Vitamin B6 supplementation increases immune responses in critically ill patients

Associations of serum vitamin B6 status with the risks of cardiovascular, cancer, and all-cause mortality in the elderly

Background

There are few studies investigating the relationship between serum vitamin B6 and mortality risk in the elderly. This study hereby evaluated the associations between biomarkers of serum vitamin B6 status and cardiovascular, cancer, and all-cause mortality risks in the elderly.

Methods

Our study included a total of 4,881 participants aged 60 years or older from the National Health and Nutrition Examination Survey (NHANES) 2005-2010. Serum vitamin B6 status was estimated based on levels of pyridoxal 5'-phosphate (PLP), 4-pyridoxic acid (4-PA), and vitamin B6 turnover rate (4-PA/PLP) detected by high-performance liquid chromatography. Survival status and corresponding causes of death were matched through the National Death Index records through December 31, 2019. Multivariate Cox regression model was adopted to assess the relationships between serum vitamin B6 status and the risk of mortality.

Results

During a median follow-up period of 10.33 years, 507 cardiovascular deaths, 426 cancer deaths, and 1995 all-cause deaths were recorded, respectively. In the multivariate-adjusted Cox model, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the highest versus the lowest quartiles of PLP, 4-PA, and 4-PA/PLP were 0.70(0.54-0.90), 1.33(0.88-2.02), and 2.01(1.41-2.79) for cardiovascular mortality, 0.73(0.52-1.02), 1.05(0.71-1.57), and 1.95(1.25-3.05) for cancer mortality, and 0.62(0.53-0.74), 1.05(0.82-1.34), and 2.29(1.87-2.79) for all-cause mortality, respectively.

Conclusion

Our study found that lower serum PLP levels were associated with increased risks of cardiovascular and all-cause mortality among the elderly population. And higher vitamin B6 turnover rate was associated with increased risks of cardiovascular, cancer, and all-cause mortality.

Vitamin supplements: Are they associated with immune status?

BACKGROUND & AIMS

Vitamins are essential nutrients, taken in very small amounts (0.01-100 mg a day). Associations between vitamin supplement intake or status and the immune system are far from consensual. Our aim was to understand the association between vitamin supplements and the immune system, namely regarding lymphocyte count and immunoglobulin levels against infectious pathogens.

METHODS

Cross-sectional study using data from the first follow-up of the CoLaus|PsyCoLaus study (April 2009 to September 2012). Participants were categorized as vitamin users and non-users. Serostatus for 15 viruses, six bacteria, and one parasite was assessed. Data for inflammatory markers (hs-CRP, IL-1β, IL-6, and TNF-α) and blood elements were also collected.

RESULTS

Of the initial 5064 participants, 3769 (74.5 %, mean age 58.3 ± 10.5 years, 53.6 % women) were retained for serostatus. On bivariate analysis, participants taking vitamins presented with higher positivity levels in three markers and lower positivity levels in two, but those differences were no longer statistically significant after multivariable analysis. 4489 participants (88.6 %, mean age 57.7 ± 10.5 years, 53.2 % women) had data for inflammatory markers; no association was found between vitamin supplement use and inflammatory markers both on bivariate and multivariable analysis. Finally, 3349 participants (66.1 %, mean age 57.3 ± 10.3 years, 53.1 % women) had data for blood elements; on bivariate analysis, vitamin supplement users had lower levels of haemoglobin and lymphocytes, but those differences were no longer significant after multivariable adjustment.

CONCLUSION

In this cross-sectional, population-based study, we found no association between vitamin supplement use and markers of immune status.

Factors influencing vitamin B6 status in domestic cats: age, disease, and body condition score

Limited studies are available on vitamin B6 status in domestic cats. To this end, we evaluated glutamate-oxaloacetate transaminase (GOT) activity in hemolysates with and without pyridoxal 5'-phosphate addition in two feline populations: a cohort of 60 healthy, domestic (sexually intact and specific pathogen-free) cats maintained under strictly controlled conditions with appropriate diets housed at the Feline Nutrition and Pet Care Center, and a cohort of 57 cats randomly selected between December 2022 to January 2023 that visited the Veterinary Medicine Teaching Hospital to seek care under different circumstances. The GOT activity expressed as the ratio with and without pyridoxal 5'-phosphate addition (primary activation ratio; PAR) decreased significantly with age in the healthy cohort. The PAR values normalized to age established a cut-off for vitamin B6 deficiency in both cohorts, identifying 17 of 101 animals as vitamin B6 deficient. Using machine learning, a partition-based model (decision tree) was built to identify the most important factors that predicted vitamin B6 deficiency while using the resulting tree to make predictions for new observations. This analysis, performed with all 101 cats, revealed that the diagnosis of an infectious, chronic or acute condition (0.55) was the main contributor, followed by age (0.26), and body condition score (optimal-overweight; 0.19). Thus, our study supports that vitamin B6 supplementation may be indicated in junior to adult animals diagnosed with an infectious, chronic, or acute conditions or healthy cats with body weight ranging from optimal to overweight. In older cats, even if healthy, underweight to optimal cats appear to be at risk of vitamin B6 deficiency.

Vitamin B6 Competition in the Tumor Microenvironment Hampers Antitumor Functions of NK Cells

Nutritional factors play crucial roles in immune responses. The tumor-caused nutritional deficiencies are known to affect antitumor immunity. Here, we demonstrate that pancreatic ductal adenocarcinoma (PDAC) cells can suppress NK-cell cytotoxicity by restricting the accessibility of vitamin B6 (VB6). PDAC cells actively consume VB6 to support one-carbon metabolism, and thus tumor cell growth, causing VB6 deprivation in the tumor microenvironment. In comparison, NK cells require VB6 for intracellular glycogen breakdown, which serves as a critical energy source for NK-cell activation. VB6 supplementation in combination with one-carbon metabolism blockage effectively diminishes tumor burden in vivo. Our results expand the understanding of the critical role of micronutrients in regulating cancer progression and antitumor immunity, and open new avenues for developing novel therapeutic strategies against PDAC.

SIGNIFICANCE

The nutrient competition among the different tumor microenvironment components drives tumor growth, immune tolerance, and therapeutic resistance. PDAC cells demand a high amount of VB6, thus competitively causing NK-cell dysfunction. Supplying VB6 with blocking VB6-dependent one-carbon metabolism amplifies the NK-cell antitumor immunity and inhibits tumor growth in PDAC models. This article is featured in Selected Articles from This Issue, p. 5.

Impact of lifestyle factors on dietary vitamin B6 intake and plasma pyridoxal 5'-phosphate level in UK adults: National Diet and Nutrition Survey Rolling Programme (NDNS) (2008-2017)

Reduction in dietary vitamin B6 intake is associated with an increased relative risk of diseases such as cancer, atherosclerosis and cognitive dysfunction. The current research has assessed vitamin B6 intakes and PLP concentrations as a marker of vitamin B6 status among the UK adult (≥ 19 years) population. This study was carried out using a cross-sectional analysis of the National Diet and Nutrition Survey Rolling Programme (NDNS) (2008-2017). The impacts of lifestyle factors, including type of diet, smoking, alcohol consumption, and commonly used medications grouped by therapeutic usage, were determined, and data were analysed using IBM SPSS®. Results are expressed as medians (25th-75th percentiles), with P values ≤ 0·05 considered statistically significant. Among UK adults, the median intakes of total population of dietary vitamin B6 met the reference nutrient intake and median plasma PLP concentrations were above the cut-off of vitamin B6 deficiency; however, we found an association between reduction in vitamin B6 intake and plasma PLP concentration and age group (P < 0·001). Smokers had significantly lower plasma PLP concentrations than non-smokers (P < 0·001). Moreover, regression analysis showed some commonly used medications were associated with plasma PLP levels reduction (P < 0·05). Taken together, we report on a tendency for dietary vitamin B6 intake and plasma PLP concentrations to decrease with age and lifestyle factors such as smoking and medication usage. This information could have important implications for smokers and in the elderly population using multiple medications (polypharmacy).

