Gut microbiome characteristics of comorbid generalized anxiety disorder and functional gastrointestinal disease: Correlation with alexithymia and personality traits

Medication use is associated with distinct microbial features in anxiety and depression

This study investigated the relationship between gut microbiota and neuropsychiatric disorders (NPDs), specifically anxiety disorder (ANXD) and/or major depressive disorder (MDD), as defined by Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV or V criteria. The study also examined the influence of medication use, particularly antidepressants and/or anxiolytics, classified through the Anatomical Therapeutic Chemical (ATC) Classification System, on the gut microbiota. Both 16S rRNA gene amplicon sequencing (16S) and shallow shotgun sequencing (WGS) were performed on DNA extracted from 666 fecal samples from the Tulsa-1000 and Neurocomputational Mechanisms of Affiliation and Personality Study Center for Biomedical Research Excellence (NeuroMAP CoBRE) cohorts. The results highlight the significant influence of medication use; antidepressant use is associated with significant differences in gut microbiota beta diversity and has a larger effect size than NPD diagnosis. Next, specific microbes were associated with ANXD and MDD, highlighting their potential for non-pharmacological intervention. Finally, the study demonstrated the capability of Random Forest classifiers to predict diagnoses of NPD and medication use from microbial profiles, suggesting a promising direction for the use of gut microbiota as biomarkers for NPD. Though the effect sizes were larger in females than males, similar trends emerged for both sexes. These findings encourage future research on the gut microbiota's role in NPD and its interactions with pharmacological treatments.

The Impact of Gut Microbiota on the Development of Anxiety Symptoms-A Narrative Review

The gut microbiota plays a key role in mental health, with growing evidence linking its composition to anxiety and depressive disorders. Research on this topic has expanded significantly in recent years. This review explores alterations in the gut microbiota of individuals with anxiety disorders and examines the potential therapeutic effects of probiotics. Background/Objectives: This review aims to analyze the alterations in gut microbiota composition in individuals with anxiety disorders and evaluate the potential therapeutic effects of probiotics in mitigating symptoms. By examining recent research, this study seeks to highlight the gut-brain connection and its implications for mental health interventions. Materials and Methods: A literature search was conducted in PubMed, Embase, CINAHL, and Google Scholar, focusing on studies investigating the relationship between gut microbiota and anxiety disorders, as well as the impact of probiotics on symptom severity. Results: The reviewed studies suggest that individuals with anxiety disorders often exhibit gut microbiota alterations, including reduced microbial diversity and a lower abundance of short-chain fatty acid-producing bacteria. Additionally, probiotics, particularly those from the Lactobacillus genus, may help alleviate anxiety symptoms by modulating gut microbiota composition. Conclusions: Gut dysbiosis appears to be closely linked to anxiety disorders, and probiotic interventions could represent a promising therapeutic avenue. However, further research is needed to clarify underlying mechanisms and optimize treatment strategies.

The role of the gut microbiome in disorders of gut-brain interaction

Disorders of Gut-Brain Interaction (DGBI) are widely prevalent and commonly encountered in gastroenterology practice. While several peripheral and central mechanisms have been implicated in the pathogenesis of DGBI, a recent body of work suggests an important role for the gut microbiome. In this review, we highlight how gut microbiota and their metabolites affect physiologic changes underlying symptoms in DGBI, with a particular focus on their mechanistic influence on GI transit, visceral sensitivity, intestinal barrier function and secretion, and CNS processing. This review emphasizes the complexity of local and distant effects of microbial metabolites on physiological function, influenced by factors such as metabolite concentration, duration of metabolite exposure, receptor location, host genetics, and underlying disease state. Large-scale in vitro work has elucidated interactions between host receptors and the microbial metabolome but there is a need for future research to integrate such preclinical findings with clinical studies. The development of novel, targeted therapeutic strategies for DGBI hinges on a deeper understanding of these metabolite-host interactions, offering exciting possibilities for the future of treatment of DGBI.

