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Eating and Weight Disorders : EWD Feb 2023Recent studies have reported a gut microbiota imbalance or dysbiosis associated with anorexia nervosa (AN), which has prompted an appraisal of its aetiological role, and... (Review)
Review
PURPOSE
Recent studies have reported a gut microbiota imbalance or dysbiosis associated with anorexia nervosa (AN), which has prompted an appraisal of its aetiological role, and the reformulation of AN as a metabo-psychiatric disorder. Thus, the aim of this paper was to critically review the current scientific findings regarding the role of microbiota in anorexia nervosa.
METHODS
A systematic study of peer-reviewed literature published in four databases between 2009 and 2022 was conducted according to PRISMA guidelines. Both human and animal studies were included.
RESULTS
A total of 18 studies were included. In animal models, both the preclinical and clinical findings were inconsistent regarding microbiota composition, faecal metabolite concentrations, and the effects of human faecal microbiota transplants.
CONCLUSION
The methodological limitations, lack of standardisation, and conceptual ambiguity hinder the analysis of microbiota as a key explanatory factor for AN.
LEVEL OF EVIDENCE
Level I, systematic review.
Topics: Animals; Humans; Anorexia Nervosa; Microbiota; Gastrointestinal Microbiome; Feces
PubMed: 36752887
DOI: 10.1007/s40519-023-01529-4 -
Frontiers in Psychology 2023In recent years, it has been described that the dysbiosis of the intestinal microbiota plays a transcendental role in several pathologies. In this sense, the importance...
INTRODUCTION
In recent years, it has been described that the dysbiosis of the intestinal microbiota plays a transcendental role in several pathologies. In this sense, the importance of the gut microbiota in the gut-brain axis, with a bidirectional communication, has been demonstrated. Furthermore, the gut microbiota has been linked with mood disorders and neuropsychiatric disorders.
METHODS
A systematic review of two databases - PubMed and Scopus - was carried out following PRISMA guidelines. We included original studies in humans with a control group published in the last 11 years, which were assessed by the Critical Appraisal Skills Program (CASP) to confirm their quality. Eighteen articles met all the selection criteria.
RESULTS
A review of the articles revealed an association between psychiatric disorders and different bacterial phyla. The studies we have reviewed have demonstrated differences between subjects with psychiatric disorders and controls and highlight a clear relationship between depression, stress, autism spectrum disorder (ASD), psychotic episodes, eating disorders, anxiety and brain function and the gut microbiota composition.
CONCLUSION
A reduction of fermentative taxa has been observed in different psychiatric disorders, resulting in a decrease in the production of short-chain fatty acids (SCFAs) and an increase in pro-inflammatory taxa, both of which may be consequences of the exacerbation of these pathologies.
PubMed: 37599717
DOI: 10.3389/fpsyg.2023.1215674 -
Nutrients Jan 2024Over recent decades, a growing body of evidence has emerged linking the composition of the gut microbiota to sleep regulation. Interestingly, the prevalence of sleep... (Review)
Review
BACKGROUND
Over recent decades, a growing body of evidence has emerged linking the composition of the gut microbiota to sleep regulation. Interestingly, the prevalence of sleep disorders is commonly related to cardiometabolic comorbidities such as diabetes, impaired lipid metabolism, and metabolic syndrome (MetS). In this complex scenario, the role of the gut-brain axis as the main communicating pathway between gut microbiota and sleep regulation pathways in the brain reveals some common host-microbial biomarkers in both sleep disturbances and MetS. As the biological mechanisms behind this complex interacting network of neuroendocrine, immune, and metabolic pathways are not fully understood yet, the present systematic review aims to describe common microbial features between these two unrelated chronic conditions.
RESULTS
This systematic review highlights a total of 36 articles associating the gut microbial signature with MetS or sleep disorders. Specific emphasis is given to studies evaluating the effect of dietary patterns, dietary supplementation, and probiotics on MetS or sleep disturbances.
CONCLUSIONS
Dietary choices promote microbial composition and metabolites, causing both the amelioration and impairment of MetS and sleep homeostasis.
