Acute Neuropsychiatric Symptoms Associated With Antibiotic Treatment of Helicobacter Pylori Infections: A Review

Advances in molecular mechanisms and therapeutic strategies for central nervous system diseases based on gut microbiota imbalance

BACKGROUD

Central nervous system (CNS) diseases pose a serious threat to human health, but the regulatory mechanisms and therapeutic strategies of CNS diseases need to be further explored. It has been demonstrated that the gut microbiota (GM) is closely related to CNS disease. GM structure disorders, abnormal microbial metabolites, intestinal barrier destruction and elevated inflammation exist in patients with CNS diseases and promote the development of CNS diseases. More importantly, GM remodeling alleviates CNS pathology to some extent.

AIM OF REVIEW

Here, we have summarized the regulatory mechanism of the GM in CNS diseases and the potential treatment strategies for CNS repair based on GM regulation, aiming to provide safer and more effective strategies for CNS repair from the perspective of GM regulation.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The abundance and composition of GM is closely associated with the CNS diseases. On the basis of in-depth analysis of GM changes in mice with CNS disease, as well as the changes in its metabolites, therapeutic strategies, such as probiotics, prebiotics, and FMT, may be used to regulate GM balance and affect its microbial metabolites, thereby promoting the recovery of CNS diseases.

Connecting the Dots: The Cerebral Lymphatic System as a Bridge Between the Central Nervous System and Peripheral System in Health and Disease

As a recently discovered waste removal system in the brain, cerebral lymphatic system is thought to play an important role in regulating the homeostasis of the central nervous system. Currently, more and more attention is being focused on the cerebral lymphatic system. Further understanding of the structural and functional characteristics of cerebral lymphatic system is essential to better understand the pathogenesis of diseases and to explore therapeutic approaches. In this review, we summarize the structural components and functional characteristics of cerebral lymphatic system. More importantly, it is closely associated with peripheral system diseases in the gastrointestinal tract, liver, and kidney. However, there is still a gap in the study of the cerebral lymphatic system. However, we believe that it is a critical mediator of the interactions between the central nervous system and the peripheral system.

Impact of nonalcoholic fatty liver disease-related metabolic state on depression

Nonalcoholic fatty liver disease (NAFLD), also recently referred as metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by hepatocyte steatosis in the setting of metabolic risk conditions and in the absence of an underlying precursor, for instance alcohol consumption, hepatotropic viruses and hepatotoxic drugs. A possible association between NAFLD and depression has been proposed, owing to intersecting pathophysiological pathways. This narrative review aimed to summarize the current evidence that illustrate the potential pathophysiological and clinical linkage between NAFLD-related metabolic state and depression. Prefrontal cortex lesions are suggested to be a consequence of liver steatosis-associated systematic hyperinflammatory state, a phenomenon also occurring in depression. In addition, depressive symptoms are present in neurotransmitter imbalances. These abnormalities seem to be correlated with NAFLD/MAFLD, in terms of insulin resistance (IR), ammonia and gut dysbiosis' impact on serotonin, dopamine, noradrenaline levels and gamma aminobutyric acid receptors. Furthermore, reduced levels of nesfatin-1 and copine-6-associated BDNF (brain-derived neurotrophic factor) levels have been considered as a probable link between NAFLD and depression. Regarding NAFLD-related gut dysbiosis, it stimulates mediators including lipopolysaccharides, short-chain fatty acids and bile acids, which play significant role in depression. Finally, western diet and IR, which are mainstay components of NAFLD/MAFLD, are, also, substantiated to affect neurotransmitters in hippocampus and produce neurotoxic lipids that contribute to neurologic dysfunction, and thus trigger emotional disturbances, mainly depressive symptoms.

Possible convulsion and electroencephalographic abnormality in a patient taking long-term oral clarithromycin: A case report

BACKGROUND

Clarithromycin is a macrolide antibiotic commonly prescribed to patients with upper respiratory and otolaryngological infections. Neuropsychiatric adverse effects of clarithromycin include agitation, insomnia, delirium, psychosis, and seizure.

CASE SUMMARY

A 52-year-old man was admitted to our hospital with a convulsion. He had > 10-year history of clarithromycin intake for chronic sinusitis. One week before admission, he started to take diltiazem for angina pectoris. On admission, his convulsion subsided. His electroencephalography showed frontal intermittent rhythmic delta activity. One week after he ceased clarithromycin, his electroencephalographic abnormalities disappeared. We suggested that the patient developed convulsions due to increased blood levels of clarithromycin caused by oral administration of diltiazem, which is involved in CYP3A metabolism.