Resveratrol Ameliorates Chronic Stress in Kennel Dogs and Mice by Regulating Gut Microbiome and Metabolome Related to Tryptophan Metabolism

Chronic stress poses threats to the physical and psychological well-being of dogs. Resveratrol (Res) is a polyphenol with antidepressant properties and has rarely been studied in dogs. This study aimed to investigate the stress-relieving effects and underlying mechanism of Res in dogs. Dogs were fed a basal diet supplemented with Res for 35 days. The fecal microbiota of the dogs was cultured with Res in vitro. The results show that Res improved the stress-related behaviors and increased the serum levels of 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF), immunoglobulin A, and antioxidant capacity in dogs. Res downregulated the hormones of the hypothalamic-pituitary-adrenal axis. The abundance of butyric-producing bacteria, like Blautia, increased, while the growth of Fusobacterium related to gut inflammation was inhibited in the Res group. A higher content of fecal butyric acid was observed in the Res group. The metabolome indicated that Res increased the fecal and serum levels of tryptophan (Trp) and decreased the consumption of Trp by microorganisms. A chronic unpredictable mild stress mouse model was established, and Res was administered for 35 days. The results show that Res ameliorated the stress-related behavior and increased the levels of Trp and 5-HT in the whole brains of mice. The relative mRNA expression of genes associated with the tight junction protein, aryl hydrocarbon receptor, and Trp transporters in the colon were upregulated. In conclusion, Res could ameliorate canine stress by increasing 5-HT, BDNF, and the antioxidant capacity and improving the immune function and stress response, which was attributed to the role of Res in the restructuring of gut microbiota and the modulation of tryptophan metabolism.

Correlation between colonoscopy difficulty and personality traits: study protocol for a prospective, observational, multicentre study

BACKGROUND

Colonoscopy is widely used for screening and treatment of early colonic lesions and is critical for the early diagnosis of colorectal cancer. However, due to its invasive nature, colonoscopy can cause pain and discomfort for patients and is often associated with prolonged insertion times or failed attempts. Difficult colonoscopy is characterised by a caecal insertion time greater than 10 min, multiple insertion attempts or failed insertion, with an incidence rate of approximately 25%. Studies have shown that objective factors such as gender, age, body mass index, bowel preparation quality and history of abdominal or pelvic surgery can make colonoscopy difficult. Integrating clinical evidence and the established impact of personality traits on certain gastrointestinal conditions, a patient's personality traits and emotional and psychological states may also influence caecal insertion time during colonoscopy. Currently, no studies have investigated the predictive role of patients' personality on the difficulty of colonoscopy. This study used the Chinese-Language 44-Item Big Five Personality Inventory to assess patients' personality traits, aiming to observe whether there is a correlation between the degree of difficulty of colonoscopy and any of the personality traits.

METHODS AND ANALYSIS

This is a prospective, observational, multicentre study. Patients undergoing colonoscopy will be required to complete the Big Five Inventory, the General Anxiety Disorder 7-item scale and the Patient Health Questionnaire 9-item Depression Scale before colonoscopy. During the colonoscopy, the endoscopist will record the primary endpoint of caecal insertion time. The Boston Bowel Preparation Scale, patients pain scores and willingness to undergo a subsequent colonoscopy will be recorded as the secondary endpoints. The study plans to enrol a total of 322 patients. Survival analysis will be used to examine the correlation between colonoscopy difficulty and the Big Five personality traits.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of the Peking Union Medical College Hospital (No. K2128). All participants in this study will provide written informed consent. The results of this study will be published in an open-access way. There is no independent data monitoring committee because this is an observational and low-risk study.

TRIAL REGISTRATION NUMBER

NCT05584423.

