Diet and the developing immune system

Antioxidant and Immune-Related Implications of Minerals in COVID-19: A Possibility for Disease Prevention and Management

Since the coronavirus disease 2019 (COVID-19) pandemic appeared, both governments and the scientific community have focused their efforts on the search for prophylactic and therapeutic alternatives in order to reduce its effects. Vaccines against SARS-CoV-2 have been approved and administered, playing a key role in the overcoming of this situation. However, they have not reached the whole world population, and several doses will be needed in the future in order to successfully protect individuals. The disease is still here, so other strategies should be explored with the aim of supporting the immune system before and during the infection. An adequate diet is certainly associated with an optimal inflammatory and oxidative stress status, as poor levels of different nutrients could be related to altered immune responses and, consequently, an augmented susceptibility to infections and severe outcomes derived from them. Minerals exert a wide range of immune-modulatory, anti-inflammatory, antimicrobial, and antioxidant activities, which may be useful for fighting this illness. Although they cannot be considered as a definitive therapeutic solution, the available evidence to date, obtained from studies on similar respiratory diseases, might reflect the rationality of deeper investigations of the use of minerals during this pandemic.

The prognostic role of micronutrient status and supplements in COVID-19 outcomes: A systematic review

Micronutrients constitute an adjuvant treatment for respiratory viral infections. Since there is no effective antiviral therapy for COVID-19 yet, adjuvant intervention for the survival of critically ill patients may be significant. Search of the PubMed, CINAHL and Cochrane databases was carried out to find human studies investigating the prognostic role of micronutrient status and the effects of micronutrient supplementation intervention in COVID-19 outcomes of adult patients. Patients with certain comorbidities (diabetes mellitus type 2, obesity, renal failure, liver dysfunction etc.) or pregnant women were excluded. 31 studies (27 observational studies and 4 clinical trials) spanning the years 2020-2021, pertaining to 8624 COVID-19 patients (mean age±SD, 61 ± 9 years) were included in this systematic review. Few studies provided direct evidence on the association of serum levels of vitamin D, calcium, zinc, magnesium, phosphorus and selenium to patients' survival or death. Vitamin D and calcium were the most studied micronutrients and those with a probable promising favorable impact on patients. This review highlights the importance of a balanced nutritional status for a favorable outcome in COVID-19. Micronutrients' deficiency on admission to hospital seems to be related to a high risk for ICU admission, intubation and even death. Nevertheless, evidence for intervention remains unclear.

Implications of Vitamins in COVID-19 Prevention and Treatment through Immunomodulatory and Anti-Oxidative Mechanisms

Since the appearance of the coronavirus disease 2019 (COVID-19) and its announcement as a global pandemic, the search for prophylactic and therapeutic options have become a priority for governments and the scientific community. The approval of several vaccines against SARS-CoV-2 is being crucial to overcome this situation, although the victory will not be achieved while the whole population worldwide is not protected against the virus. This is why alternatives should be studied in order to successfully support the immune system before and during a possible infection. An optimal inflammatory and oxidative stress status depends on an adequate diet. Poor levels of several nutrients could be related to an impaired immune response and, therefore, an increased susceptibility to infection and serious outcomes. Vitamins exert a number of anti-microbial, immunomodulatory, anti-inflammatory, and antioxidant activities, which can be of use to fight against this and several other diseases (especially vitamin D and C). Even though they cannot be considered as a definitive therapeutic option, in part owing to the lack of solid conclusions from well-designed clinical trials, currently available evidence from similar respiratory diseases may indicate that it would be rational to deeply explore the use of vitamins during this global pandemic.

Toxicology issues related to the COVID–19 outbreak

In viral pandemics, such as coronavirus disease 2019 (COVID–19), the impact of real-life exposures to multiple toxic stressors that increase immune system dysfunction is followed by the main pandemic-associated virus (SARS–CoV–2, for COVID–19) exploiting the dysfunctional immune system to trigger a chain of events ultimately leading to the pandemic (COVID–19). Thus pandemics have two main components: virology (focused on the virus) and toxicology (focused on the toxic stressors).

