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Nutrition, the digestive system and immunity in COVID-19 infection.
Bold, J, Harris, M, Fellows, L, Chouchane, M
Gastroenterology and hepatology from bed to bench. 2020;13(4):331-340
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Covid-19 needs both prevention and recovery strategies to reduce complications. This review study aimed to discuss the associations between nutrition, obesity, and the impact these have on stomach symptoms associated with Covid-19. Obesity has been identified as a risk factor for Covid-19 and this could be due to several factors such as impaired immune function, increased inflammation, increased susceptibility to infection and the high number of cells on fat tissue, which express the receptor known to allow Covid-19 into cells. The involvement of the gut microbiota of obese individuals was extensively reviewed and gut dysbiosis has been associated with many diseases, thus improving gut microbiota may go some way to improving Covid-19 outcomes. Nutritional interventions to reduce obesity need to be part of a multi-pronged strategy and the possible introduction of vitamin D supplements and probiotics. The paper did not draw any conclusions; however this paper could be used by healthcare professionals to understand the role of obesity in increasing the risk of Covid-19 infection, complications that may arise upon and after infection and nutritional strategies as part of a management plan.
Abstract
The current review aimed to synthesize the literature on the complex relationship between food consumption and nutritional status as well as the digestive system in order to examine the relationship between immunity and potential responses to COVID-19 infection. The goal is to help inform the many healthcare professionals working with COVID-19 patients. A literature search was performed on PubMed, Scopus, and EMBASE databases. Hand searches were also undertaken using Google and reference lists to identify recent evidence. Studies were critically appraised, and the findings were analyzed by narrative synthesis. Nutritional status can impact immunity in several ways, including affecting susceptibility to infection, severity of disease, and recovery time, and is therefore a significant consideration in the management of COVID-19. COVID-19 can also impact digestive function, which can further impact nutritional status. The role of Vitamin D deficiency in vulnerability to severe respiratory infections, including COVID-19, has been recognized, and it may have a role in treatment where deficiency is indicated. Healthcare professionals should be aware that obesity may be accompanied by micronutrient malnutrition including vitamin D deficiency and alterations in the microbiome and inflammatory responses, which can further impact immunity and disease severity. Multidisciplinary team-work is recommended in the management of patients with COVID-19, and approaches should include a consideration of nutritional status (both macronutrients and micronutrients), body weight, and gastrointestinal signs and symptom.
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Effect of ultra-processed diet on gut microbiota and thus its role in neurodegenerative diseases.
Martínez Leo, EE, Segura Campos, MR
Nutrition (Burbank, Los Angeles County, Calif.). 2020;71:110609
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The consumption of ultra-processed foods has increased dramatically in recent years, resulting in an overconsumption of foods that are nutritionally only suitable to be consumed occasionally. Prolonged and short-term dietary modifications can affect the composition and diversity of the gut microbiota and in turn, dysregulation of the gut microbiota may be associated with diseases of the brain. This systematic review study aimed to determine the relationship between diets high in ultra-processed foods, gut microbiota dysregulation and how this may influence early development of brain diseases. The authors first reviewed literature surrounding the role of gut microbiota on health owing to their ability to produce signalling molecules that have various functions around the body. An imbalance in the gut microbiota can result in an overproduction of signalling molecules that contribute to an unhealthy state. These signalling molecules can also act on the brain through several ways such as the nervous, circulatory, and immune systems. The review demonstrates that high fat, high sugar diets are related to increased risk for diseases such as Alzheimer’s disease and that diets high in fibre, are related to a low incidence of brain disorders, but as very few studies have looked at this in relation to gut microbiota relationships are only speculative. It was concluded that gut microbiota dysregulation could act as a clinical indicator between brain diseases and ultra-processed foods, however further studies are needed on the relationship between diet, gut microbiota and brain diseases.
Abstract
The current dietary pattern is characterized by high consumption of ultra-processed foods and lower consumption of fiber and vegetables, environmental factors that are associated directly with the current incidence of chronic metabolic diseases. Diet is an environmental factor that influences the diversity and functionality of the gut microbiota, where dietary changes have a direct action on their homeostasis. The environment created in the gut by ultra-processed foods, a hallmark of the Western diet that are recognized as trigger factors for low-grade systemic inflammatory and oxidative changes, favor the development of neurodegenerative diseases (NDs). From a systematic search, the present review analyzes the relationship and effect of the current feeding pattern, with the dysregulation of the microbiota and its influence on the development of cognitive decline. Because diagnosis of NDs is usually at late stages, this review highlights the importance of a search for stricter public health strategies regarding access to and development of ultra-processed foods.