Probing the oral-brain connection: oral microbiome patterns in a large community cohort with anxiety, depression, and trauma symptoms, and periodontal outcomes

The role of the oral microbiome in mental health has recently been appreciated within the proposed oral-brain axis. This study examined the structure and composition of the salivary microbiome in a large-scale population-based cohort of individuals reporting mental health symptoms (n = 306) compared to mentally healthy controls (n = 164) using 16S rRNA sequencing. Mental health symptoms were evaluated using validated questionnaires and included depression, anxiety, and posttraumatic stress disorder (PTSD), with accompanying periodontal outcomes. Participants also indicated current or previous diagnoses of anxiety, depression, periodontitis, and gingivitis. Mental and periodontal health variables influenced the overall composition of the oral microbiome. PTSD symptoms correlated with a lower clr-transformed relative abundance of Haemophilus sputorum and a higher clr-transformed relative abundance of Prevotella histicola. The clr-transformed relative abundance of P. histicola was also positively associated with depressive scores and negatively associated with psychological quality of life. Anxiety disorder diagnosis was associated with a lower clr-transformed relative abundance of Neisseria elongate and a higher clr-transformed relative abundance of Oribacterium asaccharolyticum. A higher clr-transformed relative abundance of Shuttleworthia and lower clr-transformed relative abundance of Capnocytophaga were evident in those who reported a clinical periodontitis diagnosis. Higher Eggerthia and lower Haemophilus parainfluenzae clr-transformed relative abundances were associated with reported clinical periodontitis diagnoses and psychotherapeutic efficacy. Functional prediction analysis revealed a potential role for tryptophan metabolism/degradation in the oral-brain axis, which was confirmed by lower plasma serotonin levels across symptomatic groups. This study sheds light on the intricate interplay between oral microbiota, periodontal and mental health outcomes, and a potential role for tryptophan metabolism in the proposed oral-brain axis, emphasizing the need for further exploration to pave the way for novel therapeutic interventions and predicting therapeutic response.

Medication Use is Associated with Distinct Microbial Features in Anxiety and Depression

This study investigated the relationship between gut microbiota and neuropsychiatric disorders (NPDs), specifically anxiety disorder (ANXD) and/or major depressive disorder (MDD), as defined by DSM-IV or V criteria. The study also examined the influence of medication use, particularly antidepressants and/or anxiolytics, classified through the Anatomical Therapeutic Chemical (ATC) Classification System, on the gut microbiota. Both 16S rRNA gene amplicon sequencing and shallow shotgun sequencing were performed on DNA extracted from 666 fecal samples from the Tulsa-1000 and NeuroMAP CoBRE cohorts. The results highlight the significant influence of medication use; antidepressant use is associated with significant differences in gut microbiota beta diversity and has a larger effect size than NPD diagnosis. Next, specific microbes were associated with ANXD and MDD, highlighting their potential for non-pharmacological intervention. Finally, the study demonstrated the capability of Random Forest classifiers to predict diagnoses of NPD and medication use from microbial profiles, suggesting a promising direction for the use of gut microbiota as biomarkers for NPD. The findings suggest that future research on the gut microbiota's role in NPD and its interactions with pharmacological treatments are needed.

A mediation analysis of the role of total free fatty acids on pertinence of gut microbiota composition and cognitive function in late life depression

BACKGROUND

Extensive evidence demonstrates correlations among gut microbiota, lipid metabolism and cognitive function. However, there is still a lack of researches in the field of late-life depression (LLD). This research targeted at investigating the relationship among gut microbiota, lipid metabolism indexes, such as total free fatty acids (FFAs), and cognitive functions in LLD.

METHODS

Twenty-nine LLD patients from the Cognitive Outcome Cohort Study of Depression in Elderly were included. Cognitive functions were estimated through the Chinese version of Montreal Cognitive Assessment (MoCA). Blood samples were collected to evaluate serum lipid metabolism parameters. Fecal samples were evaluated for gut microbiota determination via 16S rRNA sequencing. Spearman correlation, linear regression and mediation analysis were utilized to explore relationship among gut microbiota, lipid metabolism and cognitive function in LLD patients.