CONCLUSION

Clarithromycin has a relatively high safety profile and is a frequently prescribed drug. However, there are a few previous reports of clarithromycin-related convulsive disorders. Clinicians should be aware of the drug interaction and rare side effects of seizures.

Delirium associated with the use of macrolide antibiotics: a review

OBJECTIVE

This review aimed to explore and summarise available cases of delirium suspected to be associated with the use of macrolide antibiotics reported in the literature and the United States Food and Drug Administration's Adverse Event Reporting System (FAERS) database.

METHODS

Electronic searches of the literature were conducted in four online databases: PubMed/MEDLINE, Scopus, Web of Science and Serbian Citation Index (SCIndeks). A search of FAERS database was also conducted to supplement the findings of the literature search. Descriptive statistics, narrative summation and tabulation of the extracted data were made.

RESULTS

Cases of delirium which satisfied inclusion criteria were found for clarithromycin, azithromycin, erythromycin and telithromycin. Delirium was described in patients of various age groups, including children. Drug-drug interactions may have contributed to its occurrence in some of the cases. Average time to onset of delirium was 2.5 days for azithromycin and 3.3 days for clarithromycin.

CONCLUSIONS

Considering that these drugs may be a possible cause of delirium, clinicians should be aware that timely recognition of this possible side effect can lead to earlier discontinuation of the culprit drug, reduce time spent in a delirious state and improve patients' outcomes.KEY POINTSCases of delirium which satisfied inclusion criteria were found for clarithromycin, azithromycin, erythromycin and telithromycin.Cases of delirium were described in patients of various age groups, including children.Drug-drug interactions may have contributed to the occurrence of delirium in some of the cases.Time to onset of delirium ranged from 2 to 3.5 days (mean: 2.5 days) for azithromycin and from 1 to 7 days (mean: 3.3 days) for clarithromycin.Cessation of the macrolide antibiotic seems to be the best management strategy, although some of the patients may, in addition, require antipsychotics.

Do Periodontal Pathogens or Associated Virulence Factors Have a Deleterious Effect on the Blood-Brain Barrier, Contributing to Alzheimer's Disease?

The central nervous system (CNS) is protected by a highly selective barrier, the blood-brain barrier (BBB), that regulates the exchange and homeostasis of bloodborne molecules, excluding xenobiotics. This barrier forms the first line of defense by prohibiting pathogens from crossing to the CNS. Aging and chronic exposure of the BBB to pathogens renders it permeable, and this may give rise to pathology in the CNS such as Alzheimer's disease (AD). Researchers have linked pathogens associated with periodontitis to neuroinflammation and AD-like pathology in vivo and in vitro. Although the presence of periodontitis-associated bacteria has been linked to AD in several clinical studies as DNA and virulence factors were confirmed in brain samples of human AD subjects, the mechanism by which the bacteria traverse to the brain and potentially influences neuropathology is unknown. In this review, we present current knowledge about the association between periodontitis and AD, the mechanism whereby periodontal pathogens might provoke neuroinflammation and how periodontal pathogens could affect the BBB. We suggest future studies, with emphasis on the use of human in vitro models of cells associated with the BBB to unravel the pathway of entry for these bacteria to the CNS and to reveal the molecular and cellular pathways involved in initiating the AD-like pathology. In conclusion, evidence demonstrate that bacteria associated with periodontitis and their virulence factors are capable of inflecting damage to the BBB and have a role in giving rise to pathology similar to that found in AD.

Gut Hormones as Potential Therapeutic Targets or Biomarkers of Response in Depression: The Case of Motilin

Recent research has identified the gut–brain axis as a key mechanistic pathway and potential therapeutic target in depression. In this paper, the potential role of gut hormones as potential treatments or predictors of response in depression is examined, with specific reference to the peptide hormone motilin. This possibility is explored through two methods: (1) a conceptual review of the possible links between motilin and depression, including evidence from animal and human research as well as clinical trials, based on a literature search of three scientific databases, and (2) an analysis of the relationship between a functional polymorphism (rs2281820) of the motilin (MLN) gene and cross-national variations in the prevalence of depression based on allele frequency data after correction for potential confounders. It was observed that (1) there are several plausible mechanisms, including interactions with diet, monoamine, and neuroendocrine pathways, to suggest that motilin may be relevant to the pathophysiology and treatment of depression, and (2) there was a significant correlation between rs2281820 allele frequencies and the prevalence of depression after correcting for multiple confounding factors. These results suggest that further evaluation of the utility of motilin and related gut peptides as markers of antidepressant response is required and that these molecular pathways represent potential future mechanisms for antidepressant drug development.

