Assessment of microbiota in the gut and upper respiratory tract associated with SARS-CoV-2 infection

Abstract:

Background: The human microbiome plays an important role in modulating the host metabolism and immune system. Connections and interactions have been found between the microbiome of the gut and oral pharynx in the context of SARS-CoV-2 and other viral infections; hence, to broaden our understanding of host-viral responses in general and to deepen our knowledge of COVID-19, we performed a large-scale, systematic evaluation of the effect of SARS-CoV-2 infection on human microbiota in patients with varying disease severity.

Results: We processed 521 samples from 203 COVID-19 patients with varying disease severity and 94 samples from 31 healthy donors, consisting of 213 pharyngeal swabs, 250 sputa, and 152 fecal samples, and obtained meta-transcriptomes as well as SARS-CoV-2 sequences from each sample. Detailed assessment of these samples revealed altered microbial composition and function in the upper respiratory tract (URT) and gut of COVID-19 patients, and these changes are significantly associated with disease severity. Moreover, URT and gut microbiota show different patterns of alteration, where gut microbiome seems to be more variable and in direct correlation with viral load; and microbial community in the upper respiratory tract renders a high risk of antibiotic resistance. Longitudinally, the microbial composition remains relatively stable during the study period.

Conclusions: Our study has revealed different trends and the relative sensitivity of microbiome in different body sites to SARS-CoV-2 infection. Furthermore, while the use of antibiotics is often essential for the prevention and treatment of secondary infections, our results indicate a need to evaluate potential antibiotic resistance in the management of COVID-19 patients in the ongoing pandemic. Moreover, a longitudinal follow-up to monitor the restoration of the microbiome could enhance our understanding of the long-term effects of COVID-19.

Source: Li J, Jing Q, Li J, Hua M, Di L, Song C, Huang Y, Wang J, Chen C, Wu AR. Assessment of microbiota in the gut and upper respiratory tract associated with SARS-CoV-2 infection. Microbiome. 2023 Mar 3;11(1):38. doi: 10.1186/s40168-022-01447-0. PMID: 36869345; PMCID: PMC9982190. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9982190/ (Full text)

The role of the microbiota-gut-brain axis in post-acute COVID syndrome

Abstract:

The COVID-19 pandemic has resulted in the infection of hundreds of millions of individuals over the past three years, coupled with millions of deaths. Along with these more acute impacts of infection, a large subset of patients developed symptoms that collectively comprise “post-acute sequelae of COVID-19” (PASC, also known as long COVID), which can persist for months and maybe even years. In this review, we outline current knowledge on the role of impaired microbiota-gut-brain (MGB) axis signaling in the development of PASC and the potential mechanisms involved, which may lead to better understanding of disease progression and treatment options in the future.

Source: Gareau MG, Barrett KE. The role of the microbiota-gut-brain axis in post-acute COVID syndrome. Am J Physiol Gastrointest Liver Physiol. 2023 Mar 7. doi: 10.1152/ajpgi.00293.2022. Epub ahead of print. PMID: 36880667. https://journals.physiology.org/doi/abs/10.1152/ajpgi.00293.2022 (Full text available as PDF file)

SARS-CoV-2 infection induces DNA damage, through CHK1 degradation and impaired 53BP1 recruitment, and cellular senescence

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the RNA virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Although SARS-CoV-2 was reported to alter several cellular pathways, its impact on DNA integrity and the mechanisms involved remain unknown. Here we show that SARS-CoV-2 causes DNA damage and elicits an altered DNA damage response.

Mechanistically, SARS-CoV-2 proteins ORF6 and NSP13 cause degradation of the DNA damage response kinase CHK1 through proteasome and autophagy, respectively. CHK1 loss leads to deoxynucleoside triphosphate (dNTP) shortage, causing impaired S-phase progression, DNA damage, pro-inflammatory pathways activation and cellular senescence. Supplementation of deoxynucleosides reduces that. Furthermore, SARS-CoV-2 N-protein impairs 53BP1 focal recruitment by interfering with damage-induced long non-coding RNAs, thus reducing DNA repair.

