The role of gut microbiota (GM) and intestinal dysbiosis in triggering the onset and/or modulating the severity and progression of lupus nephritis (LN) has been the object of intense research over the last few years. Some alterations at the phyla level, such as the abundance of Proteobacteria and reduction in Firmicutes/Bacteroidetes (F/B) ratio and in α-diversity have been consistently reported in systemic lupus erythematosus (SLE), whereas a more specific role has been ascribed to some species (Bacteroides thetaiotaomicron and Ruminococcus gnavus) in LN. Underlying mechanisms include microbial translocation through a “leaky gut” and subsequent molecular mimicry, immune dysregulation (alteration of IFNγ levels and of balance between Treg and Th17 subsets), and epigenetic interactions. Levels of bacterial metabolites, such as butyrate and other short-chain fatty acids (SCFAs), appear to play a key role in modulating LN. Beyond bacterial components of GM, virome and mycobiome are also increasingly recognized as important players in the modulation of an immune response. On the other hand, microbiota-based therapy appears promising and includes diet, prebiotics, probiotics, symbiotics, and fecal microbiota transplantation (FMT). The modulation of microbiota could correct critical alterations, such as F/B ratio and Treg/Th17 imbalance, and blunt production of autoantibodies and renal damage. Despite current limits, GM is emerging as a powerful environmental factor that could be harnessed to interfere with key mechanisms leading to SLE, preventing flares and organ damage, including LN. The aim of this review is to provide a state-of-the-art analysis of the role of GM in triggering and modulating SLE and LN on the one hand, while exploring possible therapeutic manipulation of GM to control the disease on the other hand.

Given the ongoing COVID-19 pandemic, there is a need to identify SARS-CoV-2 and to differentiate it from other respiratory viral infections, especially influenza A and B, in various critical settings. Since their introduction, the use of rapid antigen tests has spread worldwide, but there is variability in their diagnostic accuracy. In the present study, we evaluated the clinical performance of the ID NOW™ COVID-19 2.0, a molecular point-of-care test (POCT) based on enzymatic isothermal amplification for the differential diagnosis of SARS-CoV-2 and influenza A/B in a pediatric emergency setting. A cohort of pediatric patients admitted between December 2022 and February 2023 were simultaneously tested with the POCT and standard laboratory molecular assay. Our findings showed high negative agreement of the POCT assay across the different age groups for SARS-CoV-2, influenza A, and influenza B (more than 98.0%), while its positive agreement varied significantly for the abovementioned viral species from 50.0% to 100%. These results highlight the potential of the ID NOW™ COVID-19 2.0 POCT assay as a reliable and rapid tool for excluding SARS-CoV-2 and influenza A/B infections in symptomatic pediatric patients, although its variable positive agreement suggests a need for confirmatory RT-qPCR testing in certain clinical and epidemiological settings in order to ensure accurate diagnosis and appropriate patient management.

Fecal Microbiota Transplantation (FMT) represents a promising therapeutic tool under study for several purposes and is currently applied to the treatment of recurrent Clostridioides difficile infection. However, since the use of fresh stool was affected by several issues linked to donor screening, the development of a frozen stool bank is a reliable option to standardize FMT procedures. Nevertheless, different environmental factors impact microbial viability. Herein, we report the effect of different thawing temperatures and storage conditions on bacterial suspensions in the FMT procedure. In total, 20 stool samples were divided into aliquots and tested across a combination of different storing periods (15, 30; 90 days) and thawing procedures (4 °C overnight, room temperature for 1 h; 37 °C for 5 min). Focusing on storage time, our data showed a significant reduction in viability for aerobic and anaerobic bacteria after thawing for 15 days, while no further reductions were observed until after 90 days. Instead, among the different thawing procedures, no significant differences were observed for aerobic bacteria, while for anaerobes, thawing at 37 °C for 5 min was more effective in preserving the bacterial viability. In conclusion, the frozen fecal microbiota remained viable for at least three months, with an excellent recovery rate in all three thawing conditions.

Asthma is one of the most common chronic diseases in childhood, and the gut microbiota is increasingly recognized as a key player in its pathogenesis through the gut–lung axis. This pilot, cross-sectional study analyzed the intestinal microbiota of 20 children (6–9 years) with intermittent or mild persistent asthma, in the absence of a healthy control group. Stool samples were processed with 16S rRNA sequencing (Illumina iSeq100, V3–V6 regions) and analyzed with MicrobAT-SmartSeq software. Contrary to most literature, no enrichment of Proteobacteria was detected, and Faecalibacterium was not reduced but emerged as the most abundant genus. Higher adherence to the Mediterranean diet correlated with greater microbial richness, while asthma phenotypes showed no major taxonomic differences. Pharmacological treatments modulated microbial profiles: leukotriene antagonists correlated with protective taxa, whereas inhaled corticosteroids and bronchodilators were linked to reduced beneficial functions. These findings highlight an overall eubiotic microbiota in asthmatic schoolchildren and call for larger, controlled studies to confirm these novel observations.

To carry out effective and quick identification of SARS-CoV-2 from nasopharyngeal swabs and contain outbreaks, reliable and rapid tools are needed. Herein, we compared a rapid antigen test based on active microfluidic technology to an RT-qPCR assay in pediatric and young adult patients admitted to the Pediatric Emergency Unit of a Children’s Hospital. Nasopharyngeal swabs collected from patients with suspected COVID-19 disease and from those without COVID-19 related symptoms, but requiring hospitalization, were performed with both antigen test and RT-qPCR assays. We included 375 patients with a median age of 5 years in the study, with an estimated overall prevalence of 7.2%. Overall, we observed a specificity of 97.4% (95% CI: 94.9–98.7) and a sensitivity of 66.6% (95% CI: 46.0–82.7) with a positive likelihood ratio (LR+) of 25.8 (95% CI: 12.8–51.8). In the subgroup of symptomatic patients, the specificity and the sensitivity were 95.2% (95% CI: 89.4–98.0) and 80.0% (95% CI: 44.2–96.5) respectively; LR+ was 16.6 (95% CI: 7.19–38.6). In the asymptomatic subset, the performance showed a specificity of 98.7% (95% CI: 95.8–99.7), a sensitivity of 58.8% (95% CI: 33.5–80.6), and an LR+ of 43.7 (95% CI: 13.3–144.0). Compared to RT-qPCR, the new microfluidic-based antigen test showed higher specificity (>95%) in the pediatric population, thus representing a suitable point-of-care testing (POCT) in a clinical setting with low prevalence of COVID-19.