Exploring the Effects of Probiotic Treatment on Urinary and Serum Metabolic Profiles in Healthy Individuals.

Probiotics are live microorganisms that confer health benefits when administered in adequate amounts. They are used to promote gut health and alleviate various disorders. Recently, there has been an increasing interest in the potential effects of probiotics on human physiology. In the presented study, the effects of probiotic treatment on the metabolic profiles of human urine and serum using a nuclear magnetic resonance (NMR)-based metabonomic approach were investigated. Twenty-one healthy volunteers were enrolled in the study, and they received two different dosages of probiotics for 8 weeks. During the study, urine and serum samples were collected from volunteers before and during probiotic supplementation. The results showed that probiotics had a significant impact on the urinary and serum metabolic profiles without altering their phenotypes. This study demonstrated the effects of probiotics in terms of variations of metabolite levels resulting also from the different probiotic posology. Overall, the results suggest that probiotic administration may affect both urine and serum metabolomes, although more research is needed to understand the mechanisms and clinical implications of these effects. NMR-based metabonomic analysis of biofluids is a powerful tool for monitoring host-gut microflora dynamic interaction as well as for assessing the individual response to probiotic treatment.

CHIKV strains Brazil (wt) and Ross (lab-adapted) differ with regard to cell host range and antiviral sensitivity and show CPE in human glioblastoma cell lines U138 and U251.

Chikungunya virus (CHIKV), a (re)emerging arbovirus, is the causative agent of chikungunya fever. To date, no approved vaccine or specific antiviral therapy are available. CHIKV has repeatedly been responsible for serious economic and public health impacts in countries where CHIKV epidemics occurred. Antiviral tests in vitro are generally performed in Vero-B4 cells, a well characterised cell line derived from the kidney of an African green monkey. In this work we characterised a CHIKV patient isolate from Brazil (CHIKVBrazil) with regard to cell affinity, infectivity, propagation and cell damage and compared it with a high-passage lab strain (CHIKVRoss). Infecting various cell lines (Vero-B4, A549, Huh-7, DBTRG, U251, and U138) with both virus strains, we found distinct differences between the two viruses. CHIKVBrazil does not cause cytopathic effects (CPE) in the human hepatocarcinoma cell line Huh-7. Neither CHIKVBrazil nor CHIKVRoss caused CPE on A549 human lung epithelial cells. The human astrocyte derived glioblastoma cell lines U138 and U251 were found to be effective models for lytic infection with both virus strains and we discuss their predictive potential for neurogenic CHIKV disease. We also detected significant differences in antiviral efficacies regarding the two CHIKV strains. Generally, the antivirals ribavirin, hydroxychloroquine (HCQ) and T-1105 seem to work better against CHIKVBrazil in glioblastoma cells than in Vero-B4. Finally, full genome analyses of the CHIKV isolates were done in order to determine their lineage and possibly explain differences in tissue range and antiviral compound efficacies.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.

In Vitro Selection of Lactobacillus and Bifidobacterium Probiotic Strains for the Management of Oral Pathobiont Infections Associated to Systemic Diseases.

The human oral pathobionts Aggregatibacter actinomycetemcomitans, Streptococcus mitis and Streptococcus mutans, in dysbiosis-promoting conditions, lead to oral infections, which also represent a threat to human systemic health. This scenario may be worsened by antibiotic misuse, which favours multi-drug resistance, making the research on pathogen containment strategies more than crucial. Therefore, we aimed to in vitro select the most promising probiotic strains against oral pathogen growth, viability, biofilm formation, and co-aggregation capacity, employing both the viable probiotics and their cell-free supernatants (CFSs). Interestingly, we also assessed probiotic efficacy against the three-pathogen co-culture, mimicking an environment similar to that in vivo. Overall, the results showed that Lactobacillus CFSs performed better than the Bifidobacterium, highlighting Limosilactobacillus reuteri LRE11, Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC04, and Limosilactobacillus fermentum LF26 as the most effective strains, opening the chance to deeper investigation of their action and CFS composition. Altogether, the methodologies presented in this study can be used for probiotic efficacy screenings, in order to better focus the research on a viable probiotic, or on its postbiotics, suitable in case of infections.

Oral microbiota and vitamin D impact on oropharyngeal squamous cell carcinogenesis: a narrative literature review.