Key observations are recapitulated in SARS-CoV-2-infected mice and patients with COVID-19. We propose that SARS-CoV-2, by boosting ribonucleoside triphosphate levels to promote its replication at the expense of dNTPs and by hijacking damage-induced long non-coding RNAs’ biology, threatens genome integrity and causes altered DNA damage response activation, induction of inflammation and cellular senescence.

Source: Gioia U, Tavella S, Martínez-Orellana P, Cicio G, Colliva A, Ceccon M, Cabrini M, Henriques AC, Fumagalli V, Paldino A, Presot E, Rajasekharan S, Iacomino N, Pisati F, Matti V, Sepe S, Conte MI, Barozzi S, Lavagnino Z, Carletti T, Volpe MC, Cavalcante P, Iannacone M, Rampazzo C, Bussani R, Tripodo C, Zacchigna S, Marcello A, d’Adda di Fagagna F. SARS-CoV-2 infection induces DNA damage, through CHK1 degradation and impaired 53BP1 recruitment, and cellular senescence. Nat Cell Biol. 2023 Mar 9. doi: 10.1038/s41556-023-01096-x. Epub ahead of print. PMID: 36894671. https://www.nature.com/articles/s41556-023-01096-x (Full text)

Outpatient Treatment of COVID-19 and the Development of Long COVID Over 10 Months: A Multi-Center, Quadruple-Blind, Parallel Group Randomized Phase 3 Trial

Abstract:

Background: Post-acute sequelae of COVID, termed “Long COVID”, is an emerging chronic illness potentially affecting ~10% of those with COVID-19. We sought to determine if outpatient treatment with metformin, ivermectin, or fluvoxamine could prevent Long COVID.

Methods: COVID-OUT (NCT04510194) was a decentralized, multi-site trial in the United States testing three medications (metformin, ivermectin, fluvoxamine) using a 2×3 parallel treatment factorial randomized assignment to efficiently share placebo controls. Participants, investigators, care providers, and outcomes assessors were masked to randomized treatment assignment. Inclusion criteria included: age 30 to 85 years with overweight or obesity, symptoms <7 days, enrolled within <=3 days of documented SARS-CoV-2 infection. Long COVID diagnosis from a medical provider was a pre-specified secondary outcome assessed by monthly surveys through 300 days after randomization and confirmed in medical records.

Findings: Of 1323 randomized trial participants, 1125 consented for long-term follow up, and 95.1% completed >9 months of follow up. The median age was 45 years (IQR, 37 to 54), and 56% were female (7% pregnant). The median BMI was 30 kg/m2 (IQR, 27 to 34). Overall, 8.4% reported a medical provider diagnosed them with Long COVID; cumulative incidence: 6.3% with metformin and 10.6% with matched placebo. The hazard ratio (HR) for metformin preventing Long COVID was 0.58 (95%CI, 0.38 to 0.88; P=0·009) versus placebo. The metformin effect was consistent across subgroups, including viral variants. When metformin was started within <4 days of symptom onset, the HR for Long COVID was 0.37 (95%CI, 0.15 to 0.95).  No statistical difference in Long COVID occurred in those randomized to either ivermectin (HR=0.99; 95%CI, 0.59 to 1.64) or fluvoxamine (HR=1.36; 95%CI, 0.78 to 2.34).

Interpretations: A 42% relative decrease and 4.3% absolute decrease in the Long COVID incidence occurred in participants who received early outpatient COVID-19 treatment with metformin compared to exact-matching placebo.

