are also alterations in the bioavailability and higher risks of side effects of available oral irons. The conclusions of current studies exploring effective treatment of iron deficiency in this population have been inconsistent and further well-planned randomized and prospective studies are needed. This is a narrative review of the literature on the available treatment options and strategies for treatment of ID in PMBS patients to recognize the knowledge gaps and provides topics of future research.

Understanding the role of the human gut microbiome in overweight and obesity

The gut microbiome may be related to the prevalence of overweight and obesity, but high interindividual variability of the human microbiome complicates our understanding. Obesity often occurs concomitantly with micronutrient deficiencies that impair energy metabolism. Microbiota composition is affected by diet. Host-microbiota interactions are bidirectional. We propose three pathways whereby these interactions may modulate the gut microbiome and obesity: (1) ingested compounds or derivatives affecting small intestinal transit, endogenous secretions, digestion, absorption, microbiome balance, and gut barrier function directly affect host metabolism; (2) substrate availability affecting colonic microbial composition and contact with the gut barrier; and (3) microbial end products affecting host metabolism. The quantity/concentration, duration, and/or frequency (circadian rhythm) of changes in these pathways can alter the gut microbiome, disrupt the gut barrier, alter host immunity, and increase the risk of and progression to overweight and obesity. Host-specific characteristics (e.g., genetic variations) may further affect individual sensitivity and/or resilience to diet- and microbiome-associated perturbations in the colonic environment. In this narrative review, the effects of selected interventions, including fecal microbiota transplantation, dietary calorie restriction, dietary fibers and prebiotics, probiotics and synbiotics, vitamins, minerals, and fatty acids, on the gut microbiome, body weight, and/or adiposity are summarized to help identify mechanisms of action and research opportunities.

Associations between multiple urinary metals and metabolic syndrome: Exploring the mediating role of liver function in Chinese community-dwelling elderly

BACKGROUND

Multiple metals exposure has been revealed to be related to metabolic syndrome (MetS). However, the associations and interactions between multiple metals exposure and MetS are remains controversial, and the potential mechanism of the above-mentioned is still unclear.

METHODS

The associations between urinary metals and the MetS were analyzed by multivariable logistic regression model and restricted cubic spline (RCS). Bayesian kernel machine regression (BKMR) model and quantile-based g-computation (qgcomp) were applied to explore the mixed exposure and interaction effect of metals. Mediation analysis was used to explore the role of liver function.

RESULTS

In the single metal model, multiple metals were significantly associated with MetS. RCS analysis further verified the associations between 8 metals and MetS. BKMR model and qgcomp showed that zinc (Zn), iron (Fe), and tellurium (Te) were the main factors affecting the overall effect. In addition, mediation analysis indicated that serum alanine aminotransferase (ALT) mediated 21.54% and 13.29% in the associations of vanadium (V) and Zn with the risk of MetS, respectively.

CONCLUSIONS

Elevated urinary concentration of Zn, V, Te, copper (Cu), molybdenum (Mo), and thallium (Tl) were related to the increased risk of MetS. Conversely, Fe and selenium (Se) may be protective factors for MetS in mixed exposure. Liver function may play a key role in the association of V and Zn exposure with MetS.

Diverse mechanisms by which chemical pollutant exposure alters gut microbiota metabolism and inflammation

The human gut microbiome, the host, and the environment are inextricably linked across the life course with significant health impacts. Consisting of trillions of bacteria, fungi, viruses, and other micro-organisms, microbiota living within our gut are particularly dynamic and responsible for digestion and metabolism of diverse classes of ingested chemical pollutants. Exposure to chemical pollutants not only in early life but throughout growth and into adulthood can alter human hosts' ability to absorb and metabolize xenobiotics, nutrients, and other components critical to health and longevity. Inflammation is a common mechanism underlying multiple environmentally related chronic conditions, including cardiovascular disease, multiple cancer types, and mental health. While growing research supports complex interactions between pollutants and the gut microbiome, significant gaps exist. Few reviews provide descriptions of the complex mechanisms by which chemical pollutants interact with the host microbiome through either direct or indirect pathways to alter disease risk, with a particular focus on inflammatory pathways. This review focuses on examples of several classes of pollutants commonly ingested by humans, including (i) heavy metals, (ii) persistent organic pollutants (POPs), and (iii) nitrates. Digestive enzymes and gut microbes are the first line of absorption and metabolism of these chemicals, and gut microbes have been shown to alter compounds from a less to more toxic state influencing subsequent distribution and excretion. In addition, chemical pollutants may interact with or alter the selection of more harmful and less commensal microbiota, leading to gut dysbiosis, and changes in receptor-mediated signaling pathways that alter the integrity and function of the gut intestinal tract. Arsenic, cadmium, and lead (heavy metals), influence the microbiome directly by altering different classes of bacteria, and subsequently driving inflammation through metabolite production and different signaling pathways (LPS/TLR4 or proteoglycan/TLR2 pathways). POPs can alter gut microbial composition either directly or indirectly depending on their ability to activate key signaling pathways within the intestine (e.g., PCB-126 and AHR). Nitrates and nitrites' effect on the gut and host may depend on their ability to be transformed to secondary and tertiary metabolites by gut bacteria. Future research should continue to support foundational research both in vitro, in vivo, and longitudinal population-based research to better identify opportunities for prevention, gain additional mechanistic insights into the complex interactions between environmental pollutants and the microbiome and support additional translational science.

Iron and bones: effects of iron overload, deficiency and anemia treatments on bone

Iron is a vital trace element and exerts opposing effects on bone in both iron overload and iron deficiency situations. Remarkably, iron supplementation through intravenous infusion in patients with iron deficiency can also have detrimental effects on bone in special cases. The diverse mechanisms underlying these effects and their manifestations contribute to the complexity of this relationship. Iron overload impacts both bone resorption and formation, accelerating bone resorption while reducing bone formation. These effects primarily result from the direct action of reactive oxygen species (ROS), which influence the proliferation, differentiation, and activity of both osteoclasts and osteoblasts differently. This imbalance favors osteoclasts and inhibits the osteoblasts. Simultaneously, multiple pathways, including bone morphogenic proteins, RANK ligand, and others, contribute to these actions, leading to a reduction in bone mass and an increased susceptibility to fractures. In contrast, iron deficiency induces low bone turnover due to energy and co-factor deficiency, both of which require iron. Anemia increases the risk of fractures in both men and women. This effect occurs at various levels, reducing muscular performance and, on the bone-specific level, decreasing bone mineral density. Crucially, anemia increases the synthesis of the phosphaturic hormone iFGF23, which is subsequently inactivated by cleavage under physiological conditions. Thus, iFGF23 levels and phosphate excretion are not increased. However, in specific cases where anemia has to be managed with intravenous iron treatment, constituents-particularly maltoses-of the iron infusion suppress the cleavage of iFGF23. As a result, patients can experience severe phosphate wasting and, consequently, hypophosphatemic osteomalacia. This condition is often overlooked in clinical practice and is often caused by ferric carboxymaltose. Ending iron infusions or changing the agent, along with phosphate and vitamin D supplementation, can be effective in addressing this issue.

