Vitamin B12

Abstract

Cystobactamids are nonribosomal peptide natural products that function as DNA gyrase inhibitors, exhibiting significant antibacterial activity. They are isolated from Cystobacter sp. Cbv34 and contain various alkoxy groups on para-aminobenzoic acid moieties, which are believed to play a crucial role in antibacterial functions. The alkoxy groups are generated by iterative methylations on a methoxy group by the cobalamin (Cbl)-dependent radical S-adenosylmethionine (SAM) enzyme CysS. CysS catalyzes up to three methylations to give ethoxy, isopropoxy, sec-butoxy, and tert-butoxy groups. For each methylation, CysS uses a ping-pong mechanism in which two molecules of SAM are consumed. One SAM is used to methylate cob(I)alamin, while another generates a 5'-deoxyadenosyl 5'-radical to initiate substrate methylation. However, little is known about how the enzyme promotes both Cbl methylation and iterative substrate methylation, which occur by polar SN2 and radical processes, respectively. Here, we report three X-ray crystal structures of a homolog of CysS from Corallococcus sp. CA054B. Two were determined in the presence of methoxy- and ethoxy-containing substrates, showing how CysS accommodates substrates and products during iterative methylation. The third structure, determined in the absence of a substrate, exhibits structural changes that reorient the SAM's conformation to allow for the methylation of cob(I)alamin.

Abstract

Vasoplegic syndrome is a life-threatening condition characterized by uncontrolled peripheral vasodilation, leading to profound arterial hypotension. Treatments include catecholamines, vasopressin, methylene blue (MB), hydroxocobalamin, angiotensin II, and ascorbic acid. We developed a scoping review protocol according to the Joanna Briggs Institute methodology and searched PubMed, PubMed Central, Scopus, and Cochrane Library electronic databases. A total of 23 records were included in this scoping review, out of which 13 were original research studies, seven were reviews, and three were case studies. In these studies, vasopressin, MB, hydroxocobalamin, angiotensin II, and ascorbic acid were used for vasoplegic syndrome. Vasopressin, MB, hydroxocobalamin, angiotensin II, and ascorbic acid showed rapid restoration of hemodynamics and decreased vasopressor requirement. Non-catecholamine drugs such as vasopressin, angiotensin II, MB, and hydroxocobalamin appear to be promising drugs for the treatment of patients with post-cardiac surgery vasoplegic syndrome. It is demonstrated to be effective in raising blood pressure in such patients, but these agents should be used cautiously due to their associated adverse effects.

Abstract

Neutropenia is defined as an absolute neutrophil count of less than 1,500 per μL in adults and children older than 1 year, and less than 1,000 per μL in infants. Neutropenia can be acquired or inherited. It is classified as mild (1,000-1,500 per μL), moderate (500-999 per μL), or severe (less than 500 per μL). Patient presentation can range from asymptomatic to severe illness requiring hospitalization. Acquired neutropenias and their causes include autoimmune neutropenia, chronic idiopathic neutropenia, chemotherapy-induced neutropenia, febrile neutropenia, hematologic malignancy, idiosyncratic drug-induced neutropenia, infection-related neutropenia, and nutritional deficiency (ie, vitamin B12, folate, and copper). Inherited neutropenias and their causes include bone marrow failure, cyclic neutropenia, and severe congenital neutropenia. Genetic testing may be required for diagnosis. Acquired neutropenias are treated by addressing the underlying etiologies. Some patients experiencing recurrent severe infections may benefit from granulocyte colony-stimulating factor. Most inherited neutropenias are treated with granulocyte colony-stimulating factor. Febrile neutropenia is an oncologic emergency. It is defined as a single oral temperature of 101°F or greater or a temperature of 100.4°F or greater sustained for 1 hour with an absolute neutrophil count of less than 500 per μL. Febrile neutropenia warrants emergent evaluation, but low-risk patients with a malignancy who meet strict criteria can be treated as outpatients.