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Mental Disorders Linked to Crosstalk between The Gut Microbiome and The Brain.
Choi, TY, Choi, YP, Koo, JW
Experimental neurobiology. 2020;29(6):403-416
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The gut microbiome may have a role in regular brain function and mental health and this review paper aimed to determine the mechanisms through which this may be possible. There are several mental health disorders that may be affected by the gut microbiome, major depressive disorder (MDD), anxiety disorder, autism spectrum disorder (ASD), Alzheimer’s disease (AD), and addiction. It appears that there is a correlation between a disordered gut microbiome (known as dysbiosis) and MDD, ASD and addiction. Anxiety symptoms in healthy individuals and cognitive deficits in individuals with AD have reportedly been improved with probiotics. How the gut microbiome communicates with the brain was also discussed with the enteric nervous system, vagus nerve, spinal chord, immune system and brain signalling molecules all being implicated as possible routes. Finally, the paper discussed the use of probiotics for the prevention or treatment of mental disorders, with Bifidobacteria, Lactobacillus and specifically L. reuteri, L. plantarum and L. helveticus all shown in animal models to improve aspects associated with mental disorders. Amongst the human research B. longum has been shown to relieve stress and increase cognitive function in healthy individuals. It was concluded that studies have elucidated a relationship between the gut microbiome and mental health through various routes of communication. Research should focus on how gut microbiome changes are involved in mental illness. This study could be used by healthcare professionals to further knowledge on the potential relationship between the gut microbiome and mental health.
Abstract
Often called the second brain, the gut communicates extensively with the brain and vice versa. The conversation between these two organs affects a variety of physiological mechanisms that are associated with our mental health. Over the past decade, a growing body of evidence has suggested that the gut microbiome builds a unique ecosystem inside the gastrointestinal tract to maintain the homeostasis and that compositional changes in the gut microbiome are highly correlated with several mental disorders. There are ongoing efforts to treat or prevent mental disorders by regulating the gut microbiome using probiotics. These attempts are based on the seminal findings that probiotics can control the gut microbiome and affect mental conditions. However, some issues have yet to be conclusively addressed, especially the causality between the gut microbiome and mental disorders. In this review, we focus on the mechanisms by which the gut microbiome affects mental health and diseases. Furthermore, we discuss the potential use of probiotics as therapeutic agents for psychiatric disorders.
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Bacterial Metabolites of Human Gut Microbiota Correlating with Depression.
Averina, OV, Zorkina, YA, Yunes, RA, Kovtun, AS, Ushakova, VM, Morozova, AY, Kostyuk, GP, Danilenko, VN, Chekhonin, VP
International journal of molecular sciences. 2020;21(23)
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Depression is multifactorial disease and it is the most common type of psychiatric disorder. Literature indicates that there are significant differences between the gut microbiota (GM) of patients with depression and healthy controls. The aim of this review was to examine (a) various low-molecular compounds as potential biomarkers of depression in correlation with the metabolism of the GM, and (b) ways to correct the microbiota imbalance. Results show that: - the use of the GM biomarkers, reflecting the neuromodulatory [the process by which nervous activity is regulated through classes of neurotransmitters], immunomodulatory [the process by which the body’s immune system is altered] and antioxidant statuses of the host organism, in the analysis of metagenomic [the study of a collection of genetic material (genomes) from a mixed community of organisms] data from patients with neuropsychiatric diseases, is gaining currency. - diet remains one of the most effective measures that can be taken to restore the microbial balance in the gut and alleviate the symptoms of depression. - a healthy diet during the depression therapy, along with the application of probiotics and psychobiotics, may potentially improve the course of the disease and contribute to the progress of treatment. Authors conclude that further progress in the practical understanding of the role of the GM in depression will greatly depend on correct planning of future metagenomic studies.