Increased risk of short-term depressive disorder after Helicobacter pylori eradication: A population-based nested cohort study

BACKGROUND

Depressive disorder is a major psychiatric illness, and a disturbed brain-gut-microbiome axis may contribute to its pathophysiology. Chronic Helicobacter pylori (H. pylori) infections are common in the general population and using multiple antibiotics is required for its eradication, which is associated with gut dysbiosis and may lead to depression. We aimed to evaluate the risk of psychiatrist-diagnosed depression in patients with peptic ulcer diseases (PUD) receiving anti-H. pylori therapy.

MATERIALS AND METHODS

We collected data from the National Health Insurance Research Database (NHIRD) in Taiwan on PUD patients undergoing antibiotic treatment for H. pylori infection; patients and controls were matched for age, sex, income, level of urbanization, and comorbidities.

RESULTS

Of the 1 million beneficiaries in the NHIRD, we identified 7087 patients for inclusion in the eradication cohort and 7087 matched non-eradication controls with PUD. Antibiotic therapy is associated with a short-term (<30 days) increase in the incidence of psychiatrist-diagnosed depressive disorder (p = 0.009, after multiple comparisons with Bonferroni correction) in the eradication cohort compared with the controls. Female (OR: 4.55, 95% CI: 1.53-13.48) PUD patients were more likely to display an increased risk of depression within 30 days after eradication therapy. Clarithromycin use was related to an elevated likelihood (OR: 3.14, 95% CI: 1.45-6.80) of subsequent depressive disorder within 30 days after eradication therapy.

CONCLUSIONS

Antibiotic eradication treatment for H. pylori infection is associated with a significant short-term (less than 30 days) increase in the incidence of psychiatrist-diagnosed depressive disorder, which can be overlooked by gastroenterologists and general practitioners.

Can Control Infections Slow Down the Progression of Alzheimer's Disease? Talking About the Role of Infections in Alzheimer's Disease

Alzheimer’s disease as the most common age-related dementia affects more than 40 million people in the world, representing a global public health priority. However, the pathogenesis of Alzheimer’s disease (AD) is complex, and it remains unclear. Over the past decades, all efforts made in the treatments of AD, with targeting the pathogenic amyloid β (Aβ), neurofibrillary tangles, and misfolded tau protein, were failed. Recently, many studies have hinted that infection, and chronic inflammation that caused by infection are crucial risk factors for AD development and progress. In the review, we analyzed the role of infections caused by bacteria, viruses, and other pathogens in the pathogenesis of AD and its animal models, and explored the therapeutic possibility with anti-infections for AD. However, based on the published data, it is still difficult to determine their causal relationship between infection and AD due to contradictory results. We think that the role of infection in the pathogenesis of AD should not be ignored, even though infection does not necessarily cause AD, it may act as an accelerator in AD at least. It is essential to conduct the longitudinal studies and randomized controlled trials in humans, which can determine the role of infection in AD and clarify the links between infection and the pathological features of AD. Finding targeting infection drugs and identifying the time window for applying antibacterial or antiviral intervention may be more promising for future clinical therapeutic strategies in AD.

Personalizing the Care and Treatment of Alzheimer's Disease: An Overview

Alzheimer's disease (AD) is a progressive, complex, and multifactorial neurodegenerative disorder, still without effective and stable therapeutic strategies. Currently, available medications for AD are based on symptomatic therapy, which include acetylcholinesterase (AChE) inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonist. Additionally, medications such as antipsychotic drugs, antidepressants, sedative, and hypnotic agents, and mood stabilizers are used for the management of behavioral and psychological symptoms of dementia (BPSD). Clinical research has been extensively investigated treatments focusing on the hallmark pathology of AD, including the amyloid deposition, tau hyperphosphorylation, neuroinflammation, and vascular changes; however, so far without success, as all new potential drugs failed to show significant clinical benefit. The underlying heterogeneous etiology and diverse symptoms of AD suggest that a precision medicine strategy is required, which would take into account the complex genetic, epigenetic, and environmental landscape of each AD patient. The article provides a comprehensive overview of the literature on AD, the current and potential therapy of both cognitive symptoms as well as BPSD, with a special focus on gut microbiota and epigenetic modifications as new emerging drug targets. Their specific patterns could represent the basis for novel individually tailored approaches aimed to optimize precision medicine strategies for AD prevention and treatment. However, the successful application of precision medicine to AD demands a further extensive research of underlying pathological processes, as well as clinical and biological complexity of this multifactorial neurodegenerative disorder.

