Background: Anti-SARS-CoV-2 neutralizing monoclonal antibodies (mAbs) have been shown to have clinical benefits in treating high-risk patients with mild-moderate COVID-19. SARS-CoV-2 RNA in serum (RNAemia), is usually associated with severe disease and deaths. This study evaluates real-life data on the effectiveness of mAbs therapies against SARS-CoV-2 infections by different viral variants, particularly in the presence of RNAemia, focusing on clinical outcomes. Methods: From March 2021 to May 2022, high-risk patients with PCR-confirmed mild-moderate COVID-19 were enrolled at the Clinic of Infectious Diseases, San Paolo Hospital in Milan. Patients received Bamlanivimab/Bamlanivimab + Etesevimab/Casirivimab + Imdevimab/Sotrovimab based on Agenzia Italiana del Farmaco (AIFA) guidelines and prevalent SARS-CoV-2 variants. Nasopharyngeal swabs (NPS) and plasma samples were collected at infusion (t0) and after 7 days (t1). NPS viral loads and RNAemia were quantified using RT-qPCR, and variant typing was conducted. Clinical outcomes were evaluated, including time to symptom resolution and adverse effects. Results: Among 176 enrolled patients, treatment efficacy was observed in 96.6% with a median time to symptom resolution of 12 days (IQR 10–19). Viral load significantly decreased in both NPS and plasma by day 7 post-treatment (p<0.001). At t0, RNAemia was present in 61.9% of patients and NPS viral loads were higher in patients with RNAemia (p=0.002). However, after treatment, no significant differences in viral loads and times to symptom resolution were noted between patients with and without RNAemia. Omicron-infected patients exhibited higher plasma viral loads compared to Alpha and Delta variants (p<0.001) and the presence of RNAemia was significantly associated with Omicron (p<0.001). Vaccinated patients achieved faster recovery regardless of variant type (p=0.001). Conclusion: Early administration of anti-SARS-CoV-2 mAbs in high-risk patients significantly reduced viral loads in NPS and plasma and improved clinical outcomes. Despite the presence of RNAemia, these tailored mAb therapies led to favorable recovery times and minimal adverse effects.

Background/Objectives: Phenylketonuria (PKU) is an inherited metabolic disorder requiring early and lifelong dietary management through a low-phenylalanine (Phe) diet supplemented with Phe-free protein substitutes (PS). Recently developed slow-release PS formulations aim to mimic natural protein absorption, enhancing metabolic stability and tolerability. The PREMP study (effect of Protein RElease on the Microbiota composition and function in Phenylketonuric subjects) assessed the effects of a slow-release, Phe-free PS on gut microbiota composition and metabolic parameters in patients with PKU. Methods: Patients aged ≥6 years with PKU were enrolled from two Italian centers (Milan and Naples). Participants replaced ≥50% of their usual protein equivalent (P.Eq.) intake from Phe-free PS with a slow-release PS for 4 months. Clinical, biochemical, and nutritional assessments were performed at baseline and post-intervention. Gut microbiota composition was analyzed by 16S rRNA gene sequencing, and fecal fatty acids were quantified by gas chromatography–mass spectrometry. Results: Thirteen patients (median age 17 years) completed the intervention, replacing on average 78% of their usual P.Eq. intake with the slow-release formulation. Plasma phenylalanine and tyrosine levels remained stable, while fasting insulin (p = 0.0185) and HOMA-IR (p = 0.0099) significantly decreased, indicating improved insulin sensitivity. Anthropometric and dietary parameters showed no significant changes. Gut microbiota diversity remained stable, with modest increases in microbial richness and beneficial genera such as Bacteroides, Bifidobacterium, and Gemmiger, while Hafnia, Anaerostipes and Romboutsia decreased. Fecal butyrate and other fatty acids showed slight, non-significant increases. Conclusions: The slow-release PS was safe, well-tolerated, and improved insulin sensitivity without affecting amino acid or nutritional status. Microbial changes suggest potential benefits for gut health, warranting confirmation in larger, long-term studies.