RESULTS

Spearman correlation analysis revealed significant correlations among Akkermansia abundance, total Free Fatty Acids (FFAs) and MoCA scores (P < 0.05). Multiple regression indicated Akkermansia and total FFAs significantly predicted MoCA scores (P < 0.05). Mediation analysis demonstrated that the correlation between decreased Akkermansia relative abundance and cognitive decline in LLD patients was partially mediated by total FFAs (Bootstrap 95%CI: 0.023-0.557), accounting for 43.0% of the relative effect.

CONCLUSION

These findings suggested a significant relationship between cognitive functions in LLD and Akkermansia, as well as total FFAs. Total FFAs partially mediated the relationship between Akkermansia and cognitive functions. These results contributed to understanding the gut microbial-host lipid metabolism axis in the cognitive function of LLD.

Determining Risk Factors for Functional Gastrointestinal Disorder among Muslim University Students in Indonesia

Functional gastrointestinal disorders (FGIDs) are disorders of the gastrointestinal tract without a clear structural or biochemical cause. FGIDs can interfere with a person's daily life. Several psychological conditions can cause FGIDs as psychosomatic disorders. Five factors are thought to affect a person's FGID condition, namely Generalized Anxiety Disorder (GAD), life satisfaction, perceived stress, perceived social support, and religiosity. This study aims to analyze the determinants of FGID conditions and the role of religiosity as a moderator variable. This study used a quantitative approach with correlation methods. A total of 383 Indonesian Muslim students participated as respondents in this study. The instruments used in this study were the life satisfaction scale, perceived stress-10 scale, perceived social support multidimensional scale, GAD-7, Duke University Religion Index, and FGID scale. Research data were collected online from research respondents. Furthermore, the research data analysis technique used was partial structural equation modeling (PLS-SEM). The results of this study indicate that GAD, life satisfaction, and perceived stress are determinants of FGID conditions in Indonesian Muslim students. The results also show that religiosity acts as a moderator variable in the influence of GAD conditions on a person's FGID condition.

Microbiota in Autism Spectrum Disorder: A Systematic Review

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by several core symptoms: restricted interests, communication difficulties, and impaired social interactions. Many ASD children experience gastrointestinal functional disorders, impacting their well-being. Emerging evidence suggests that a gut microbiota imbalance may exacerbate core and gastrointestinal symptoms. Our review assesses the gut microbiota in children with ASD and interventions targeting microbiota modulation. The analysis of forty-four studies (meta-analyses, reviews, original research) reveals insights into the gut microbiota-ASD relationship. While specific microbiota alterations are mixed, some trends emerge. ASD children exhibit increased Firmicutes (36-81%) and Pseudomonadota (78%) and decreased Bacteroidetes (56%). The Bacteroidetes to Firmicutes ratio tends to be lower (56%) compared to children without ASD, which correlates with behavioral and gastrointestinal abnormalities. Probiotics, particularly Lactobacillus, Bifidobacterium, and Streptococcus strains, show promise in alleviating behavioral and gastrointestinal symptoms (66%). Microbiota transfer therapy (MTT) seems to have lasting benefits for the microbiota and symptoms in one longitudinal study. Prebiotics can potentially help with gastrointestinal and behavioral issues, needing further research for conclusive efficacy due to different interventions being used. This review highlights the gut microbiota-ASD interplay, offering potential therapeutic avenues for the gut-brain axis. However, study heterogeneity, small sample sizes, and methodological variations emphasize the need for comprehensive, standardized research. Future investigations may unveil complex mechanisms linking the gut microbiota to ASD, ultimately enhancing the quality of life for affected individuals.