Source: Bramante, Carolyn and Buse, John B. and Liebovitz, David and Nicklas, Jacinda and Puskarich, Michael and Cohen, Kenneth R. and Belani, Hrishikesh and Anderson, Blake and Huling, Jared D. and Thompson, Jennifer and Pullen, Matthew and Wirtz, Esteban Lemus and Siegel, Lianne and Proper, Jennifer and Odde, David J. and Klatt, Nichole and Sherwood, Nancy E. and Lindberg, Sarah and Karger, Amy B. and Beckman, Kenneth B. and Erickson, Spencer and Fenno, Sarah and Hartman, Katrina and Rose, Michael and Mehta, Tanvi and Patel, Barkha and Griffiths, Gwendolyn and Bhat, Neeta and Murray, Thomas A. and Boulware, David R., Outpatient Treatment of COVID-19 and the Development of Long COVID Over 10 Months: A Multi-Center, Quadruple-Blind, Parallel Group Randomized Phase 3 Trial. Available at SSRN: https://ssrn.com/abstract=4375620 or http://dx.doi.org/10.2139/ssrn.4375620

Long-term gastrointestinal outcomes of COVID-19

Abstract:

A comprehensive evaluation of the risks and 1-year burdens of gastrointestinal disorders in the post-acute phase of COVID-19 is needed but is not yet available. Here we use the US Department of Veterans Affairs national health care databases to build a cohort of 154,068 people with COVID-19, 5,638,795 contemporary controls, and 5,859,621 historical controls to estimate the risks and 1-year burdens of a set of pre-specified incident gastrointestinal outcomes.

We show that beyond the first 30 days of infection, people with COVID-19 exhibited increased risks and 1-year burdens of incident gastrointestinal disorders spanning several disease categories including motility disorders, acid related disorders (dyspepsia, gastroesophageal reflux disease, peptic ulcer disease), functional intestinal disorders, acute pancreatitis, hepatic and biliary disease.

The risks were evident in people who were not hospitalized during the acute phase of COVID-19 and increased in a graded fashion across the severity spectrum of the acute phase of COVID-19 (non-hospitalized, hospitalized, and admitted to intensive care). The risks were consistent in comparisons including the COVID-19 vs the contemporary control group and COVID-19 vs the historical control group as the referent category.

Altogether, our results show that people with SARS-CoV-2 infection are at increased risk of gastrointestinal disorders in the post-acute phase of COVID-19. Post-covid care should involve attention to gastrointestinal health and disease.

Source: Xu, E., Xie, Y. & Al-Aly, Z. Long-term gastrointestinal outcomes of COVID-19. Nat Commun 14, 983 (2023). https://doi.org/10.1038/s41467-023-36223-7 https://www.nature.com/articles/s41467-023-36223-7 (Full text)

Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis

Abstract:

Billions of years of co-evolution has made mitochondria central to the eukaryotic cell and organism life playing the role of cellular power plants, as indeed they are involved in most, if not all, important regulatory pathways. Neurological disorders depending on impaired mitochondrial function or homeostasis can be caused by the misregulation of “endogenous players”, such as nuclear or cytoplasmic regulators, which have been treated elsewhere. In this review, we focus on how exogenous agents, i.e., viral pathogens, or unbalanced microbiota in the gut-brain axis can also endanger mitochondrial dynamics in the central nervous system (CNS).

Neurotropic viruses such as Herpes, Rabies, West-Nile, and Polioviruses seem to hijack neuronal transport networks, commandeering the proteins that mitochondria typically use to move along neurites. However, several neurological complications are also associated to infections by pandemic viruses, such as Influenza A virus and SARS-CoV-2 coronavirus, representing a relevant risk associated to seasonal flu, coronavirus disease-19 (COVID-19) and “Long-COVID”.

Emerging evidence is depicting the gut microbiota as a source of signals, transmitted via sensory neurons innervating the gut, able to influence brain structure and function, including cognitive functions. Therefore, the direct connection between intestinal microbiota and mitochondrial functions might concur with the onset, progression, and severity of CNS diseases.

Source: Righetto I, Gasparotto M, Casalino L, Vacca M, Filippini F. Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis. Biomolecules. 2023 Jan 13;13(1):169. doi: 10.3390/biom13010169. PMID: 36671555; PMCID: PMC9855674. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9855674/ (Full text)

Investigating brain cortical activity in patients with post-COVID-19 brain fog

Abstract:

Brain fog is a kind of mental problem, similar to chronic fatigue syndrome, and appears about 3 months after the infection with COVID-19 and lasts up to 9 months. The maximum magnitude of the third wave of COVID-19 in Poland was in April 2021.