Nutraceuticals as Modulators of Immune Function: A Review of Potential Therapeutic Effects

Dietary supplementation with nutraceuticals can promote optimal immune system activation, modulating different pathways that enhance immune defenses. Therefore, the immunity-boosting effects of nutraceuticals encompass not only immunomodulatory but also antioxidant, antitumor, antiviral, antibacterial, and antifungal properties, with therapeutic effects against diverse pathological conditions. However, the complexity of the pathways that regulate the immune system, numerous mechanisms of action, and heterogeneity of the immunodeficiencies, and subjects treated make their application in the clinical field difficult. Some nutraceuticals appear to safely improve immune system function, particularly by preventing viral and bacterial infections in specific groups, such as children, the elderly, and athletes, as well as in frail patients, such as those affected by autoimmune diseases, chronic diseases, or cancer. Several nutraceuticals, such as vitamins, mineral salts, polyunsaturated omega-3 fatty acids, many types of phytocompounds, and probiotic strains, have the most consolidated evidence in humans. In most cases, further large and long-term randomized clinical trials are needed to confirm the available preliminary positive data.

Gut and urinary microbiota: the causes and potential treatment measures of renal cell carcinoma

Mounting evidence suggests that the gut microbiota plays a crucial role in the development and treatment of various cancers. Recent research on the urinary microbiota challenges the long-standing belief that urine is sterile, as urinary microbiota has been implicated in the development of bladder and prostate cancers, similar to the role of gut microbiota in cancer development. Although the precise involvement of microbiota in the proliferation and differentiation of renal cell carcinoma (RCC) remains unclear, dysbiosis is considered one possible mechanism by which microbiota may contribute to RCC development and treatment. This review summarizes potential mechanisms by which gut microbiota may contribute to the development of RCC, and provides evidence for the involvement of urinary microbiota in RCC. We also explore the role of gut microbiota in RCC treatment and propose that the composition of gut microbiota could serve as a predictive marker for the potential efficacy of immune checkpoint inhibitors (ICIs) in RCC patients. Additionally, evidence suggests that modulating the abundance and distribution of microbiota can enhance the therapeutic effects of drugs, suggesting that microbiota may serve as a promising adjuvant therapy for RCC. Overall, we believe that further investigation into the gut and urinary microbiome of RCC patients could yield valuable insights and strategies for the prevention and personalized treatment of RCC.

Association of Recent and Long-Term Supplement Intakes With Laboratory Indices in Patients With COVID-19 in Tehran, Iran, During 2020

Background

Although previous studies observed the relationship between individual dietary supplements and enhancing body resistance against viruses, few studies have been conducted regarding the role of different supplements in treatment of COVID-19. This article aims to determine the association of recent and long-term supplement consumption on the biochemical indices and impatient duration among patients with COVID-19.

Methods

In this cross-sectional study on 300 adult men and women with COVID-19, recent and long-term supplement intakes were investigated by using a questionnaire. In addition, lifestyle was also assessed in aspects of fruits and vegetable consumption, physical activity, sleeping duration, fluid intake, and smoking status. Furthermore, the laboratory and paraclinical parameters were obtained from medical records. The relationship between supplement intake with the length of hospitalization and clinical laboratory tests was investigated by one-way analysis of variance (ANOVA).

Results

Those patients with supplement intake in the last 2 months had a significantly lower amount of blood urea nitrogen (BUN) (31.31 ± 13.87 vs. 37.57 ± 19.77 mg/dL, P: 0.002) and higher serum 25(OH)D (28.13 ± 14.09 vs. 23.81 ± 13.55 ng/mL, P: 0.03). Subjects with long-term supplement intake had a significantly lower invasive oxygen support (0.00 vs 5.10 %, P: 0.05), lactate dehydrogenase (LDH) (498.11 ± 221.43 vs. 576.21 ± 239.84 U/L, P: 0.02), fewer days of fever (0.49 ± 3.54 vs. 2.64 ± 9.21, P: 0.02), and higher serum 25(OH)D (31.03 ± 13.20 vs. 22.29± 13.42 ng/mL, P < 0.001). The length of hospital stay was practically the same between groups who received and did not receive supplementation during the 2 months prior to hospitalization (6.36 ± 3.32 vs. 6.71 ± 4.33 days, P: 0.004). Similarly, people who took supplements during the past year had practically similar hospitalization lengths (6.29 ± 4.13 vs. 6.74 ± 3.55 days, P: 0.004).

Conclusion

In conclusion, although practically the length of hospital stay was the same in both groups of supplement consumers and others, immune-boosting supplements were associated with improved several laboratory indices. However, due to the cross-sectional nature of our study, further longitudinal studies seem to be essential.

Vitamin B6 Metabolism Determines T Cell Anti-Tumor Responses

Targeting T cell metabolism is an established method of immunomodulation. Following activation, T cells engage distinct metabolic programs leading to the uptake and processing of nutrients that determine cell proliferation and differentiation. Redirection of T cell fate by modulation of these metabolic programs has been shown to boost or suppress immune responses in vitro and in vivo. Using publicly available T cell transcriptomic and proteomic datasets we identified vitamin B6-dependent transaminases as key metabolic enzymes driving T cell activation and differentiation. Inhibition of vitamin B6 metabolism using the pyridoxal 5'-phosphate (PLP) inhibitor, aminoxyacetic acid (AOA), suppresses CD8+ T cell proliferation and effector differentiation in a dose-dependent manner. We show that pyridoxal phosphate phosphatase (PDXP), a negative regulator of intracellular vitamin B6 levels, is under the control of the hypoxia-inducible transcription factor (HIF1), a central driver of T cell metabolism. Furthermore, by adoptive transfer of CD8 T cells into a C57BL/6 mouse melanoma model, we demonstrate the requirement for vitamin B6-dependent enzyme activity in mediating effective anti-tumor responses. Our findings show that vitamin B6 metabolism is required for CD8+ T cell proliferation and effector differentiation in vitro and in vivo. Targeting vitamin B6 metabolism may therefore serve as an immunodulatory strategy to improve anti-tumor immunotherapy.

The effect of supplementation with vitamins A, B, C, D, and E on disease severity and inflammatory responses in patients with COVID-19: a randomized clinical trial

BACKGROUND AND OBJECTIVE

Because of the effect of vitamins on modulating the immune system function, we have evaluated the effect of supplementation with vitamins A, B, C, D, and E in ICU-admitted patients with COVID-19.

