Background: The gut–lung axis could be a potential therapeutic target for improving post-acute COVID-19 symptoms, and probiotics have been proposed as possible modulators. Aim: We conducted a pilot study to understand alterations in the gut–lung axis and to explore the effects of a probiotic in post-acute COVID-19 disease. Methods: We included patients after severe COVID-19 disease (sCOV, n = 21) in a randomized, placebo-controlled trial to test the effect of a probiotic (Pro-Vi 5, Institute Allergosan, Graz, Austria) in a six-month intervention and used patients after mild disease (mCOV, n = 10) as controls, to compare the intestinal microbiome, metabolome, and patient-reported outcomes and biomarkers along the gut–lung axis at baseline and throughout probiotic intervention. Results: Compared to mCOV patients, sCOV patients showed lower microbial richness, which was significantly improved by probiotic intervention. A reorganization of Ruminococcaceae and Lachnospiraceae taxa was observed in sCOV patients but remained unaffected by the intervention. Serum metabolome showed a dysregulation of lipoproteins in accordance with higher BMI and comorbidities in sCOV patients. HDL and LDL fractions/components were temporarily decreased in the probiotic group. Stool metabolome was altered at baseline in sCOV patients and an increase in L-DOPA after 3 months and butyrate after 6 months of intervention could be observed. Probiotics partially improved reduced quality of life and modulated altered immune responses in sCOV patients. Increased intestinal permeability at baseline remained unaffected. Conclusion: The study provides evidence of long-term alterations of the gut–lung axis after severe COVID-19 infection and suggests that probiotics can modulate the biomarkers of the gut–lung axis.

Oxidative albumin modification and impaired albumin binding function have been described both in chronic liver failure and for therapeutic albumin solutions. The aim of the present study was to evaluate the effect of albumin infusion on redox state and binding function of circulating albumin. We studied 20 patients with cirrhosis who routinely received albumin infusions for prevention of post-paracentesis circulatory dysfunction or treatment of hepatorenal syndrome. We measured albumin fractions by redox state of cysteine-34 and albumin binding properties using dansylsarcosine as site II ligand. Therapeutic albumin solutions showed high contents of human nonmercaptalbumin-1 and human nonmercaptalbumin-2, exceeding the respective values in our patients with decompensated cirrhosis. An initial protocol for the first nine patients sampled at baseline, 24 h and 48 h after albumin infusion revealed no significant changes of oxidized albumin species or albumin binding properties. However, a modified protocol for the remaining 11 patients sampled at baseline, <1 h after and 24 h after albumin infusion revealed short-lived changes of oxidized albumin species while no changes in albumin binding properties were observed. In conclusion, therapeutic albumin infusion transiently changed albumin redox state but did not improve binding function of circulating albumin in chronic liver failure.

Microbiome research is becoming increasingly relevant in both medicine and other socially significant areas, including agriculture, food security, and ecology. Many studies associate dysbiotic changes in the gut microbiome and other human organs with the development of pathological conditions. For instance, changes in the gut microbiota have been associated with the development of cardiovascular and respiratory diseases, which are the leading causes of death worldwide. The development of rapid screening methods for complex microbiome dynamics may in the future become the methods of choice for early diagnosis and monitoring the progression and effectiveness of treatment for microbiome-associated diseases in clinical diagnostic centers. This review article will examine the main currently proposed approaches to microbiome fingerprinting, including denaturing gradient gel electrophoresis, temperature gradient gel electrophoresis, terminal restriction fragment length polymorphism, automated rRNA intergenic spacer analysis, single-strand conformation polymorphism, amplicon length heterogeneity-PCR, cytometric fingerprinting, and high-resolution melting curve analysis. We compare the advantages and disadvantages of these methods, assess their potential for rapid screening of microbiome composition changes, and propose directions for further research in this area.

Microbiome research is becoming increasingly relevant in both medicine and other socially significant areas, including agriculture, food security, and ecol

Introduction. Bacteria need CRISPR-Cas systems to form an adaptive immune response necessary for protection against infectious agents. In addition, in rece