Topics: Humans; Metabolic Syndrome; Brain-Gut Axis; Probiotics; Diet; Gastrointestinal Microbiome; Dysbiosis
PubMed: 38337675
DOI: 10.3390/nu16030390 -
Neuroscience and Biobehavioral Reviews Jul 2023Sex disparities are evident in the biological response to acute stressors, with a suggested influence of ovarian hormones on hypothalamic-pituitary-adrenal (HPA) axis... (Meta-Analysis)
Meta-Analysis Review
Sex disparities are evident in the biological response to acute stressors, with a suggested influence of ovarian hormones on hypothalamic-pituitary-adrenal (HPA) axis functioning. This systematic review and meta-analysis investigates differences in HPA axis reactivity to acute psychosocial or physiological stressors between menstrual cycle phases. A systematic literature search of six databases resulted in 12 longitudinal studies (n = 182) examining HPA axis reactivity in healthy, naturally-cycling, non-breastfeeding participants aged between 18 and 45 years in at least two cycle phases. The quality of cortisol and menstrual cycle assessment was rated and a descriptive synthesis and meta-analysis of HPA axis reactivity between two broader and five more precise cycle phases was conducted. Three studies provided sufficient data for the meta-analysis and showed a significant, small-sized effect, indicating higher cortisol reactivity in the luteal than in the follicular cycle phase. More primary studies with high-quality menstrual cycle and cortisol assessment are needed. The review did not receive funding and was pre-registered (PROSPERO; CRD42020181632).
Topics: Female; Humans; Adolescent; Young Adult; Adult; Middle Aged; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Stress, Psychological; Menstrual Cycle
PubMed: 37149074
DOI: 10.1016/j.neubiorev.2023.105212 -
Food Science & Nutrition Oct 2022Axis I disorders are one of the major health burdens worldwide. Evidence suggests that Mediterranean diet has key biological factors associated with reducing the... (Review)
Review
Axis I disorders are one of the major health burdens worldwide. Evidence suggests that Mediterranean diet has key biological factors associated with reducing the progression of these disorders. This systematic review aimed to clarify the relationship between Mediterranean diet and Axis I disorders. PubMed and Scopus databases were searched from January 2016 up to June 2021. Those observational studies in English language that assessed the relationship between Mediterranean diet and Axis I disorders (such as depression, anxiety, eating disorders, schizophrenia, etc.) were included in this review. The Newcastle-Ottawa Scale was used to evaluate the quality of studies. Thirty-six studies (15 cohorts, 19 cross-sectional, and 2 case-control) met the inclusion criteria. The results revealed that more than two-thirds of the studies (25 studies, 69.44%) had significant protective relationship between receiving Mediterranean diet and reducing the symptoms or incidence of Axis I disorders. Most studies were performed on depression (29 studies measured depression at least as one of the Axis I disorders), of which 72.41% reported an inverse relationship. There were also 9 studies on anxiety (studies that measured anxiety at least as one of the Axis I disorders), that 77.77% of them observed protective association. Moreover, majority of the studies (25 studies, 69.44%) had high quality, of which 76% found an inverse relationship. In conclusion, it seems that the Mediterranean diet can reduce the symptoms or the occurrence of Axis I disorders (especially depression and anxiety). However, more extensive review studies, particularly with interventional designs, are necessary to prove the result.
PubMed: 36249971
DOI: 10.1002/fsn3.2950 -
Frontiers in Pharmacology 2018Studies have shown that traumatic experiences may affect hormonal systems mediated by the hypothalamic-pituitary-adrenal (HPA) axis and the oxytocinergic system. This... (Review)
Review
Studies have shown that traumatic experiences may affect hormonal systems mediated by the hypothalamic-pituitary-adrenal (HPA) axis and the oxytocinergic system. This effect is the result of long-term impairments in hypothalamic structures and negative feedback mechanisms within the HPA axis, structures that mediate the response to stress. This deregulation reduces the production and release of cortisol and oxytocin (OXT), which may alter stress responses and lead to increased vulnerability to impairments from stressful experiences. The presence of gene polymorphisms might also have an impact on the vulnerability to psychopathology. We made a systematic review of articles dealing with the relationship between OXT and traumatic emotional experiences in humans. Thirty-five studies were reviewed and significant associations between experiences of emotional trauma (ET) and OXT were found. The main results showed that the presence of ET and post-traumatic stress disorder (PTSD) is strongly associated with reductions in endogenous OXT, and also that the acute effects of OXT administrations in individuals with ET tend to be anxiolytic only in less severe forms. In victims of recent traumatic experiences (RTE), OXT increased the re-experience of traumas and restored the function of different neural networks associated with fear control/extinction in PTSD patients. The results available also suggest that gene receptor polymorphisms may have a protective function in different outcomes after the experience of traumatic events. We conclude that the relationship between ET and OXT is multifaceted, complex, and mediated by contextual and individual factors. Directions for future studies are suggested considering the gaps in the available literature.
