Metabolic disturbances associated with antipsychotic drug treatment in patients with schizophrenia: State-of-the-art and future perspectives

[Metabolic adverse drug reactions related to psychotropic drugs]

Metabolic adverse drug reactions (mADR) related to psychotropic drugs have significant health-related effects including weight gain, impaired glucose tolerance, diabetes mellitus and dyslipidemia as well as economic relevance. Nearly all antipsychotics (AP) and many antidepressants (AD) and mood stabilisers may induce weight gain. Weight development in the first weeks or months after the beginning of the therapy is the strongest predictor for weight gain related to AP and AD. The most important risk factors for mADR are antagonistic effects at H1-, 5-HT2C- und M3-receptors and antidopaminergic effects. However, several other systems are also relevant. Systematic monitoring of metabolic parameters is recommended in all patients treated with substances that are associated with an increased risk of mADR. Lifestyle modification, dietary measures, exercise therapy, dose reduction, change and discontinuation of the substance, and additional treatment with metformin and topiramate are evidence-based treatment options for AP-associated weight gain. GLP-1 receptor agonists such as liraglutide are also promising.

Relationship between stable smoking behavior and cognitive function in male schizophrenia patients

OBJECTIVE

To explore the relationship between stable smoking behavior and cognitive function in male schizophrenia patients.

METHODS

A simple random sampling method is applied to select 120 patients with schizophrenia admitted to a hospital from August 2020 to December 2022 as the subjects. They are divided into two groups based on whether they smoked or not. Their cognitive function is evaluated using the Stroop test (SWCT), continuous task test (CPT), and Chinese version of the Schizophrenic Cognitive Function Battery Test (MCCB). The Spearman correlation analysis is applied to verify the correlation between smoking behavior and SWCT, CPT, and MCCB in patients. Additionally, the Fagerstrom Nicotine Dependence Scale (FTND) is used to evaluate the nicotine dependence degree in smoking group patients. Pearson correlation analysis verifies the correlation between nicotine dependence and SWCT, CPT, MCCB in smoking group patients.

RESULTS

Among 120 patients include in this study, 3 have symptoms during the trial period, and 1 patient has an error in filling out the questionnaire, all of which are excluded. Finally, 116 valid documents are collected, with an effective recovery rate of 96.67%. According to the SWCT test results, the number of single word errors, single word time, double word errors, and double word time in the smoking group exceed the non-smoking group (P < 0.05). According to the CPT test results, the number of correct reactions in the smoking group is below the non-smoking group. The correct average reaction time, error rate of interference items, and error rate of ineffective items exceed the non-smoking group (P < 0.05). According to the MCCB test results, the scores of connectivity, visual spatial memory, and continuous operation test in the smoking group are below the non-smoking group (P < 0.05). The Spearman correlation analysis results show that stable smoking behavior in male schizophrenia patients is positively correlated with the number of single word errors, double word errors, double word time, correct mean reaction time, interference item error rate, and invalid item error rate (r = 0.216-0.524, P < 0.05). It is also positively correlated with the number of correct reactions, immediate memory, language function, delayed memory, MCCB connectivity, visual spatial memory, and continuous operation (r = -0.212-0.356, P < 0.05). The Pearson correlation analysis results show that the nicotine dependence degree in stable male schizophrenia patients is negatively correlated with monochromatic error count, immediate memory, visual span, attention, and MCCB scores (r = -0.321-0.930, P < 0.05).

CONCLUSION

Smoking in male schizophrenic patients may have impacts on their cognitive function. This impact worsens as the patient's nicotine dependence increases, especially on their memory function. Effective measures should be taken in clinical practice to correct patients' smoking behavior, reduce their nicotine dependence, and improve their cognitive function.

Olanzapine, but not haloperidol, exerts pronounced acute metabolic effects in the methylazoxymethanol rat model

AIM

Widely used second-generation antipsychotics are associated with adverse metabolic effects, contributing to increased cardiovascular mortality. To develop strategies to prevent or treat adverse metabolic effects, preclinical models have a clear role in uncovering underlying molecular mechanisms. However, with few exceptions, preclinical studies have been performed in healthy animals, neglecting the contribution of dysmetabolic features inherent to psychotic disorders.