Reproducible microbiome composition signatures of anxiety and depressive symptoms

The gut microbiome is a significant contributor to mental health, with growing evidence linking its composition to anxiety and depressive disorders. Gut microbiome composition is associated with signs of anxiety and depression both in clinically diagnosed mood disorders and subclinically in the general population and may be influenced by dietary fibre intake and the presence of chronic pain. We provide an update of current evidence on the role of gut microbiome composition in depressive and anxiety disorders or symptoms by reviewing available studies. Analysing data from three independent cohorts (osteoarthritis 1 (OA1); n = 46, osteoarthritis 2 (OA2); n = 58, and healthy controls (CON); n = 67), we identified microbial composition signatures of anxiety and depressive symptoms at genus level and cross-validated our findings performing meta-analyses of our results with results from previously published studies. The genera Bifidobacterium (fixed-effect beta (95% CI) = -0.22 (-0.34, -0.10), p = 3.90e-04) and Lachnospiraceae NK4A136 group (fixed-effect beta (95% CI) = -0.09 (-0.13, -0.05), p = 2.53e-06) were found to be the best predictors of anxiety and depressive symptoms, respectively, across our three cohorts and published literature taking into account demographic and lifestyle covariates, such as fibre intake. The association with anxiety was robust in accounting for heterogeneity between cohorts and supports previous observations of the potential prophylactic effect of Bifidobacterium against anxiety symptoms.

Efficacy of Cognitive Behavioral Therapy With Local Wisdom and Web-Based Counseling on Generalized Anxiety Disorders and Functional Gastrointestinal Disorders in Adolescent College Girls: Protocol for a Randomized Controlled Trial

BACKGROUND

The high academic demands experienced by students will often have an impact on the quality of their mental and physical health. The most common health problems reported are gastrointestinal disorders. This condition tends to manifest in the emergence of generalized anxiety disorders (GADs) and reduces the quality of life and productivity. The population that experiences this disorder the most is female adolescents, and this condition occurs in both South African and Indonesian populations. The use of drugs, especially benzodiazepines, often causes psychological conditions as side effects. For this reason, it is necessary to have a solution in the form of a targeted and efficient approach to reduce psychological symptoms that arise from functional gastrointestinal disorders (FGIDs) in the form of anxiety.

OBJECTIVE

The purpose of this study is to produce and implement a counseling intervention model to assist female students with GADs caused by FGID factors using an approach combining cognitive behavioral therapy (CBT), web-based counseling, and local wisdom in Indonesian and South African populations.

METHODS

The research subjects will comprise 118 female adolescent students from Indonesia and 118 female adolescent students from South Africa, making a total sample of 236 participants, and the study will use a prospective, parallel randomized controlled trial design. The recruitment process will begin in July 2023, and the trial will begin in August 2023. The posttest assessment data gathering will take place by November 2023. Questionnaires that will be used in this study include the Functional Gastrointestinal Disorder Checklist (FGI-Checklist) to collect data related to FGIDs and the Generalized Anxiety Disorder 7-item (GAD-7) to measure the anxiety conditions experienced by respondents.

RESULTS

By adopting the intention-to-treat principle, there will be significant mean changes in GAD scores and FGID scores after exposure to this combined approach in the Indonesian and South African populations. Implementing this comprehensive intervention will improve the students' psychological symptoms related to FGIDs and ultimately enhance their overall well-being.

CONCLUSIONS

This study will develop and implement a model of counseling intervention for female students with GADs obtained from FGIDs using a combination approach to CBT, web-based counseling, and local wisdom in both the Indonesian and South African populations. The trial findings will contribute to our understanding of the effects of CBT combined with local wisdom and web-based counseling approaches that mental health counselors can use to treat GAD-affected adolescent girls who have FGIDs.

TRIAL REGISTRATION

UMIN Clinical Trial Registry UMIN000051386; https://tinyurl.com/yjwz8kht.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/50316.

Association between gut microbiota and psychiatric disorders: a systematic review

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.