Abstract

Peripheral nerve injuries remain a significant clinical challenge due to suboptimal functional recovery, even with surgical intervention. This article critically reviews current adjunctive strategies aimed at enhancing outcomes after peripheral nerve repair. The modalities discussed include electrical stimulation, erythropoietin, tacrolimus, methylcobalamin, gene therapy and stem cell-based interventions. For each modality, we examine proposed mechanisms of action, quality of evidence and translational relevance. Special attention is given to differentiating findings from animal models and their applicability to clinical practice. Rather than highlighting speculative biological mechanisms, this review focusses on evaluating the clinical utility and limitations of each approach to guide evidence-based therapeutic decisions. Level of Evidence: Level V (Therapeutic).

Abstract

Background Substantial variation in testing rates in adults with hypertension across UK primary care suggest that patients are not receiving optimal monitoring. Aim To develop a minimal set of evidence-based blood tests for adults with hypertension. Design Rapid review, routine data analyses, and consensus study. Setting Primary care. Method We examined the rationale and evidence for tests recommended by guidelines or used commonly in adults with hypertension using stepwise rapid evidence reviews. A consensus group, including clinicians and patients, voted to include or exclude each test in the testing panel based on the evidence. If there was no consensus (>80%), additional evidence was sought through rapid reviews or analyses of primary care records, which was subject to further voting. Results We identified 16 routinely ordered tests. We found consistent, good evidence that eGFR to detect chronic kidney disease and HbA1c to detect diabetes is beneficial for patients. We found no or inconsistent evidence of the benefit of routinely measuring lipids, electrolytes, haemoglobin, thyroid function, clotting biomarkers, calcium, ferritin, folate acid, or vitamin B12. We found good evidence that there is no benefit in routinely monitoring liver function, inflammation markers, or brain natriuretic peptide. Conclusion We identified a minimal set of evidence-based blood tests to monitor adults with hypertension. This panel includes eGFR, HbA1c, potassium and sodium. Implementing these recommendations could reduce harms associated with unwarranted variation in care. Further research is needed to clarify the role of tests with inconsistent evidence and determine the optimal frequency of testing.

Abstract

Vitamin B12 (B12) is a strong antioxidant and a cofactor for methionine synthase supporting DNA/RNA/protein methylation. We previously demonstrated that oral high-dose B12 supplement mitigates diabetic cardiomyopathy in Akita diabetic mice expressing twice the normal levels of Elmo1 (Engulfment and cell motility 1). To assess how B12 prevents early kidney damage, we treated Elmo1HH mice and diabetic Elmo1HH Ins2Akita/+ mice with or without B12 in drinking water starting at 8 weeks of age. At 16 weeks, markedly reduced mesangial expansion was detected in the B12-treated diabetic kidneys (22% of glomeruli affected vs. 70% in the untreated diabetic kidneys). RNAseq analysis of the kidneys revealed that B12 suppressed expression of genes for adaptive immune response, while it upregulated those for solute carrier transporters and antioxidant genes. Strikingly, B12 treatment suppressed activators of circadian rhythm, Clock and Bmal1, and upregulated repressors like Cry1/2, Per1-3 and Dbp, suggesting a shift in their rhythmicity. B12 also upregulated linker histone H1 variants, and enhanced chromatin stability and cell cycle regulation. In BU.MPT proximal tubular cells in culture, B12 shifted forward the circadian expression phase of Bmal1 and Per1. Taken together, B12 supplement effectively mitigates early development of diabetic nephropathy in diabetic mice, potentially involving regulation of circadian rhythm.

Abstract

Diabetic neuropathy is a debilitating complication of type 2 diabetes mellitus (T2DM), largely driven by systemic inflammation and metabolic disturbances. This cross-sectional study assessed the relationship between interleukin-6 (IL-6), vitamin B12, lipid profile, and nerve conduction parameters in T2DM patients with and without neuropathy. Sixty participants were divided evenly into two groups: T2DM without neuropathy (control) and T2DM with confirmed neuropathy (case). Biochemical parameters measured included fasting and postprandial glucose, glycated hemoglobin (HbA1c), vitamin B12, IL-6, renal function, and detailed lipid profiling. Nerve conduction studies assessed sensory and motor nerves in upper and lower limbs. The neuropathy group showed higher IL-6 levels, lower vitamin B12 concentrations, and an atherogenic lipid profile characterised by increased triglycerides, VLDL, and non-HDL cholesterol. Marked reductions in nerve conduction velocities were evident in both sensory and motor nerves, especially in the common peroneal and posterior tibial nerves, which had high diagnostic accuracy with AUC values of 0.88 and 0.84, respectively. Univariate regression identified IL-6 as significantly associated with decreased conduction velocity in radial sensory and posterior tibial nerves. Supporting these clinical findings, in silico pathway enrichment analyses highlighted key roles for IL-6 signalling, vitamin B12 metabolism, lipid pathways, and myelination in diabetic neuropathy pathogenesis. These integrated data underscore inflammation and metabolic dysfunction as pivotal drivers, with IL-6 and nerve conduction studies serving as promising early biomarkers and therapeutic targets.