The Microbiota-Gut-Brain Axis and Alzheimer's Disease: Neuroinflammation Is to Blame?

For years, it has been reported that Alzheimer’s disease (AD) is the most common cause of dementia. Various external and internal factors may contribute to the early onset of AD. This review highlights a contribution of the disturbances in the microbiota–gut–brain (MGB) axis to the development of AD. Alteration in the gut microbiota composition is determined by increase in the permeability of the gut barrier and immune cell activation, leading to impairment in the blood–brain barrier function that promotes neuroinflammation, neuronal loss, neural injury, and ultimately AD. Numerous studies have shown that the gut microbiota plays a crucial role in brain function and changes in the behavior of individuals and the formation of bacterial amyloids. Lipopolysaccharides and bacterial amyloids synthesized by the gut microbiota can trigger the immune cells residing in the brain and can activate the immune response leading to neuroinflammation. Growing experimental and clinical data indicate the prominent role of gut dysbiosis and microbiota–host interactions in AD. Modulation of the gut microbiota with antibiotics or probiotic supplementation may create new preventive and therapeutic options in AD. Accumulating evidences affirm that research on MGB involvement in AD is necessary for new treatment targets and therapies for AD.

Gut-Brain Axis: Role of Gut Microbiota on Neurological Disorders and How Probiotics/Prebiotics Beneficially Modulate Microbial and Immune Pathways to Improve Brain Functions

The gut microbiome acts as an integral part of the gastrointestinal tract (GIT) that has the largest and vulnerable surface with desirable features to observe foods, nutrients, and environmental factors, as well as to differentiate commensals, invading pathogens, and others. It is well-known that the gut has a strong connection with the central nervous system (CNS) in the context of health and disease. A healthy gut with diverse microbes is vital for normal brain functions and emotional behaviors. In addition, the CNS controls most aspects of the GI physiology. The molecular interaction between the gut/microbiome and CNS is complex and bidirectional, ensuring the maintenance of gut homeostasis and proper digestion. Besides this, several mechanisms have been proposed, including endocrine, neuronal, toll-like receptor, and metabolites-dependent pathways. Changes in the bidirectional relationship between the GIT and CNS are linked with the pathogenesis of gastrointestinal and neurological disorders; therefore, the microbiota/gut-and-brain axis is an emerging and widely accepted concept. In this review, we summarize the recent findings supporting the role of the gut microbiota and immune system on the maintenance of brain functions and the development of neurological disorders. In addition, we highlight the recent advances in improving of neurological diseases by probiotics/prebiotics/synbiotics and fecal microbiota transplantation via the concept of the gut-brain axis.

Target Dysbiosis of Gut Microbes as a Future Therapeutic Manipulation in Alzheimer's Disease

Alzheimer’s disease (AD) is commonly an age-associated dementia with neurodegeneration. The pathogenesis of AD is complex and still remains unclear. The inflammation, amyloid β (Aβ), and neurofibrillary tangles as well misfolded tau protein in the brain may contribute to the occurrence and development of AD. Compared with tau protein, Aβ is less toxic. So far, all efforts made in the treatments of AD with targeting these pathogenic factors were unsuccessful over the past decades. Recently, many studies demonstrated that changes of the intestinal environment and gut microbiota via gut–brain axis pathway can cause neurological disorders, such as AD, which may be involved in the pathogenesis of AD. Thus, remodeling the gut microbiota by various ways to maintain their balance might be a novel therapeutic strategy for AD. In the review article, we analyzed the characteristics of gut microbiota and its dysbiosis in AD and its animal models and investigated the possibility of targeting the gut microbiota in the treatment of the patients with AD in the future.

Antimicrobial prescriptions and adherence to prudent use guidelines for selected canine diseases in Switzerland in 2016

Background

Antimicrobial resistance is an increasing problem in human and veterinary medicine and is closely linked to the use of antimicrobials. The objective of this study was to describe antimicrobial prescriptions for selected canine diseases in Switzerland during 2016.