An emerging body of research is revealing the microbiota pivotal involvement in determining the health or disease state of several human niches, and that of vitamin D also in extra-skeletal regions. Nevertheless, much of the oral microbiota and vitamin D reciprocal impact in oropharyngeal squamous cell carcinogenesis (OPSCC) is still mostly unknown. On this premise, starting from an in-depth scientific bibliographic analysis, this narrative literature review aims to show a detailed view of the state of the art on their contribution in the pathogenesis of this cancer type. Significant differences in the oral microbiota species quantity and quality have been detected in OPSCC-affected patients; in particular, mainly high-risk human papillomaviruses (HR-HPVs), Fusobacterium nucleatum, Porphyromonas gingivalis, Pseudomonas aeruginosa, and Candida spp. seem to be highly represented. Vitamin D prevents and fights infections promoted by the above identified pathogens, thus confirming its homeostatic function on the microbiota balance. However, its antimicrobial and antitumoral actions, well-described for the gut, have not been fully documented for the oropharynx yet. Deeper investigations of the mechanisms that link vitamin D levels, oral microbial diversity and inflammatory processes will lead to a better definition of OPSCC risk factors for the optimization of specific prevention and treatment strategies.

The Caspase-Activated DNase drives inflammation and contributes to defense against viral infection.

Mitochondria react to infection with sub-lethal signals in the apoptosis pathway. Mitochondrial signals can be inflammatory but mechanisms are only partially understood. We show that activation of the caspase-activated DNase (CAD) mediates mitochondrial pro-inflammatory functions and substantially contributes to host defense against viral infection. In cells lacking CAD, the pro-inflammatory activity of sub-lethal signals was reduced. Experimental activation of CAD caused transient DNA-damage and a pronounced DNA damage response, involving major kinase signaling pathways, NF-κB and cGAS/STING, driving the production of interferon, cytokines/chemokines and attracting neutrophils. The transcriptional response to CAD-activation was reminiscent of the reaction to microbial infection. CAD-deficient cells had a diminished response to viral infection. Influenza virus infected CAD-deficient mice displayed reduced inflammation in lung tissue, higher viral titers and increased weight loss. Thus, CAD links the mitochondrial apoptosis system and cell death caspases to host defense. CAD-driven DNA damage is a physiological element of the inflammatory response to infection.

Growth Conditions Influence Lactobacillus Cell-Free Supernatant Impact on Viability, Biofilm Formation, and Co-Aggregation of the Oral Periodontopathogens Fusobacterium nucleatum and Porphyromonas gingivalis.

Fusobacterium nucleatum and Porphyromonas gingivalis human periodontopathogens play a leading part in oral squamous cell carcinoma through cell proliferation, invasion, and persistent inflammation promotion and maintenance. To explore how the activity of Lactobacillus-derived cell-free supernatants (CFSs) can be influenced by growth medium components, CFSs were produced both in the standard MRS and the novel animal-derivative-free "Terreno Industriale Lattobacilli" (TIL) media, and in vitro screened for the containment of F. nucleatum and P. gingivalis both single and co-cultured and also for the interference on their co-aggregation. The viability assay demonstrated that the Limosilactobacillus reuteri LRE11 and Ligilactobacillus salivarius LS03 MRS-produced CFSs were significantly more effective against single and co-cultured pathogens. All the other CFSs significantly improved their efficacy when produced in TIL. Both MRS- and TIL-produced CFSs significantly inhibited the single and co-cultured pathogen biofilm formation. Only Levilactobacillus brevis LBR01 CFS in MRS specifically reduced F. nucleatum and P. gingivalis co-aggregation, while viable LBR01, LS03, and LRE11 in MRS significantly co-aggregated with the pathogens, but only LS03 cultivated in TIL improved this effect. This work paves the way to better consider environmental growth conditions when screening for probiotic and postbiotic efficacy as crucial to pathogen aggregation, adhesion to the host's niches, and exclusion.

Lactobacillus johnsonii LJO02 (DSM 33828) Cell-Free Supernatant and Vitamin D Improve Wound Healing and Reduce Interleukin-6 Production in Staphylococcus aureus-Infected Human Keratinocytes.

Methicillin-resistant biofilm-forming Staphylococcus spp. are found in about 25% of the overall cases of chronic wounds, which can undergo malignant degeneration and be associated with skin cancer. Although antimicrobial agents are clinically used to counteract pathogens and promote wound healing, they are increasingly ineffective against multi-drug resistant bacteria. Moreover, they can induce dysbiosis, which favors opportunistic pathogen infections and alters immune responses. Consequently, research on pathogen containment strategies is crucial. We aimed to evaluate the potential beneficial effect of Lactobacillus johnsonii LJO02 cell-free supernatant (CFS) and vitamin D, as single treatments or in combination, on cell viability, wound healing, and the pro-inflammatory interleukin-6 (IL-6) production of a Staphylococcus aureus-infected human immortalized keratinocyte cell line (HaCaT) in vitro model. The analysis showed that LJO02 CFS 20% v/v ratio and 100 nM vitamin D promoted infected cell viability and wound healing and significantly reduced IL-6 production. However, their effect was not synergic, since no significant difference between the single and combined treatments was observed. LJO02 CFS topic application and vitamin D supplementation could provide a valuable strategy for attenuating S. aureus-induced pathogenesis, promoting wound healing and opening new therapeutic strategies supporting the conventional approaches.

