Probiotics and Antimicrobial Proteins最新文献

Clostridial infections, known for their severity and rapid progression, present significant challenges in both clinical and veterinary fields. These bacteria, which can survive without oxygen and produce protective spores, cause many diseases, ranging from simple gastrointestinal disorders to severe and potentially fatal infections including botulism, tetanus, and gas gangrene. The rising occurrence of antibiotic-resistant strains and the repetitive character of some Clostridial illnesses, including Clostridioides difficile infections (CDI), highlight the immediate need for alternate treatment approaches. Postbiotics, which are metabolites derived from probiotics, are showing great potential as effective agents against these diseases. The current study offers a comprehensive investigation of the potential of postbiotics as therapeutic agents for treating Clostridial infections, including C. difficile, Clostridium perfringens, Clostridium botulinum, and Clostridium tetani. It also examines the processes by which postbiotics exert their effects. Preliminary investigations have shown that postbiotics have promising antibacterial and antibiofilm properties, indicating their potential as adjunct agents in methods for controlling microbial growth. Nevertheless, more study is required to thoroughly demonstrate their medicinal uses.

The rapid increase in microbial antibiotic resistance in Clostridioides difficile (C. difficile) strains and the formation of hypervirulent strains have been associated with a global increase in the incidence of C. difficile infection (CDI) and subsequently, an increase in the rate of recurrence. These consequences have led to an urgent need to develop new and promising alternative strategies to control this pathogen. Engineered probiotics are exciting new bacterial strains produced by editing the genome of the original probiotics. Recently, engineered probiotics have been used to develop delivery vehicles for vaccines, diagnostics, and therapeutics. Recent studies have demonstrated engineered probiotics may potentially be an effective approach to control or treat CDI. This review provides a brief overview of the considerations for engineered probiotics for medicinal use, with a focus on recent preclinical research using engineered probiotics to prevent or treat CDI. We also address the challenges faced in the production of engineered strains and how they may be overcome in the application of these agents to meet patient needs in the future.

Interest in Saccharomyces and non-Saccharomyces yeasts as biotechnological agents is growing worldwide. Here, Kluyveromyces marxianus GBC2 and two Saccharomyces cerevisiae strains FBZ4 and FBK9 were isolated from pomegranate (Punica granatum) and fig (Ficus carica), respectively, and extensively characterized for their probiotic attributes and health benefits. Overall, these strains were found to be γ-hemolytic, non-cytotoxic against Caco-2 cells, and sensitive to therapeutic antifungals. In terms of probiotic characterization, the strains were able to survive at pH 2 and in 1% bile and had high hydrophobicity and self-aggregation properties, which could explain their ability to form biofilm on a polystyrene and adhere to Caco-2 cells. Adhesion rates of 23.52%, 14.05%, and 9.44% were recorded at 37 °C for K. marxianus GBC2, S. cerevisiae FBK9, and S. cerevisiae FBZ4, respectively. Furthermore, biological screening showed a cholesterol assimilation of 54.32% for K. marxianus GBC2 and almost 33% for both Saccharomyces, more than 73% α-amylase inhibition, and good antioxidant potential for all strains; however, only K. marxianus GBC2 showed antibacterial activity against Staphylococcus aureus ATCC 25923. In light of these findings, the strains could be potential candidates for the development of novel functional foods and for probiotic applications.

Antimicrobial peptides (AMPs) are favoured because of their broad-spectrum antimicrobial properties and because they do not easily develop microbial resistance. However, the low yield and difficult extraction processes of AMPs have become bottlenecks in large-scale industrial applications and scientific research. Microbial recombinant production may be the most economical and effective method of obtaining AMPs in large quantities. In this paper, we review the mechanism, summarize the current status of microbial recombinant production, and focus on strategies to improve the yield and activity of AMPs, in order to provide a reference for their large-scale production.