Abstract
Depression is a global threat to mental health that affects around 264 million people worldwide. Despite the considerable evolution in our understanding of the pathophysiology of depression, no reliable biomarkers that have contributed to objective diagnoses and clinical therapy currently exist. The discovery of the microbiota-gut-brain axis induced scientists to study the role of gut microbiota (GM) in the pathogenesis of depression. Over the last decade, many of studies were conducted in this field. The productions of metabolites and compounds with neuroactive and immunomodulatory properties among mechanisms such as the mediating effects of the GM on the brain, have been identified. This comprehensive review was focused on low molecular weight compounds implicated in depression as potential products of the GM. The other possible mechanisms of GM involvement in depression were presented, as well as changes in the composition of the microbiota of patients with depression. In conclusion, the therapeutic potential of functional foods and psychobiotics in relieving depression were considered. The described biomarkers associated with GM could potentially enhance the diagnostic criteria for depressive disorders in clinical practice and represent a potential future diagnostic tool based on metagenomic technologies for assessing the development of depressive disorders.
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The Role of Bacteria and Its Derived Metabolites in Chronic Pain and Depression: Recent Findings and Research Progress.
Li, S, Hua, D, Wang, Q, Yang, L, Wang, X, Luo, A, Yang, C
The international journal of neuropsychopharmacology. 2020;23(1):26-41
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Depression is closely associated with chronic pain yet the connection between these comorbidities is ambiguous. Recent studies have shown alterations in the gut microbiome may contribute to cognitive dysfunction via the microbiota-gut-brain axis. The aim of this systematic review is to summarize the existing evidence of the role of the gut microbiome in chronic pain and depression and explore potential mechanisms of gut dysbiosis in the development of these conditions. This review found metabolic products from the gut microbiota can mediate neuro-inflammation and neuro-immunity pathways in pain and depression, and that dysbiosis in the gut may contribute to the cause of chronic pain and depression. The authors conclude the metabolic products from the gut bacteria offer new insights to the connection between the gut microbiota and mechanisms of pain and depression, while showing potential as a therapeutic target.
Abstract
BACKGROUND Chronic pain is frequently comorbid with depression in clinical practice. Recently, alterations in gut microbiota and metabolites derived therefrom have been found to potentially contribute to abnormal behaviors and cognitive dysfunction via the "microbiota-gut-brain" axis. METHODS PubMed was searched and we selected relevant studies before October 1, 2019. The search keyword string included "pain OR chronic pain" AND "gut microbiota OR metabolites"; "depression OR depressive disorder" AND "gut microbiota OR metabolites". We also searched the reference lists of key articles manually. RESULTS This review systematically summarized the recent evidence of gut microbiota and metabolites in chronic pain and depression in animal and human studies. The results showed the pathogenesis and therapeutics of chronic pain and depression might be partially due to gut microbiota dysbiosis. Importantly, bacteria-derived metabolites, including short-chain fatty acids, tryptophan-derived metabolites, and secondary bile acids, offer new insights into the potential linkage between key triggers in gut microbiota and potential mechanisms of depression. CONCLUSION Studying gut microbiota and its metabolites has contributed to the understanding of comorbidity of chronic pain and depression. Consequently, modulating dietary structures or supplementation of specific bacteria may be an available strategy for treating chronic pain and depression.
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Gut hormones in microbiota-gut-brain cross-talk.
Sun, LJ, Li, JN, Nie, YZ
Chinese medical journal. 2020;133(7):826-833
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The bidirectional communication between the gastrointestinal tract and the brain, termed the gut-brain axis (GBA), is evidenced to to play a role in physiological and psychological health. While precise communication pathways are not yet clear, it is hypothesised this pathway may be an important therapeutic target in complex psychiatric and gastrointestinal disorders. The aim of this review is to summarize the role of gut hormones in the GBA and focus on how the microbiota interact with these hormones in health and disease. The literature shows the gut microbiota can affect the metabolism of various gut hormones, and these hormones can influence the microbiota. Evidence suggests this cross-talk may be a key regulator in appetite, immune response, stress response, and metabolism. Based on this review, the authors conclude the gut microbiota-hormone homeostatic relationship provides insight on the complex communication between the gut and the brain. They suggest future research should target the microbiota-hormones-gut-brain axis to develop new therapeutic strategies to psychiatric disorders.
Abstract
The homeostasis of the gut-brain axis has been shown to exert several effects on physiological and psychological health. The gut hormones released by enteroendocrine cells scattered throughout the gastrointestinal tract are important signaling molecules within the gut-brain axis. The interaction between gut microbiota and gut hormones has been greatly appreciated in gut-brain cross-talk. The microbiota plays an essential role in modulating many gut-brain axis-related diseases, ranging from gastrointestinal disorders to psychiatric diseases. Similarly, gut hormones also play pleiotropic and important roles in maintaining health, and are key signals involved in gut-brain axis. More importantly, gut microbiota can affect the release and functions of gut hormones. This review highlights the role of gut microbiota in the gut-brain axis and focuses on how microbiota-related gut hormones modulate various physiological functions. Future studies could target the microbiota-hormones-gut brain axis to develop novel therapeutics for different psychiatric and gastrointestinal disorders, such as obesity, anxiety, and depression.