METHODS

In this study, methylazoxymethanol acetate (MAM) was prenatally administered to pregnant Sprague-Dawley rats at gestational day 17 to induce a well-validated neurodevelopmental model of schizophrenia mimicking its assumed pathogenesis with persistent phenotype. Against this background, the dysmetabolic effects of acute treatment with olanzapine and haloperidol were examined in female rats.

RESULTS

Prenatally MAM-exposed animals exhibited several metabolic features, including lipid disturbances. Half of the MAM rats exposed to olanzapine had pronounced serum lipid profile alteration compared to non-MAM controls, interpreted as a reflection of a delicate MAM-induced metabolic balance disrupted by olanzapine. In accordance with the drugs' clinical metabolic profiles, olanzapine-associated dysmetabolic effects were more pronounced than haloperidol-associated dysmetabolic effects in non-MAM rats and rats exposed to MAM.

CONCLUSION

Our results demonstrate metabolic vulnerability in female prenatally MAM-exposed rats, indicating that findings from healthy animals likely provide an underestimated impression of metabolic dysfunction associated with antipsychotics. In the context of metabolic disturbances, neurodevelopmental models possess a relevant background, and the search for adequate animal models should receive more attention within the field of experimental psychopharmacology.

Modulation of Leucine Sensors to Mitigate Antipsychotics-Induced Metabolic Syndrome: A New Vista

Second-generation antipsychotics (SGAs) are currently the mainstay in the pharmacotherapy of some psychiatric disorders, which have improved the quality of life of millions of patients globally. A broad spectrum of activity and diminished liabilities of extrapyramidal side effects have made SGAs better alternatives compared to first-generation antipsychotics. Nevertheless, they display a complex profile of activity by affecting an array of biological targets and, as a result, are associated with a constellation of metabolic abnormalities such as hyperglycemia, dyslipidemia, weight gain, and cardiovascular problems. The SGAs-induced metabolic syndrome's exact mechanism has remained nebulous, but some evidence points the finger at mTOR signaling. In this viewpoint, we propose potential strategies to prevent or alleviate the SGA-induced metabolic adverse effects by modulating the activity of the leucine sensors, Sestrins.

Antipsychotic-Induced Weight Gain in Severe Mental Illness: Risk Factors and Special Considerations

PURPOSE OF REVIEW

Weight gain is a disconcerting issue experienced by patients treated with antipsychotics (APs). This review summarizes current knowledge on the prevalence, etiology, and risk factors for antipsychotic-induced weight gain (AIWG), and evidence for interventions, including special considerations.

RECENT FINDINGS

Predisposing risk factors for AIWG include lack of prior AP exposure, sex, and age. AP dose and duration of exposure are additional treatment-related factors that may contribute to this issue. Among current approaches to target AIWG, metformin has the most evidence to support its use, and this is increasingly reflected in clinical guidelines. While lifestyle approaches are recommended, cost-effectiveness and scalability represent limitations. More research is needed to identify newer treatment options and inform clinical recommendations for AIWG. Concerns around scope of practice in psychiatry to address AIWG and related comorbidities will require enhanced training opportunities and interdisciplinary collaborations, as well as updated position statements/practice guidelines emphasizing prevention.

Antipsychotic-Induced Metabolic Syndrome: A Review

Schizophrenia, a serious psychiatric disorder, is among the top 10 global causes of disability and affects nearly 1% of the world population. Antipsychotics constitute the best treatment for patients with schizophrenia, however, this treatment class carries a high risk of metabolic syndrome, including lipid abnormalities. Indeed, the risk of metabolic syndrome would be increased in the population with schizophrenia compared to the general population. The objective is to summarize the prevalence, the mechanisms, and the potential treatments of antipsychotic-induced metabolic syndrome. This is a narrative review of the literature. We searched the electronic database Medline, accessed through PubMed, to find studies that investigated the prevalence and treatments of metabolic syndrome in the adult population using antipsychotics. The prevalence of metabolic syndrome in patients treated with antipsychotics ranges from 37% to 63%. Antipsychotic iatrogenic effects include weight gain/increased waist circumference, dyslipidemia, insulin resistance/type 2 diabetes, and hypertension. Clozapine and olanzapine are reported to precipitate the onset of metabolic syndrome features. In patients with metabolic syndrome, an antipsychotic with less metabolic side effects such as lurasidone, lumateperone, ziprasidone, and aripiprazole should be prioritized. Unlike medications, aerobic exercise and dietetic counseling were found to be efficient as the nonpharmacologic treatment of antipsychotic-induced metabolic syndrome. Few pharmacological treatments were proven effective against weight gain in this patient population. The risk of metabolic syndrome induced by antipsychotics should be early recognized and closely monitored. Primary and secondary prevention of metabolic syndrome or onset of its feature might help reduce the risk of death for patients using antipsychotics.