Dietary iron intake has long-term effects on the fecal metabolome and microbiome

Iron is essential for life, but its imbalances can lead to severe health implications. Iron deficiency is the most common nutrient disorder worldwide, and iron dysregulation in early life has been found to cause long-lasting behavioral, cognitive, and neural effects. However, little is known about the effects of dietary iron on gut microbiome function and metabolism. In this study, we sought to investigate the impact of dietary iron on the fecal metabolome and microbiome by using mice fed with three diets with different iron content: an iron deficient, an iron sufficient (standard), and an iron overload diet for 7 weeks. Additionally, we sought to understand whether any observed changes would persist past the 7-week period of diet intervention. To assess this, all feeding groups were switched to a standard diet, and this feeding continued for an additional 7 weeks. Analysis of the fecal metabolome revealed that iron overload and deficiency significantly alter levels of peptides, nucleic acids, and lipids, including di- and tri-peptides containing branched-chain amino acids, inosine and guanosine, and several microbial conjugated bile acids. The observed changes in the fecal metabolome persist long after the switch back to a standard diet, with the cecal gut microbiota composition and function of each group distinct after the 7-week standard diet wash-out. Our results highlight the enduring metabolic consequences of nutritional imbalances, mediated by both the host and gut microbiome, which persist after returning to the original standard diets.

The toxicological analysis and assessment of essential elements (Cu, Fe, Mn, Zn) in Food for Special Medical Purposes (FSMP) dedicated to oncological patients available in Polish pharmacies

Foods for Special Medical Purposes (FSMP) for oncology patients, available in pharmacies, play a crucial role in providing nutrition and supplementation. However, the scientific literature lacks comprehensive research on the safety of essential trace elements in these products. This study aimed to assess Cu, Fe, Mn and Zn levels in commonly prescribed FSMPs (n = 23) from Polish pharmacies. Using ICP-MS after microwave-induced digestion (using concentrated nitric acid and hydrogen peroxide), we evaluated element levels. Our research used three approaches: the raw score for Cu, Fe, Mn, and Zn; single intake per serving; and the daily ration, compared with the reference values of the European Food Safety Authority. Discrepancies were found between the actual and declared product compositions, influenced by the route of administration and the recommended intake. Despite variations, all products were considered safe for oncological patients based on current evidence. However, it is recommended to have clear guidelines for FSMPs in cancer care. This pioneering study evaluates the safety and quality of prescription FSMPs for cancer patients from toxicological and nutritional perspectives, highlighting the need for standardised protocols in pharmacy-dispensed FSMPs.

How aging influences the gut-bone marrow axis and alters hematopoietic stem cell regulation

The gut microbiome has come to prominence across research disciplines, due to its influence on major biological systems within humans. Recently, a relationship between the gut microbiome and hematopoietic system has been identified and coined the gut-bone marrow axis. It is well established that the hematopoietic system and gut microbiome separately alter with age; however, the relationship between these changes and how these systems influence each other demands investigation. Since the hematopoietic system produces immune cells that help govern commensal bacteria, it is important to identify how the microbiome interacts with hematopoietic stem cells (HSCs). The gut microbiota has been shown to influence the development and outcomes of hematologic disorders, suggesting dysbiosis may influence the maintenance of HSCs with age. Short chain fatty acids (SCFAs), lactate, iron availability, tryptophan metabolites, bacterial extracellular vesicles, microbe associated molecular patterns (MAMPs), and toll-like receptor (TLR) signalling have been proposed as key mediators of communication across the gut-bone marrow axis and will be reviewed in this article within the context of aging.

Direct and macrophage stimulation mediated effects of active, inactive, and cell-free supernatant forms of Akkermansia muciniphila and Faecalibacterium duncaniae on hepcidin gene expression in HepG2 cells

Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.

GUT MICROBIOME DIVERSITY OF THREE RHINOCEROS SPECIES IN EUROPEAN ZOOS

The wild rhinoceros populations have declined drastically in the past decades because the rhinoceros are heavily hunted for their horns. Zoological institutions aim to conserve rhinoceros populations in captivity, but one of the challenges of ex situ conservation is to provide food sources that resemble those available in the wild. Considering that the mammalian gut microbiota is a pivotal player in their host's health, the gut microbiota of rhinoceros may also play a role in the bioavailability of nutrients. Therefore, this study aims to characterize the fecal microbiome composition of grazing white rhinoceros (WR; Ceratotherium simum) and greater one-horned rhinoceros (GOHR; Rhinoceros unicornis) as well as the browsing black rhinoceros (BR; Diceros bicornis) kept in European zoos. Over the course of 1 yr, 166 fecal samples in total were collected from 9 BR (n = 39), 10 GOHR (n = 56), and 14 WR (n = 71) from 23 zoological institutions. The bacterial composition in the samples was determined using 16S rRNA gene Illumina sequencing. The fecal microbiomes of rhinoceros clustered by species, with BR clustering more distantly from GOHR and WR. Furthermore, the data report clustering of rhinoceros microbiota according to individual rhinoceros and institutional origin, showing that zoological institutions play a significant role in shaping the gut microbiome of rhinoceros species. In addition, BR exhibit a relatively higher microbial diversity than GOHR and WR. BR seem more susceptible to microbial gut changes and appear to have a more diverse microbiome composition among individuals than GOHR and WR. These data expand on the role of gut microbes and can provide baseline data for continued efforts in rhinoceros conservation and health status.