Postharvest losses in fruits and vegetables exert substantial economic and environmental repercussions. Chemical interventions are being widely utilized for the past six decades which may lead to significant health complications. Bioprotection of fruits and vegetables is the need of the hour in which use of lactic acid bacteria (LAB) with GRAS status predominantly stands out. Incorporation of LAB in postharvest fruits and vegetables suppresses the growth of spoilage organisms by synthesizing various antimicrobial compounds such as bacteriocins, organic acids, hydrogen peroxide (H₂O₂), exopolysaccharides (EPS), and BLIS. For example, Pediococcus acidilactici, Lactobacillus plantarum, and Limosilactobacillus fermentum convert natural sugars in fruits and vegetables to lactic acid and create an acidic environment that do not favour spoilage organisms. LAB can improve the bioavailability of vitamins and minerals and enrich the phenolic profile and bioactivity components. LAB has remarkable physiological characteristics like resistance towards bacteriophage, proteolytic activity, and polysaccharide production which adds to the safety of foods. They modify the sensory properties and preserve the nutritional quality of fruits and vegetables. They can also perform therapeutic role in the intestinal tract as they tolerate low pH, high salt concentration. Thus application of LAB, whether independently or in conjunction with stabilizing agents as edible coatings, is regarded as an exceptionally promising methodology for ensuring safer consumption of fruits and vegetables. This review addresses the most recent research findings that harness the antagonistic property of lactic acid bacterial metabolites, formulations and coatings containing their bioactive compounds for extended shelf life of fruits and vegetables.

Inflammatory bowel disease (IBD) is a chronic immune-inflammatory disease. Gut microbes, intestinal immunity, and gut barrier function play a critical role in IBD. Growing evidence suggests that synbiotic may offer therapeutic benefits for individuals with colitis, suggesting an alternative therapy against colitis. With this in mind, we creatively prepared a new synbiotic combination consisting of a probiotic strain (Limosilactobacillus reuteri) along with one prebiotic chitooligosaccharides (COS). The protective effects of the synbiotic on DSS-induced colitis and the underlying mechanisms were investigated. We demonstrated that the synbiotic ameliorated colitis in mice, as evidenced by a significant remission in body weight loss and colon shortening, and a decreased disease activity index (DAI). Notably, synbiotic reduced the intestinal inflammation and injury by synergistically decreasing inflammatory factors, inhibiting TLR4/Myd88/NF-κB/NLRP3 signaling, preventing macrophage infiltration, and enhancing the integrity of the intestinal barrier. Moreover, synbiotic selectively promoted the growth of beneficial bacteria (e.g., Akkermansia, Lactobacillus) but decreased the pathogenic bacteria (e.g., Helicobacter). BugBase's analysis supported its ameliorated role in reducing pathogenic bacteria. Collectively, our findings revealed the novel synbiotic had a potential to treat colitis, which was associated with its anti-inflammatory and microbiota-balancing properties. This study will contribute to the development of functional synbiotic products for IBD therapy and will provide valuable insights into their mechanisms.

A major growing concern in the human and animal health sector is the emergence of antibiotic-resistant pathogenic bacteria due to the indiscriminate use of antibiotics. The exogenous application of bacteriophage endolysins causes abrupt lysis of the bacterial cell wall, which computes them as alternatives to antibiotics. Although naturally occurring endolysins may display limitations in solubility, lytic activity, and narrow lytic spectrum, novel strategies like developing chimeric endolysins and using endolysins in synergism with other antimicrobial agents are required to improve the lytic activity of natural endolysins. The modular structure of endolysins led to the development of novel chimeric endolysins via shuffling enzymatic and cell wall binding domains of different endolysins, using endolysins in a synergistic approach, and their applications in various in vitro and in vivo experiments and different applicable areas. This article aims to review the role of chimeric endolysins and their use in synergistic mode with other biofilm-reducing agents to control biofilm formation and deteriorating pre-formed biofilms in food, dairy, and medical industries. Promoting further development of phage technology and innovation in antibiotic therapy can achieve long-term sustainable development and economic returns.

