Role of gut-lung microbiome crosstalk in COVID-19

Exploring the complex role of gut microbiome in the development of precision medicine strategies for targeting microbial imbalance-induced colon cancer

The gut microbiome has been increasingly recognized as a key player in the development and progression of colon cancer. Alterations in the gut microbiota, known as dysbiosis, can lead to a variety of medical issues. Microbial adaptation through signals and small molecules can enhance pathogen colonization and modulate host immunity, significantly impacting disease progression. Quorum sensing peptides and molecules have been linked to the progression of colon cancer. Various interventions, such as fecal microbiota transplantation, probiotics, prebiotics, synbiotics, and antibiotics, have been used to reverse dysbiosis with mixed results and potential side effects. Thus, a personalized approach to treatment selection based on patient characteristics, such as individual gut microbiota manipulation, is necessary to prevent and treat diseases like colon cancer. With advances in metagenomic sequencing and other omics technologies, there has been a growing interest in developing precision medicine strategies for microbial imbalance-induced colon cancer. This review serves as a comprehensive synthesis of current knowledge on the gut microbiome involvement in colon cancer. By exploring the potential of utilizing the gut microbiome as a target for precision medicine, this review underscores the exciting opportunities that lie ahead. Although challenges exist, the integration of microbiome data into precision medicine approaches has the potential to revolutionize the management of colon cancer, providing patients with more personalized and effective treatment options.

Molecular Accounting and Profiling of Human Respiratory Microbial Communities: Toward Precision Medicine by Targeting the Respiratory Microbiome for Disease Diagnosis and Treatment

The wide diversity of microbiota at the genera and species levels across sites and individuals is related to various causes and the observed differences between individuals. Efforts are underway to further understand and characterize the human-associated microbiota and its microbiome. Using 16S rDNA as a genetic marker for bacterial identification improved the detection and profiling of qualitative and quantitative changes within a bacterial population. In this light, this review provides a comprehensive overview of the basic concepts and clinical applications of the respiratory microbiome, alongside an in-depth explanation of the molecular targets and the potential relationship between the respiratory microbiome and respiratory disease pathogenesis. The paucity of robust evidence supporting the correlation between the respiratory microbiome and disease pathogenesis is currently the main challenge for not considering the microbiome as a novel druggable target for therapeutic intervention. Therefore, further studies are needed, especially prospective studies, to identify other drivers of microbiome diversity and to better understand the changes in the lung microbiome along with the potential association with disease and medications. Thus, finding a therapeutic target and unfolding its clinical significance would be crucial.

The impact of infection with COVID-19 on the respiratory microbiome: A narrative review

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has affected millions of individuals with various implications. Consistent with the crucial role of the microbiome in determining health and disease in humans, various studies have investigated the gut and respiratory microbiome effect on the COVID-19. Microbiota dysbiosis might support the entry, replication, and establishment of SARS-CoV-2 infection by modulating various mechanisms. One of the main mechanisms that the modulation of respiratory microbiota composition during the COVID-19 infection affects the magnitude of the disease is changes in innate and acquired immune responses, including inflammatory markers and cytokines and B- and T-cells. The diversity of respiratory microbiota in COVID-19 patients is controversial; some studies reported low microbial diversity, while others found high diversity, suggesting the role of respiratory microbiota in this disease. Modulating microbiota diversity and profile by supplementations and nutrients can be applied prophylactic and therapeutic in combating COVID-19. Here, we discussed the lung microbiome dysbiosis during various lung diseases and its interaction with immune cells, focusing on COVID-19.

Quorum sensing: a new perspective to reveal the interaction between gut microbiota and host

Quorum sensing (QS), a chemical communication process between bacteria, depends on the synthesis, secretion and detection of signal molecules. It can synchronize the gene expression of bacteria to promote cooperation within the population and improve competitiveness among populations. The preliminary exploration of bacterial QS has been completed under ideal and highly controllable conditions. There is an urgent need to investigate the QS of bacteria under natural conditions, especially the QS of intestinal flora, which is closely related to health. Excitingly, growing evidence has shown that QS also exists in the intestinal flora. The crosstalk of QS between gut microbiota and the host is systematically clarified in this review.

Did Climate Change Influence the Emergence, Transmission, and Expression of the COVID-19 Pandemic?

The human race has survived many epidemics and pandemics that have emerged and reemerged throughout history. The novel coronavirus Severe Acute Respiratory Syndrome SARS-CoV-2/COVID-19 is the latest pandemic and this has caused major health and socioeconomic problems in almost all communities of the world. The origin of the virus is still in dispute but most likely, the virus emerged from the bats and also may involve an intermediate host before affecting humans. Several other factors also may have affected the emergence and outcome of the infection but in this review, we make a case for a possible role of climate change. The rise in industrialization-related human activities has created a marked imbalance in the homeostasis of environmental factors such as temperature and other weather and these might even have imposed conditions for the emergence of future coronavirus cycles. An attempt is made in this review to explore the effect of ongoing climate changes and discuss if these changes had a role in facilitating the emergence, transmission, and even the expression of the COVID-19 pandemic. We surmise that pandemics will be more frequent in the future and more severely impactful unless climate changes are mitigated.

Lung microbiota dysbiosis and the implications of SARS-CoV-2 infection in pregnancy

There are a great number of beneficial commensal microorganisms constitutively colonizing the mucosal lining of the lungs. Alterations in the microbiota profile have been associated with several respiratory diseases such as pneumonia and allergies. Lung microbiota dysbiosis might play an important role in the pathogenic mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as elicit other opportunistic infections associated with coronavirus disease 2019 (COVID-19). With its increasing prevalence and morbidity, SARS-CoV-2 infection in pregnant mothers is inevitable. Recent evidence shows that angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) act as an entry receptor and viral spike priming protein, respectively, for SARS-CoV-2 infection. These receptor proteins are highly expressed in the maternal-fetal interface, including the placental trophoblast, suggesting the possibility of maternal-fetal transmission. In this review, we discuss the role of lung microbiota dysbiosis in respiratory diseases, with an emphasis on COVID-19 and the possible implications of SARS-CoV-2 infection on pregnancy outcome and neonatal health.