Severity of the Omicron SARS-CoV-2 variant compared with the previous lineages: A systematic review.

The Omicron variant was first detected in October 2021, which evolved from the original SARS-CoV-2 strain and was found to possess many mutations. Immune evasion was one of the notable consequences of these mutations. Despite Omicron exhibiting increased transmissibility, the rates of hospitalizations and deaths among patients infected with this variant were substantially lower when compared to other strains. However, concluding that the Omicron variant is less severe than other variants of SARS-CoV-2 requires consideration of multiple factors, including the vaccination status of infected patients as well as any previous infections with other variants. This review compiled data about any reported indicators of severity in Omicron-infected patients, including studies comparing Omicron with other variants while adjusting for confounders. A comprehensive search was conducted using different databases to target any studies about Omicron. In total, 62 studies met our inclusion criteria and were included in this study. Many studies reported a significantly reduced risk of hospitalization, ICU admission, need for oxygenation/ventilation, and death in Omicron-infected patients compared to patients infected with other variants, such as Delta. Some studies, however, reported comparable severity in Omicron infected patients as to other variants emphasizing a substantial risk for severe illness. Furthermore, the COVID-19 vaccines were less effective against Omicron relative to previous lineages, except after receiving the booster dose. One study recommended vaccination during pregnancy, which may help prevent future cases of severe SARS-CoV-2 pneumonia in neonates and young infants due to the transfer of humoral response from the mother.

Role of previous infection with SARS-CoV-2 in protecting against omicron reinfections and severe complications of COVID-19 compared to pre-omicron variants: a systematic review.

BACKGROUND: The SARS-CoV-2 virus elicited a major public concern worldwide since December 2019 due to the high number of infections and deaths caused by COVID-19. The Omicron variant was detected in October 2021 which evolved from the wild-type SARS-CoV-2 and was found to possess many mutations. Omicron exhibited high transmissibility and immune evasion as well as reduced severity when compared to the earlier variants. Although vaccinated individuals were largely protected against infections in previous waves, the high prevalence of both reinfections and breakthrough infections with Omicron was observed. The aim of this review is to understand the effectiveness of previous infection on subsequent reinfection, given its significance in driving public health policy, including vaccination prioritization and lockdown requirements. METHODS: A comprehensive literature search was conducted using several databases to target studies reporting data related to the effectiveness of the previous infection with SARS-CoV-2 in protecting against the Omicron variant. Screening of the studies, quality assessment and data extraction were conducted by two reviewers for each study. RESULTS: Only 27 studies met our inclusion criteria. It was observed that previous infection was less effective in preventing reinfections with the Omicron variant compared to the Delta variant irrespective of vaccination status. Furthermore, being fully vaccinated with a booster dose provided additional protection from the Omicron variant. Additionally, most infections caused by Omicron were asymptomatic or mild and rarely resulted in hospitalizations or death in comparison to the Delta wave. CONCLUSION: A majority of the studies reached a consensus that although previous infection provides some degree of immunity against Omicron reinfection, it is much lower in comparison to Delta. Full vaccination with two doses was more protective against Delta than Omicron. Receiving a booster dose provided additional protection against Omicron. It is therefore clear that neither vaccination nor previous infection alone provide optimal protection; hybrid immunity has shown the best results in terms of protecting against either Omicron or Delta variants. However, additional research is needed to quantify how long immunity from vaccination versus previous infection lasts and whether individuals will benefit from variant-specific vaccinations to enhance protection from infection.

The effect of microbiome-modulating probiotics, prebiotics and synbiotics on glucose homeostasis in type 2 diabetes: A systematic review, meta-analysis, and meta-regression of clinical trials.