METHODS

This study was a randomized and single-blinded clinical trial in which 60 subjects were randomly assigned to two groups. The intervention group (n=30) received vitamins, and the control group did not receive any vitamin or placebo. The intervention was included 25,000 IU daily of vitamins A, 600,000 IU once during the study of D, 300 IU twice daily of E, 500 mg four times daily of C, and one amp daily of B complex for 7 days. At baseline and after the 7-day intervention, the serum levels of inflammatory markers, vitamins, and the SOFA score were assessed. In addition, the mortality rate and duration of hospitalization were evaluated after the intervention (IRCT registration number: IRCT20200319046819N1/registration date: 2020-04-04, https://www.irct.ir/trial/46838 ).

RESULTS

Significant changes were detected in serum levels of vitamins (p < 0.001 for all vitamins), ESR (p < 0.001), CRP (p = 0.001), IL6 (p = 0.003), TNF-a (p = 0.001), and SOFA score (p < 0.001) after intervention compared with the control group. The effect of vitamins on the mortality rate was not statistically significant (p=0.112). The prolonged hospitalization rate to more than 7 days was significantly lower in the intervention group than the control group (p=0.001). Regarding the effect size, there was a significant and inverse association between receiving the intervention and prolonged hospitalization (OR = 0.135, 95% CI 0.038-0.481; p=0.002); however, after adjusting for confounders, it was not significant (OR=0.402, 95% CI 0.086-1.883; p=0.247).

CONCLUSION

Supplementation with vitamins A, B, C, D, and E could improve the inflammatory response and decrease the severity of disease in ICU-admitted patients with COVID-19.

Association of nutrition status and hospital-acquired infections in older adult orthopedic trauma patients

BACKGROUND

Malnutrition is linked to suboptimal outcomes following elective surgery. Trauma patients do not typically have an opportunity for preoperative nutrition optimization and may be at risk for malnutrition. Our goal was to investigate whether nutrition status is associated with development of hospital-acquired infections (HAIs) in older adult, orthopedic trauma patients.

METHODS

We performed a retrospective analysis of data between January 1, 2017, and August 30, 2018, from the Massachusetts General Hospital Geriatric Inpatient Fracture Trauma Service. Admission nutrition status was assessed using the Mini Nutritional Assessment (MNA) and HAIs were validated through the American College of Surgeons National Surgical Quality Improvement Project database. To investigate whether nutrition status is associated with HAIs, we performed a multivariable logistic regression analysis controlling for age, sex, Charlson Comorbidity Index, glomerular filtration rate, and type of anesthesia.

RESULTS

Four hundred sixty-one patients comprised the analytic cohort. Multivariable regression analysis demonstrated that each unit increment in MNA score was associated with a 13% reduction in risk of HAI (odds ratio, 0.87; 95% CI, 0.79-0.97). Furthermore, adjusting for timing of perioperative antibiotics, perioperative transfusions, or development of pressure injury during hospitalization did not materially change these results.

CONCLUSION

Our results demonstrate that malnutrition is highly prevalent in older adult, orthopedic trauma patients and that nutrition status may influence the risk of developing HAIs in this cohort of patients. Further studies are needed to determine whether optimizing perioperative nutrition in older adult, orthopedic trauma patients can reduce infectious complications and improve overall health outcomes.

The regulatory effects of pyridoxine deficiency on the grass carp (Ctenopharyngodon idella) gill barriers immunity, apoptosis, antioxidant, and tight junction challenged with Flavobacterium columnar

The effects of dietary pyridoxine (PN) on the gill immunity, apoptosis, antioxidant and tight junction of grass cap (Ctenopharyngodon idella) were investigated in this study. Fish were fed semi-purified diets containing graded levels of PN for 10 weeks, and then challenged with Flavobacterium columnare by bath immersion exposure for 3 days. The results indicated that compared with the optimal PN level, PN deficiency resulted in a decline in the antimicrobial compound production of gill. In addition, PN deficiency up-regulated the pro-inflammatory cytokines and down-regulated the anti-inflammatory cytokines gene expression, which might be associated with the enhanced nuclear factor κB p65 and the inhibited target of rapamycin signalling pathways, respectively, suggesting that PN deficiency could impair gill immune barrier function. Furthermore, PN deficiency (1) induced cell apoptosis, which may be partly associated with the (apoptotic protease activating factor-1, Bcl-2 associated X protein)/caspase-9 and c-Rel/tumor necrosis factor α (rather than FasL)/caspase-8 mediated apoptosis pathway. (2) Inhibited Kelch-like ECH-associating protein 1a/NF-E2-related factor 2 mRNA expression, decreased the mRNA expression and activities of antioxidant enzymes, increased the levels of reactive oxygen species, protein carbonyl and malondialdehyde. (3) Increased the mRNA expression level of myosin light chain kinase, which may be result in the down-regulation of tight junction complexes such as zonula occludens 1, occludin and claudins (expect claudin-12 and claudin-15). These results suggest that PN deficiency could impair gill physical barrier function. In summary, dietary PN deficiency could cause the impairment of gill barrier function associated with immunity, apoptosis, antioxidant and tight junction, which may result in the increased the susceptibility of fish to pathogenic bacteria. Moreover, based on the gill rot morbidity, LZ activity and MDA content, the dietary PN requirements for grass cap were estimated to be 4.85, 4.78 and 4.77 mg kg^-1 diet, respectively.

Importance of Dietary Changes During the Coronavirus Pandemic: How to Upgrade Your Immune Response

The new coronavirus pandemic continues to spread causing further public health, social, and economic issues. The disparities in the rates of death between countries poses questions about the importance of lifestyle habits and the immune status of populations. An exploration of dietary habits and COVID-19-related death might unravel associations between these two variables. Indeed, while both nutritional excess and deficiency are associated with immunodeficiency, adequate nutrition leading to an optimally functioning immune system may be associated with better outcomes with regards to preventing infection and complications of COVID-19, as well as developing a better immune response to other pathogenic viruses and microorganisms. This article outlines the key functions of the immune system and how macronutrients, micronutrients, and metabolites from the gut microbiome can be essential in the development of an efficient immune system. In addition, the effects of intermittent fasting on the inflammatory state as well as metabolic parameters will be discussed.

Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota

The interaction between nutrition and the immune system is very complex. In particular, at every stage of the immune response, specific micronutrients, including vitamins and minerals play a key role and often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual's overall nutrition status and pattern of dietary intake (comprised of nutrients and non-nutritive bioactive compounds and food) and any supplementation with nutraceuticals including vitamins and minerals, can influence positively or negatively the function of the immune system. This influence can occur at various levels from the innate immune system and adaptive immune system to the microbiome. Although there are conflicting evidence, the current results point out that dietary supplementation with some nutrients such as vitamin D and zinc may modulate immune function. An update on the complex relationship between nutrition, diet, and the immune system through gut microbiota is the aim of this current review. Indeed, we will provide the overview of the link among immune function, nutrition and gut microbiota, paying particular attention at the effect of the Mediterranean diet on the immune system, and finally we will speculate the possible role of the main one functional supplements on immune function.

Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis

The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization. Challenges arise concerning how to optimally support the immune system in the general population, especially under self-confinement. An optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay. For example, sufficient protein intake is crucial for optimal antibody production. Low micronutrient status, such as of vitamin A or zinc, has been associated with increased infection risk. Frequently, poor nutrient status is associated with inflammation and oxidative stress, which in turn can impact the immune system. Dietary constituents with especially high anti-inflammatory and antioxidant capacity include vitamin C, vitamin E, and phytochemicals such as carotenoids and polyphenols. Several of these can interact with transcription factors such as NF-kB and Nrf-2, related to anti-inflammatory and antioxidant effects, respectively. Vitamin D in particular may perturb viral cellular infection via interacting with cell entry receptors (angiotensin converting enzyme 2), ACE2. Dietary fiber, fermented by the gut microbiota into short-chain fatty acids, has also been shown to produce anti-inflammatory effects. In this review, we highlight the importance of an optimal status of relevant nutrients to effectively reduce inflammation and oxidative stress, thereby strengthening the immune system during the COVID-19 crisis.

Healthy Human Gastrointestinal Microbiome: Composition and Function After a Decade of Exploration

The human gastrointestinal (GI) tract contains communities of microbes (bacteria, fungi, viruses) that vary by anatomic location and impact human health. Microbial communities differ in composition based on age, diet, and location in the gastrointestinal tract. Differences in microbial composition have been associated with chronic disease states. In terms of function, microbial metabolites provide key signals that help maintain healthy human physiology. Alterations of the healthy gastrointestinal microbiome have been linked to the development of various disease states including inflammatory bowel disease, diabetes, and colorectal cancer. While the definition of a healthy GI microbiome cannot be precisely identified, features of a healthy gut microbiome include relatively greater biodiversity and relative abundances of specific phyla and genera. Microbes with desirable functional profiles for the human host have been identified, in addition to specific metabolic features of the microbiome. This article reviews the composition and function of the healthy human GI microbiome, including the relative abundances of different bacterial taxa and the specific metabolic pathways and classes of microbial metabolites contributing to human health and disease prevention.

A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection

Immune support by micronutrients is historically based on vitamin C deficiency and supplementation in scurvy in early times. It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response. Adequate amounts are essential to ensure the proper function of physical barriers and immune cells; however, daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. Certain populations have inadequate dietary micronutrient intakes, and situations with increased requirements (e.g., infection, stress, and pollution) further decrease stores within the body. Several micronutrients may be deficient, and even marginal deficiency may impair immunity. Although contradictory data exist, available evidence indicates that supplementation with multiple micronutrients with immune-supporting roles may modulate immune function and reduce the risk of infection. Micronutrients with the strongest evidence for immune support are vitamins C and D and zinc. Better design of human clinical studies addressing dosage and combinations of micronutrients in different populations are required to substantiate the benefits of micronutrient supplementation against infection.

The relationship between plasma albumin, alkaline phosphatase and pyridoxal phosphate concentrations in plasma and red cells: Implications for assessing vitamin B6 status

BACKGROUND

Plasma concentrations of most vitamins decrease as part of the systemic inflammatory response (SIR). Thus low plasma values do not necessarily indicate deficiency. Vitamin B6 status is usually assessed by measurement of pyridoxal phosphate (PLP) in plasma, although vitamin concentrations in blood cells tend to be better markers of cellular stores. In health, plasma PLP appears to be determined primarily by intake, its binding to albumin, and its hydrolysis by alkaline phosphatase (ALP).

OBJECTIVE

To examine, using in vitro studies, the effect of albumin concentration and ALP activity on PLP concentration in plasma and red blood cells of healthy subjects (HS) and critically ill patients (CI).

DESIGN

Heparin and EDTA (ALP inhibited) whole blood samples from HS (n = 8) and CI (n = 26) were incubated with PLP. Concentration of PLP in plasma and red cells was measured. Albumin and ALP levels were determined in plasma.

RESULTS

In PLP incubated heparin samples, there was a strong direct relationship between albumin in the concentration range 10-44 g/L and increase in plasma PLP concentration (r_s = 0.93, P < 0.001) and an inverse relationship with increase in red cell PLP concentration (r_s = -0.90, P < 0.001). In contrast, ALP activity was inversely associated with increase in plasma PLP concentration (r_s = -0.42; P = 0.013) and directly associated with red cell PLP concentration (r_s = 0.49; P = 0.003).

CONCLUSIONS

Plasma albumin concentration and to a lesser extent ALP activity influences PLP concentration in plasma and red cells. In conditions associated with low albumin (e.g. SIR) or altered ALP activity, red cell PLP measurements are more likely to be reliable than plasma measurements in differentiating true from apparent vitamin B6 deficiency and to guide vitamin B6 supplementation.

Vitamin B6 improves blood parameters in rats fed a protein-deficient diet and subjected to moderate, long-term exercise

Vitamin B₆ is necessary for many enzymatic pathways (glucose and lipid metabolism, DNA/RNA synthesis, or modulation of gene expression) and affects immune cell function and blood-forming processes. We hypothesised that supplementing a protein-deficient diet with vitamin B₆ may reduce the negative impact of protein malnutrition. Here, we evaluated the effect of moderate, long-term exercise (ninety days) on selected blood parameters in rats fed a normal diet, a protein-deficient diet, or a protein-deficient diet supplemented with vitamin B₆. Selected haematological, immunological, and biochemical parameters were examined. A protein-deficient diet lasting 90 days caused significant reduction in body mass, increased activity of aminotransferases (asparagine and alanine), an increased percentage of innate cells in the blood, and decreased haemoglobin concentration in the blood. Adding vitamin B₆ significantly increased body and muscle mass, decreased liver parameters, and caused normalisation of haemoglobin concentration and the proportion of white blood cells in the blood. These results indicate that vitamin B₆ supplementation significantly improves the health of protein-malnourished rats and paves the way for the development of novel anti-malnutrition therapies.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Effects of vitamin B-6 supplementation on oxidative stress and inflammatory response in neonatal rats receiving hyperoxia therapy

Hyperoxia is often used in the treatment of neonates. However, protracted use of hyper-oxia leads to significant morbidity. The purpose of this study was to evaluate the effects of vitamin B-6 supplementation on oxidative stress and inflammatory responses in neonatal rats undergoing hyperoxia therapy. The study consisted of 2 parts: a survival study and a vitamin B-6 efficacy study for 16 days. Neonatal rats were randomly divided into either the control group, B-6 group (subcutaneously injected with 90 mg/kg/d of pyridoxal 5′-phosphate [PLP]), O₂ group (treated with 85% oxygen), or O₂ + B-6 group (simultaneously treated with 85% oxygen and 90 mg/kg/d PLP). After the survival study was done, the vitamin B-6 efficacy study was performed with duplicate neonatal rats sacrificed on the 3rd, 6th, 9th, and 16th day. Serum inflammatory cytokines, tissue pathology, and malondialdehyde (MDA) levels were measured. In the survival study, the survival rate of neonatal rats in the control, B-6, O₂, and O₂ + B-6 group on the 16th day were 100%, 100%, 25%, and 62.50%, respectively. The efficacy study showed lung polymorphonuclear granulocyte (PMN) and macrophage infiltration, increased liver hemopoiesis, and higher MDA levels in liver homogenates at days 3 through 16 in the O₂ group. Vitamin B-6 supplementation considerably increased serum inflammatory cytokines in either the 6th or 9th day and decreased liver MDA level before the 6th day. These results indicate that neonatal rats receiving hyperoxia treatment suffered divergent serum inflammatory responses and were in increased liver oxidative stress. Vitamin B-6 supplementation seemed to improve survival rates, change systemic inflammatory response, and decrease liver oxidative stress while neonatal rats were under hyperoxia treatment.