Gender differences in prevalence and associated factors of metabolic syndrome in first-treatment and drug-naïve schizophrenia patients

BACKGROUND

Metabolic syndromes (MetS) are clinical syndromes involving multiple pathological states with distinct gender-specific clinical patterns. As a serious disorder associated with psychiatric conditions, the prevalence of MetS is significantly higher in the population with schizophrenia (Sch). The aim of this paper is to report gender differences in the prevalence, associated factors and severity-related factors of MetS in first-treatment and drug-naïve (FTDN) patients with Sch.

METHODS

A total of 668 patients with FTDN Sch were included in this study. We collected socio-demographic and general clinical information on the target population, measured and evaluated common metabolic parameters and routine biochemical indicators, and assessed the severity of psychiatric symptoms using Positive and Negative Symptom Scale (PANSS).

RESULTS

In the target group, the prevalence of MetS was significantly higher in women (13.44%, 57/424) than in men (6.56%, 16/244). In the males, waist circumference (WC), fasting blood glucose (FBG), diastolic blood pressure (DBP), and triglycerides (TG) were risk factors for MetS, while systolic blood pressure (SBP), TG, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and platelet (PLT) were risk factors for the females. More importantly, for the females, we found that age, LDL-C, PANSS scores and blood creatinine (CRE) were risk factors for higher MetS scores, while onset age and hemoglobin (HGB) were protective factors.

CONCLUSION

There are significant gender differences in the prevalence of MetS and its factors among patients with FTDN Sch. The prevalence of MetS is higher and the factors that influence MetS are more numerous and extensive in females. The mechanisms of this difference need further research and clinical intervention strategies should be formulated with gender differences.

Serum Metabolic Profile in Schizophrenia Patients With Antipsychotic-Induced Constipation and Its relationship With Gut Microbiome

BACKGROUND AND HYPOTHESIS

Antipsychotics (APs), the cornerstone of schizophrenia treatment, confer a relatively high risk of constipation. However, the mechanisms underpinning AP-induced constipation are poorly understood. Thus, we hypothesized that (1) schizophrenia patients with AP-induced constipation have distinct metabolic patterns; (2) there is more than one mechanism at play in producing this adverse drug effect; and (3) AP-associated changes in the gut microbiome are related to the altered metabolic profiles.

STUDY DESIGN

Eighty-eight schizophrenia patients, including 44 with constipation (C) and 44 matched patients without constipation (NC), were enrolled in this study. Constipation was diagnosed by Rome IV criteria for constipation and colonic transit time using radiopaque markers (ROMs) while severity was evaluated with the Bristol Stool Form Scale (BSS) and Constipation Assessment Scale (CAS). Fasting blood samples were drawn from all participants and were subjected to non-targeted liquid chromatography-mass spectrometry (LC-MS) metabolomic analysis.

STUDY RESULTS

Eleven metabolites were significantly altered in AP-induced constipation which primarily disturbed sphingolipid metabolism, choline metabolism, and sphingolipid signaling pathway (P value < .05, FDR < 0.05). In the C group, changes in the gut bacteria showed a certain degree of correlation with 2 of the significantly altered serum metabolites and were associated with alterations in choline metabolism.

CONCLUSIONS

Our findings indicated that there were disturbances in distinct metabolic pathways that were associated with AP-induced constipation. In addition, this study presents evidence of a link between alterations in the gut microbiome and host metabolism which provides additional mechanistic insights on AP-induced constipation.