Circulating Trimethylamine-N-Oxide Is Elevated in Liver Transplant Recipients

Liver transplant recipients (LTRs) have lower long-term survival rates compared with the general population. This underscores the necessity for developing biomarkers to assess post-transplantation mortality. Here we compared plasma trimethylamine-N-oxide (TMAO) levels with those in the general population, investigated its determinants, and interrogated its association with all-cause mortality in stable LTRs. Plasma TMAO was measured in 367 stable LTRs from the TransplantLines cohort (NCT03272841) and in 4837 participants from the population-based PREVEND cohort. TMAO levels were 35% higher in LTRs compared with PREVEND participants (4.3 vs. 3.2 µmol/L, p < 0.001). Specifically, TMAO was elevated in LTRs with metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, and polycystic liver disease as underlying etiology (p < 0.001 for each). Among LTRs, TMAO levels were independently associated with eGFR (std. β = -0.43, p < 0.001) and iron supplementation (std. β = 0.13, p = 0.008), and were associated with mortality (29 deaths during 8.6 years follow-up; log-rank test p = 0.017; hazard ratio of highest vs. lowest tertile 4.14, p = 0.007). In conclusion, plasma TMAO is likely elevated in stable LTRs, with impaired eGFR and iron supplementation as potential contributory factors. Our preliminary findings raise the possibility that plasma TMAO could contribute to increased mortality risk in such patients, but this need to be validated through a series of rigorous and methodical studies.

The Arabidopsis RTH plays an important role in regulation of iron (Fe) absorption and transport

KEY MESSAGE

RTH may activate Fe assimilation related genes to promote Fe absorption, transport and accumulation in Arabidopsis. Iron (Fe) is an important nutrient element. The Fe absorption and transport in plants are well investigated over the past decade. Our previous work indicated that RTE1-HOMOLOG (RTH), the homologous gene of reversion-to-ethylene sensitivity 1 (RTE1), plays a role in ethylene signaling pathway. However, its function in Fe absorption and transport is largely unknown. In the present study, we found that RTH was expressed in absorptive tissue and conducting tissue, including root hairs, root vascular bundle, and leaf veins. Under high Fe concentration, the seedling growth of rth-1 mutant was better, while the RTH overexpression lines were retarded compared to the wild type (Col-0). When treated with EDTA-Fe3+ (400 μM), the chlorophyll content and ion leakage rate were higher and lower in rth-1 than those of Col-0, respectively. By contrast, the chlorophyll contents and ion leakage rates of RTH overexpression lines were decreased and hastened compared with Col-0, respectively. Fe measurement indicated that the Fe contents of rth-1 were lower than those of Col-0, whereas those of RTH overexpression lines were comparably higher. Gene expression analysis revealed that Fe absorption and transport genes AHA2, IRT1, FIT, FPN1, and YSL1 decreased in rth-1 but increased in RTH overexpression lines compared with Col-0. Additionally, Y2H (yeast two-hybrid) and BiFC (bimolecular fluorescence complementation) assays showed that RTH can physically interact with hemoglobin 1 (HB1) and HB2. All these findings suggest that RTH may play an important role in regulation of Fe absorption, transport, and accumulation in Arabidopsis.

Association between Food or Nutrients and Gut Microbiota in Healthy and Helminth-Infected Women of Reproductive Age from Zanzibar, Tanzania

Modulating the gut microbiota is recognised as one strategy for preventing and fighting diseases. While the significant impact of diet on the gut microbiota's composition and function has been extensively researched, there is a notable lack of studies on the interactions between diet, microbiota, and helminth infections. Here, we used a combination of self-reported food intake and a 16S rDNA sequencing approach to analyse the composition of the gut microbiota in women of reproductive age from the two main islands of the Zanzibar archipelago, where helminth infections are endemic. We also applied a Spearman correlation analysis to food/nutrients and gut microbiota. Our results reveal that, despite close ethnic and cultural ties, the participants' gut microbiota differs depending on their location. A nutrient intake analysis revealed deficiencies in minerals and vitamins, indicating an imbalanced diet. A correlation analysis identified bacterial taxa consistently correlated with specific food or nutrients in healthy women from both locations, and in two types of helminth infections. Escherichia/Shigella abundances, usually associated with Trichuris trichiura infection, consistently correlated with insufficient levels of vitamins B2 and B12. In conclusion, our findings suggest that the increased consumption of specific food like cassava and fish, as well as essential nutrients such as calcium, B vitamins, and vitamin A, may modulate the gut microbiota of populations residing in regions where helminth infections are endemic.

Investigation the mechanism of iron overload-induced colonic inflammation following ferric citrate exposure

Iron overload occurs due to excessive iron intake compared to the body's demand, leading to iron deposition and impairment of multiple organ functions. Our previous study demonstrated that chronic oral administration of ferric citrate (FC) caused colonic inflammatory injury. However, the precise mechanism underlying this inflammatory response remains unclear. The current study aims to investigate the mechanism by which iron overload induced by FC exposure leads to colonic inflammation. To accomplish this, mice were orally exposed to three different concentrations of FC (71 mg/kg/bw (L), 143 mg/kg/bw (M) and 286 mg/kg/bw (H)) for continuous 16 weeks, with the control group receiving ultrapure water (C). Exposure to FC caused disturbances in the excretory system, altered colonic flora alpha diversity, and enriched pathogenic bacteria, such as Mucispirillum, Helicobacter, Desulfovibrio, and Shigella. These changes led to structural disorders of the colonic flora and an inflammatory response phenotype characterized by inflammatory cells infiltration, atrophy of intestinal glands, and irregular thickening of the intestinal wall. Mechanistic studies revealed that FC-exposure activated the NF-κB signaling pathway by up-regulating TLR4, MyD88, and NF-κB mRNA levels and protein expression. This activation resulted in increased production of pro-inflammatory cytokines, further contributing to the colonic inflammation. Additionally, in vitro experiments in SW480 cells confirmed the activation of NF-κB signaling pathway by FC exposure, consistent with the in vivo findings. The significance of this study lies in its elucidation of the mechanism by which iron overload caused by FC exposure leads to colonic inflammation. By identifying the role of pathogenic bacteria and the NF-κB signaling pathway, this study could potentially offer a crucial theoretical foundation for the research on iron overload, as well as provide valuable insights for clinical iron supplementation.