Anti-inflammatory effect of dietary pork extract on proliferation and cytokine secretion using mouse primary splenocytes

The anti-inflammatory effects of boiled pork meat (BPM) and hot water extracts of pork meat (WPM) on splenocyte proliferation and T cell cytokine regulation in BALB/c mice were evaluated. The proliferation of splenocytes in high concentration WPM groups was significantly higher than the control stimulated by LPS and Con A. In the white blood cells, WPM groups had significantly higher counts of lymphocytes and lower counts of neutrophils than the control (p<0.05). The Th1 (IFN-γ, TNF-α, IL-2) and Th2 (IL-4, IL-5, IL-10) cytokine levels in high-concentration WPM groups were higher than those in the control. In addition, TNF-α/IL-10 and IL-2/IL-4 secretions of splenocytes in the high concentration WPM group with LPS or Con A treatment was significantly lower than the control (p<0.05). Therefore, this study suggested that high concentration of WPM had anti-inflammatory effects on the primary splenocyte, which indicating that water extracts of pork meat can enhance the immune system of mice.

Dietary pyridoxine deficiency reduced growth performance and impaired intestinal immune function associated with TOR and NF-κB signalling of young grass carp (Ctenopharyngodon idella)

The objective of this study was to evaluate the effects of dietary pyridoxine (PN) deficiency on growth performance, intestinal immune function and the potential regulation mechanisms in young grass carp (Ctenopharyngodon idella). Fish were fed six diets containing graded levels of PN (0.12-7.48 mg/kg) for 70 days. After that, a challenge test was conducted by infection of Aeromonas hydrophila for 14 days. The results showed that compared with the optimal PN level, PN deficiency: (1) reduced the production of innate immune components such as lysozyme (LZ), acid phosphatase (ACP), complements and antimicrobial peptides and adaptive immune components such as immunoglobulins in three intestinal segments of young grass carp (P < 0.05); (2) down-regulated the mRNA levels of anti-inflammatory cytokines such as transforming growth factor β (TGF-β), interleukin 4/13A (IL-4/13A) (rather than IL-4/13B), IL-10 and IL-11 partly relating to target of rapamycin (TOR) signalling [TOR/ribosomal protein S6 kinases 1 (S6K1) and eIF4E-binding proteins (4E-BP)] in three intestinal segments of young grass carp; (3) up-regulated the mRNA levels of pro-inflammatory cytokines such as tumour necrosis factor α (TNF-α) [not in the proximal intestine (PI) and distal intestine (DI)], IL-1β, IL-6, IL-8, IL-12p35, IL-12p40, IL-15 and IL-17D [(rather than interferon γ2 (IFN-γ2)] partly relating to nuclear factor kappa B (NF-κB) signalling [IκB kinase β (IKKβ) and IKKγ/inhibitor of κBα (IκBα)/NF-κB (p65 and c-Rel)] in three intestinal segments of young grass carp. These results suggest that PN deficiency could impair the intestinal immune function, and the potential regulation mechanisms were partly associated with TOR and NF-κB signalling pathways. In addition, based on percent weight gain (PWG), the ability against enteritis and LZ activity, the dietary PN requirements for young grass carp were estimated to be 4.43, 4.75 and 5.07 mg/kg diet, respectively.

Assessment of Micronutrient Status in Critically Ill Children: Challenges and Opportunities

Micronutrients refer to a group of organic vitamins and inorganic trace elements that serve many functions in metabolism. Assessment of micronutrient status in critically ill children is challenging due to many complicating factors, such as evolving metabolic demands, immature organ function, and varying methods of feeding that affect nutritional dietary intake. Determination of micronutrient status, especially in children, usually relies on a combination of biomarkers, with only a few having been established as a gold standard. Almost all micronutrients display a decrease in their serum levels in critically ill children, resulting in an increased risk of deficiency in this setting. While vitamin D deficiency is a well-known phenomenon in critical illness and can predict a higher need for intensive care, serum concentrations of many trace elements such as iron, zinc, and selenium decrease as a result of tissue redistribution in response to systemic inflammation. Despite a decrease in their levels, supplementation of micronutrients during times of severe illness has not demonstrated clear benefits in either survival advantage or reduction of adverse outcomes. For many micronutrients, the lack of large and randomized studies remains a major hindrance to critically evaluating their status and clinical significance.

Biochemical Features of Beneficial Microbes: Foundations for Therapeutic Microbiology

Commensal and beneficial microbes secrete myriad products which target the mammalian host and other microbes. These secreted substances aid in bacterial niche development, and select compounds beneficially modulate the host and promote health. Microbes produce unique compounds which can serve as signaling factors to the host, such as biogenic amine neuromodulators, or quorum-sensing molecules to facilitate inter-bacterial communication. Bacterial metabolites can also participate in functional enhancement of host metabolic capabilities, immunoregulation, and improvement of intestinal barrier function. Secreted products such as lactic acid, hydrogen peroxide, bacteriocins, and bacteriocin-like substances can also target the microbiome. Microbes differ greatly in their metabolic potential and subsequent host effects. As a result, knowledge about microbial metabolites will facilitate selection of next-generation probiotics and therapeutic compounds derived from the mammalian microbiome. In this article we describe prominent examples of microbial metabolites and their effects on microbial communities and the mammalian host.

Gut microbiome, metabolome, and allergic diseases

The number of patients with allergic and inflammatory disorders has been increasing during the past several decades. Accumulating evidence has refined our understanding of the relationship between allergic diseases and the gut microbiome. In addition, the gut microbiome is now known to produce both useful and harmful metabolites from dietary materials. These metabolites and bacterial components help to regulate host immune responses and potentially affect the development of allergic diseases. Here, we describe recent findings regarding the immunologic crosstalk between commensal bacteria and dietary components in the regulation of host immunity and the influence of this relationship on the development of allergic diseases.

Vitamin B6 Reduces Neurochemical and Long-Term Cognitive Alterations After Polymicrobial Sepsis: Involvement of the Kynurenine Pathway Modulation

Neurological dysfunction as a result of neuroinflammation has been reported in sepsis and cause high mortality. High levels of cytokines stimulate the formation of neurotoxic metabolites by kynurenine (KYN) pathway. Vitamin B₆ (vit B₆) has anti-inflammatory and antioxidant properties and also acts as a cofactor for enzymes of the KYN pathway. Thus, by using a relevant animal model of polymicrobial sepsis, we studied the effect of vit B₆ on the KYN pathway, acute neurochemical and neuroinflammatory parameters, and cognitive dysfunction in rats. Male Wistar rats (250-300 g) were submitted to cecal ligation and perforation (CLP) and divided into sham + saline, sham + vit B₆, CLP + saline, and CLP + vit B₆ (600 mg/kg, s.c.) groups. Twenty-four hours later, the prefrontal cortex and hippocampus were removed for neurochemical and neuroinflammatory analyses. Animals were followed for 10 days to determine survival rate, when cognitive function was assessed by behavioral tests. Vitamin B₆ interfered in the activation of kynurenine pathway, which led to an improvement in neurochemical and neuroinflammatory parameters and, consequently, in the cognitive functions of septic animals. Thus, the results indicate that vit B₆ exerts neuroprotective effects in acute and late consequences after sepsis.