Microbiota, Oxidative Stress, and Skin Cancer: An Unexpected Triangle.

Mounting evidence indicates that the microbiota, the unique combination of micro-organisms residing in a specific environment, plays an essential role in the development of a wide range of human diseases, including skin cancer. Moreover, a persistent imbalance of microbial community, named dysbiosis, can also be associated with oxidative stress, a well-known emerging force involved in the pathogenesis of several human diseases, including cutaneous malignancies. Although their interplay has been somewhat suggested, the connection between microbiota, oxidative stress, and skin cancer is a largely unexplored field. In the present review, we discuss the current knowledge on these topics, suggesting potential therapeutic strategies.

An animal derivative-free medium enhances Lactobacillus johnsonii LJO02 supernatant selective efficacy against the methicillin (oxacillin)-resistant Staphylococcus aureus virulence through key-metabolites.

The spread of multidrug-resistant bacteria, such as the skin commensal Staphylococcus aureus, is a worldwide health challenge; new methods to counteract opportunistic pathogen growth and virulence are urgent. We compared the activity of Lacticaseibacillus rhamnosus LR06 (DSM 21981) and Lactobacillus johnsonii LJO02 (DSM 33828) cell-free supernatants (CFSs) produced in the conventional animal derivative-based MRS medium and an innovative animal derivative-free broth (TIL) versus the MDR S. aureus (ATCC 43300). CFS influence was assessed towards the viability, metabolic activity, and ability to form biofilm of the MDR strain through optical density, alamarBlue assay, and crystal violet staining; their content in short-chain fatty acids, lactic acid, and proteins was analysed via high-resolution mass spectrometry and gas chromatography. All CFSs reduce viable and metabolically active S. aureus, being TIL more efficient compared to MRS in stimulating lactic acid bacteria metabolism and decreasing S. aureus biofilm formation. Particularly, the CFS from LJO02 grown in TIL has the best efficacy, revealing a high amount of lactic acid and 59 peculiar proteins; its effectiveness is partially maintained upon trypsin and proteinase K treatments, but not by pepsin and pH basification. Therefore, antagonistic CFSs may represent a strategic prevention approach, with bacteriotherapeutic and bio-repair potential.

Macrophages expressing TREM-1 are involved in the progression of HPV16-related oropharyngeal squamous cell carcinoma.

INTRODUCTION: Many types of research have been performed to improve the diagnosis, therapy, and prognosis of oropharyngeal carcinomas (OP-SCCs). Since they arise in lymphoid-rich areas and intense lymphocytic infiltration has been related to a better prognosis, a TREM-1 putative function in tumour progression and survival has been hypothesized. MATERIALS AND METHODS: Twenty-seven human papillomavirus (HPV) 16+ OP-SCC specimens have been analyzed to relate TREM-1 expression with histiocytic and lymphocytic markers, HPV presence and patients' outcome. RESULTS: No differences have been shown between intratumoral and stromal CD4+ cells, while intratumoral CD8+ lymphocytes are higher with respect to the tumour stroma (p = .0005). CD68+ cells are more than CD35+ and TREM-1+; their presence is related to CD35± and TREM-1± histiocytes (p = .005 and .026, respectively). Intratumoral CD4+ lymphocytes are higher in p16+ cases (11/27) than in p16- (p = .042); moreover, p16 positivity correlates to a better survival (p = .034). CD4+, CD8+ and CD35+ cells have no impact on survival, while CD68 expression heavily influences progression and bad outcome (p = .037). TREM-1 positivity also leads to worst overall survival (p = .001): peritumoral expression and death-cause relationship are always significant, particularly when the cause is OP-SCC (p = .000). CONCLUSION: While p16 shows to better stratify HPV16+ patients' outcome, TREM-1+ macrophages suggest their key importance in HPV-related OP-SCCs progression.KEY MESSAGESTREM-1 positivity correlates to the worst overall survival of HPV16-positive OPSCCs-affected patients.p16-positive HPV16 related OPSCCs patients have a better prognosis with respect to p16-negative ones.

Anti-flavivirus Activity of Different Tritylated Pyrimidine and Purine Nucleoside Analogues.

A series of tritylated and dimethoxytritylated analogues of selected pyrimidine and purine nucleosides were synthesized and evaluated for their in vitro inhibitory activity against two important members of the genus Flavivirus in the Flaviviridae family, the yellow fever (YFV) and dengue viruses (DENV). Among all compounds tested, the 5'-O-tritylated and the 5'-O-dimethoxytritylated 5-fluorouridine derivatives exerted potency against YFV. Interestingly in the series of purine analogues, the 5'O, N-bis-tritylated fludarabine derivative revealed strong inhibitory activity against DENV at µm concentrations, however significantly weaker potency against YFV.