Abstract

Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) influence erythropoiesis; however, data on the prevalence and determinants of anemia in acromegaly are limited. This study aimed to investigate the frequency, characteristics, and risk factors of anemia in patients with acromegaly.

Abstract

Vancomycin (VCM) is an essential glycopeptide antibiotic employed for treating methicillin-resistant Staphylococcus infections. However, its clinical use is limited by nephrotoxicity. Vitamin B12 (Vit B12) possesses antioxidant, anti-inflammatory, and anti-fibrotic properties that may protect against nephrotoxicity. However, Vitamin B12 bioavailability is inherently low. Therefore, nanotechnology-based approaches have been employed to overcome these limitations. Our research examined the formulation and preclinical assessment of Vitamin B12 nanocapsules (Vit B12 NC) against VCM-induced oxidative and, endoplasmic reticulum (ER) stress, inflammation, and fibrosis in rats. Nephrotoxicity was induced by administering VCM, followed by treatment with oral Vit B12 NC. Renal function, oxidative and ER stress markers, inflammatory cytokines, fibrosis markers, and histopathological changes in kidney tissue were evaluated. Vit B12 NC treatment reduced serum creatinine, uric acid, and urea levels, raised antioxidant enzyme activities (catalase and total antioxidant capacity), and decreased malondialdehyde (MDA) levels. It also downregulated ER stress markers, including inositol-requiring enzyme 1 (IRE1), TNF receptor-associated factor 2 (TRAF2), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP). Inflammatory mediators such as Toll-like receptor 4 (TLR4), interleukin-17 (IL-17), and interleukin-18 (IL-18) were also repressed. Also, it reduced renal fibrosis as indicated by decreased expression of VIM, miR-382-5p, and miR-92a-3p. Furthermore, it reversed the histopathological alterations in renal tissues. These findings suggest that Vit B12 NC exhibits promising nephroprotective potential against VCM-induced nephrotoxicity.

Abstract

Inflammatory skin conditions affect chronically a notable number of patients worldwide. Despite their prevalence, effective long-term treatments with minimal side effects remain limited. In this piece of work, three lipid-based nanocarriers were developed and applied topically to enhance the dermal delivery of two drugs, cyanocobalamin (vitamin B12) and cyclosporine A (CsA), with different physicochemical properties and negligible skin absorption (>500 Da). Previous reports show potential activity of both drugs to tackle inflammatory states. However, these studies provide only partial insights into the formulation process or lack strategies to optimize B12 and CsA skin delivery. Herein, we report a comprehensive approach covering the design, development, and complete evaluation of these systems, representing the first complete evidence of B12 and CsA application to inflammatory skin purposes through a nanotechnological strategy. Specifically, conventional liposomes (L), transfersomes (T) and ethosomes (E) were designed, produced and characterized. They showed optimal properties in terms of size (<300 nm) and homogeneity (PDI <0.3) for transdermal and dermal administration. Besides, the drug entrapment efficiency was adequate according to the physicochemical properties of each one of the loaded drugs. The drug permeability through the skin was assessed ex vivo, showing negligible passive diffusion of free-drugs and enhanced skin absorption of both drugs when the lipid-based nanosystems were used. Particularly, transfersomes and ethosomes provided the best permeation flux through the skin. At high nanoparticle concentrations, liposomal and transfersomal dispersions exhibited good biocompatibility (>70 %). Transfersomal formulations (T-CsA and T-B12) were selected to test their activity in three in vivo murine models of skin inflammation: TPA-induced cutaneous inflammation and delayed type hypersensitivity (DTH) models. Both formulations demonstrated promising activity in the TPA model, mainly regarding leukocyte infiltration. Nevertheless, only T-B12 showed anti-inflammatory effects in the acute DTH model, mainly regarding edema formation and slightly concerning cell infiltration. Finally, these formulations exhibit their full potential in diminishing chronic skin inflammatory states, as T-CsA and T-B12 notably normalized the inflammatory response: pro-inflammatory cytokine downregulation, decrease of cellular infiltration, edema reduction and negligible histopathological damage.