Rice bran constituents: immunomodulatory and therapeutic activities

Rice bran, one of the most abundant and valuable byproducts produced during the rice milling process, is of steadily growing interest in recent years due to its potential health benefits. Evidence is rapidly accumulating for the beneficial effects of nutraceuticals. However, the potential benefits of rice bran are found in several of its bioactive ingredients including oils, polysaccharides, proteins, and micronutrients. In addition, a significant advantage of rice bran is that it contains more than 100 antioxidants and several categories of bioactive phytonutrients, such as polyphenols, phytosterols, tocotrienols, γ-oryzanol, B vitamins, minerals, and trace minerals. As an immunomodulator, rice bran has beneficial constituents such as polysaccharides, proteins, and oils. Numerous studies also reported that potent antioxidants in rice bran included immune system enhancing compounds, such as phytosterols, polysaccharides, minerals and trace minerals including magnesium, selenium, zinc, vitamin E, omega-3 fatty acids and several other phytonutrients. We believe that this review will be a valuable resource for more studies on rice barn as a dietary source.

Effects of Vitamin B6 Deficiency on the Composition and Functional Potential of T Cell Populations

The immune system is critical in preventing infection and cancer, and malnutrition can weaken different aspects of the immune system to undermine immunity. Previous studies suggested that vitamin B6 deficiency could decrease serum antibody production with concomitant increase in IL4 expression. However, evidence on whether vitamin B6 deficiency would impair immune cell differentiation, cytokines secretion, and signal molecule expression involved in JAK/STAT signaling pathway to regulate immune response remains largely unknown. The aim of this study is to investigate the effects of vitamin B6 deficiency on the immune system through analysis of T lymphocyte differentiation, IL-2, IL-4, and INF-γ secretion, and SOCS-1 and T-bet gene transcription. We generated a vitamin B6-deficient mouse model via vitamin B6-depletion diet. The results showed that vitamin B6 deficiency retards growth, inhibits lymphocyte proliferation, and interferes with its differentiation. After ConA stimulation, vitamin B6 deficiency led to decrease in IL-2 and increase in IL-4 but had no influence on IFN-γ. Real-time PCR analysis showed that vitamin B6 deficiency downregulated T-bet and upregulated SOCS-1 transcription. This study suggested that vitamin B6 deficiency influenced the immunity in organisms. Meanwhile, the appropriate supplement of vitamin B6 could benefit immunity of the organism.

Relationship between Total Fruit and Vegetable Intake and Self-Reported Knee Pain in Older Adults

OBJECTIVES

Knee pain is one of the most common symptoms of knee osteoarthritis (OA) that affects the quality of life in the older adults, and identifying the contributing factors of knee pain is important. We hypothesized that higher fruit and vegetable consumption might be associated with the severity of knee pain lower prevalence of severe knee pain by affecting pain perception in the knee joint. Therefore, we investigated the relationship between self-reported knee pain and the consumption of fruits vegetables, carotenoids and vitamin C and self-reported knee pain.

DESIGN

Nationally representative cross sectional study.

SETTING

2010-2011 rounds of the Korean National Health and Nutrition Examination Survey.

PARTICIPANTS

A total of 6588 subjects aged ≥50 years were participated.

METHODS

Severity of knee pain was estimated using a 10-point numeric rating scale (NRS). Daily intake of fruits, vegetables, and vitamins were estimated using data from 24-hour recalls and food frequency questionnaires.

RESULTS

The NRS scores of knee pain decreased significantly with increasing fruit and vegetable intake quartiles. A multivariate logistic regression analysis showed that the fourth quartile of vegetable and fruit consumption was associated with decreased prevalence of severe knee pain (OR 0.59, 95% CI 0.48-0.73) compared with first quartile of vegetable and fruit consumption; however, carotenoids and vitamin C consumption was not associated with the severity of knee pain.

CONCLUSIONS

In conclusion, severe knee pain was independently associated with fruit and vegetable consumption. Our findings suggest that intake of whole fruits and vegetables may help improve knee pain in older adults.

Inflammation, vitamin B6 and related pathways

The active form of vitamin B6, pyridoxal 5'-phosphate (PLP), serves as a co-factor in more than 150 enzymatic reactions. Plasma PLP has consistently been shown to be low in inflammatory conditions; there is a parallel reduction in liver PLP, but minor changes in erythrocyte and muscle PLP and in functional vitamin B6 biomarkers. Plasma PLP also predicts the risk of chronic diseases like cardiovascular disease and some cancers, and is inversely associated with numerous inflammatory markers in clinical and population-based studies. Vitamin B6 intake and supplementation improve some immune functions in vitamin B6-deficient humans and experimental animals. A possible mechanism involved is mobilization of vitamin B6 to the sites of inflammation where it may serve as a co-factor in pathways producing metabolites with immunomodulating effects. Relevant vitamin B6-dependent inflammatory pathways include vitamin B6 catabolism, the kynurenine pathway, sphingosine 1-phosphate metabolism, the transsulfuration pathway, and serine and glycine metabolism.

Vitamin B6 status, immune response and inflammation markers in kidney transplant recipients treated with polyclonal anti-thymocyte globulin

BACKGROUND/OBJECTIVES

Vitamin B6 status has an impact on the body's inflammatory and immune responses. Immunosuppressive therapy may influence vitamin B6 metabolism in kidney transplant recipients. Treatment with polyclonal anti-thymocyte globulin (ATG) is associated with long-term changes in inflammatory and immune parameters. It is not known if ATG therapy also may have an impact on vitamin B6 status in kidney transplant recipients. We aimed to analyze the impact of therapy with ATG on vitamin B6 status, immune response, and the profile of inflammatory cytokines.

SUBJECT/METHODS

This was a retrospective, observational study that included 44 kidney allograft recipients. Twenty patients received induction therapy with ATG (6 to 24 months before enrollment). Twenty-four patients constituted the control group, matched with respect to time since transplantation. The B6 vitamers, total lymphocyte count, CD3 percentage, interleukin (IL)-6, -7, and -10, transforming growth factor β, interferon γ, and chemokine ligand 21 were analyzed in a study group.

RESULTS

All indicators of vitamin B6 status were lower in the ATG group than in the control group. There were also significant differences with respect to immune response (significantly lower total lymphocyte count and CD3 in the ATG group) and inflammatory status (significantly higher IL-6 and IL-10 in the ATG group). Vitamin B6 vitamers and derivatives were not related to lymphocyte count and cytokine levels or to estimated glomerular filtration rate and age of the study population.

CONCLUSIONS

Vitamin B6 stores and active forms are lower in kidney transplant recipients treated with ATG. ATG therapy promotes CD3 and total lymphocyte depletion and increases indicators of inflammation. We found no associations between vitamers of B6, immune response cells, and inflammatory cytokines in study population.

Direct and Functional Biomarkers of Vitamin B6 Status

Measures of B6 status are categorized as direct biomarkers and as functional biomarkers. Direct biomarkers measure B6 vitamers in plasma/serum, urine and erythrocytes, and among these plasma pyridoxal 5'-phosphate (PLP) is most commonly used. Functional biomarkers include erythrocyte transaminase activities and, more recently, plasma levels of metabolites involved in PLP-dependent reactions, such as the kynurenine pathway, one-carbon metabolism, transsulfuration (cystathionine), and glycine decarboxylation (serine and glycine). Vitamin B6 status is best assessed by using a combination of biomarkers because of the influence of potential confounders, such as inflammation, alkaline phosphatase activity, low serum albumin, renal function, and inorganic phosphate. Ratios between substrate-products pairs have recently been investigated as a strategy to attenuate such influence. These efforts have provided promising new markers such as the PAr index, the 3-hydroxykynurenine:xanthurenic acid ratio, and the oxoglutarate:glutamate ratio. Targeted metabolic profiling or untargeted metabolomics based on mass spectrometry allow the simultaneous quantification of a large number of metabolites, which are currently evaluated as functional biomarkers, using data reduction statistics.