A review of the effect of iron supplementation on the gut microbiota of children in developing countries and the impact of prebiotics

Iron is essential for many physiological functions of the body, and it is required for normal growth and development. Iron deficiency (ID) is the most common form of micronutrient malnutrition and is particularly prevalent in infants and young children in developing countries. Iron supplementation is considered the most effective strategy to combat the risk of ID and ID anaemia (IDA) in infants, although iron supplements cause a range of deleterious gut-related problems in malnourished children. The purpose of this review is to assess the available evidence on the effect of iron supplementation on the gut microbiota during childhood ID and to further assess whether prebiotics offer any benefits for iron supplementation. Prebiotics are well known to improve gut-microbial health in children, and recent reports indicate that prebiotics can mitigate the adverse gut-related effects of iron supplementation in children with ID and IDA. Thus, provision of prebiotics alongside iron supplements has the potential for an enhanced strategy for combatting ID and IDA among children in the developing world. However, further understanding is required before the benefit of such combined treatments of ID in nutritionally deprived children across populations can be fully confirmed. Such enhanced understanding is of high relevance in resource-poor countries where ID, poor sanitation and hygiene, alongside inadequate access to good drinking water and poor health systems, are serious public health concerns.

Iron Fortification and Inulin Supplementation in Early Infancy: Evaluating the Impact on Iron Metabolism and Trace Mineral Status in a Piglet Model

Background

Infant formula in the United States contains abundant iron, raising health concerns about excess iron intake in early infancy.

Objectives

Using a piglet model, we explored the impact of high iron fortification and prebiotic or synbiotic supplementation on iron homeostasis and trace mineral bioavailability.

Methods

Twenty-four piglets were stratified and randomly assigned to treatments on postnatal day 2. Piglets were individually housed and received an iron-adequate milk diet (AI), a high-iron milk diet (HI), HI supplemented with 5% inulin (HI with a prebiotic [HIP]), or HIP with an oral gavage of Ligilactobacillus agilis YZ050, an inulin-fermenting strain, every third day (HI with synbiotic [HIS]). Milk was provided in 14 meals daily, mimicking formula feeding in infants. Fecal consistency score and body weight were recorded daily or every other day. Blood and feces were sampled weekly, and tissues collected on postnatal day 29. Data were analyzed using mixed model analysis of variance with repeated measures whenever necessary.

Results

Diet did not affect growth. HI increased hemoglobin, hematocrit, and serum iron compared to AI. Despite marginal adequacy, AI upregulated iron transporter genes and maintained satisfactory iron status in most pigs. HI upregulated hepcidin gene expression in liver, caused pronounced tissue iron deposition, and markedly increased colonic and fecal iron. Inulin supplementation, regardless of L. agilis YZ050, not only attenuated hepatic iron overload but also decreased colonic and fecal iron without altering pH or the expression of iron regulatory genes. HI lowered zinc (Zn) and copper (Cu) in the duodenum and liver compared to AI, whereas HIP and HIS further decreased Zn and Cu in the liver and diminished colonic and fecal trace minerals.

Conclusions

Early-infancy excessive iron fortification causes iron overload and compromises Zn and Cu absorption. Inulin decreases trace mineral absorption likely by enhancing gut peristalsis and stool frequency.

Oral iron therapy: Current concepts and future prospects for improving efficacy and outcomes

Iron deficiency (ID) and iron-deficiency anaemia (IDA) are global public health concerns, most commonly afflicting children, pregnant women and women of childbearing age. Pathological outcomes of ID include delayed cognitive development in children, adverse pregnancy outcomes and decreased work capacity in adults. IDA is usually treated by oral iron supplementation, typically using iron salts (e.g. FeSO4 ); however, dosing at several-fold above the RDA may be required due to less efficient absorption. Excess enteral iron causes adverse gastrointestinal side effects, thus reducing compliance, and negatively impacts the gut microbiome. Recent research has sought to identify new iron formulations with better absorption so that lower effective dosing can be utilized. This article outlines emerging research on oral iron supplementation and focuses on molecular mechanisms by which different supplemental forms of iron are transported across the intestinal epithelium and whether these transport pathways are subject to regulation by the iron-regulatory hormone hepcidin.

Spotlight on iron overload and ferroptosis: Research progress in female infertility

Iron is an essential trace element for organisms. However, iron overload, which is common in haematological disorders (e.g. haemochromatosis, myelodysplastic syndromes, aplastic anaemia, and thalassaemia, blood transfusion-dependent or not), can promote reactive oxygen species generation and induce ferroptosis, a novel form of programmed cell death characterised by excess iron and lipid peroxidation, thus causing cell and tissue damage. Infertility is a global health concern. Recent evidence has indicated the emerging role of iron overload and ferroptosis in female infertility by inducing hypogonadism, causing ovary dysfunction, impairing preimplantation embryos, attenuating endometrial receptivity, and crosstalk between subfertility-related disorders, such as polycystic ovary syndrome and endometriosis. In addition, gut microbiota and their metabolites are involved in iron metabolism, ferroptosis, and female infertility. In this review, we systematically elaborate on the current research progress in female infertility with a novel focus on iron overload and ferroptosis and summarise promising therapies targeting iron overload and ferroptosis to recover fertility in women. In summary, our study provides new insights into female infertility and offers literature references for the clinical management of female infertility associated with iron overload and ferroptosis, which may be beneficial for females with haematopoietic disorders suffering from both iron overload and infertility.

The Effect of Oral Iron Supplementation/Fortification on the Gut Microbiota in Infancy: A Systematic Review and Meta-Analysis

(1) Background: Iron is an essential metal for the proper growth and neurodevelopment of infants. To prevent and treat iron deficiency, iron supplementation or fortification is often required. It has been shown, though, that it affects the synthesis of gut microbiota. (2) Methods: This paper is a systematic review and meta-analysis of the effect of oral iron supplementation/fortification on the gut microbiota in infancy. Studies in healthy neonates and infants who received per os iron with existing data on gut microbiota were included. Three databases were searched: PUBMED, Scopus, and Google Scholar. Randomized controlled trials (RCTs) were included. Quality appraisal was assessed using the ROB2Tool. (3) Results: A total of six RCTs met inclusion criteria for a systematic review, and four of them were included in the meta-analysis using both the fixed and random effects methods. Our results showed that there is very good heterogeneity in the iron group (I2 = 62%), and excellent heterogeneity in the non-iron group (I2 = 98%). According to the meta-analysis outcomes, there is a 10.3% (95% CI: -15.0--5.55%) reduction in the bifidobacteria population in the iron group and a -2.96% reduction for the non-iron group. There is a confirmed difference (p = 0.02) in the aggregated outcomes between iron and non-iron supplement, indicative that the bifidobacteria population is reduced when iron supplementation is given (total reduction 6.37%, 95%CI: 10.16-25.8%). (4) Conclusions: The abundance of bifidobacteria decreases when iron supplementation or fortification is given to infants.

Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota

Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.

Investigating the role of iron status in the development of coeliac disease: a Mendelian randomisation study

OBJECTIVE

The environmental trigger behind the increasing prevalence of coeliac disease is not known. One suggested cause is iron deficiency, which is common in coeliac disease. We aimed to evaluate this possible association with Mendelian randomisation (MR), which under certain assumptions can suggest a causal relationship.

DESIGN

We conducted a two-sample MR study examining the relationship between single nucleotide polymorphisms (SNPs) associated with iron status and the presence of coeliac disease. The SNPs were drawn from a meta-analysis of three genome-wide association studies (GWAS). The association between these SNPs and coeliac disease was assessed using GWAS summary statistics from the UK Biobank. This consists of 336 638 white British individuals, 1855 with coeliac disease. We performed an MR Egger test for pleiotropy and assessed the plausibility of the assumptions of MR to evaluate for possible causality.

RESULTS

There were four SNPs strongly associated with systemic iron status. These were not associated with known risk factors for coeliac disease. All four SNPs were available in the UK Biobank coeliac disease summary statistics. Harmonising exposure and outcome associations, we found that higher iron status was negatively associated with risk of coeliac disease (OR per 1 SD increase in serum iron: 0.65, 95% CI 0.47 to 0.91). Leave-one-out analyses had consistent results, and no single SNP drove the association. All three assumptions of MR appeared plausible.

CONCLUSION

We found that genetically lower iron levels were associated with an increased risk of coeliac disease. Our findings highlight a potential opportunity for coeliac disease prevention.

A critical evaluation of prenatal supplements: Are they meeting the mark?

Prenatal supplements are commonly used to support maternal health and fetal development during pregnancy. However, there are concerns regarding their efficacy and safety. This review article provides a critical evaluation of prenatal supplements, including their types, benefits, criticisms, factors affecting their efficacy, and popular brands. It also offers recommendations for their use and identifies future research directions. Our analysis suggests that while prenatal supplements can offer important benefits, including reduced risk of birth defects and improved fetal growth and development, there are also concerns regarding their regulation, dosages, and potential harm to the mother and fetus. Pregnant women should carefully evaluate the ingredients, dosages, efficacy, and safety of prenatal supplements with the guidance of their healthcare provider. Future research should focus on standardizing dosages and regulation of prenatal supplements to ensure consistent quality, safety, and efficacy.

Comparable Evaluation of Nutritional Benefits of Lactobacillus plantarum and Bacillus toyonensis Probiotic Supplementation on Growth, Feed Utilization, Health, and Fecal Microbiota in Pre-Weaning Male Calves

This study was conducted to investigate the impact of probiotic supplementation using Lactobacillus plantarum DSA 20174 and/or Bacillus toyonensis ATCC 55050 on growth performance, blood parameters, hematological measures, and fecal microbiota in pre-weaning Holstein calves. Thirty-two four-day-old male calves with a similar genetic background, weighing an average of 38.27 ± 0.12 kg, were randomly assigned to four groups. The groups consisted of a control group (CON) without supplementation, a group receiving B. toyonensis (BT) at 3 × 109 cfu/calf/day, a group receiving L. plantarum (LP) at 1 × 1010 cfu/calf/day, and a group receiving a combination of LP and BT (LP + BT) at half the dosage for each. The study found that calves supplemented with LP and LP + BT experienced significant improvements in average daily gain and final body weight compared to the control group. The LP + BT group showed the most positive effects on TDMI, starter intake, and CP intake. RBC counts tended to be higher in the probiotic groups, with the LP + BT group having the highest values. The LP + BT group also had higher total protein, albumin, globulin, and hematocrit concentrations. All probiotic groups showed higher serum IgG concentrations. Probiotic supplementation led to increased total bacterial count and decreased levels of E. coli, salmonella, and clostridium. The LP + BT group had a significant decrease in coliform count, while both LP and LP + BT groups had increased Lactobacillus populations. In conclusion, LP + BT probiotic supplement showed the most beneficial effects on growth, feed efficiency, blood constituents, and modulation of fecal microbiota composition.

Exploring the human microbiome - A step forward for precision medicine in breast cancer

BACKGROUND

The second most frequent cancer in the world and the most common malignancy in women is breast cancer. Breast cancer is a significant health concern in India with a high mortality-to-incidence ratio and presentation at a younger age.

RECENT FINDINGS

Recent studies have identified gut microbiota as a significant factor that can have an influence on the development, treatment, and prognosis of breast cancer. This review article aims to describe the influence of microbial dysbiosis on breast cancer occurrence and the possible interactions between oncobiome and specific breast cancer molecular subtypes. The review further also discusses the role of epigenetics and diet/nutrition in the regulation of the gut and breast microbiome and its association with breast cancer prevention, therapy, and recurrence. Additionally, the recent technological advances in microbiome research, including next-generation sequencing (NGS) technologies, genome sequencing, single-cell sequencing, and microbial metabolomics along with recent advances in artificial intelligence (AI) have also been reviewed. This is an attempt to present a comprehensive status of the microbiome as a key cancer biomarker.

CONCLUSION

We believe that correlating microbiome and carcinogenesis is important as it can provide insights into the mechanisms by which microbial dysbiosis can influence cancer development and progression, leading to the potential use of the microbiome as a tool for prognostication and personalized therapy.

Intravenous ferric carboxymaltose and ferric derisomaltose alter the intestinal microbiome in female iron-deficient anemic mice

Iron deficiency anemia (IDA) is a leading global health concern affecting approximately 30% of the population. Treatment for IDA consists of replenishment of iron stores, either by oral or intravenous (IV) supplementation. There is a complex bidirectional interplay between the gut microbiota, the host's iron status, and dietary iron availability. Dietary iron deficiency and supplementation can influence the gut microbiome; however, the effect of IV iron on the gut microbiome is unknown. We studied how commonly used IV iron preparations, ferric carboxymaltose (FCM) and ferric derisomaltose (FDI), affected the gut microbiome in female iron-deficient anemic mice. At the phylum level, vehicle-treated mice showed an expansion in Verrucomicrobia, mostly because of the increased abundance of Akkermansia muciniphila, along with contraction in Firmicutes, resulting in a lower Firmicutes/Bacteroidetes ratio (indicator of dysbiosis). Treatment with either FCM or FDI restored the microbiome such that Firmicutes and Bacteroidetes were the dominant phyla. Interestingly, the phyla Proteobacteria and several members of Bacteroidetes (e.g., Alistipes) were expanded in mice treated with FCM compared with those treated with FDI. In contrast, several Clostridia class members were expanded in mice treated with FDI compared with FCM (e.g., Dorea spp., Eubacterium). Our data demonstrate that IV iron increases gut microbiome diversity independently of the iron preparation used; however, differences exist between FCM and FDI treatments. In conclusion, replenishing iron stores with IV iron preparations in clinical conditions, such as inflammatory bowel disease or chronic kidney disease, could affect gut microbiome composition and consequently contribute to an altered disease outcome.