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The role of diet and probiotics in prevention and treatment of bacterial vaginosis and vulvovaginal candidiasis in adolescent girls and non-pregnant women.
Mizgier, M, Jarzabek-Bielecka, G, Mruczyk, K, Kedzia, W
Ginekologia polska. 2020;91(7):412-416
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In adolescent girls and non-pregnant women, vaginitis, including fungal infections, is a common problem. Vaginitis clinically manifests as abnormal vaginal discharge, irritation, itching, burning and discomfort, and is especially prevalent with a decrease in immunity. The normal bacterial flora of the vagina and cervix protect against the development of pathogenic strains, while abnormal flora tend to be the most common starting point for the development of infections. The aim of this study was to determine the role of proper diet and probiotics and prebiotics use in relation to therapy and prophylaxis of vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV) in non-pregnant women and girls. This review shows that: - An unbalanced diet can be a risk factor for BV. Women tend to be more exposed to BV if they have poor micronutrient status, including vitamins A, E, D, C and beta carotene — indicating a lower fruit and vegetable intake. - Many studies proved that regulated use of probiotics, administered both orally and vaginally, are effective in the prevention and treatment of vaginal infections such as BV and VVC. - To create a positive environment for probiotics, it is important to provide prebiotics that support the development of probiotic strains. Authors conclude that gynaecologists, obstetricians, general practitioners and dieticians should share their findings, and raise awareness among the general population as to the importance of optimal nutrition. Probiotics and prebiotics could be considered to prevent infections of the genital tract, reduce associated disease, and maintain reproductive health.
Abstract
The article raises important issues regarding the use of diet and probiotics in prevention and treatment of vaginitis. Vaginitis is defined as any condition with symptoms of abnormal vaginal discharge. The most common causes of vaginitis are vulvovaginal candidiasis (VVC), trichomoniasis and bacterial vaginosis (BV). Vaginitis has been linked to itching, burning, pain, discharge, irritation and also adverse reproductive and obstetric health outcomes. Moreover, microorganisms that build vaginal flora in the state of bacterial vaginosis are a source of cervicitis and endometritis (often in subclinical forms) and pelvic inflammatory disease (PID) The proper diet and probiotics consumption may influence the composition of the gut microbiota, improve gut integrity, and have an impact on maintaining and recovering the normal vaginal microbiota. Future studies and reviews investigating the role of diet and probiotics in changes to gut and vaginal microbiome need to focus on deciphering the mechanismus of host bacteria interaction in vulvovaginal health.
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The Malnutritional Status of the Host as a Virulence Factor for New Coronavirus SARS-CoV-2.
Briguglio, M, Pregliasco, FE, Lombardi, G, Perazzo, P, Banfi, G
Frontiers in medicine. 2020;7:146
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This opinion article explores the role of an individual’s nutrition status when subjected to infection by viruses, in particular Covid-19. Distinction is made between the susceptibility to infection in the first instance and the ability to persist in fighting infection once it is established. For Covid-19, it is argued that a healthier nutritional status, in particular Vitamins A, B, C, D and E, iron selenium and zinc, will lower susceptibility to infection, lower the severity of the virus and therefore reduce the length of time an individual has to find reserves to fight the virus. More severe cases of Covid-19 infection also often include gastro-intestinal symptoms which further exacerbate nutritional status with lowered appetite. The authors conclude that malnourished individuals may be more susceptible to Covid-19 infection and that nutritional support is vital in severe cases. The article includes a useful diagram of both hyponutrition and hypernutrition and possible impacts of Covid-19.
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Is copper beneficial for COVID-19 patients?
Raha, S, Mallick, R, Basak, S, Duttaroy, AK
Medical hypotheses. 2020;142:109814
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Copper (Cu) is an essential micronutrient that plays an important role in both the innate and adaptive immune response. It has been shown that Cu-deficient humans show increased susceptibility to viral infections. While there is no current vaccine or drug available for the novel coronavirus SARS-CoV-2 (COVID-19), it is critical to identify ways to slow the spread until treatments are found. The aim of this study was to review available data and explore whether increased Cu-levels can boost the immunity in people at risk of COVID-19. While there is a definitive need for clinical trials, the available research does show an association between Cu-deficiency and a weakened immune system. Also, current models for optimal Cu intake indicate that a large portion of the United States population may have Cu-deficiency. Based on this available data, the authors conclude that Cu supplementation may have a protective effect against COVID-19, especially in people at risk for Cu-deficiency.