Lacticaseibacillus paracasei K56 (L. paracasei K56) is a probiotic with weight-loss effects. However, symbiosis research on the combined effects of Lacticaseibacillus paracasei K56 and prebiotics is lacking. Therefore, the aim of this study was to investigate the effects of L. paracasei K56, xylooligosaccharide (XOS), galactooligosaccharide (GOS), polyglucose (PG), and their synbiotic combinations (XOS + K56, GOS + K56, and PG + K56) on metabolism and gut composition in children with obesity, using an in vitro fermentation model. Fecal samples were collected from 14 children with obesity for in vitro fermentation, and the effects of the various treatments in gas production and short chain fatty acid synthesis (SCFAs) were assessed. Treatment with probiotics, prebiotics, and synbiotics regulated gut microbiota and metabolites in children with obesity. GOS and XOS had higher degradation rates than PG + K56 synbiotics in the gut microbiota of children with obesity. Moreover, treatment with XOS, GOS, and their synbiotic combinations, (XOS + K56) and (GOS + K56), significantly reduced the production of gas, propionic acid, and butyric acid compared with PG + K56 treatment. Treatments with GOS + K56 and XOS + K56 altered the composition of the gut microbiota, improved the abundance of Bifidobacteria and Lactobacilli, and reduced the abundance of Escherichia/Shigella. Overall, this study provides a theoretical foundation for the use of K56-based synbiotics.

Helicobacter pylori, a pathogenic bacterium responsible for multiple gastrointestinal disorders, has emerged as a major global concern due to rise in antibiotic resistance. Unwanted side effects of antibiotics therapy are further complicating the treatment strategies. Consequently, an alternative approach, using probiotics has emerged as a promising solution for treating H. pylori infections. Probiotics have shown considerable potential in increasing the cure rate and reducing the side effects through diverse mechanisms. Among the widely employed probiotics, Lactobacillus spp. has garnered particular attention in this review. After reviewing the studies on effects of Lactobacillus spp. on H. pylori, it is evident that several Lactobacillus spp. have demonstrated their potential efficacy against H. pylori infection, when administered alone or in conjunction with antibiotics, in a strain-specific manner. Furthermore, the inclusion of Lactobacillus spp. in the treatment regimen has also been associated with a reduction in the side effects related to antibiotic-based therapies. Future research may focus on identifying optimal strains and treatment regimens, understanding the long-term impacts of use, and determining their role in preventing H. pylori infection in various populations.

Direct-fed microorganisms (DFM) are recognized as an alternative to antibiotic-based growth promoters in poultry production due to their health benefits. DFM, however, should undergo rigorous safety testing to ensure they meet the criteria to be "Generally Recognized as Safe." This study assessed eight bacterial consortia (BC) isolated from the ileal and cecal intestinal regions of wild-type chickens, subjecting them to probiotic tests. Subsequently, they were spray- and freeze-dried to evaluate their storage stability for 30 days. BC5-I and BC7-I, isolated from the ileum, emerged as promising DFM, displaying a high content of Lactobacillales using a selective medium and higher susceptibility to Gram-positive and Gram-negative antibiotics. These BC showed a high tolerance to temperature (> 90%), pH > 4 (88-98%), and antagonist effects against Escherichia coli and Salmonella. BC5-I exhibited superior survival in the simulated gastric conditions and satisfactory intestine mucus adhesion. Freeze-drying was the best method to obtain BC5-I and BC7-I powders, with a survival efficiency of 80.3% and 73.2%, respectively, compared to the beginning of storage. BC5-I presented the lowest cell death rate and prolonged half-life through survival storage kinetics. BC5-I only contained Lactobacillus, and Limosilactobacillus reuteri was the predominant species in liquid (78.3%) and freeze-dried (59.8%) forms. BC5-I stands out as a promising Lactobacillus-based DFM that could improve chicken intestinal health and enhance meat and egg production.