Determinants of Gastrointestinal Group B Streptococcus Carriage in Adults

Background

Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal Gram-positive bacterium found in the human gastrointestinal and urogenital tracts. Much of what is known about GBS relates to the diseases it causes in pregnant people and neonates. However, GBS is a common cause of disease in the general population with 90% of GBS mortality occurring in non-pregnant people. There are limited data about the predisposing factors for GBS and the reservoirs in the body. To gain an understanding of the determinants of gastrointestinal GBS carriage, we used stool samples and associated metadata to determine the prevalence and abundance of GBS in the gut microbiome of adults and find risk factors for GBS status.

Methods

We used 754 stool samples collected from adults in Wisconsin from 2016-2017 to test for the prevalence and abundance of GBS using a Taqman probe-based qPCR assay targeting two GBS-specific genes: cfp and sip. We compared the microbiome compositions of the stool samples by GBS status using 16S rRNA analysis. We compared associations with GBS status and 557 survey variables collected during sample acquisition (demographics, diet, overall health, and reproductive health) using univariate and multivariate analyses.

Results

We found 137/754 (18%) of participants had detectable GBS in their stool samples with a median abundance of 104 copies per nanogram of starting DNA. There was no difference in GBS status or abundance based on gender. Beta-diversity, Bray-Curtis and Unweighted UniFrac, was significantly different based on carrier status of the participant. Prior to p-value correction, 59/557 (10.6%) survey variables were significantly associated with GBS carrier status and 11/547 (2.0%) variables were significantly associated with abundance (p-value<0.05). After p-value correction, 2/547 (0.4%) variables were associated with GBS abundance: an increased abundance of GBS was associated with a decreased frequency since last dental checkup (p<0.001) and last dental cleaning (p<0.001). Increased GBS abundance was significantly associated with increased frequency of iron consumption (p=0.007) after p-value correction in multivariate models.

Conclusions

GBS is found in stool samples from adults in Wisconsin at similar frequencies as pregnant individuals screened with rectovaginal swabs. We did not find associations between risk factors historically associated with GBS in pregnant people, suggesting that risk factors for GBS carriage in pregnancy may differ from those in the general population. We found that frequency of iron consumption and dental hygiene are risk factors for GBS carriage in Wisconsin adults. Given that these variables were not assayed in previous GBS surveys, it is possible they also influence carriage in pregnant people. Taken together, this work serves as a foundation for future work in developing approaches to decrease GBS abundance in carriers.

Bacteria from the gut influence the host micronutrient status

Micronutrient deficiencies or "hidden hunger" remains a serious public health problem in most low- and middle-income countries, with severe consequences for child development. Traditional methods of treatment and prevention, such as supplementation and fortification, have not always proven to be effective and may have undesirable side-effects (i.e., digestive troubles with iron supplementation). Commensal bacteria in the gut may increase bioavailability of specific micronutrients (i.e., minerals), notably by removing anti-nutritional compounds, such as phytates and polyphenols, or by the synthesis of vitamins. Together with the gastrointestinal mucosa, gut microbiota is also the first line of protection against pathogens. It contributes to the reinforcement of the integrity of the intestinal epithelium and to a better absorption of micronutrients. However, its role in micronutrient malnutrition is still poorly understood. Moreover, the bacterial metabolism is also dependent of micronutrients acquired from the gut environment and resident bacteria may compete or collaborate to maintain micronutrient homeostasis. Gut microbiota composition can therefore be modulated by micronutrient availability. This review brings together current knowledge on this two-way relationship between micronutrients and gut microbiota bacteria, with a focus on iron, zinc, vitamin A and folate (vitamin B9), as these deficiencies are public health concerns in a global context.

Hydrolysis of pea protein differentially modulates its effect on iron bioaccessibility, sulfur availability, composition and activity of gut microbial communities in vitro

Both plant proteins and iron supplements can demonstrate high susceptibility to escape small intestinal digestion and absorption, hence are often present throughout colonic fermentation. Whilst colonic iron delivery may adversely affect the gut microbiota and epithelial integrity, nascent evidence suggests that pea proteins may possess beneficial prebiotic and antioxidant effects during gut fermentation. This study investigated the interaction between exogenously added iron and pea protein isolate (PPI) or pea protein hydrolysate (PPH) during in vitro gastrointestinal digestion and colonic fermentation. Results revealed that enzymatic hydrolysis mitigated the crude protein's inhibitory effects on iron solubility during small intestinal digestion. Colonic fermentation of iron-containing treatments led to an increase in iron bioaccessibility and was characterized by a loss of within-species diversity, a marked increase in members of Proteobacteria, and eradication of some species of Lactobacillaceae. Although these patterns were also observed with pea proteins, the extent of the effects differed. Only PPI displayed significantly higher levels of total short-chain fatty acids in the presence of iron, accompanied by greater abundance of Propionibacteriaceae relative to other treatments. Additionally, we provide evidence that the iron-induced changes in the gut microbiome may be associated with its effect on endogenous sulfur solubility. These findings highlight the potential trade-off between protein-induced enhancements in fortified iron bioaccessibility and effects on the gut microbiome, and the role of iron in facilitating colonic sulfur delivery.