Abstract
Copper (Cu) is an essential micronutrient for both pathogens and the hosts during viral infection. Cu is involved in the functions of critical immune cells such as T helper cells, B cells, neutrophils natural killer (NK) cells, and macrophages. These blood cells are involved in the killing of infectious microbes, in cell-mediated immunity and the production of specific antibodies against the pathogens. Cu-deficient humans show an exceptional susceptibility to infections due to the decreased number and function of these blood cells. Besides, Cu can kill several infectious viruses such as bronchitis virus, poliovirus, human immunodeficiency virus type 1(HIV-1), other enveloped or nonenveloped, single- or double-stranded DNA and RNA viruses. Moreover, Cu has the potent capacity of contact killing of several viruses, including SARS-CoV-2. Since the current outbreak of the COVID-19 continues to develop, and there is no vaccine or drugs are currently available, the critical option is now to make the immune system competent to fight against the SARS-CoV-2. Based on available data, we hypothesize that enrichment of plasma copper levels will boost both the innate and adaptive immunity in people. Moreover, owing to its potent antiviral activities, Cu may also act as a preventive and therapeutic regime against COVID-19.
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The Specific Carbohydrate Diet and Diet Modification as Induction Therapy for Pediatric Crohn's Disease: A Randomized Diet Controlled Trial.
Suskind, DL, Lee, D, Kim, YM, Wahbeh, G, Singh, N, Braly, K, Nuding, M, Nicora, CD, Purvine, SO, Lipton, MS, et al
Nutrients. 2020;12(12)
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Crohn’s disease is a painful chronic lifelong condition where the digestive tract gets inflamed. Environmental insults and gut microbial changes may contribute to immune dysregulation by activating and upregulating the immune system in Crohn’s disease. During this single-centre, randomised, double-blind, diet-controlled study, ten male active Crohn's disease patients aged seven to eighteen were randomly assigned to either a specific carbohydrate diet, a modified specific carbohydrate diet, or a whole food diet. All diet groups showed a reduction in symptoms, inflammation, and a positive change in the gut microbial composition after 12 weeks, depending on the degree of variability in the dietary regimen. Based on the results of this study, an exclusionary diet eliminating grains, sugar, dairy, and processed foods may have a positive impact on reducing Crohn's disease symptoms, inflammation, and improving gut microbial composition and biochemical markers. In the future, robust studies with a larger sample size will be needed to figure out better dietary strategies for Crohn's disease. Healthcare professionals can, however, use these results to identify dietary choices that can reduce Crohn's disease symptoms.
Abstract
BACKGROUND Crohn's disease (CD) is a chronic inflammatory intestinal disorder associated with intestinal dysbiosis. Diet modulates the intestinal microbiome and therefore has a therapeutic potential. The aim of this study is to determine the potential efficacy of three versions of the specific carbohydrate diet (SCD) in active Crohn's Disease. METHODS 18 patients with mild/moderate CD (PCDAI 15-45) aged 7 to 18 years were enrolled. Patients were randomized to either SCD, modified SCD(MSCD) or whole foods (WF) diet. Patients were evaluated at baseline, 2, 4, 8 and 12 weeks. PCDAI, inflammatory labs and multi-omics evaluations were assessed. RESULTS Mean age was 14.3 ± 2.9 years. At week 12, all participants (n = 10) who completed the study achieved clinical remission. The C-reactive protein decreased from 1.3 ± 0.7 at enrollment to 0.9 ± 0.5 at 12 weeks in the SCD group. In the MSCD group, the CRP decreased from 1.6 ± 1.1 at enrollment to 0.7 ± 0.1 at 12 weeks. In the WF group, the CRP decreased from 3.9 ± 4.3 at enrollment to 1.6 ± 1.3 at 12 weeks. In addition, the microbiome composition shifted in all patients across the study period. While the nature of the changes was largely patient specific, the predicted metabolic mode of the organisms increasing and decreasing in activity was consistent across patients. CONCLUSIONS This study emphasizes the impact of diet in CD. Each diet had a positive effect on symptoms and inflammatory burden; the more exclusionary diets were associated with a better resolution of inflammation.