Vitamins B6 and cancer

Epidemiologic and laboratory animal studies have suggested that the availability of vitamin B6 modulates cancer risk. The means by which B6 mediates this effect is not known with any surety but it has been reported that high dietary vitamin B6 attenuates and low dietary vitamin B6 increases the risk of cancer. In fact vitamin B6 is widely distributed in foods and overt deficiency of this vitamin is not common. Nevertheless, marginal or secondary vitamin B6 deficiency, which might have an adverse effect on carcinogenesis, is rather common especially among old adults and alcoholics. This chapter addressed currently available information regarding the relationship between vitamin B6 and cancer.

Micronutrient supplementation and T cell-mediated immune responses in patients with tuberculosis in Tanzania

Limited studies exist regarding whether incorporating micronutrient supplements during tuberculosis (TB) treatment may improve cell-mediated immune response. We examined the effect of micronutrient supplementation on lymphocyte proliferation response to mycobacteria or T-cell mitogens in a randomized trial conducted on 423 patients with pulmonary TB. Eligible participants were randomly assigned to receive a daily dose of micronutrients (vitamins A, B-complex, C, E, and selenium) or placebo at the time of initiation of TB treatment. We found no overall effect of micronutrient supplements on lymphocyte proliferative responses to phytohaemagglutinin or purified protein derivatives in HIV-negative and HIV-positive TB patients. Of HIV-negative TB patients, the micronutrient group tended to show higher proliferative responses to concanavalin A than the placebo group, although the clinical relevance of this finding is not readily notable. The role of nutritional intervention in this vulnerable population remains an important area of future research.

Commensal bacteria at the interface of host metabolism and the immune system

The mammalian gastrointestinal tract, the site of digestion and nutrient absorption, harbors trillions of beneficial commensal microbes from all three domains of life. Commensal bacteria, in particular, are key participants in the digestion of food, and are responsible for the extraction and synthesis of nutrients and other metabolites that are essential for the maintenance of mammalian health. Many of these nutrients and metabolites derived from commensal bacteria have been implicated in the development, homeostasis and function of the immune system, suggesting that commensal bacteria may influence host immunity via nutrient- and metabolite-dependent mechanisms. Here we review the current knowledge of how commensal bacteria regulate the production and bioavailability of immunomodulatory, diet-dependent nutrients and metabolites and discuss how these commensal bacteria-derived products may regulate the development and function of the mammalian immune system.

Higher plasma homocysteine is associated with lower vitamin B6 status in critically ill surgical patients

BACKGROUND

Hyperhomocysteinemia might be at least partially due to compromised B vitamin status in critically ill patients and has been linked with critical illness. This study was conducted to examine the association between plasma homocysteine with B vitamins and clinical outcomes in critically ill surgical patients.

METHODS

Thirty-two patients in the surgical intensive care unit (SICU) were enrolled. Disease severity (Acute Physiology and Chronic Health Evaluation II score), hematological values, serum and erythrocyte folate, serum vitamin B₁₂, plasma, and erythrocyte pyridoxal 5'-phosphate (PLP) were determined within 24 hours of admission and again after 7 days.

RESULTS

The prevalence of hyperhomocysteinemia in the patients was either 46.9% (plasma homocysteine ≥12 µmol/L) or 31.3% (plasma homocysteine ≥15 µmol/L) on day 1 in the SICU and increased to 62.5% (plasma homocysteine ≥12 µmol/L) and 37.5% (plasma homocysteine ≥15 µmol/L) on day 7 after admission to the SICU. Plasma homocysteine, serum folate, and vitamin B₁₂ significantly increased by day 7, whereas plasma and erythrocyte PLP remained constant throughout the study. Plasma homocysteine was not correlated with serum folate and vitamin B₁₂. However, plasma and erythrocyte PLP on day 1 were adversely associated with day 1 levels of plasma homocysteine after adjusting for potential confounders. Plasma homocysteine on day 1 or changes (Δ day 7-day 1) did not show any association with clinical outcomes.

CONCLUSIONS

Lower plasma PLP might be a significant factor for increased plasma homocysteine in critically ill surgical patients. The association between plasma homocysteine and clinical outcomes was not found.

The relationships between plasma and red cell vitamin B2 and B6 concentrations and the systemic and local inflammatory responses in patients with colorectal cancer

B vitamins have been implicated in cancer pathogenesis. It is therefore of interest that plasma B6 falls as part of the systemic inflammatory response (SIR), whereas red cell concentrations do not. The modified Glasgow Prognostic Score (mGPS) is a validated inflammation-based prognostic score that consists of a combination of albumin and C-reactive protein concentrations. The aim of this study was to examine the relationships between the concentrations of plasma and red cell vitamin B concentrations, the local and systemic inflammatory response in patients with colorectal cancer. Preoperative venous blood of 108 patients with colorectal cancer were analyzed for C-reactive protein, albumin, flavin adenine dinucleotide (FAD), and pyridoxal phosphate (PLP), and lymphocyte counts. Pathological slides were retrieved for assessment of inflammatory cell infiltration. Increasing mGPS was associated with lower plasma PLP concentrations (P < 0.01) but not plasma and red cell FAD and red cell PLP concentrations. Increasing tumor stage was associated with the presence of venous invasion (P < 0.01) and low-grade inflammatory cell infiltrate (P < 0.05) but not the SIR, FAD, or PLP concentrations. A low-grade inflammatory cell infiltrate was not significantly associated with any other parameter. The presence of a SIR was associated with lower concentrations of plasma PLP but not red cell PLP concentrations in patients with colorectal cancer. Neither FAD and PLP were associated with the tumor inflammatory cell infiltrate.

Vitamin B6 and the immunity in kidney transplant recipients

OBJECTIVE

The study aimed to determine vitamin B6 status in elderly (age ≥ 60 years) and younger (age <60 years) recipients of allogeneic kidney graft and to investigate associations between vitamin B6 status and immunity markers.

DESIGN

A retrospective observational study.

SETTING

The study was conducted at the Medical University of Gdańsk, Poland.

SUBJECTS

We recruited 34 kidney allograft recipients (17 males and 17 females) and allocated them into 2 groups: patients aged ≥ 60 years (18 patients) and those aged <60 years (16 patients). Exclusion criteria included patients receiving vitamin B6 supplementation or drugs known to influence vitamin B6 metabolism.

MAIN OUTCOME MEASURE

Plasma levels of pyridoxal 5'-phosphate (PLP), pyridoxal, pyridoxine, pyridoxamine, pyridoxamine 5'-phosphate, and 4 pyridoxic acid were determined by high-performance liquid chromatography. Measured immunity markers were serum cytokines (interleukin-6, interleukin-10, and transforming growth factor-β), levels of T-lymphocyte subsets, and the proliferative ability of peripheral blood mononuclear cells.