Comprehensive genomic analysis of hypocholesterolemic probiotic Enterococcus faecium LR13 reveals unique proteins involved in cholesterol-assimilation

Hypercholesterolemia is a major risk factor for cardiovascular diseases (CVDs). Chemotherapeutic agents for CVDs exhibit several side effects. Specific probiotics with hypocholesterolemic effects can be safe and effective alternatives to chemotherapeutics. Here, we have analyzed and compared the genome of a novel rhizospheric Enterococcus faecium LR13 cholesterol-assimilating probiotic with other probiotic/pathogenic E. faecium strains to discern genetic factors underlying probiotic efficacy and cholesterol-assimilation. Genomic analyses of E. faecium probiotic strains revealed that LR13 and WEFA23 (cholesterol-assimilating probiotics) harbored 21 unique proteins absent in non-cholesterol-assimilating probiotics. Of these, 14 proteins could directly help in cholesterol-assimilation by producing short chain fatty acids, lipid (sterol) transport and membrane stabilization, and bile salt hydrolase activity. This suggests that cholesterol-assimilation is an intrinsic, strain-specific trait exhibited by probiotics with a specific genetic constitution. Moreover, the unique proteins identified in this study can serve as biomarkers for discerning/characterizing cholesterol-assimilating probiotics as novel biotherapeutics against CVDs.

Effect of dietary iron supplementation on the equine fecal microbiome

Iron is an essential element for all living organisms, including bacteria, as several virulence factors and replication components are influenced by iron concentration. The objective of this study was to determine whether the composition and diversity of the fecal microbiota of adult horses are affected by supplemental dietary iron. Ten clinically healthy horses were randomly divided into a control and an iron-supplemented group (n = 5). The treated group was supplemented with oral ferrous sulphate monohydrate (720 ppm of iron), whereas the control group received 320 ppm of iron daily for 15 d. Fecal samples were collected before and 5, 10, 15, and 30 d after supplementation and frozen at -80°C. DNA was sequenced using an Illumina MiSeq platform and data were analyzed using the software Mothur and linear discriminant analysis (LDA) effect size (LEfSe). Iron supplementation caused no change in the overall composition of the fecal microbiota, but some minor changes were observed in the low-abundant bacteria, as well as an increased alpha diversity after 15 d of supplementation. Significant differences in community composition of the fecal microbiota over time were observed in both groups, highlighting the importance of a control group, as there are variables that cannot be controlled in microbiome studies.

The Link between Iron Turnover and Pharmacotherapy in Transplant Patients

Iron is a transition metal that plays a crucial role in several physiological processes. It can also exhibit toxic effects on cells, due to its role in the formation of free radicals. Iron deficiency and anemia, as well as iron overload, are the result of impaired iron metabolism, in which a number of proteins, such as hepcidin, hemojuvelin and transferrin, take part. Iron deficiency is common in individuals with renal and cardiac transplants, while iron overload is more common in patients with hepatic transplantation. The current knowledge about iron metabolism in lung graft recipients and donors is limited. The problem is even more complex when we consider the fact that iron metabolism may be also driven by certain drugs used by graft recipients and donors. In this work, we overview the available literature reports on iron turnover in the human body, with particular emphasis on transplant patients, and we also attempt to assess the drugs’ impact on iron metabolism, which may be useful in perioperative treatment in transplantology.

The effect of probiotics on immune responses and their therapeutic application: A new treatment option for multiple sclerosis

Multiple sclerosis (MS) is known as a chronic inflammatory disease (CID) that affects the central nervous system and leads to nerve demyelination. However, the exact cause of MS is unknown, but immune system regulation and inhibiting the function of inflammatory pathways may have a beneficial effect on controlling and improving the disease. Studies show that probiotics can alter the gut microbiome, thereby improving and affecting the immune system and inflammatory responses in patients with MS. The results show that probiotics have a good effect on the recovery of patients with MS in humans and animals. The present study investigated the effect of probiotics and possible therapeutic mechanisms of probiotics on immune cells and inflammatory cytokines. This review article showed that probiotics could improve immune cells and inflammatory cytokines in patients with MS and can play an effective role in disease management and control.

Adequacy of Iodine Status and Associations with Gut Health: A Prospective Cohort Study among Infants in 8 Low- and Middle-Income Countries

BACKGROUND

Environmental enteric dysfunction increases the likelihood of micronutrient deficiencies among infants, but few studies have assessed the potential impact of gut health on urinary iodine concentration (UIC) among this vulnerable group.

OBJECTIVES

We describe the trends of iodine status among infants from 6 to 24 mo old and examine the associations between intestinal permeability, inflammation, and UIC from 6 to 15 mo of age.

METHODS

Data from 1557 children enrolled in this birth cohort study conducted in 8 sites were included in these analyses. UIC was measured at 6, 15, and 24 mo of age by using the Sandell-Kolthoff technique. Gut inflammation and permeability were assessed using the concentrations of fecal neopterin (NEO), myeloperoxidase (MPO) and alpha-1-antitrypsin (AAT), and lactulose-mannitol ratio (LM). A multinomial regression analysis was used to assess the classified UIC (deficiency or excess). Linear mixed regression was used to test the effect of interactions among biomarkers on logUIC.

RESULTS

All studied populations had adequate (≥100 μg/L) to excess (≥371 μg/L) median UIC at 6 mo. Between 6 and 24 mo, 5 sites displayed a significant decline in the infant's median UIC. However, median UIC remained within the optimal range. An increase of NEO and MPO concentrations by +1 unit in ln scale reduced the risk of low UIC by 0.87 (95% CI: 0.78-0.97) and 0.86 (95% CI: 0.77-0.95), respectively. AAT moderated the association between NEO and UIC (P < 0.0001). The shape of this association appears to be asymmetric and in a reverse J-shape, with a higher UIC observed at both lower NEO and AAT concentrations.

CONCLUSIONS

Excess UIC was frequent at 6 mo and tended to normalize at 24 mo. Aspects of gut inflammation and increased permeability appear to reduce the prevalence of low UIC in children aged 6 to 15 mo. Programs addressing iodine-related health should consider the role of gut permeability in vulnerable individuals.

A New Artificial Intelligence Approach Using Extreme Learning Machine as the Potentially Effective Model to Predict and Analyze the Diagnosis of Anemia

The procedure to diagnose anemia is time-consuming and resource-intensive due to the existence of a multitude of symptoms that can be felt physically or seen visually. Anemia also has several forms, which can be distinguished based on several characteristics. It is possible to diagnose anemia through a quick, affordable, and easily accessible laboratory test known as the complete blood count (CBC), but the method cannot directly identify different kinds of anemia. Therefore, further tests are required to establish a gold standard for the type of anemia in a patient. These tests are uncommon in settings that offer healthcare on a smaller scale because they require expensive equipment. Moreover, it is also difficult to discern between beta thalassemia trait (BTT), iron deficiency anemia (IDA), hemoglobin E (HbE), and combination anemias despite the presence of multiple red blood cell (RBC) formulas and indices with differing optimal cutoff values. This is due to the existence of several varieties of anemia in individuals, making it difficult to distinguish between BTT, IDA, HbE, and combinations. Therefore, a more precise and automated prediction model is proposed to distinguish these four types to accelerate the identification process for doctors. Historical data were retrieved from the Laboratory of the Department of Clinical Pathology and Laboratory Medicine, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia for this purpose. Furthermore, the model was developed using the algorithm for the extreme learning machine (ELM). This was followed by the measurement of the performance using the confusion matrix and 190 data representing the four classes, and the results showed 99.21% accuracy, 98.44% sensitivity, 99.30% precision, and an F1 score of 98.84%.