The research referred here aimed at carrying out the investigation comprising the electrophysiological analysis of the patients who suffered from COVID-19 and had symptoms of brain fog (sub-cohort A), suffered from COVID-19 and did not have symptoms of brain fog (sub-cohort B), and the control group that had no COVID-19 and no symptoms (sub-cohort C). The aim of this article was to examine whether there are differences in the brain cortical activity of these three sub-cohorts and, if possible differentiate and classify them using the machine-learning tools. The dense array electroencephalographic amplifier with 256 electrodes was used for recordings.

The event-related potentials were chosen as we expected to find the differences in the patients’ responses to three different mental tasks arranged in the experiments commonly known in experimental psychology: face recognition, digit span, and task switching. These potentials were plotted for all three patients’ sub-cohorts and all three experiments. The cross-correlation method was used to find differences, and, in fact, such differences manifested themselves in the shape of event-related potentials on the cognitive electrodes.

The discussion of such differences will be presented; however, an explanation of such differences would require the recruitment of a much larger cohort. In the classification problem, the avalanche analysis for feature extractions from the resting state signal and linear discriminant analysis for classification were used. The differences between sub-cohorts in such signals were expected to be found. Machine-learning tools were used, as finding the differences with eyes seemed impossible. Indeed, the A&B vs. C, B&C vs. A, A vs. B, A vs. C, and B vs. C classification tasks were performed, and the efficiency of around 60-70% was achieved.

In future, probably there will be pandemics again due to the imbalance in the natural environment, resulting in the decreasing number of species, temperature increase, and climate change-generated migrations. The research can help to predict brain fog after the COVID-19 recovery and prepare the patients for better convalescence. Shortening the time of brain fog recovery will be beneficial not only for the patients but also for social conditions.

Source: Wojcik GM, Shriki O, Kwasniewicz L, Kawiak A, Ben-Horin Y, Furman S, Wróbel K, Bartosik B, Panas E. Investigating brain cortical activity in patients with post-COVID-19 brain fog. Front Neurosci. 2023 Feb 9;17:1019778. doi: 10.3389/fnins.2023.1019778. PMID: 36845422; PMCID: PMC9947499. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9947499/ (Full text)

Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre

Abstract:

Introduction: Long-COVID-19 impacts health-related quality of life (HR-QoL) but data is scarce. The aim of this study was to describe and prospectively assess the prevalence and risk factors for long-COVID-19 after hospital discharge, and to evaluate its impact on patient HR-QoL.

Material and methods: Single-centre longitudinal study including all COVID-19 patients discharged between December 2020 and February 2021. Patients were contacted remotely at three, six and nine months. Data were collected as follows: 1) Long-COVID-19 symptoms were self-reported; 2) HRQoL were assessed using the 3-level EuroQoL-5D (EQ-5D-3L) questionnaire. Pregnant women, demented, bedridden, and non-Portuguese-speaking patients were excluded.

Results: The three-, six- and nine-month assessments were completed by 152, 117 and 110 patients (median age: 61 years; male sex: 56.6%). Long-COVID-19 (≥ 1 symptom) was reported by 66.5%, 62.4% and 53.6% of patients and HR-QoL assessment showed impairment of at least some domain in 65.8%, 69.2% and 55.4% of patients at three, six and nine months, respectively. Fatigue was the most common long-COVID-19 symptom. Anxiety/depression domain was the most frequently affected in all three time-points, peaking at six months (39%), followed by pain/discomfort and mobility domains. Long-COVID-19 was associated with the impairment of all EQ-5D-3L domains except for self-care domain at each time-point. Neither intensive care unit admission nor disease severity were associated with long-COVID-19 nor with impairment of any EQ-5D-3L domain. After adjusting for sex, age, frailty status, and comorbid conditions, long-COVID-19 remained significantly associated with HR-QoL impairment at three (OR 4.27, 95% CI 1.92 – 9.52, p < 0.001), six (OR 3.46, 95% CI 1.40 – 8.57, p = 0.007) and nine months (OR 4.13, 95% CI 1.62 – 10.55, p = 0.003) after hospital discharge. In a longitudinal analysis, patients reporting long-COVID-19 at three months had an EQ-5D-3L index value decreased by 0.14 per visit (p < 0.001) compared to those without long-COVID-19 and both groups had a non-significant change in mean EQ-5D-3L index over the nine-month period (time-point assessment, Z = 0.91, p = 0.364).