Abstract

The clinical manifestations of AMAG are diverse and easily overlooked. The exact diagnostic criteria for AMAG are yet to be standardized, and serological tests lack clinical practices.

Abstract

Chronic intestinal inflammation in dogs is common worldwide; however, it can be very difficult to manage and predict clinical response to different treatment protocols.

Abstract

Current surveillance strategies for autoimmune gastritis (AIG) lack consensus, and the prognostic role of serum biomarkers remains unclear. This meta-analysis aimed to evaluate the correlation between serum biomarkers and the risks of gastric lesions in AIG patients.

Abstract

Brain-derived neurotrophic factor (BDNF) levels are lower in diabetic patients compared to healthy individuals, and may be further affected by nephropathy. This study aimed to evaluate serum BDNF levels in diabetic patients with nephropathy without complications and compare them to levels in healthy control subjects.

Abstract

Low kisspeptin levels are observed in those with reproductive difficulties. This study was designed to examine and compare kisspeptin levels in women with infertility and miscarriages. Moreover, the aim of this study was to evaluate the possible relationship between kisspeptin levels and the C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene, as well as certain biochemical parameters in these two groups.

Abstract

To investigate whether vitamin B12 levels affect IVF-ET pregnancy outcomes.

Abstract

Endozoicomonas is an omnipresent marine bacterial genus, associated with various marine organisms, that contributes to host health, nutrient cycling and disease resistance. Nonetheless, its genomic features remain poorly characterised due to a paucity of high-quality genomes. In this study, we sequenced 5 novel Endozoicomonas strains and re-sequenced 1 known strain to improve genomic resolution. By integrating these 6 high-quality genomes with 31 qualified published genomes, our pan-genomic analysis revealed variation in genetic traits among clades. Notably, Endozoicomonas lacks quorum-sensing capabilities, suggesting resistance to quorum quenching mechanisms. It also lacks the capacity to synthesise and transport vitamin B12, indicating that it does not supply this nutrient to holobionts. Remarkably, Endozoicomonas genomes encode 92 identified giant proteins (15-65 kbp). These proteins cluster into three major groups associated with antimicrobial peptide synthesis, exotoxin production and cell adhesion. Additionally, we found that Endozoicomonas has acquired prophages from diverse sources via infection or other types of gene transfer. Notably, CRISPR-Cas sequences suggest evolutionary trajectories independent of both prophage acquisition and phylogenetic lineage, implying potential geographic influences or environmental pressures. This study provides new insights into the genomic diversity of Endozoicomonas and its genetic adaptations to diverse hosts.

Abstract

In tissue engineering, natural and synthetic nanofibers that can regenerate body damage have been successfully used in the repair of many lesion types, including peripheral neural lesions, in recent years. So, we developed three different nanofibers that we think can regenerate peripheral nerve damage. Three different nanofibers based on biodegradable poly-ε-caprolactone (PCL); Pure PCL (PCL) nanofiber, 70% PCL and 30% bioactive glass (PCL/BG) hybrid nanofiber, and 0.1% vitamin B12 added (PCL/BG)-B12 hybrid nanofiber were produced by electrospinning. Sol-gel method was used in the synthesis of biomaterials containing bioactive glass. The nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and fourier transform infrared spectroscopy (FT-IR). Cell viability assays were performed with healthy L929 fibroblast cells and PC12 cells to evaluate the biocompatibility of nanofibers. Neuronal differentiation of PC12 cells were stimulated by nerve growth factor (NGF). To assess the differentiation levels of PC12 cells, the length of neurites and number of outgrowing neurites per cell was evaluated morphologically, and NGF production levels of the cells were determined by ELISA. The results suggest that these biocompatible nanofibers stimulated PC12 cell survival and neuronal differentiation. Among these scaffolds, PCL/BG-B12 nanofibers strikingly triggered NGF production of PC12 cells as a hallmark of neuroregeneration. Thus, the nanofibers are capable of neuroprotective properties due to their safe, supporting proliferation, and NGF-releasing capacity. Additionally, it could be suggested that the PCL/BG nanofiber and vitamin B12 have the potential to be used in further studies for neurodegenerative diseases.

