The OM-85 bacterial lysate: a new tool against SARS-CoV-2?

The emergence of SARS-CoV-2, a novel coronavirus, caused the global Coronavirus disease of 2019 (COVID-19) pandemic. Because SARS-CoV-2 mutates rapidly, vaccines that induce immune responses against viral components critical for target cell infection strongly mitigate but do not abrogate viral spread, and disease rates remain high worldwide. Complementary treatments are therefore needed to reduce the frequency and/or severity of SARS-CoV-2 infections. OM-85, a standardized lysate of 21 bacterial strains often found in the human airways, has immuno-modulatory properties and is widely used empirically in Europe, South America and Asia for the prophylaxis of recurrent upper airway infections in adults and children, with excellent safety profiles. In vitro studies from our laboratory recently demonstrated that OM-85 inhibits SARS-CoV-2 epithelial cell infection by downregulating SARS-CoV-2 receptor expression, raising the possibility that this bacterial extract might eventually complement the current COVID-19 therapeutic toolkit. Here we discuss how our results and those from other groups are fostering progress in this emerging field of research.

Postbiotics: From emerging concept to application

The microbiome innovation has resulted in an umbrella term, postbiotics, which refers to non-viable microbial cells, metabolic byproducts and their microbial components released after lysis. Postbiotics, modulate immune response, gene expression, inhibit pathogen binding, maintain intestinal barriers, help in controlling carcinogenesis and pathogen infections. Postbiotics have antimicrobial, antioxidant, and immunomodulatory properties with favorable physiological, immunological, neuro-hormonal, regulatory and metabolic reactions. Consumption of postbiotics relieves symptoms of various diseases and viral infections such as SARS-CoV-2. Postbiotics can act as alternatives for pre-probiotic specially in immunosuppressed patients, children and premature neonates. Postbiotics are used to preserve and enhance nutritional properties of food, elimination of biofilms and skin conditioning in cosmetics. Postbiotics have numerous advantages over live bacteria with no risk of bacterial translocation from the gut to blood, acquisition of antibiotic resistance genes. The process of extraction, standardization, transport, and storage of postbiotic is more natural. Bioengineering techniques such as fermentation technology, high pressure etc., may be used for the synthesis of different postbiotics. Safety assessment and quality assurance of postbiotic is important as they may induce stomach discomfort, sepsis and/or toxic shock. Postbiotics are still in their infancy compared to pre- and pro- biotics but future research in this field may contribute to improved physiological functions and host health. The current review comprehensively summarizes new frontiers of research in postbiotics. Copyright © 2022 Aggarwal, Sabharwal, Kaushik, Joshi, Aayushi and Suri.

Immunoprophylaxis of influenza, acute and recurrent respiratory infections during the COVID-19 pandemic

The article notes features of the last epidemic season (2020-2021) in the form of extremely low activity of influenza viruses with SARS-CoV-2 remaining dominant in the etiological structure of acute respiratory viral infections. Presented own data indicating the heterogeneity of SARS-CoV-2 (Alpha, Delta, B.1.1.317, B.1.1.397, B.1.1.523) isolated from hospitalized patients was noted. An increase in the etiological role of bocavirus, alpha-coronavirus and metapneumovirus with a decrease in the frequency of parainfluenza viruses, adenoviruses, rhinoviruses and respiratory syncytial virus was established. An unusual shift of the period of maximum activity of respiratory syncytial virus to the 20th week was noted. Attention is paid to the need during the ongoing pandemic COVID-19 to fully immunize children as part of the National Immunization Calendar, also emphasized the role of mandatory annual vaccination against influenza. It is noted that the maximum protective effect of immunoprophylaxis of influenza acute and recurrent respiratory infections can be achieved with a combination of vaccination with bacterial lysates. The article presents a review of the literature and our data demonstrating the safety, good tolerability, and high clinical and immunological efficiency of polyvalent mechanical bacterial lysate for the prevention of acute and recurrent respiratory infections in children. It is shown that the use of polyvalent mechanical bacterial lysate during the prevaccination period makes it possible to substantially reduce the frequency of intercurrent infections, which reduces the number of temporary medical withdrawals and increases the coverage of vaccinations against influenza in organized groups to 85.1%. The role of trained immunity as one of the possible mechanisms providing nonspecific immunoprophylaxis during influenza vaccination and the use of bacterial lysates is discussed. © 2021, Remedium Group Ltd. All rights reserved.

Viral infections and wheezing-asthma inception in childhood: is there a role for immunomodulation by oral bacterial lysates?

Severe and recurrent infections of the respiratory tract in early childhood constitute major risk factors for the development of bronchial hyper-responsiveness and obstructive respiratory diseases in later life. In the first years of life, the vast majority of respiratory tract infections (RTI) leading to wheezing and asthma are of a viral origin and severity and recurrence are the consequence of a greater exposure to infectious agents in a period when the immune system is still relatively immature. Therefore, boosting the efficiency of the host immune response against viral infections seems to be a rational preventative approach. In the last decades it has been demonstrated that living in farm environments, i.e. early-life exposure to microbes, may reduce the risk of allergic and infectious disorders, increasing the immune response efficacy. These findings have suggested that treatment with bacterial lysates could promote a nonspecific immunomodulation useful in the prevention of recurrent RTIs and of wheezing inception and persistence. Experimental and clinical studies showing the reduction of RTI frequency and severity in childhood and elucidating the involved mechanisms can support this hypothesis.