Investigation of Potential Gut Health Biomarkers in Broiler Chicks Challenged by Campylobacter jejuni and Submitted to a Continuous Water Disinfection Program.

The exploration of novel biomarkers to assess poultry health is of paramount importance, not only to enhance our understanding of the pathogenicity of zoonotic agents but also to evaluate the efficacy of novel treatments as alternatives to antibiotics. The present study aimed to investigate potential gut health biomarkers in broiler chicks challenged by Campylobacter jejuni and subjected to a continuous water disinfection program. A total of 144 one-day-old hatched broiler chicks were randomly allocated to four treatment groups with four replicates each, according to the following experimental design: Group A received untreated drinking water; Group B received drinking water treated with 0.01-0.05% v/v Cid 2000™ (hydrogen peroxide, acetic acid and paracetic acid); Group C was challenged by C. jejuni and received untreated drinking water; and Group D was challenged by C. jejuni and received drinking water treated with 0.01-0.05% v/v Cid 2000™. The use of Cid 2000™ started on day 1 and was applied in intervals until the end of the experiment at 36 days, while the C. jejuni challenge was applied on day 18. Potential biomarkers were investigated in serum, feces, intestinal tissue, intestinal content, and liver samples of broilers. Statistical analysis revealed significant increases (p < 0.001) in serum cortisol levels in C. jejuni-challenged broilers. Serum fluorescein isothiocyanate dextran (FITC-d) increased significantly (p = 0.004) in broilers challenged by C. jejuni and treated with drinking water disinfectant, while fecal ovotransferrin concentration also increased significantly (p < 0.001) in broilers that received the drinking water disinfectant alone. The gene expression levels of occludin (p = 0.003) and mucin-2 (p < 0.001) were significantly upregulated in broilers challenged by C. jejuni, while mucin-2 significantly increased in birds that were challenged and received the drinking water disinfectant (p < 0.001). TLR-4 expression levels were significantly (p = 0.013) decreased in both groups that received the drinking water disinfectant, compared to the negative control group. Finally, the C. jejuni challenge significantly increased (p = 0.032) the crypt depth and decreased (p = 0.021) the villus height-to-crypt-depth ratio in the ileum of birds, while the tested disinfectant product increased (p = 0.033) the villus height in the jejunum of birds. Furthermore, the counts of C. jejuni in the ceca of birds (p = 0.01), as well as its translocation rate to the liver of broilers (p = 0.001), were significantly reduced by the addition of the water disinfectant. This research contributes to novel insights into the intricate interplay of water disinfection and/or C. jejuni challenge with potential intestinal biomarkers. In addition, it emphasizes the need for continued research to unveil the underlying mechanisms, expands our understanding of broiler responses to these challenges and identifies breakpoints for further investigations.

Dissecting the Genetic Basis of the Technological, Functional, and Safety Characteristics of Lacticaseibacillus paracasei SRX10.

Nonstarter lactic acid bacteria (NSLAB) are major contributors to the unique characteristics (e.g., aroma, flavor, texture) of dairy and nondairy fermented products. Lc. paracasei SRX10 is an NSLAB strain originally isolated from a traditional Greek cheese and previously shown to exhibit favorable biotechnological characteristics. More specifically, the strain showed tolerance to simulated gastrointestinal conditions, exopolysaccharide (EPS) biosynthetic capacity, and lack of hemolytic activity and was used in the production of yoghurt and feta cheese with distinct organoleptic characteristics. The aim of the present study was to investigate these traits at the genome level through whole-genome sequencing (WGS), annotation, and comparative genomics. Functional annotation of the genome revealed that Lc. paracasei SRX10 can utilize different carbon sources, leading to the generation of flavor compounds, including lactic acid, acetate, ethanol, and acetoin. Similarly, full clusters for fatty acid biosynthesis, protein and peptide degradation, as well as genes related to survival under extreme temperatures, osmotic shock, and oxidative stress were annotated. Importantly, no transferable antibiotic resistance genes or virulence factors were identified. Finally, strain-specific primers based on genome-wide polymorphisms were designed for the efficient and rapid identification of Lc. paracasei SRX10 via multiplex PCR in fermented products.