Methods

Dogs presented to two university hospitals and 14 private practices for acute diarrhoea (AD; n=371), suspected or confirmed urinary tract infections (UTIs; n=245), respiratory tract infections (RTIs; n=274) or wound infections (WIs; n=175) were included. Clinical history, diagnostic work-up and antimicrobial prescription (class, dosage and duration) were retrospectively assessed. A justification score was applied to evaluate appropriateness of antimicrobial therapy based on available national and international consensus guidelines.

Results

Antimicrobials were prescribed in 65 per cent of dogs with AD, 88 per cent with UTI, 62 per cent with RTI and 90 per cent with WI. The most prescribed antimicrobial classes (monotherapy and combination therapy) were potentiated aminopenicillins (59 per cent), nitroimidazoles (22 per cent), non-potentiated aminopenicillins (16 per cent) and fluoroquinolones (13 per cent). Overall, 38 per cent (95 per cent CI 0.35 to 0.41) of the prescriptions were in accordance with consensus guidelines. In dogs with AD, antimicrobial therapy was associated with the presence of haemorrhagic diarrhoea (P<0.05) and complied in 32 per cent with consensus guidelines, which recommend antimicrobial treatment only when sepsis is suspected. A bacterial aetiology was confirmed via culture and/or sediment examination in 36 per cent of dogs with suspected UTI.

Conclusions

Overall, adherence to consensus guidelines was poor both, at university hospitals and private practices. Antimicrobial stewardship measures are therefore needed to improve prudent use.

The Psychotic Impact of Helicobacter pylori Gastritis and Functional Dyspepsia on Depression: A Systematic Review

The clinical practice of adding antidepressant drugs to the therapy for the eradication of Helicobacter pylori (H. pylori) in addition to the standard drug regimen is not yet well established. This study aims to establish if there is an association between H. pylori gastritis and depression and to further analyze the therapeutic effect of antidepressants on symptomatic relief in gastritis. A systematic review was done using articles collected within the last seven years without regional or language localization obtained using PubMed, PubMed Central® (PMC), Google Scholar, and the Cochrane controlled trials. The search terms included Helicobacter pylori, depression, functional dyspepsia, and antidepressants. We selected three randomized controlled trials (RCTs), eight cross-sectional studies, four prospective studies, one cohort study, and two review articles. Trials that were prescribed antidepressants for clinical improvement of dyspepsia in patients with H. pylori gastritis that showed no improvement after eradication therapy standard regimen were included. In conclusion, patients who showed no improvement in functional dyspepsia after H. pylori eradication were seen to improve on antidepressant therapy. Further investigation and studies to analyze this correlation are recommended.

Antibiotics, gut microbiota, and Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease whose various pathophysiological aspects are still being investigated. Recently, it has been hypothesized that AD may be associated with a dysbiosis of microbes in the intestine. In fact, the intestinal flora is able to influence the activity of the brain and cause its dysfunctions.Given the growing interest in this topic, the purpose of this review is to analyze the role of antibiotics in relation to the gut microbiota and AD. In the first part of the review, we briefly review the role of gut microbiota in the brain and the various theories supporting the hypothesis that dysbiosis can be associated with AD pathophysiology. In the second part, we analyze the possible role of antibiotics in these events. Antibiotics are normally used to remove or prevent bacterial colonization in the human body, without targeting specific types of bacteria. As a result, broad-spectrum antibiotics can greatly affect the composition of the gut microbiota, reduce its biodiversity, and delay colonization for a long period after administration. Thus, the action of antibiotics in AD could be wide and even opposite, depending on the type of antibiotic and on the specific role of the microbiome in AD pathogenesis.Alteration of the gut microbiota can induce changes in brain activity, which raise the possibility of therapeutic manipulation of the microbiome in AD and other neurological disorders. This field of research is currently undergoing great development, but therapeutic applications are still far away. Whether a therapeutic manipulation of gut microbiota in AD could be achieved using antibiotics is still not known. The future of antibiotics in AD depends on the research progresses in the role of gut bacteria. We must first understand how and when gut bacteria act to promote AD. Once the role of gut microbiota in AD is well established, one can think to induce modifications of the gut microbiota with the use of pre-, pro-, or antibiotics to produce therapeutic effects.

Acute psychotic symptoms following a single dose of levofloxacin

The objective of our case report was to raise awareness of the neurotoxic potential of levofloxacin in naïve patients. In patients with severe infections and comorbidities, it would be difficult to discriminate the neurotoxic effects of levofloxacin from those of the medical condition itself. Thus, health professionals should be aware of the early onset CNS effects of levofloxacin in naïve patients.