Stressful events induce long-term gut microbiota dysbiosis and associated post-traumatic stress symptoms in healthcare workers fighting against COVID-19.

OBJECTIVE: The microbiota-gut-brain axis is a key pathway perturbed by prolonged stressors to produce brain and behavioral disorders. Frontline healthcare workers (FHWs) fighting against COVID-19 typically experience stressful event sequences and manifest some mental symptoms; however, the role of gut microbiota in such stress-induced mental problems remains unclear. We investigated the association between the psychological stress of FHW and gut microbiota. METHODS: We used full-length 16S rRNA gene sequencing to characterize the longitudinal changes in gut microbiota and investigated the impact of microbial changes on FHWs' mental status. RESULTS: Stressful events induced significant depression, anxiety, and stress in FHWs and disrupted the gut microbiome; gut dysbiosis persisted for at least half a year. Different microbes followed discrete trajectories during the half-year of follow-up. Microbes associated with mental health were mainly Faecalibacterium spp. and [Eubacterium] eligens group spp. with anti-inflammatory effects. Of note, the prediction model indicated that low abundance of [Eubacterium] hallii group uncultured bacterium and high abundance of Bacteroides eggerthii at Day 0 (immediately after the two-month frontline work) were significant determinants of the reappearance of post-traumatic stress symptoms in FHWs. LIMITATIONS: The lack of metabolomic evidence and animal experiments result in the unclear mechanism of gut dysbiosis-related stress symptoms. CONCLUSION: The stressful event sequences of fighting against COVID-19 induce characteristic longitudinal changes in gut microbiota, which underlies dynamic mental state changes.

The microbiome in atopic patients and potential modifications in the context of the severe acute respiratory syndrome coronavirus 2 pandemic.

PURPOSE OF REVIEW: Data regarding the effects of coronavirus disease 2019 (COVID-19) on host-microbiome alteration and subsequent effects on susceptibility and clinical course of COVID-19, especially in atopic patients, are currently limited. Here, we review the studies regarding the microbiome of atopic patients with other respiratory infections and discuss the potential role of probiotics as therapeutic targets for COVID-19 to decrease its susceptibility and severity of COVID-19. RECENT FINDINGS: Respiratory tract virus infection affects the gut and airway microbiome structures and host's immune function. Diverse factors in atopic diseases affect the airway and gut microbiome structures, which are expected to negatively influence host health. However, response to respiratory virus infection in atopic hosts depends on the preexisting microbiome and immune responses. This may explain the inconclusiveness of the effects of COVID-19 on the susceptibility, morbidity, and mortality of patients with atopic diseases. Beneficial probiotics may be a therapeutic adjuvant in COVID-19 infection as the beneficial microbiome can decrease the viral load in the early phase of respiratory virus infection and improve the morbidity and mortality. SUMMARY: Application of probiotics can be a potential adjuvant treatment in respiratory virus infection to improve host immune responses and disturbed microbiome structures in atopic patients. Further related studies involving COVID-19 are warranted in near future.

COVID-19 Pandemic and Dysbiosis: Can the Ivermectin Hysteria Lead to an Increase of Autoimmune Neuroinflammatory Diseases?

The pandemic caused by the SARS-CoV-2 has made new treatments a goal for the scientific community. One of these treatments is Ivermectin. Here we discuss the hypothesis of dysbiosis caused by the use of Ivermectin and the possible impacts on neuroinflammatory diseases after the end of the pandemic.

Gut microbiota composition reflects disease severity and dysfunctional immune responses in patients with COVID-19.

OBJECTIVE: Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. We investigated whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus. METHODS: In this two-hospital cohort study, we obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. RESULTS: Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication (p<0.01). Several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase. CONCLUSION: Associations between gut microbiota composition, levels of cytokines and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of COVID-19 severity possibly via modulating host immune responses. Furthermore, the gut microbiota dysbiosis after disease resolution could contribute to persistent symptoms, highlighting a need to understand how gut microorganisms are involved in inflammation and COVID-19.

Is periodontal disease a risk factor for severe COVID-19 illness?

Periodontal disease (PD) comprises a group of diseases involving inflammatory aspects of the host and dysbiotic events that affect periodontal tissues and could have systemic implications. Diverse factors and comorbidities have been closely associated with PD such as diabetes, obesity, aging, hypertension, and so on; although, underlying mechanisms or causal associations have not been established completely. Interestingly, these same factors have been widely associated with progression or severe coronavirus disease 2019 (COVID-19), an illness caused by coronavirus SARS-CoV-2. Since inflammatory and dysbiotic factors as well as comorbidities affect systemic health, it is possible that periodontal status indicates the risk of complication of COVID-19. However, assessment of oral health history including periodontal status in COVID-19 patients has not been reported. Knowing PD is associated with severe COVID-19 could help identify risk groups and establish pertinent recommendations.