A systematic review of gut microbiota profile in COVID-19 patients and among those who have recovered from COVID-19.

OBJECTIVES: Given the scale and persistence of coronavirus disease 2019 (COVID-19), significant attention has been devoted to understanding the relationship between human gut microbiota and COVID-19. In this systematic review we aimed to comprehensively assess the gut microbiota composition in patients infected with COVID-19 and those recovered from COVID-19 in comparison to healthy controls (HCs). METHODS: Peer-reviewed articles and preprints published up to September 1, 2022, were searched in Ovid MEDLINE, Ovid EMBASE, and SCOPUS. Observational studies reporting the gut microbiota profile in adult (≥18 years) COVID-19 patients or those recovered from COVID-19 compared to HCs were eligible for inclusion in this systematic review. The quality assessment of studies was performed using the Newcastle-Ottawa scale. RESULTS: We identified 27 studies comprising 18 studies that compared COVID-19 patients and six that compared recovered COVID-19 patients to HCs, while the other three studies compared both COVID-19 and recovered COVID-19 patients to HCs. Compared to HCs, decreased gut microbial diversity and richness and a distinctive microbial composition were reported in COVID-19 patients and recovered COVID-19 patients. In COVID-19 patients, Bacteroidetes were found to be enriched, and Firmicutes depleted. Decreased short-chain fatty acid (SCFA)-producing bacteria, such as Faecalibacterium, Ruminococcus, and Bifidobacterium, among others, were also observed in COVID-19 patients, which were not restored to normal levels in those who recovered. CONCLUSION: Gut dysbiosis was evident in COVID-19, and available data suggested that dysbiosis persisted even in recovered COVID-19 patients, with decreased Firmicutes and SCFA-producing bacteria.

Gastrointestinal Symptoms of Monkeypox Infection: A systematic review and meta-analysis.

Since early May 2022, outbreaks of Monkeypox (Mpox) cases have emerged and become a global concern. Studies exploring the gastrointestinal symptoms and/or liver injury of Mpox are still very limited. This systematic review and meta-analysis is the first to summarize the gastrointestinal symptoms reported by Mpox patients. We searched for Mpox studies published until October 21, 2022, in MEDLINE, EMBASE, SCOPUS, and organization websites. Mpox studies were observational studies that reported at least one of either gastrointestinal symptoms and/or liver injury in Mpox patients. Meta-analysis was done to obtain the pooled prevalence of gastrointestinal symptoms in Mpox patients. Subgroup analyses were done based on the study location, age groups, and Mpox Clades. The quality of included studies was assessed using the NIH Quality Assessment Tool. Overall, 31 studies that reported gastrointestinal symptoms and/or liver injury in Mpox patients were included. The reported gastrointestinal symptoms were abdominal pain, anorexia, diarrhea, nausea, and vomiting. There is a lack of reporting for liver injury. The most prevalent gastrointestinal symptoms in Mpox patients were anorexia (47%; 95% confidence interval [CI] 41%-53%), followed by vomiting (12%; 95% CI 11%-13%), nausea (10%; 95% CI 9%-11%), abdominal pain (9%; 95% CI 8%-10%), and diarrhea (5%; 95% CI 4%-6%). Additionally, the prevalence of proctitis, rectal/anal pain, and rectal bleeding were 11% (95% CI 11%-12%), 25% (95% CI 24%-27%), and 12% (95% CI 11%-13%), respectively. Anorexia was the most frequently reported gastrointestinal symptom in Mpox patients, followed by vomiting, nausea, abdominal pain, and diarrhea. Proctitis is a novel presentation of Mpox in the 2022 outbreak.