Development of a Multiplex PCR Assay for Efficient Detection of Two Potential Probiotic Strains Using Whole Genome-Based Primers.

Probiotics are microorganisms that exert strain-specific health-promoting effects on the host. Τhey are employed in the production of functional dairy or non-dairy food products; still, their detection in these complex matrices is a challenging task. Several culture-dependent and culture-independent methods have been developed in this direction; however, they present low discrimination at the strain level. Here, we developed a multiplex PCR assay for the detection of two potential probiotic lactic acid bacteria (LAB) strains, Lactiplantibacillus plantarum L125 and Lp. pentosus L33, in monocultures and yogurt samples. Unique genomic regions were identified via comparative genomic analysis and were used to produce strain-specific primers. Then, primer sets were selected that produced distinct electrophoretic DNA banding patterns in multiplex PCR for each target strain. This method was further implemented for the detection of the two strains in yogurt samples, highlighting its biotechnological applicability. Moreover, it can be applied with appropriate modifications to detect any bacterial strain with available WGS.

The Role of the Gut Microbiome in Cancer Immunotherapy: Current Knowledge and Future Directions.

Cancer immunotherapy is a treatment modality that aims to stimulate the anti-tumor immunity of the host to elicit favorable clinical outcomes. Immune checkpoint inhibitors (ICIs) gained traction due to the lasting effects and better tolerance in patients carrying solid tumors in comparison to conventional treatment. However, a significant portion of patients may present primary or acquired resistance (non-responders), and thus, they may have limited therapeutic outcomes. Resistance to ICIs can be derived from host-related, tumor-intrinsic, or environmental factors. Recent studies suggest a correlation of gut microbiota with resistance and response to immunotherapy as well as with the incidence of adverse events. Currently, preclinical and clinical studies aim to elucidate the unique microbial signatures related to ICI response and anti-tumor immunity, employing metagenomics and/or multi-omics. Decoding this complex relationship can provide the basis for manipulating the malleable structure of the gut microbiota to enhance therapeutic success. Here, we delve into the factors affecting resistance to ICIs, focusing on the intricate gut microbiome-immunity interplay. Additionally, we review clinical studies and discuss future trends and directions in this promising field.

Evaluating the Role of Probiotics in the Prevention and Management of Age-Related Diseases.

The human lifespan has been significantly increased due to scientific advancements in the management of disease; however, the health span of the aging population does not follow the same trend. Aging is the major risk factor for multimorbidity that is derived from the progressive loss of homeostasis, immunological and stem cell exhaustion, as well as exacerbated inflammation responses. Age-related diseases presenting with high frequencies include neurodegenerative, musculoskeletal, cardiovascular, metabolic diseases and cancer. These diseases can be co-morbid and are usually managed using a disease-specific approach that can eventually lead to polypharmacy, low medication adherence rates and undesired drug-drug interactions. Novel studies suggest targeting the shared biological basis of age-related diseases to retard the onset and manage their manifestations. Harvesting the anti-inflammatory and immunomodulatory capacity of probiotics to tackle the root cause of these diseases, could pose a viable alternative. In this article, a comprehensive review of the effects of probiotic supplementation on the molecular pathogenesis of age-related diseases, and the potential of probiotic treatments as preventative or alleviatory means is attempted. Furthermore, issues on the safety and efficiency of probiotic supplementation, as well as the pitfalls of current clinical studies are discussed, while new perspectives for systematic characterization of probiotic benefits on aged hosts are outlined.

Probiotics in Extraintestinal Diseases: Current Trends and New Directions.

Probiotics are defined as live microorganisms that when administered in adequate amounts confer a health benefit to the host. Their positive supplementation outcomes on several gastrointestinal disorders are well defined. Nevertheless, their actions are not limited to the gut, but may also impart their beneficial effects at distant sites and organs. In this regard, in this review article we: (i) comprehensively describe the main mechanisms of action of probiotics at distant sites, including bones, skin, and brain; (ii) critically present their therapeutic potential against bone, skin, and neuronal diseases (e.g., osteoporosis, non-healing wounds and autoimmune skin illnesses, mood, behavior, memory, and cognitive impairments); (iii) address the current gaps in the preclinical and clinical research; and (iv) indicate new research directions and suggest future investigations.