Autointoxication and historical precursors of the microbiome-gut-brain axis

Association between dopamine receptor D2 Taq IA gene polymorphism (rs1800497) and personality traits

Objective

This study aimed to find a potential association between the DRD2 Taq1A gene polymorphism (rs1800497 C32806T) and personality traits.

Methods

In all, 249 youths were recruited for this study. The Short-form Revised Eysenck Personality Questionnaire was administered to assess personality traits. The participants were genotyped for the DRD2 Taq1A polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. Statistical analysis was carried out to find a possible association between the genotypes and aspects of personality traits assessed.

Results

The frequencies of the A1 and A2 alleles in our sampled population were 215 (43.2%) and 283 (56.8%), while the frequencies of A1A1, A1A2, and A2A2 were 67 (26.9%), 81 (32.5%), and 101 (40.6%), respectively. The study population was not in Hardy-Weinberg equilibrium (χ2 = 17.64, p < 0.001). The A2 allele was significantly associated with extraversion. Although this allele was also associated with neuroticism, psychoticism, and lie, the association was not significant.

Conclusion

The A2 allele of the DRD2 Taq1A polymorphism was found to be more associated with extraversion, as measured by the Short-form Revised Eysenck Personality Questionnaire.

Anorexia nervosa and microbiota: systematic review and critical appraisal

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.

Health Literacy, Equity, and Communication in the COVID-19 Era of Misinformation: Emergence of Health Information Professionals in Infodemic Management

The health information management (HIM) field’s contribution to health care delivery is invaluable in a pandemic context where the need for accurate diagnoses will hasten responsive, evidence-based decision-making. The COVID-19 pandemic offers a unique opportunity to transform the practice of HIM and bring more awareness to the role that frontline workers play behind the scenes in safeguarding reliable, comprehensive, accurate, and timely health information. This transformation will support future research, utilization management, public health surveillance, and forecasting and enable key stakeholders to plan and ensure equitable health care resource allocation, especially for the most vulnerable populations. In this paper, we juxtapose critical health literacy, public policy, and HIM perspectives to understand the COVID-19 infodemic and new opportunities for HIM in infodemic management.

Backstage of Eating Disorder-About the Biological Mechanisms behind the Symptoms of Anorexia Nervosa

Anorexia nervosa (AN) represents a disorder with the highest mortality rate among all psychiatric diseases, yet our understanding of its pathophysiological components continues to be fragmentary. This article reviews the current concepts regarding AN pathomechanisms that focus on the main biological aspects involving central and peripheral neurohormonal pathways, endocrine function, as well as the microbiome-gut-brain axis. It emerged from the unique complexity of constantly accumulating new discoveries, which hamper the ability to look at the disease in a more comprehensive way. The emphasis is placed on the mechanisms underlying the main symptoms and potential new directions that require further investigation in clinical settings.

Role of gut microbiota in brain function and stress-related pathology

Gut microbiota are responsible for a variety of metabolic activities including food digestion and production of biologically active substances. Moreover, several recent works, including our own, have also shown that gut microbiota play an important role not only in the development of brain function but also in the pathology of stress-related diseases and neurodevelopmental disorders. In this review, we focus on the interaction between gut microbes and the brain-gut axis and introduce some basic concepts and recent developments in this area of research.

Biogenic Amines: Signals Between Commensal Microbiota and Gut Physiology

There is increasing interest in the interactions among the gut microbiota, gut, and brain, which is often referred to as the "microbiota-gut-brain" axis. Biogenic amines including dopamine, norepinephrine, serotonin, and histamines are all generated by commensal gut microorganisms and are suggested to play roles as signaling molecules mediating the function of the "microbiota-gut-brain" axis. In addition, such amines generated in the gut have attracted attention in terms of possible clues into the etiologies of depression, anxiety, and even psychosis. This review covers the latest research related to the potential role of microbe-derived amines such as catecholamine, serotonin, histamine, as well as other trace amines, in modulating not only gut physiology but also brain function of the host. Further attention in this field can offer not only insight into expanding the fundamental roles and impacts of the human microbiome, but also further offer new therapeutic strategies for psychological disorders based on regulating the balance of resident bacteria.