Obesity, antioxidants and negative symptom improvement in first-episode schizophrenia patients treated with risperidone

Negative symptoms remain a main therapeutic challenge in patients with schizophrenia (SZ). Obesity is associated with more severe negative symptoms after the first episode of psychosis. Oxidative stress caused by an impaired antioxidant defense system is involved in the pathophysiology of SZ. Yet, it is unclear regarding the role of obesity and antioxidants in negative symptom improvements in SZ. Therefore, this longitudinal study was designed to assess the impact of obesity on antioxidant defenses and negative symptom improvements in first-episode SZ patients. A total of 241 medication-naive and first-episode patients with SZ were treated with risperidone for 3 months. Outcome measures including symptoms, body weight, and total antioxidant status (TAS) levels were measured at baseline and the end of the third month. We found that after 12 weeks of treatment with risperidone, the body weight increased and clinical symptoms significantly improved. Baseline body mass index (BMI) was negatively correlated with negative symptom improvement after treatment and an increase in TAS was negatively associated with an increase in BMI only in the high BMI group. More importantly, the TAS × BMI interaction at baseline was an independent predictor of negative symptom improvement. Our longitudinal study indicates that the improvement in negative symptoms by risperidone was associated with baseline BMI and TAS levels in patients with SZ. Baseline BMI and TAS may be a predictor for negative improvement in SZ patients after risperidone treatment.

Functional Characterization of Six SLCO1B1 (OATP1B1) Variants Observed in Finnish Individuals with a Psychotic Disorder

Variants in the SLCO1B1 (solute carrier organic anion transporter family member 1B1) gene encoding the OATP1B1 (organic anion transporting polypeptide 1B1) protein are associated with altered transporter function that can predispose patients to adverse drug effects with statin treatment. We explored the effect of six rare SLCO1B1 single nucleotide variants (SNVs) occurring in Finnish individuals with a psychotic disorder on expression and functionality of the OATP1B1 protein. The SUPER-Finland study has performed exome sequencing on 9381 individuals with at least one psychotic episode during their lifetime. SLCO1B1 SNVs were annotated with PHRED-scaled combined annotation-dependent (CADD) scores and the Ensembl variant effect predictor. In vitro functionality studies were conducted for the SNVs with a PHRED-scaled CADD score of >10 and predicted to be missense. To estimate possible changes in transport activity caused by the variants, transport of 2',7'-dichlorofluorescein (DCF) in OATP1B1-expressing HEK293 cells was measured. According to the findings, additional tests with rosuvastatin and estrone sulfate were conducted. The amount of OATP1B1 in crude membrane fractions was quantified using a liquid chromatography tandem mass spectrometry-based quantitative targeted absolute proteomics analysis. Six rare missense variants of SLCO1B1 were identified in the study population, located in transmembrane helix 3: c.317T>C (p.106I>T), intracellular loop 2: c.629G>T (p.210G>V), c.633A>G (p.211I>M), c.639T>A (p.213N>L), transmembrane helix 6: 820A>G (p.274I>V), and the C-terminal end: 2005A>C (p.669N>H). Of these variants, SLCO1B1 c.629G>T (p.210G>V) resulted in the loss of in vitro function, abolishing the uptake of DCF, estrone sulfate, and rosuvastatin and reducing the membrane protein expression to 31% of reference OATP1B1. Of the six rare missense variants, SLCO1B1 c.629G>T (p.210G>V) causes a loss of function of OATP1B1 transport in vitro and severely decreases membrane protein abundance. Carriers of SLCO1B1 c.629G>T might be susceptible to altered pharmacokinetics of OATP1B1 substrate drugs and might have increased likelihood of adverse drug effects such as statin-associated musculoskeletal symptoms.

Impact of SGLT2 inhibitors on metabolic status in patients with psychiatric disorders undergoing treatment with second‑generation antipsychotics (Review)

Metabolic dysfunctions have been reported in patients diagnosed with severe mental illnesses who are undergoing treatment with antipsychotics, especially second-generation agents. Sodium-glucose co-transporter 2 inhibitors (SGLT2Is) and glucagon-like peptide receptor agonists are new-generation antidiabetics whose favourable effects in the treatment of diabetes mellitus in the non-psychiatric population may raise interest in their use in patients presenting with severe mental illnesses and metabolic comorbidities possibly related to the use of antipsychotics. The objectives of this review were to investigate the evidence to support the use of SGLT2Is in this population and to find the most important aspects that need to be addressed by future research. A total of one preclinical trial, two guideline-format clinical recommendations, one systematic review and one case report were found, and their conclusions were analysed. The results support the following conclusions: i) SGLT2Is may be combined with metformin in selected cases of type 2 diabetes mellitus in the context of antipsychotic treatment, as they have been associated with favourable metabolic effects; and ii) data for the recommendation of SGLT2Is as second-line treatment in patients with diabetes mellitus who are also treated with olanzapine or clozapine are supported by very limited preclinical and clinical evidence. Further high-quality, large-scale research is needed in the field of the management of metabolic dysfunctions in patients with severe psychiatric illnesses who undergo treatment with second-generation antipsychotics.