Abstract

The structural complexity of natural products arises from the complexity of their biosynthetic pathways and directly contributes to their biological activities. Guided by this principle, we screened 500 microbial extracts using high-throughput screening to identify structurally novel inhibitors of coronavirus main protease, 3CLpro. We discovered and structurally characterized a new scaffold, cobaltribin, the only isolated cobalt-containing natural product except vitamin B12 cobalamins. We further analyzed cobaltribin analogs to expand this unique class of anticoronavirus compounds. Furthermore, evidence from our bioinformatic, isotope labeling, and gene deletion analyses suggested that cobaltribin is a tribrid natural product resulting from an unprecedented terpene-polyketide (PK)-nonribosomal peptide (NRP) trihybridized biosynthesis. Notably, cobaltribin inhibits live severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in infected Vero E6 cells without toxicity to the host, demonstrating its promise as a therapeutic candidate against SARS-CoV-2.

Abstract

Klotho, a transmembrane protein with pleiotropic antiaging properties, is increasingly recognized as a central regulator of longevity and metabolic resilience. Primarily expressed in the kidneys and brain, Klotho governs phosphate and calcium homeostasis, modulates redox signaling, and influences key metabolic pathways, including PI3K/AKT and IGF-1. Declining Klotho expression is associated with both biological and chronological aging and has been mechanistically implicated in the pathogenesis of chronic kidney disease, cardiovascular disease, neurodegeneration, and metabolic dysfunction.

Abstract

Supportive agents, such as vitamin B12 (cobalamin, B12) and granulocyte colony-stimulating factor (G-CSF), are widely used during chemotherapy; however, their direct effects on tumor biology are not well understood. We evaluated the impact of pharmacological B12 and G-CSF, alone or in combination with cisplatin, on hormone receptor-positive (MCF-7) and triple-negative (MDA-MB-231) breast cancer cells, conducting in vitro assays of cell viability, cytotoxicity, caspase activation, mitochondrial membrane potential, and cytolytic protein expression. Neither B12 nor G-CSF alone induced cytotoxicity; instead, both promoted proliferation in a dose- and time-dependent manner. When combined with cisplatin, they consistently attenuated drug-induced cytotoxicity, suppressed caspase-3/-8/-9 activation, preserved mitochondrial integrity, and reduced perforin/granzyme expression, exhibiting stronger effects in MCF-7 cells. G-CSF markedly increased proliferation (>130% at 50 ng/mL), while B12 modestly enhanced viability and mitigated cisplatin-induced damage, particularly in triple-negative cells. These findings indicate that B12 and G-CSF can impair cisplatin efficacy by blunting apoptotic signaling and mitochondrial injury in different breast cancer subtypes. These preclinical findings warrant prospective, biomarker-driven in vivo and clinical studies to delineate the clinical contexts in which B12 and G-CSF can be safely integrated into supportive care without compromising antitumor efficacy.

Abstract

Hypothyroidism is characterized by insufficient production of thyroid hormones, which are crucial for metabolism. It often causes adrenal gland disturbances.