RESULTS

Concentrations of all vitamin B6 vitamers in plasma (PLP, pyridoxal, pyridoxamine 5'-phosphate, pyridoxamine, pyridoxine, 4 pyridoxic acid) were comparable in the 2 studied groups. There were no cases of PLP deficiency in the study population, but 29% of patients had PLP concentrations more than the upper reference limit. Vitamin B6 vitamer concentrations were not influenced by gender, estimated glomerular filtration rate, and circulating phosphate concentration. There was no difference in immunity markers according to age. However, the plasma concentrations of vitamin B6 vitamers were inversely associated with levels of CD28(+) lymphocyte subsets, as well as with the proliferative response of peripheral blood mononuclear cells in both groups.

CONCLUSIONS

No cases of vitamin B6 deficiency were found among kidney allograft recipients, and we report inverse links between vitamin B6 vitamer concentrations and markers of cellular immunity, suggesting that bioactive vitamin B6 concentration in kidney allograft recipients merits further investigation.

Micronutrient supplementation for critically ill adults: a systematic review and meta-analysis

OBJECTIVE

This systematic review assessed the effects of micronutrient supplementation on adults recovering from critical illness. Primary outcomes included clinical endpoints (mortality, infectious complications, length of intensive care unit and of hospital stay). Secondary outcomes included descriptions of practice issues, micronutrient status, morbidity, course of the acute-phase response, and oxidative stress.

METHODS

Electronic bibliographic databases, bibliographies of retrieved articles, and personal files were searched and reviewed. Randomized controlled trials (RCTs) of micronutrient supplementation in adult critically ill patients administered enterally and/or parenterally in addition to their routine care were included. Two authors independently extracted data and assessed trial quality. The random-effects model was used to estimate overall relative risk (RR)/mean difference and effect size. P<0.05 was considered statistically significant.

RESULTS

Fifteen (n=1714) and 18 (n=1849) RCTs were included for the primary and secondary objectives, respectively. Fourteen trials (n=1468) showed a statistically significant decrease in overall mortality (RR 0.78, 95% confidence interval 0.67-0.90, I2=0%, P=0.0009). Six RCTs (n=1194) indicated a statistically significant decrease in 28-d mortality (RR 0.75, 95% confidence interval 0.63-0.88, I2=0%, P=0.0006). Micronutrient supplementation was not associated with a decrease in infectious complications, length of intensive care unit, or length of hospital stay. In subgroup analyses, a sensitivity analysis of combined micronutrients indicated a significant decrease in mortality (RR 0.69, 95% confidence interval 0.54-0.90, I2=2%, P=0.006). The secondary outcomes confirmed that timing, duration, and dosing appear to be key factors to ensure optimal clinical benefit.

CONCLUSION

This review does suggest a potential benefit of micronutrient supplementation in critically ill adults by possibly being associated with a decrease in mortality.

A combined Phase I and II open-label study on the immunomodulatory effects of seaweed extract nutrient complex

Background:

Isolated fucoidans from brown marine algae have been shown to have a range of immune-modulating effects. This exploratory study aimed to determine whether a seaweed nutrient complex containing a blend of extracts from three different species of brown algae plus nutrients is safe to administer and has biological potential as an immune modulator. The study was undertaken as an open-label combined Phase I and II study.

Methods:

Participants (n = 10) were randomized to receive the study medication at either a 100 mg (n = 5) or 1000 mg (n = 5) dose over 4 weeks. The primary outcome measurement was in vivo changes in lymphocyte subsets. The secondary outcome measures were ex vivo changes in T-lymphocyte (CD4 and CD8) activation, phagocytosis of granulocytes and monocytes, T helper 1/T helper 2 cytokines, and serum oxygen radical absorbance capacity.

Results:

The preparation was found to be safe over the 4 weeks at both doses tested. There were no clinically relevant changes to blood measurements of hemopoietic, hepatic, or renal function. Immunomodulatory measurements showed no dose response between the two doses. The combined results from the two doses demonstrated a significant increase in cytotoxic T cell numbers and phagocytic capacity in monocytes, and a significant decrease in levels of the inflammatory cytokine interleukin 6. A separate analysis of the 100 mg dose (n = 5) alone showed a significant linear component over time (P < 0.05) for phagocytosis by both granulocytes and monocytes.

Conclusion:

The seaweed nutrient complex was safe to use when taken orally over 4 weeks. The preparation was demonstrated to have potential as an immune modulator, and this bioactivity deserves further exploration.

Enhancement of vitamin B(6) levels in seeds through metabolic engineering

As a versatile cofactor for many enzymes catalyzing important biochemical reactions, vitamin B(6) is required for all cellular organisms. In contrast to bacteria, fungi and plants, which have the ability to synthesize vitamin B(6)de novo, animals have to take up the vitamin from their diet. Plants are the major source of vitamin B(6) for animals. The recent identification of vitamin B(6) biosynthetic enzymes PDX1 and PDX2 in plants makes it possible to regulate the biosynthesis of this important vitamin. In this study, we generated Arabidopsis plants overexpressing the PDX1 and/or PDX2 gene and used a liquid chromatography/mass spectrometry/mass spectrometry method to determine the levels of different forms of vitamin B(6) in these transgenic plants. It was found that expression of the PDX genes under control of the CaMV 35S promoter caused only a limited increase in pyridoxine contents in dry seeds but not in shoots or roots. When using the Arabidopsis seed-specific 12S promoter to drive the expression of the PDX genes, the levels of vitamin B(6) increased more than twofold in transgenic plants. Our work demonstrates that it is feasible to enhance vitamin B(6) content in seeds by metabolic engineering.

Relation between pyridoxal and pyridoxal phosphate concentrations in plasma, red cells, and white cells in patients with critical illness

BACKGROUND

Evidence suggests that the relation between plasma and red cell vitamin B-6 concentrations is perturbed as part of the systemic inflammatory response in critically ill patients.

OBJECTIVE

The aim was to examine the cross-sectional and longitudinal interrelations between pyridoxal (PL) and pyridoxal phosphate (PLP) concentrations in plasma and red and white cells in patients with critical illness.

DESIGN

PLP and PL concentrations were measured by HPLC in plasma and red and white cells in normal subjects (n = 126) and critically ill patients (n = 96) on admission and on follow-up.

RESULTS

On admission, compared with the controls, median plasma PLP and PL (P < 0.001 and < 0.01, respectively) and red cell PLP and PL (P < 0.001 and < 0.05, respectively) and their ratio (PLP:PL) in plasma and red cells (P < 0.001 and < 0.01, respectively) were significantly lower in the critically ill. In critically ill patients, plasma PLP:PL was significantly lower than red cell PLP:PL (P = 0.001) and white cell PLP:PL (P = 0.008). Plasma PL concentration was directly associated with both red cell PL (r(s) = 0.73, P < 0.001) and white cell PL (r(s) = 0.68, P < 0.001). Red cell PL and white cell PL were directly associated with red cell PLP (r(s) = 0.82, P < 0.001) and white cell PLP (r(s) = 0.68, P < 0.001), respectively. Longitudinal measurements (n = 48) were similar.

CONCLUSIONS

The relation between plasma PLP and PL was significantly perturbed in critical illness. This effect was less pronounced in red and white cells. Therefore, these results confirm the hypothesis that intracellular PLP concentrations are more likely to be a reliable measure of status than are plasma measurements in the critically ill patient.