Pharmacological Strategies for Bipolar Disorders in Acute Phases and Chronic Management with a Special Focus on Lithium, Valproic Acid, and Atypical Antipsychotics

Bipolar disorders (BDs) are a heterogeneous group of severe affective disorders generally described by the alternation of (hypo)manic, depressive, and mixed phases, with euthymic intervals of variable duration. BDs are burdened with high psychiatric and physical comorbidity, increased suicide risk and reduced life expectancy. In addition, BDs can progress into complicated forms (e.g., mixed states, rapid/irregular cycling), which are more difficult to treat and often require personalized pharmacological combinations. Mood stabilizers, particularly Lithium and Valproic acid (VPA), still represent the cornerstones of both acute and chronic pharmacotherapies of BDs. Lithium is the gold standard in BD-I and BDII with typical features, while VPA seems more effective for atypical forms (e.g., mixed-prevalence and rapid-cycling). However, despite appropriate mood stabilization, many patients show residual symptoms, and more than a half recur within 1-2 years, highlighting the need of additional strategies. Among these, the association of atypical antipsychotics (AAPs) with mood stabilizers is recurrent in the treatment of acute phases, but it is also being growingly explored in the maintenance pharmacotherapy. These combinations are clinically more aggressive and often needed in the acute phases, whereas simplifying pharmacotherapies to mood stabilizers only is preferable in the long-term, whenever possible. When mood stabilizers are not enough for maintenance treatment, Quetiapine and, less consistently, Aripiprazole have been proposed as the most advisable adjunctive strategies, for their safety and tolerability profiles. However, in view of the increased risk of serious adverse effects, a careful patient-centered balance between costs and benefits is mandatory.

Multi-omics analysis identifies rare variation in leptin/PPAR gene sets and hypermethylation of ABCG1 contribute to antipsychotics-induced metabolic syndromes

Antipsychotic-induced metabolic syndrome (APs-induced Mets) is the most common adverse drug reaction, which affects more than 60% of the psychiatric patients. Although the etiology of APs-induced Mets has been extensively investigated, there is a lack of integrated analysis of the genetic and epigenetic factors. In this study, we performed genome-wide, whole-exome sequencing (WES) and epigenome-wide association studies in schizophrenia (SCZ) patients with or without APs-induced Mets to find the underlying mechanisms, followed by in vitro and in vivo functional validations. By population-based omics analysis, we revealed that rare functional variants across in the leptin and peroxisome proliferator-activated receptors (PPARs) gene sets were imbalanced with rare functional variants across the APs-induced Mets and Non-Mets cohort. Besides, we discovered that APs-induced Mets are hypermethylated in ABCG1 (chr21:43642166-43642366, adjusted P < 0.05) than Non-Mets, and hypermethylation of this area was associated with higher TC (total cholesterol) and TG (triglycerides) levels in HepG2 cells. Candidate genes from omics studies were furtherly screened in C. elegans and 17 gene have been verified to associated with olanzapine (OLA) induced fat deposit. Among them, several genes were expressed differentially in Mets cohort and APs-induced in vitro/in vivo models compared to controls, demonstrating the validity of omics study. Overexpression one of the most significant gene, PTPN11, exhibited compromised glucose responses and insulin resistance. Pharmacologic inhibition of PTPN11 protected HepG2 cell from APs-induced insulin resistance. These findings provide important insights into our understanding of the mechanism of the APs-induced Mets.

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction

The high prevalence of metabolic syndrome in persons with schizophrenia has spurred investigational efforts to study the mechanism beneath its pathophysiology. Early psychosis dysfunction is present across multiple organ systems. On this account, schizophrenia may be a multisystem disorder in which one organ system is predominantly affected and where other organ systems are also concurrently involved. Growing evidence of the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, such as an association with cognitive dysfunction, altered autonomic nervous system regulation, desynchrony in the resting-state default mode network, and shared genetic liability, suggest that metabolic syndrome and schizophrenia are connected via common pathways that are central to schizophrenia pathogenesis, which may be underpinned by oxytocin system dysfunction. Oxytocin, a hormone that involves in the mechanisms of food intake and metabolic homeostasis, may partly explain this piece of the puzzle in the mechanism underlying this association. Given its prosocial and anorexigenic properties, oxytocin has been administered intranasally to investigate its therapeutic potential in schizophrenia and obesity. Although the pathophysiology and mechanisms of oxytocinergic dysfunction in metabolic syndrome and schizophrenia are both complex and it is still too early to draw a conclusion upon, oxytocinergic dysfunction may yield a new mechanistic insight into schizophrenia pathogenesis and treatment.