Neutrophil-to-lymphocyte ratio on admission to predict the severity and mortality of COVID-19 patients: A meta-analysis.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR), an inflammatory marker, was suggested to be predictive of severity and mortality in COVID-19 patients. Here, we investigated whether NLR levels on admission could predict the severity and mortality of COVID-19 patients. METHODS: A literature search was conducted on 23 July 2020 to retrieve all published articles, including grey literature and preprints, investigating the association between on-admission NLR values and severity or mortality in COVID-19 patients. A meta-analysis was performed to determine the overall standardized mean difference (SMD) in NLR values and the pooled risk ratio (RR) for severity and mortality with the 95% Confidence Interval (95%CI). RESULTS: A total of 38 articles, including 5699 patients with severity outcomes and 6033 patients with mortality outcomes, were included. The meta-analysis showed that severe and non-survivors of COVID-19 had higher on-admission NLR levels than non-severe and survivors (SMD 0.88; 95%CI 0.72-1.04; I2 = 75.52% and 1.87; 95%CI 1.25-2.49; I2 = 97.81%, respectively). Regardless of the different NLR cut-off values, the pooled mortality RR in patients with elevated vs. normal NLR levels was 2.74 (95%CI 0.98-7.66). CONCLUSION: High NLR levels on admission were associated with severe COVID-19 and mortality. Further studies need to focus on determining the optimal cut-off value for NLR before clinical use.

Platelet-to-lymphocyte ratio, a novel biomarker to predict the severity of COVID-19 patients: A systematic review and meta-analysis

Platelet-to-lymphocyte ratio (PLR), a novel inflammatory marker, has been suggested to predict the severity of COVID-19 patients. This systematic review aims to evaluate the association between PLR levels on admission and the severity of COVID-19 patients. A systematic literature search was done on 23 July 2020 to identify peer-reviewed studies, preprints, and grey literatures. Research articles comparing the PLR value on admission in adult patients with COVID-19 with varying degrees of severity were included in the analysis. The following keywords were used for the search: ?COVID-19?, ?PLR?, ?severity?, and ?mortality?. A total of seven studies were included in the meta-analysis, six of which were conducted in China. From a total of 998 participants included, 316 (31.7%) had severe diseases;and those in the severe group were generally older and had underlying diseases compared to the non-severe group. In comparison to non-severe patients, the meta-analysis showed that severe COVID-19 patients had higher PLR levels on admission (SMD 0.68;95%CI 0.43-0.93;I2 =58%). High PLR levels on admission were associated with severe COVID-19 cases. Therefore, the on-admission PLR level is a novel, cost-effective, and readily available biomarker with a promising prognostic role for determining the severity of COVID-19 patients.

D-dimer levels on admission and all-cause mortality risk in COVID-19 patients: a meta-analysis.

D-dimer level on admission is a promising biomarker to predict mortality in patients with COVID-19. In this study, we reviewed the association between on-admission D-dimer levels and all-cause mortality risk in COVID-19 patients. Peer-reviewed studies and preprints reporting categorised D-dimer levels on admission and all-cause mortality until 24 May 2020 were searched for using the following keywords: 'COVID-19', 'D-dimer' and 'Mortality'. A meta-analysis was performed to determine the pooled risk ratio (RR) for all-cause mortality. In total, 2911 COVID-19 patients from nine studies were included in this meta-analysis. Regardless of the different D-dimer cut-off values used, the pooled RR for all-cause mortality in patients with elevated vs. normal on-admission D-dimer level was 4.77 (95% confidence interval (CI) 3.02-7.54). Sensitivity analysis did not significantly affect the overall mortality risk. Analysis restricted to studies with 0.5 µg/ml as the cut-off value resulted in a pooled RR for mortality of 4.60 (95% CI 2.72-7.79). Subgroup analysis showed that the pooled all-cause mortality risk was higher in Chinese vs. non-Chinese studies (RR 5.87; 95% CI 2.67-12.89 and RR 3.35; 95% CI 1.66-6.73; P = 0.29). On-admission D-dimer levels showed a promising prognostic role in predicting all-cause mortality in COVID-19 patients, elevated D-dimer levels were associated with increased risk of mortality.