The present chapter will focus mainly on the immune system toxicology component. It identifies the factors shown most frequently to increase immune system dysfunction, and then addresses vaccine toxicology in detail. The chapter concludes by reviewing two types of treatments: immune-augmenting and immune-strengthening. The immune-augmenting approaches are virology-centric (e.g., quarantine, face masks, repurposed antiviral treatments, vaccines, etc.), and the immune-strengthening approaches are toxicology-centric (e.g., eliminating the factors that contribute to immune system dysfunction, and adding factors that increase immune system health).

[Editorial] COVID‑19: Post‑lockdown guidelines

Since March, 2020, in response to the COVID‑19 pandemic, many countries have been on lockdown (at different levels of severity), restricting many activities and businesses that involve gatherings of large numbers of people in close proximity. Currently (early June, 2020), countries across the globe are in different stages of easing lockdown restrictions. Public policies for behaviors and actions during this transition period vary widely across countries and within country jurisdictions. The present editorial will address potential policies that could minimize resurgence of the present pandemic (the 'second‑wave') and reduce the likelihood and severity of similar future pandemics.

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.

Maternal diet before and during pregnancy and risk of asthma and allergic rhinitis in children

BACKGROUND

Consumption of certain foods during pregnancy has been shown to have beneficial effects on childhood asthma and allergic disease development and aggravation. However, most studies provide conflicting results and the relationships between maternal preconceptional diet and risks of childhood asthma and allergic disease have not previously been explored. The objective of this study was to assess maternal diet during the year before pregnancy and the last 3 months of pregnancy and investigate their associations with the risks of asthma, wheezing, allergic rhinitis and atopic dermatitis in young children.

METHODS

The study sample consisted of 1140 mother-child pairs from the EDEN cohort. Mothers had responded to the food frequency questionnaires used to assess diet before and during pregnancy. Children were followed up using health questionnaires. The health outcomes studied were: asthma, wheezing, allergic rhinitis and atopic dermatitis by the age of 3 years.

RESULTS

Using multivariable-adjusted logistic regression models, significant inverse associations were observed between cooked green vegetable consumption before pregnancy and childhood asthma; consumption of eggs and raw vegetables before and during pregnancy, consumption of grains before pregnancy, and consumption of cooked green vegetables during pregnancy and allergic rhinitis. For the first time, a significant positive association was found between meat intake during the preconceptional period and a risk of wheezing, allergic rhinitis and atopic dermatitis.

CONCLUSIONS

Based on our findings, preconceptional and prenatal maternal intake of certain type of food groups may be preventive against asthma, wheezing and allergic rhinitis, whereas higher maternal intake of meat before pregnancy may increase the risk of wheezing, allergic rhinitis and atopic dermatitis in young children.

Moderate physical training attenuates perinatal low-protein-induced spleen lymphocyte apoptosis in endotoxemic adult offspring rats

PURPOSE

To evaluate the effects of a moderate physical training (T) on the blood and splenic lymphocytes subsets and the rate of apoptosis in adult offspring submitted to perinatal low-protein (LP) diet.

METHODS

Male Wistar rats were divided according to their mother's diet: control (C, 17 % casein) and undernourished (LP, 8 % casein). At the 60th day, pups were submitted to moderate physical training (8 weeks, 5 days week(-1), 60 min day(-1), at 70 % of VO2max). After T period, pups received an injection of lipopolysaccharide (LPS). B, NK, and TCD3+ lymphocytes subsets were analyzed by flow cytometry. Spleen lymphocytes apoptosis was evaluated by DNA fragmentation, phosphatidylserine externalization (PSE), and mitochondrial transmembrane depolarization (MTD) using a flow cytometer. Plasma TNF-α concentrations were analyzed by ELISA.

RESULTS

LP + LPS pups showed a higher percentage of blood B, CD4+, and NK and a reduction in TCD3+, CD8+ than C pups. The percentage of NK and CD3+ was restored in LP + T + LPS pups. In the spleen, T normalized the percentage of NK in LP + LPS pups. LP + LPS pups showed a higher percentage of cells with PSE and MTD than C + LPS pups that was attenuated by T. The concentration of TNF-α was higher in LP + LPS than C + LPS, but it was attenuated in LP + T + LPS pups.

CONCLUSION

Moderate physical training was able to revert the effects of perinatal LP diet on circulation lymphocytes subsets and attenuated splenic lymphocytes apoptosis and plasma TNF-α concentrations.