PubMed: 29545749
DOI: 10.3389/fphar.2018.00154 -
Journal of Affective Disorders Jun 2018The link between the abnormalities of the Hypothalamic-pituitary-adrenal (HPA) axis and depression has been one of the most consistently reported findings in psychiatry.... (Review)
Review
BACKGROUND
The link between the abnormalities of the Hypothalamic-pituitary-adrenal (HPA) axis and depression has been one of the most consistently reported findings in psychiatry. At the same time, multiple studies have demonstrated a stronger association between the increased activation of HPA-axis and melancholic, or endogenous depression subtype. This association has not been confirmed for the atypical subtype, and some researchers have suggested that as an antinomic depressive subtype, it may be associated with the opposite type, i.e. hypo-function, of the HPA-axis, similarly to PTSD. The purpose of this systematic review is to summarise existing studies addressing the abnormalities of the HPA-axis in melancholic and/or atypical depression.
METHOD
We conducted a systematic review in the literature by searching MEDLINE, PsycINFO, OvidSP and Embase databases until June 2017. The following search items were used: "hypothalamic-pituitary-adrenal" OR "HPA" OR "cortisol" OR "corticotropin releasing hormone" OR "corticotropin releasing factor" OR "glucocorticoid*" OR "adrenocorticotropic hormone" OR "ACTH" AND "atypical depression" OR "non-atypical depression" OR "melancholic depression" OR "non-melancholic depression" OR "endogenous depression" OR "endogenomorphic depression" OR "non-endogenous depression". Search limits were set to include papers in English or German language published in peer-reviewed journals at any period. All studies were scrutinized to determine the main methodological characteristics, and particularly possible sources of bias influencing the results reported.
RESULTS
We selected 48 relevant studies. Detailed analysis of the methodologies used in the studies revealed significant variability especially regarding the samples' definition comparing the HPA axis activity of melancholic patients to atypical depression, including healthy controls. The results were subdivided into 4 sections: (1) 27 studies which compared melancholic OR endogenous depression vs. non-melancholic or non-endogenous depression or controls; (2) 9 studies which compared atypical depression or atypical traits vs. non-atypical depression or controls; (3) 7 studies which compared melancholic or endogenous and atypical depression subtypes and (4) 5 studies which used a longitudinal design, comparing the measures of HPA-axis across two or more time points. While the majority of studies did confirm the association between melancholic depression and increased post-challenge cortisol levels, the association with increases in basal cortisol and basal ACTH were less consistent. Some studies, particularly those focusing on reversed vegetative symptoms, demonstrated a decrease in the activity of the HPA axis in atypical depression compared to controls, but the majority did not distinguish it from healthy controls.
CONCLUSIONS
In conclusion, our findings indicate that there is a difference in the activity of the HPA-axis between melancholic and atypical depressive subtypes. However, these are more likely explained by hypercortisolism in melancholia; and most often normal than decreased function in atypical depression. Further research should seek to distinguish a particular subtype of depression linked to HPA-axis abnormalities, based on symptom profile, with a focus on vegetative symptoms, neuroendocrine probes, and the history of adverse childhood events. New insights into the dichotomy addressed in this review might be obtained from genetic and epigenetic studies of HPA-axis related genes in both subtypes, with an emphasis on the presence of vegetative symptoms.
Topics: Adrenocorticotropic Hormone; Biomarkers; Corticotropin-Releasing Hormone; Depression; Depressive Disorder; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System
PubMed: 29150144
DOI: 10.1016/j.jad.2017.09.052 -
Frontiers in Endocrinology 2022Until recently, glucagon was considered a mere antagonist to insulin, protecting the body from hypoglycemia. This notion changed with the discovery of the liver-alpha...
Until recently, glucagon was considered a mere antagonist to insulin, protecting the body from hypoglycemia. This notion changed with the discovery of the liver-alpha cell axis (LACA) as a feedback loop. The LACA describes how glucagon secretion and pancreatic alpha cell proliferation are stimulated by circulating amino acids. Glucagon in turn leads to an upregulation of amino acid metabolism and ureagenesis in the liver. Several increasingly common diseases (e.g., non-alcoholic fatty liver disease, type 2 diabetes, obesity) disrupt this feedback loop. It is important for clinicians and researchers alike to understand the liver-alpha cell axis and the metabolic sequelae of these diseases. While most of previous studies have focused on fasting concentrations of glucagon and amino acids, there is limited knowledge of their dynamics after glucose administration. The authors of this systematic review applied PRISMA guidelines and conducted PubMed searches to provide results of 8078 articles (screened and if relevant, studied in full). This systematic review aims to provide better insight into the LACA and its mediators (amino acids and glucagon), focusing on the relationship between glucose and the LACA in adult and pediatric subjects.