Abstract

Probiotics and vitamins face substantial challenges in preserving their viability and stability during processing, storage, and gastrointestinal transit. This study aimed to develop co-encapsulated formulations comprising Lactiplantibacillus plantarum JYLP-326 and vitamin B12 (vitB12) using a fluidized bed coating. The coatings used included a single hydroxypropyl methylcellulose acetate succinate (HPMCAS) and two composite HPMCAS systems incorporating either the hydrophilic triacetin (TR) or lipophilic oleic acid plasticizer. The physicochemical properties of the HPMCAS films were modulated by the inclusion of different plasticizers, thereby influencing the performance of the coated granules. The fluidized bed-coating process effectively preserved probiotic viability and vitB12 stability. The integration of TR into HPMCAS enhanced the pH-responsive controlled release by reinforcing the hydrogen bonding network. This feature resulted in only 3.3 % of vitB12 released in simulated gastric fluid and 94.7 % released in simulated intestinal fluid, while maintaining probiotic viability at over 95 % survival. All coated granules demonstrated high probiotic survival rates, exceeding 97 %, during a 10-day storage period at 4 °C and 25 °C, although the presence of plasticizers reduced thermal resistance at 40 °C. This study demonstrates that HPMCAS-based fluidized bed coating, optimized with specific plasticizers, represents an effective approach for encapsulating sensitive bioactive components while preserving their functional efficacy throughout manufacturing, storage and consumption. The extensive data obtained in this study offer a basis for established strategies aimed at developing oral fortified foods that enhance stability and facilitate controlled release.

Abstract

TEMPI syndrome (telangiectasia, erythrocytosis with increased erythropoietin, monoclonal gammopathy, perinephritic fluid collections, and intrapulmonary shunts) was described by David Sykes in 2011. By the end of March 2025, we have found descriptions of 35 cases of TEMPI syndrome in the literature. Non-IgM monoclonal gammopathy of clinical significance was diagnosed in 23 patients, multiple myeloma in 10 patients and Waldenström's macroglobulinemia in only 2 cases. Sykes estimated the median interval from the first symptoms to the diagnosis at 10 years. For many years, these patients were treated for a misdiagnosis of secondary erythrocytosis or primary polycythemia.

Abstract

The most effective and expedient way to improve the supply of the population with the essential nutrients is additional enrichment of food and the use of functional food, food for special dietary uses and dietary supplements in nutrition. One of the micronutrient delivery systems is liposome - microscopic phospholipid vesicle. The purpose of the review was to characterize the methods of obtaining liposomal forms of nutrients, to analyze the range of liposomal forms of nutrients of domestic and foreign production. Material and methods. Literature data were searched using library platforms PubMed, eLIBRARY, scholar.google mainly for the last 5 years, by keywords: liposomes; liposomal dietary supplements. E-commerce platforms (pharmacy aggregators Apteka.ru, Yuteka, marketplaces Amazon, ebay) have been analyzed. Results. The review describes classification, methods of obtaining liposomal forms of nutrients. Foreign manufacturers produce liposomal forms of individual vitamins (D3, B12, C) and their combinations, mineral elements (magnesium, iron), as well as coenzyme Q10, peptides. Liposomal forms of individual vitamins (A, B9, C), iron, vitamin B complex, glutathione had been registered in the Russian Federation as dietary supplements. There are evidences of a faster increase in serum calcidiol level compared to the oil form when taking vitamin D3 in liposomal form and improved correction of iron deficiency in patients when using liposomal forms of iron. Conclusion. The creation of liposomal forms of micronutrients is a promising direction for the production of foods for special dietary uses.

Abstract

Type 1 Diabetes Mellitus is known to be associated with multiple co-morbidities. Vitamin B12 deficiency is a potential co- morbidity that might have been overlooked in these patients. The aim of this study is to evaluate the serum level of vitamin B 12 in a well-defined population of Type 1 diabetes.

Abstract

Edible insects are gaining popularity as a sustainable source of proteins, minerals, vitamins, and bioactive compounds. Insects are nutritious, antibacterial, anti-inflammatory, and antioxidant. Modern processing methods, including roasting, drying, fermentation, and hydrolysis, improve the taste, safety, and digestibility of foods derived from insects. This comprehensive review integrates nutritional, bioactive, and technical aspects to explain edible insects as a future food.