Maternal multivitamin supplementation reduces the risk of diarrhoea among HIV-exposed children through age 5 years

BACKGROUND

The aim of this study was to determine whether maternal vitamin supplementation affects long-term mortality and morbidity of children born to HIV-infected mothers.

METHODS

In total, 1078 HIV-infected pregnant woman were enrolled in a double-blind, 2×2 factorial, randomised, placebo-controlled trial in Tanzania. Data were collected for 874 children at monthly clinic visits through a median age of 51 months.

RESULTS

Maternal receipt of multivitamins (HR=0.93; 95% CI: 0.70-1.22) or vitamin A (HR=1.00; 95% CI: 0.76-1.32) did not affect all-cause child mortality through age 5 years. Among HIV-negative children, maternal multivitamin supplementation was associated with a lower mortality rate up to 5 years (HR=0.60; 95% CI: 0.38-0.95), primarily in children <2 years of age. Maternal vitamin A supplementation did not significantly affect child mortality up to 5 years (HR=0.76; 95% CI: 0.48-1.20). Children born to mothers who received multivitamins had a lower risk of all types of diarrhoea (RR=0.86; 95% CI: 0.75-0.98) through 5 years of age. The reduced risk of watery diarrhoea persisted in children from 2-5 years of age (RR=0.71; 95% CI: 0.54-0.95).

CONCLUSIONS

Maternal vitamin supplementation during pregnancy and lactation may be associated with long-lasting affects in HIV-exposed children [ClinicalTrials.gov Identifier: NCT00197743].

Immunomodulatory activities of Yoyo bitters: recommended dose precipitated inflammatory responses in male Wistar rats

This study investigated the immunomodulatory capabilities of the sub-chronic administration of Yoyo bitters in male Wistar rats. Eighteen rats weighing 86.2 +/- 4.43 g were randomly picked into three equal groups. The rats were acclimatized for 14 days, after which 0.308 and 0.462 mL kg(-1) b.wt. of Yoyo bitters were administered once daily to groups B and C respectively for 56 days, while group A received distilled water. The feed intake, body weight, blood glucose, interleukin 2 (IL-2), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha), haematological parameters, serum lipid profile and uric acid, liver reduced glutathione and malodialdehyde were determined. The feed intake, body weight and blood glucose concentrations were reduced (p < 0.05) at the doses. No changes were recorded in the concentration of serum IL-2 (p > 0.05), but IL-6 decreased (p < 0.05) in group B and increased (p < 0.05) in group C, while TNF-alpha were increased (p < 0.05) dose dependent. The haematological parameters were decreased at all the doses (p < 0.05), except the ESR, WBC and lymphocytes that were increased (p < 0.05) and platelets in group C (p < 0.05). The serum total cholesterol, TAG, LDL-C and atherogenic index were decreased (p < 0.05) and HDL-C increased (p < 0.05) in group B only. Serum uric acid was reduced (p < 0.05) in group B, but increased in group C with the concentration of liver MDA (p < 0.05). The study, therefore, established that a dose lower than the manufacturer's recommended dose presented the desired immunomodulatory activities and the habitual use of Yoyo bitters at the adult recommended dose calls for caution.

Fetal programming of CVD and renal disease: animal models and mechanistic considerations

The developmental origins of health and disease hypothesis postulates that exposure to a less than optimal maternal environment during fetal development programmes physiological function, and determines risk of disease in adult life. Much evidence of such programming comes from retrospective epidemiological cohorts, which demonstrate associations between birth anthropometry and non-communicable diseases of adulthood. The assertion that variation in maternal nutrition drives these associations is supported by studies using animal models, which demonstrate that maternal under- or over-nutrition during pregnancy can programme offspring development. Typically, the offspring of animals that are undernourished in pregnancy exhibit a relatively narrow range of physiological phenotypes that includes higher blood pressure, glucose intolerance, renal insufficiency and increased adiposity. The observation that common phenotypes arise from very diverse maternal nutritional insults has led to the proposal that programming is driven by a small number of mechanistic processes. The remodelling of tissues during development as a consequence of maternal nutritional status being signalled by endocrine imbalance or key nutrients limiting processes in the fetus may lead to organs having irreversibly altered structures that may limit their function with ageing. It has been proposed that the maternal diet may impact upon epigenetic marks that determine gene expression in fetal tissues, and this may be an important mechanism connecting maternal nutrient intakes to long-term programming of offspring phenotype. The objective for this review is to provide an overview of the mechanistic basis of fetal programming, demonstrating the critical role of animal models as tools for the investigation of programming phenomena.

