Evolving Technologies in Gastrointestinal Microbiome Era and Their Potential Clinical Applications

Microfluidic systems for infectious disease diagnostics

Microorganisms, encompassing both uni- and multicellular entities, exhibit remarkable diversity as omnipresent life forms in nature. They play a pivotal role by supplying essential components for sustaining biological processes across diverse ecosystems, including higher host organisms. The complex interactions within the human gut microbiota are crucial for metabolic functions, immune responses, and biochemical signalling, particularly through the gut-brain axis. Viruses also play important roles in biological processes, for example by increasing genetic diversity through horizontal gene transfer when replicating inside living cells. On the other hand, infection of the human body by microbiological agents may lead to severe physiological disorders and diseases. Infectious diseases pose a significant burden on global healthcare systems, characterized by substantial variations in the epidemiological landscape. Fast spreading antibiotic resistance or uncontrolled outbreaks of communicable diseases are major challenges at present. Furthermore, delivering field-proven point-of-care diagnostic tools to the most severely affected populations in low-resource settings is particularly important and challenging. New paradigms and technological approaches enabling rapid and informed disease management need to be implemented. In this respect, infectious disease diagnostics taking advantage of microfluidic systems combined with integrated biosensor-based pathogen detection offers a host of innovative and promising solutions. In this review, we aim to outline recent activities and progress in the development of microfluidic diagnostic tools. Our literature research mainly covers the last 5 years. We will follow a classification scheme based on the human body systems primarily involved at the clinical level or on specific pathogen transmission modes. Important diseases, such as tuberculosis and malaria, will be addressed more extensively.

A Review on the Protective Effects of Probiotics against Alzheimer's Disease

This review summarizes the protective effects of probiotics against Alzheimer's disease (AD), one of the most common neurodegenerative disorders affecting older adults. This disease is characterized by the deposition of tau and amyloid β peptide (Aβ) in different parts of the brain. Symptoms observed in patients with AD include struggles with writing, speech, memory, and knowledge. The gut microbiota reportedly plays an important role in brain functioning due to its bidirectional communication with the gut via the gut-brain axis. The emotional and cognitive centers in the brain are linked to the functions of the peripheral intestinal system via this gut-brain axis. Dysbiosis has been linked to neurodegenerative disorders, indicating the significance of gut homeostasis for proper brain function. Probiotics play an important role in protecting against the symptoms of AD as they restore gut-brain homeostasis to a great extent. This review summarizes the characteristics, status of gut-brain axis, and significance of gut microbiota in AD. Review and research articles related to the role of probiotics in the treatment of AD were searched in the PubMed database. Recent studies conducted using animal models were given preference. Recent clinical trials were searched for separately. Several studies conducted on animal and human models clearly explain the benefits of probiotics in improving cognition and memory in experimental subjects. Based on these studies, novel therapeutic approaches can be designed for the treatment of patients with AD.

Review of the role of gastrointestinal multiplex polymerase chain reaction in the management of diarrheal illness

Acute and chronic diarrheal illness secondary to gastrointestinal infection is a significant cause of morbidity and mortality around the world. A cornerstone of management includes prompt diagnosis and appropriate treatment of culprit pathogens. Timely diagnosis can improve patient care, assist in infection control, and prevent disease outbreaks. Historical methods of diagnosis include traditional culture methods and stool analysis. These are limited by long turnaround time and inability to simultaneously assess multiple pathogens. The advent of multiplexed nucleic acid amplification tests first began with the Food and Drug Administration-approved respiratory virus multiplex polymerase chain reaction (PCR) panel in 2009, followed by gastrointestinal infections in 2013, and neurological infections in 2014. We conducted a review of current literature pertaining to the clinical utility of a gastrointestinal multiplex PCR in management of acute and chronic diarrhea in patients. To date, seven platforms approved by the US Food and Drug Administration are used in detection of various bacterial, viral, and parasitic causative organisms for diagnosis of gastrointestinal infections. The sensitivity and specificity of each assay vary depending on the tested organism. Interpretation of a positive result has to be tailored to the clinical context. Further studies are required to establish the utility of gastrointestinal multiplex PCR from a cost-based perspective, whether specific enteropathogens such as Clostridioides difficile are better assessed with toxin gene detection and whether new parameters such as cycle threshold values can improve clinical application of test results.

Gut microbiota and cardiovascular diseases axis: a review

Gut microbiota, a term that includes microorganisms present in the gastrointestinal tract, has become very attractive lately due to its propensity to act as a virtual organ with endocrine functions, generating various bio-active metabolites, while playing an important role in human health and diseases, including cardiovascular diseases (CVDs). Focusing on the latter field, gastrointestinal dysbiosis, that is the imbalance in the gut microbiota composition, has been linked to various pathologies such as hypertension, atherosclerosis, myocardial infarction and heart failure. Several pathways were demonstrated to play a role in the complex and intertwined association between the gut microbiota and host, including metabolic endotoxemia, alteration of pattern recognition receptors and short-chain fatty acids, uremic toxins, bile acids and trimethylamine-N-oxide levels, leading to CVDs. Understanding these pathways can allow to identifying metabolites that could be useful predictors for detecting incipient CVDs stages and potential therapeutic targets. In this review, we summarize the pathways associating the gut microbiota with CVDs.