Short-chain fatty acids (SCFAs) are widely used as functional readouts of gut microbial activity in vivo. The growing adoption of decentralised study designs and self-collection protocols has amplified the need for reliable room-temperature storage and shipment strategies. However, SCFAs volatility and the persistence of post-collection microbial metabolism raise concerns regarding pre-analytical stability and the interpretability of measured concentrations. We assessed the temporal stability of fatty acids (FAs) across intestinal and systemic matrices under room-temperature storage. Untreated stool was compared with two nucleic acid stabilisation devices (SMART-eNAT and OMNIgene-GUT), while whole blood, plasma, and dried blood spots (DBS) were evaluated as minimally invasive systemic sampling strategies. Profiles were quantified using complementary GC-MS and LC-MS/MS workflows. Untreated stool (n = 32) showed fermentation-driven increases in major SCFAs, whereas immediate freezing preserved baseline profiles. SMART-eNAT maintained faecal FA stability for up to 21 days, while OMNIgene-GUT exhibited baseline and time-dependent alterations. In systemic matrices (n = 20), plasma and whole blood showed an upward drift, whereas DBS declined initially before stabilising after approximately 14 days. FA measurements are highly matrix- and device-dependent. Our findings provide practical guidance for the selection of sampling strategies in microbiome-associated FA studies and emphasise the need for controlled pre-analytical conditions in decentralised microbiome studies.

: Background: Short-chain fatty acids (SCFAs) are widely used as functional readouts of gut microbial activity in vivo . The growing adoption of decentralised study designs and self-collection protocols has amplified the need for reliable room-temperature storage and shipment strategies. However, SCFAs volatility and the persistence of post-collection microbial metabolism raise concerns regarding pre-analytical stability and the interpretability of measured concentrations. Methods: We assessed the temporal stability of fatty acids (FAs) across intestinal and systemic matrices under room-temperature storage. Untreated stool was compared with two nucleic acid stabilisation devices (eNAT and OMNIgene-GUT), while whole blood, plasma and dried blood spots (DBS) were evaluated as minimally invasive systemic sampling strategies. Profiles were quantified using complementary GC-MS and LC-MS/MS workflows. Results: Untreated stool showed fermentation-driven increases in major SCFAs, whereas immediate freezing preserved baseline profiles. eNAT maintained faecal FA stability for up to 21 days, while OMNIgene-GUT exhibited baseline and time-dependent alterations. In systemic matrices, plasma and whole blood showed upward drift, whereas DBS declined initially before stabilising after approximately 14 days. Conclusions: FA measurements are highly matrix- and device-dependent. Our findings provide practical guidance for the selection of sampling strategies in microbiome-associated FA studies and emphasise the need for controlled pre-analytical conditions in decentralised microbiome studies.

Background/Objectives: Gut microbiota (GM) dysbiosis has been implicated in multiple sclerosis (MS) pathogenesis, influencing inflammation and neurodegeneration, but findings remain inconsistent due to environmental and methodological variability. This study aimed to identify possible microbial biomarkers of MS status and disease severity by profiling gut microbiota and short-chain fatty acid (SCFA) patterns in people with relapsing–remitting MS (pwRRMS), using household-matched healthy controls (HC) to minimize environmental variability. Methods: Twenty-four pwRRMS and their respective household-matched healthy controls (HC) were enrolled, with dietary and lifestyle habits monitored. GM composition was assessed by 16S rRNA gene sequencing, and fecal SCFAs were quantified using gas chromatography–mass spectrometry. PwRRMS were stratified by Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Severity Score (MSSS). Results: β-diversity did not differ between groups. However, α-diversity was significantly reduced in pwRRMS, particularly in those with greater disability. Reduced diversity was associated with lower abundance of butyrate-producing genera (Roseburia, Faecalibacterium, Coprococcus) and enrichment of Oscillibacter and UBA1819, alongside a downward trend in fecal butyrate and propionate levels. Conclusions: RRMS and greater disease severity are associated with gut microbial alterations characterized by reduced SCFA-producing bacteria. Despite limitations including small sample size and sex imbalance, the household-matched design strengthens internal validity. Our findings highlight the potential of targeting the gut microbiota, an accessible compartment within the gut–brain axis, for MS management.