A new framework for childhood health promotion: the role of policies and programs in building capacity and foundations of early childhood health

Although the connection between early life experiences and later health is becoming increasingly clear, what is needed, now, is a new organizing framework for childhood health promotion, grounded in the latest science. We review the evidence base to identify the steps in the overall pathway to ensuring better health for all children. A key factor in optimizing health in early childhood is building capacities of parents and communities. Although often overlooked, capacities are integral to building the foundations of lifelong health in early childhood. We outline a framework for policymakers and practitioners to guide future decision-making and investments in early childhood health promotion.

Risk of asthma and allergic outcomes in the offspring in relation to maternal food consumption during pregnancy: a Finnish birth cohort study

BACKGROUND

Epidemiological and immunological studies suggest that maternal diet during pregnancy might affect the development of allergic diseases in the offspring. The authors set out to study the effect of maternal food consumption during pregnancy on the emergence of the International Study of Asthma and Allergies in Childhood (ISAAC)-based allergic outcomes: asthma, allergic rhinitis, and wheeze by the 5 yr of age.

METHODS

Data from 2441 children at 5 yr of age were analyzed within the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study, a population-based birth cohort study. Maternal diet was assessed with a validated food frequency questionnaire.

RESULTS

In multiple regression models adjusted for known confounders, low maternal consumption of leafy vegetables (adjusted odds ratio [aOR]: 1.55; 95% CI: 1.21, 1.98), malaceous fruits (aOR: 1.45; 95% CI: 1.15, 1.84), and chocolate (aOR: 1.36; 95% CI: 1.09, 1.70) were positively associated with the risk of wheeze in children. High maternal consumption of fruit and berry juices was positively associated with the risk of allergic rhinitis (aOR: 1.40; 95% CI: 1.03, 1.90) in children. No associations were observed between maternal food consumption and asthma.

CONCLUSIONS

Development of allergic diseases in preschool children may be influenced by intrauterine exposure to maternal diet.

Immunology and probiotic impact of the newborn and young children intestinal microflora

Human body has developed a holistic defence system, which mission is either to recognize and destroy the aggressive invaders or to evolve mechanisms permitting to minimize or restore the consequences of harmful actions. The host immune system keeps the capital role to preserve the microbial intestinal balance via the barrier effect. Specifically, pathogenic invaders such as, bacteria, parasites, viruses and other xenobiotic invaders are rejected out of the body via barriers formed by the skin, mucosa and intestinal flora. In case physical barriers are breached, the immune system with its many components comes into action in order to fence infection. The intestine itself is considered as an "active organ" due to its abundant bacterial flora and to its large metabolic activity. The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations. Which bacterial species are needed for inducing a proper barrier effect is not known, but it is generally accepted that this barrier function can be strongly supported by providing benefic alimentary supplements called functional foods. In this vein it is stressed the fact that early intestinal colonization with organisms such as Lactobacilli and Bifidobacteria and possibly subsequent protection from many different types of diseases. Moreover, this benefic microflora dominated but Bifidobacteria and Lactobacilli support the concept of their ability to modify the gut microbiota by reducing the risk of cancer following their capacity to decrease β-glucoronidase and carcinogen levels. Because of their beneficial roles in the human gastrointestinal tract, LAB are referred to as "probiotics", and efforts are underway to employ them in modern nutrition habits with so-called functional foods. Members of Lactobacillus and Bifidobacterium genera are normal residents of the microbiota in the human gastrointestinal tract, in which they developed soon after birth. But, whether such probiotic strains derived from the human gut should be commercially employed in the so-called functional foods is a matter of debate between scientists and the industrial world. Within a few hours from birth the newborn develops its normal bacterial flora. Indeed human milk frequently contains low amounts of non-pathogenic bacteria like Streptococcus, Micrococcus, Lactobacillus, Staphylococcus, Corynebacterium and Bifidobacterium. In general, bacteria start to appear in feces within a few hours after birth. Colonization by Bifidobacterium occurs generally within 4 days of life. Claims have been made for positive effects of Bifidobacterium on infant growth and health. The effect of certain bacteria having a benefic action on the intestinal ecosystem is largely discussed during the last years by many authors. Bifidobacterium is reported to be a probiotic bacterium, exercising a beneficial effect on the intestinal flora. An antagonism has been reported between B. bifidum and C. perfringens in the intestine of newborns delivered by cesarean section. The aim of the probiotic approach is to repair the deficiencies in the gut flora and restore the protective effect. However, the possible ways in which the gut microbiota is being influenced by probiotics is yet unknown.