The pharmacological treatment of schizophrenia: How far have we come?

Schizophrenia is a chronic and often severe mental disorder for which antipsychotic drugs are the cornerstone of treatment. Although the essential mechanism of action of these drugs has not changed much since they were first discovered in the 1950s, there have been numerous advances in the context in which these drugs are prescribed, as well as in the considerations for their optimal use. In this review, we summarize five selected issues in which the psychopharmacological treatment of schizophrenia has most evolved. Namely, these are the shift of outcomes of interest from symptoms to recovery, the development of stratified approaches to select the most appropriate treatment for each individual, the recognition of treatment nonadherence as a critical factor determining outcomes, the recommendations for maintenance treatment, and, finally, the promise of new antipsychotic compounds that innovate in their mechanisms of action, improving efficacy/safety profiles. Finally, we discuss how some of these advances have already delivered to improved outcomes in the real world, whereas others have demonstrated efficacy under optimal circumstances yet have not been translated into better outcomes in the community. Thus, the road ahead includes both identifying novel treatments that engage the psychopathology of the illness and improve the efficacy/tolerability profile of currently available agents, as well as developing interventions that mitigate the barriers for the use of novel interventions, some of them already existing, in the real world.

Mental and Body Health: The Association between Psychological Factors, Overweight, and Blood Pressure in Young Adults

Comorbidity between cardiometabolic risk factors and major mental health disorders is a public health concern. The close interconnection between the mental and physical aspects of health precludes considering each condition separately. Accordingly, this study sought to explore the interrelationships between psychological factors, overweight, and blood pressure in young adults. One hundred and forty-five young adults participated in the study and were classified according to two independent characteristics: weight condition (normal weight, overweight) and blood pressure (low blood pressure, high blood pressure). Anxiety, depression, and emotional dysregulation were assessed. The results confirmed certain associations, highlighting how cardiometabolic risk factors, such as blood pressure and body mass index, were associated in different ways with mental health, although an interaction between the variables was not reported. In particular, a relationship between body mass index and depression and between anxiety and blood pressure was detected.

The schizophrenia and gut microbiota: A bibliometric and visual analysis

BACKGROUND

Many studies have explored the link between the gut microbiota and schizophrenia. To date, there have been no bibliometric analyses to summarize the association between the gut microbiota and schizophrenia. We aimed to conduct a bibliometric study of this association to determine the current status and areas for advancement in this field.

MATERIALS AND METHODS

Publications related to the gut microbiota and schizophrenia were retrieved from the Web of Science Core Collection (WoSCC). The WoSCC literature analysis wire and VOSviewer 1.6.16 were used to conduct the analysis.

RESULTS

In total, 162 publications were included in our study. The publications generally showed an upward trend from 2014. A total of 873 authors from 355 organizations and 40 countries/regions contributed to this field. The leading authors were Timothy Dinan, John F Cryan, and Emily Severance. The leading institutions were Johns Hopkins University, the University College Cork, and the University of Toronto. The most productive countries were the United States (US), China, and Canada. In total, 95 journals contributed to this field. Among them, the top three productive journals were Schizophrenia Research, Progress in Neuro Psychopharmacology Biological Psychiatry, and Frontiers in Psychiatry. The important keywords in the clusters were gut microbiome, bipolar disorder, schizophrenia, antipsychotics, weight gain, metabolic syndrome, gut-brain axis, autism, depression, inflammation, and brain.

CONCLUSION

The main research hotspots involving the connection between schizophrenia and the gut microbiota were the characteristics of the microbiota composition in schizophrenia patients, the gut-brain axis, and microbial-based interventions for schizophrenia. The studies about the association between gut microbiota and schizophrenia are limited, and more studies are needed to provide new insights into the gut microbiota in the pathogenesis and treatment of schizophrenia.