AIM/HYPOTHESIS: The globally escalating diabetes epidemic is responsible for significant morbidity and mortality. Microbiome-modulating nutraceuticals have been investigated for their potential to restore metabolic and floral homeostasis in type 2 diabetic patients METHODS: A systematic review, meta-analyses and meta-regressions were conducted to investigate the effect of probiotics, prebiotics, and synbiotics on various biomarkers of glucose homeostasis based on a multi-database search of clinical trials published through April 10, 2022. Data was pooled using random effects meta-analyses and reported as mean differences with 95% confidence intervals (CIs), followed by univariate linear model meta-regression. RESULTS: Data from 68 trial comparisons across 58 studies (n = 3835) revealed that, compared to placebo/control group, administration of pro/pre/synbiotics was associated with statistically significant changes in fasting plasma glucose (-12.41 mg/dl [95% CI: -15.94; -8.88], p 0.0001), glycated hemoglobin (-0.38% [95% CI: -0.47; -0.30], p 0.0001), fasting insulin (-1.49 µU/mL [95% CI: -2.12; -0.86], p 0.0001), HOMA-IR (-0.69 [95% CI: -1.16; -0.23], p = 0.0031) and QUICKI (0.0148 [95% CI: 0.0052; 0.0244], p = 0.0025), but not C-peptide (-0.0144 ng/mL [95% CI: -0.2564; -0.2275], p = 0.9069). Age, baseline BMI, baseline biomarker value, pro/prebiotic dosage, trial duration, nutraceutical type, and recruitment region significantly affected the potential of pro/pre/synbiotics use as personalized diabetes adjunct therapy. Lastly, we discuss unexplained observations and directives for future trials, with the aim of maximizing our understanding of how microbiome-modulating nutraceuticals can treat various metabolic diseases CONCLUSIONS: Pro/pre/synbiotic supplementation improved glucose homeostasis in diabetic patients. Our results support their potential use as adjunct therapy for improving glycemia and insulinemia alongside pharmacological therapeutics.

Development and characterization of microsatellite primers for Triops granarius (Branchiopoda: Notostraca) using MiSeq technology.

BACKGROUND: Next-generation sequencing technology has allowed for the rapid development of microsatellites, neutral polymorphic markers that can be used for the analysis of population structure. METHODS AND RESULTS: In this study, we performed whole-genome sequencing using the Illumina MiSeq system and de novo assembly to design microsatellite primers for Triops granarius populations in Qatar. The developed microsatellites are suitable for future studies of genetic structuring among geographically isolated freshwater pools. A total of 23 different primer pairs produced typical microsatellite results, with each pair successfully amplified in up to 40 individuals. Only five of the loci produced a significant departure from Hardy-Weinberg equilibrium. CONCLUSIONS: Some of the underlying mechanisms regarding the few loci that deviated from HWE may be further investigated to determine the source of deviation. As T. granarius is the most widely distributed species of the family, the development of these molecular markers would be useful for conducting population genetics and biogeographical studies broadly.

Can probiotic, prebiotic, and synbiotic supplementation modulate the gut-liver axis in type 2 diabetes? A narrative and systematic review of clinical trials.

Background: Type 2 diabetes, one of the most common noncommunicable diseases, is a metabolic disorder that results in failed homeostatic control in several body systems, including hepatic function. Due to the gut microbiome's potential role in diabetes' pathogenesis, prebiotics, probiotics, and synbiotics have been proposed as complimentary therapeutic approaches aimed at microbiota readjustment. Methods: A systematic review was conducted on PubMed, Scopus, Web of Science, Embase, and the Cochrane Library examining the effect of probiotics, prebiotics, and synbiotics on hepatic biomarkers in patients with diabetes. Results: From 9,502 search hits, 10 studies met the inclusion criteria and were included in this review. A total of 816 participants (460 intervention and 356 control) were investigated for the effects of nine different hepatic biomarker measurements including aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, bilirubin, liver steatosis, liver stiffness, fatty liver index, and gamma-glutamyl transferase levels. Of the 13 intervention groups analyzed from the 10 studies, 3 were prebiotic interventions, 3 were single species probiotic interventions, 3 were multi-species probiotic interventions, and 4 were synbiotic interventions. Nutraceuticals used in these trials included six genera of bacteria (Lactobacillus, Bifidobacterium, Streptococcus, Acetobacter, Lactococcus, and Propionibacterium), five different prebiotic formulations (inulin, inulin and beta carotene, chicory inulin enriched with oligofructose, galacto-oligosaccharides syrup, and powdered cinnamon), or a combination of these to form multi-species probiotics or synbiotics. Conclusion: Although some studies showed insignificant changes in hepatic biomarkers, generally the results yielded a decrease in liver damage due to reduced oxidative stress, pro-inflammatory cytokines, gut dysbiosis, and insulin resistance which led to improvements in hepatic biomarker levels.