Abstract

In combined treatments with antibiotics and bacteriophages (phages), antibiotics have the potential to influence phage infectivity, exhibiting effects that vary from synergistic to antagonistic. Here, we investigated the effects of various classes of antibiotics on Escherichia coli infection by phages that use different receptors, including vitamin B12 outer membrane transporter (BtuB), lipopolysaccharide (LPS), outer membrane protein A (OmpA), and nucleoside-specific porin (Tsx). Among the antibiotics tested, ampicillin did not affect phage infection, whereas colistin, chloramphenicol, and tetracycline inhibited phage infection irrespective of the phage receptor. In contrast, kanamycin inhibited infection of kanamycin-resistant E. coli by the BtuB-targeting phages, but not by the phages using LPS, OmpA, or Tsx. The receptor-specific antagonistic effect of kanamycin on BtuB-targeting phage infection was stronger than the effect observed with colistin, chloramphenicol, or tetracycline. When using a btuB-knockout mutant, we observed reduced kanamycin accumulation and increased kanamycin resistance compared to wild-type E. coli, suggesting that BtuB might be involved in kanamycin uptake. These results suggest that the antagonism between kanamycin and BtuB-targeting phage infection may be linked to the role of BtuB in facilitating kanamycin uptake. This study shows that the antimicrobial activity of phage-antibiotic combinations may be phage-receptor-specific, highlighting the need to consider phage receptors when selecting optimal combinations for effective phage therapy.

Abstract

Background and Objectives: The development of non-dairy probiotic products is a challenge for the food industry, while cereals, as probiotic carriers, provide the means to incorporate probiotics, prebiotics, and fiber into the human diet. The present study investigated the effects of Lactococcus cremoris spp. immobilized on oat flakes on blood and urine biomarkers in a randomized placebo-controlled single-blind clinical trial. Materials and Methods: Fifty-four eligible participants were randomized into a placebo or probiotic group that consumed 5 g of oat flakes daily for 12 weeks. Blood and urine samples were collected at the baseline, 6 weeks, and 12 weeks to assess the glycemic, lipemic, inflammatory, immunological, and antioxidant biomarkers, as well as the vitamin levels. Results: The intervention group exhibited a significant reduction in their hs-CRP levels (p = 0.002) and a trend toward decreased IL-6 levels (p = 0.035) at week 12 compared to the control group, suggesting a potential anti-inflammatory effect. Additionally, a significant reduction in insulin levels was observed in the probiotic group at week 6, with a clinical trend toward differentiation despite the absence of statistically significant differences between the groups. Furthermore, there were promising results regarding certain biomarkers, such as vitamin B12 and cortisol levels, in the probiotic group. Conclusions: The twelve-week consumption of Lactococcus cremoris spp. immobilized on oat flakes resulted in improvements in inflammatory, metabolic, and stress-related biomarkers. These results support the examined concept of non-dairy probiotic products, though further research is needed to confirm their efficacy and clarify their underlying mechanisms.

Abstract

Ribosomally synthesized and posttranslationally modified peptides (RiPPs) are a growing class of natural products. Multinuclear nonheme iron-dependent oxidative enzymes (MNIOs, previously DUF692) are involved in a range of unprecedented biochemical reactions. Over 13,500 putative MNIO-encoding biosynthetic gene clusters (BGCs) have been identified by sequence similarity networks. In this study, we investigated a set of precursor peptides containing a conserved FHAFRF motif in MNIO-encoding BGCs. These BGCs contain genes encoding an MNIO, a RiPP recognition element-containing protein, an arginase, a hydroxylase, and a vitamin B12-dependent radical SAM enzyme (B12-rSAM). Using heterologous reconstitution of a representative BGC from Peribacillus simplex (pbs cluster) in E. coli, we demonstrated that the MNIO in conjunction with the partner protein catalyzes ortho-hydroxylation of each of the phenylalanine residues in the conserved FRF motif, the arginase forms an ornithine from the arginine, the ornithine residue is hydroxylated, and the B12-rSAM cross-links the ortho-Tyr side chains by a C-C linkage forming a macrocycle. A protease matures the RiPP to its final form. The elucidated structure shares close similarity to biphenomycins, a class of peptide antibiotics for which the biosynthetic pathway has not been characterized. Substrate scope studies suggest some tolerance of the MNIO and the B12-rSAM enzymes. This study expands the diverse array of posttranslational modifications catalyzed by MNIOs and B12-rSAM enzymes, deorphanizes biphenomycin biosynthesis, and provides a platform for the production of analogs from orthologous BGCs.