Conclusion: Clinical sequelae associated with long-COVID-19 can persist for at least nine months after hospital discharge in most patients and can impair long-term HR-QoL in more than half of patients regardless of disease severity, and clinicodemographic characteristics.

Source: Gaspar P, Dias M, Parreira I, Gonçalves HD, Parlato F, Maione V, Atalaia Barbacena H, Carreiro C, Duarte L. Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre. Acta Med Port. 2023 Feb 24. doi: 10.20344/amp.19047. Epub ahead of print. PMID: 36827994. https://www.actamedicaportuguesa.com/revista/index.php/amp/article/view/19047 (Full text)

Long COVID: An unpredicted multisystem syndrome of COVID-19 disease

Abstract:

Long COVID is multisystem syndrome with nonspecific symptoms and organic signs of unidentified pathology occurs after COVID-19 disease. Long COVID symptoms has been documented in some cases irrespective of disease severity or hospitalization.
Long COVID symptoms has significant impact on quality of life in those cases suffered from disease in recent past and lingering to almost two years since infection. Importantly, not all cases of COVID-19 were shown long COVID symptoms. Pathophysiology resulting into long COVID manifestations is still not completely validated.
Researchers have reported ‘immune dysregulation’ and ‘coagulation abnormalities’ are probable pathophysiological mechanism for long COVID. Some of the long COVID effects shown complete reversibility including post COVID lung fibrosis. Reboot system to restore immune dysregulation and recovery in long COVID is real concern. Vaccination has not shown significant effect modifying long COVID manifestation. [Editor’s note: See conclusion in full text for a contradictory statement.]
Source: Hital Vishnu Patil, Neel Tandel and Gajanan Godhali. Long COVID: An unpredicted multisystem syndrome of COVID-19 disease. World Journal of Advanced Pharmaceutical and Life Sciences, 2023, 04(01), 005012. https://www.researchgate.net/publication/368757849_Long_COVID_An_unpredicted_multisystem_syndrome_of_COVID-19_disease (Full text)

Social Stigma, Mental Health, Stress, and Health-Related Quality of Life in People with Long COVID

Abstract:

A considerable amount of people who have been infected with SARS-CoV-2 experience ongoing symptoms, a condition termed long COVID. This study examined nuanced experiences of social stigma in people with long COVID and their associations with perceived stress, depressive symptoms, anxiety, and mental and physical health-related quality of life (hrqol).
A total of N = 253 participants with long COVID symptoms (mean age = 45.49, SD = 12.03; n = 224, 88.5% women) completed a cross-sectional online survey on overall social stigma and the subfacets enacted and perceived external stigma, disclosure concerns, and internalized stigma. Data were analysed using multiple regression and controlling for overall burden of consequences of long COVID, overall burden of symptoms of long COVID, and outcome-specific confounders.
In line with our preregistered hypotheses, total social stigma was related to more perceived stress, more depressive symptoms, higher anxiety, and lower mental hrqol, but—in contrast to our hypothesis—it was unrelated to physical hrqol after controlling for confounders. The three subscales of social stigma resulted in differential associations with the outcomes.
Social stigma experiences go hand in hand with worse mental health in people with long COVID. Future studies should examine potential protective factors to buffer the effects of social stigma on people’s well-being.
Source: Scholz U, Bierbauer W, Lüscher J. Social Stigma, Mental Health, Stress, and Health-Related Quality of Life in People with Long COVID. International Journal of Environmental Research and Public Health. 2023; 20(5):3927. https://doi.org/10.3390/ijerph20053927. https://www.mdpi.com/1660-4601/20/5/3927 (Full text)