Pediatric asthma: an integrative approach to care

Asthma in children and young adults is a complex disease with many different phenotypic expressions. Diagnosis is often made based on history and lung function including measuring airway reversibility. However, in children younger than 6 years of age, the diagnosis is more difficult because many children wheeze in the first 4-6 years of life, especially with viral infections. For those children, asthma treatment is often started empirically. Those who go on to develop chronic asthma most likely have a genetic predisposition and exposure to various environmental factors resulting in chronic inflammation of the lower respiratory tract. There are established national guidelines for diagnosing and treating asthma in children and adults. For persistent asthma, it is recommended that medications be taken on a regular basis after identifying and avoiding environmental triggers. Because many factors play a role in developing asthma in children, many nonmedical approaches to asthma and asthma-like conditions have been promoted even when the diagnosis is at times uncertain. The nonmedical approaches and therapies are often referred to as complementary and alternative medicine (CAM). This review will discuss the conventional therapies recommended for children with asthma in addition to CAM therapies, some of which have supporting scientific evidence. Integrating conventional and CAM therapies can prove to be an effective way to treat pediatric asthma, a common and chronic childhood lung disorder. A case is provided to illustrate how such an integrative approach was used in the successful treatment of a child with moderate persistent asthma.

Early-life environment, developmental immunotoxicology, and the risk of pediatric allergic disease including asthma

Incidence of childhood allergic disease including asthma (AD-A) has risen since the mid-20th century with much of the increase linked to changes in environment affecting the immune system. Childhood allergy is an early life disease where predisposing environmental exposures, sensitization, and onset of symptoms all occur before adulthood. Predisposition toward allergic disease (AD) is among the constellation of adverse outcomes following developmental immunotoxicity (DIT; problematic exposure of the developing immune system to xenobiotics and physical environmental factors). Because novel immune maturation events occur in early life, and the pregnancy state itself imposes certain restrictions on immune functional development, the period from mid-gestation until 2 years after birth is one of particular concern relative to DIT and AD-A. Several prenatal-perinatal risk factors have been identified as contributing to a DIT-mediated immune dysfunction and increased risk of AD. These include maternal smoking, environmental tobacco smoke, diesel exhaust and traffic-related particles, heavy metals, antibiotics, environmental estrogens and other endocrine disruptors, and alcohol. Diet and microbial exposure also significantly influence immune maturation and risk of allergy. This review considers (1) the critical developmental windows of vulnerability for the immune system that appear to be targets for risk of AD, (2) a model in which the immune system of the DIT-affected infant exhibits immune dysfunction skewed toward AD, and (3) the lack of allergy-relevant safety testing of drugs and chemicals that could identify DIT hazards and minimize problematic exposure of pregnant women and children.

What can epidemiology tell us about systemic lupus erythematosus?

Systemic lupus erythematosus (SLE) is an often-severe autoimmune rheumatic disease most commonly diagnosed in women in their childbearing years. It is thought to develop when genetically predisposed individuals are exposed to one or more environmental triggers. This review outlines the epidemiologic evidence for several putative risk factors including cigarette smoke, hormonal and reproductive factors, environmental silica and infectious exposures, as well as many yet to be identified. We also review the evidence for factors associated with increased disease activity and adverse outcomes in SLE. We review the literature on the epidemiology of SLE, its distribution, potential risk factors for its onset and for adverse outcomes. The information considered in this review was gathered through extensive review of the literature. Online Pubmed literature searches, previous reviews of the epidemiology of SLE and original studies were employed. Epidemiologic studies have helped to identify some of these potential risk factors, including exogenous hormone use, cigarette smoking, infections such as Epstein-Barr virus (EBV) and crystalline silica exposure, but many more have yet to be studied. These exposures may interact with multiple genetic factors in determining susceptibility to SLE. While epidemiologic research has contributed an enormous amount to our understanding of the disease and its pathogenesis, there are many more avenues of epidemiologic research that deserve to be pursued.