Topics: Adult; Humans; Child; Glucose; Glucagon; Glucagon-Secreting Cells; Diabetes Mellitus, Type 2; Liver; Amino Acids
PubMed: 36686477
DOI: 10.3389/fendo.2022.1061682 -
Spine Deformity Nov 2022To assess clinical and safety outcomes associated with different rod materials and diameters in adult spinal deformity (ASD) surgery. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To assess clinical and safety outcomes associated with different rod materials and diameters in adult spinal deformity (ASD) surgery.
METHODS
A systematic literature review and meta-analysis evaluated ASD surgery using pedicle screw fixation systems with rods of different materials and sizes. Postoperative outcomes (i.e., Cobb, sagittal vertical axis, and pelvic tilt angle) and complications (i.e., pseudarthrosis and rod breakage) were assessed. Random effects models (REMs) pooled data for outcomes reported in ≥ 2 studies.
RESULTS
Among 50 studies evaluating ASD surgery using pedicle screw fixation systems, 17 described rod material/diameter. Postoperative outcomes did not statistically differ between cobalt-chromium (CoCr) vs. titanium (Ti) rods (n = 2 studies; mean [95% confidence interval (CI)] sagittal vertical axis angle: CoCr 37.00° [18.58°-55.42°] and Ti 32.58° [24.62°-40.54°]; mean [95% CI] pelvic tilt angle: CoCr 26.20° [22.87°-29.53°] and Ti 20.15° [18.0°-22.31°]). The pooled proportion (95% CI) of pseudarthrosis was 15% (7-22%) for CoCr and 12% (- 8-32%) for stainless steel (SS) (n = 2 studies each; Chi = 0.07, p = 0.79). The pooled proportion (95% CI) of broken rods was 12% (1-22%) for Ti (n = 3 studies) and 10% (2-19) for CoCr (n = 1 study). Among 6.0-6.35 mm rods, the pooled (95% CI) postoperative Cobb angle (n = 2) was 12.01° (9.75°-14.28°), sagittal vertical axis angle (n = 4) was 35.32° (30.02°-40.62°), and pelvic tilt angle was 21.11° (18.35°-23.86°).
CONCLUSIONS
For ASD patients undergoing posterior fixation and fusion, there are no statistically significant differences in postoperative outcomes or complications among rods of varying materials and diameters. Benchmark postsurgical outcomes and complication rates by rod material and diameter are provided.
LEVEL OF EVIDENCE
III.
Topics: Adult; Humans; Spinal Fusion; Stainless Steel; Titanium; Chromium Alloys; Pseudarthrosis; Cobalt; Chromium
PubMed: 35904725
DOI: 10.1007/s43390-022-00556-y -
Advances in Medical Sciences Mar 2018More profound understanding of the relationship between the burnout and the limbic system function can provide better insight into brain structures associated with the... (Meta-Analysis)
Meta-Analysis Review
More profound understanding of the relationship between the burnout and the limbic system function can provide better insight into brain structures associated with the burnout syndrome. The objective of this review is to explore all evidence of limbic brain structures associated with the burnout syndrome. In total, 13 studies were selected. Four of them applied the neuroimaging technology to investigate the sizes/volumes of the limbic brain structures of burnout patients. Six other studies were to investigate the hypothalamus-pituitary-adrenal (HPA) axis of burnout patients. Based on the results of the studies on the HPA-axis and neuroimaging of the limbic brain structures, one can see great impact of the chronic occupational stress on the limbic structures in terms of HPA dysregulation, a decrease of BDNF, impaired neurogenesis and limbic structures atrophy. It can be concluded that chronic stress inhibits the feedback control pathway in the HPA axis, causes the decrease of brain-derived neurotrophic factor (BDNF), then impaired neurogenesis and eventually neuron atrophy.
Topics: Burnout, Professional; Humans; Limbic System; Neuroimaging
PubMed: 29175078
DOI: 10.1016/j.advms.2017.11.004