Lactobacillus johnsonii L531 Ameliorates Salmonella enterica Serovar Typhimurium Diarrhea by Modulating Iron Homeostasis and Oxidative Stress via the IRP2 Pathway

Salmonella enterica serovar Typhimurium (S. Typhimurium) has evolved mechanisms to evade the host's nutritional immunity and thus promote bacterial growth by using the iron in the host. However, the detailed mechanisms of S. Typhimurium induce dysregulation of iron homeostasis and whether Lactobacillus johnsonii L531 can alleviate the iron metabolism disorder caused by S. Typhimurium has not been fully elucidated. Here, we show that S. Typhimurium activated the expression of iron regulatory protein 2 (IRP2), transferrin receptor 1, and divalent metal transporter protein 1 and suppressed the expression of iron exporter ferroportin, which resulted in iron overload and oxidative stress, inhibiting the key antioxidant proteins NF-E2-related factor 2, Heme Oxygenase-1, and Superoxide Dismutase in vitro and in vivo. L. johnsonii L531 pretreatment effectively reversed these phenomena. IRP2 knockdown inhibited iron overload and oxidative damage induced by S. Typhimurium in IPEC-J2 cells, while IRP2 overexpression promoted iron overload and oxidative damage caused by S. Typhimurium. Interestingly, the protective effect of L. johnsonii L531 on iron homeostasis and antioxidant function was blocked following IRP2 overexpression in Hela cells, demonstrating that L. johnsonii L531 attenuates disruption of iron homeostasis and consequent oxidative damage caused by S. Typhimurium via the IRP2 pathway, which contributes to the prevention of S. Typhimurium diarrhea in mice.

Pseudomonas aeruginosa virulence attenuation by inhibiting siderophore functions

Pseudmonas aeruginosa is a Gram-negative bacterium known to be ubiquitous and recognized as one of the leading causes of infections such as respiratory, urinary tract, burns, cystic fibrosis, and in immunocompromised individuals. Failure of antimicrobial therapy has been documented to be attributable due to the development of various resistance mechanisms, with a proclivity to develop additional resistance mechanisms rapidly. P. aeruginosa virulence attenuation is an alternate technique for disrupting pathogenesis without impacting growth. The iron-scavenging siderophores (pyoverdine and pyochelin) generated by P. aeruginosa have various properties like scavenging iron, biofilm formation, quorum sensing, increasing virulence, and toxicity to the host. As a result, developing an antivirulence strategy, specifically inhibiting the P. aeruginosa siderophore, has been a promising therapeutic option to limit their infection. Several natural, synthetic compounds and nanoparticles have been identified as potent inhibitors of siderophore production/biosynthesis, function, and transport system. The current review discussed pyoverdine and pyochelin's synthesis and transport system in P. aeruginosa. Furthermore, it is also focused on the role of several natural and synthetic compounds in reducing P. aeruginosa virulence by inhibiting siderophore synthesis, function, and transport. The underlying mechanism involved in inhibiting the siderophore by natural and synthetic compounds has also been explained. KEY POINTS: • Pseudomonas aeruginosa is an opportunistic pathogen linked to chronic respiratory, urinary tract, and burns infections, as well as cystic fibrosis and immunocompromised patients. • P. aeruginosa produces two virulent siderophores forms: pyoverdine and pyochelin, which help it to survive in iron-deficient environments. • The inhibition of siderophore production, transport, and activity using natural and synthesized drugs has been described as a potential strategy for controlling P. aeruginosa infection.

Effect of Diets Varying in Iron and Saturated Fat on the Gut Microbiota and Intestinal Inflammation: A Crossover Feeding Study among Older Females with Obesity

Obesity is considered an independent risk factor for colorectal cancer (CRC). Altered nutrient metabolism, particularly changes to digestion and intestinal absorption, may play an important role in the development of CRC. Iron can promote the formation of tissue-damaging and immune-modulating reactive oxygen species. We conducted a crossover, controlled feeding study to examine the effect of three, 3-week diets varying in iron and saturated fat content on the colonic milieu and systemic markers among older females with obesity. Anthropometrics, fasting venous blood and stool were collected before and after each diet. There was a minimum 3-week washout period between diets. Eighteen participants consumed the three diets (72% Black; mean age 60.4 years; mean body mass index 35.7 kg/m2). Results showed no effect of the diets on intestinal inflammation (fecal calprotectin) or circulating iron, inflammation, and metabolic markers. Pairwise comparisons revealed less community diversity between samples (beta diversity, calculated from 16S rRNA amplicon sequences) among participants when consuming a diet low in iron and high in saturated fat vs. when consuming a diet high in iron and saturated fat. More studies are needed to investigate if dietary iron represents a salient target for CRC prevention among individuals with obesity.

Metallobiology of Lactobacillaceae in the gut microbiome

Lactobacillaceae are a diverse family of lactic acid bacteria found in the gut microbiota of humans and many animals. These bacteria exhibit beneficial effects on intestinal health, including modulating the immune system and providing protection against pathogens, and many species are frequently used as probiotics. Gut bacteria acquire essential metal ions, like iron, zinc, and manganese, through the host diet and changes to the levels of these metals are often linked to alterations in microbial community composition, susceptibility to infection, and gastrointestinal diseases. Lactobacillaceae are frequently among the organisms increased or decreased in abundance due to changes in metal availability, yet many of the molecular mechanisms underlying these changes have yet to be defined. Metal requirements and metallotransporters have been studied in some species of Lactobacillaceae, but few of the mechanisms used by these bacteria to respond to metal limitation or excess have been investigated. This review provides a current overview of these mechanisms and covers how iron, zinc, and manganese impact Lactobacillaceae in the gut microbiota with an emphasis on their biochemical roles, requirements, and homeostatic mechanisms in several species.