Probiotics and Antimicrobial Proteins最新文献

Antioxidants found naturally in foods have a significant effect on preventing several human diseases. However, the use of synthetic antioxidants in studies has raised concerns about their potential link to liver disease and cancer. The findings show that postbiotics have the potential to act as a suitable alternative to chemical antioxidants in the food and pharmaceutical sectors. Postbiotics are bioactive compounds generated by probiotic bacteria as they ferment prebiotic fibers in the gut. These compounds can also be produced from a variety of substrates, including non-prebiotic carbohydrates such as starches and sugars, as well as proteins and organic acids, all of which probiotics utilize during the fermentation process. These are known for their antioxidant, antibacterial, anti-inflammatory, and anti-cancer properties that help improve human health. Various methodologies have been suggested to assess the antioxidant characteristics of postbiotics. While there are several techniques to evaluate the antioxidant properties of foods and their bioactive compounds, the absence of a convenient and uncomplicated method is remarkable. However, cell-based assays have become increasingly important as an intermediate method that bridges the gap between chemical experiments and in vivo research due to the limitations of in vitro and in vivo assays. This review highlights the necessity of transitioning towards more biologically relevant cell-based assays to effectively evaluate the antioxidant activity of postbiotics. These experiments are crucial for assessing the biological efficacy of dietary antioxidants. This review focuses on the latest applications of the Caco-2 cell line in the assessment of cellular antioxidant activity (CAA) and bioavailability. Understanding the impact of processing processes on the biological properties of postbiotic antioxidants can facilitate the development of new food and pharmaceutical products.

Mitigating steatosis is essential for delaying the progression of alcoholic liver disease. The effect and mechanism of Lactiplantibacillus plantarum P101 (LP.P101) on alleviating alcohol-induced hepatic lipid accumulation were investigated in our study. The mouse model was constructed by a short-term (10-day)-plus-binge ethanol feeding and gavaged with 10⁸ CFU/mL of LP.P101 daily. Lipid droplet in the liver was significantly reduced by LP.101 intervention on AMPK activation. However, when AMPK was inhibited by dorsomorphin, the levels of related indicators (ALT, TG, etc.) and the expression levels of AMPK and relevant genes in the liver converged to that of the alcohol-fed group. Compared with the alcohol-fed group, LP.P101 reduced the relative abundance of Firmicutes and increased that of Bacteroidetes. Parabacteroides merdae was negatively correlated with lipid accumulation, and unclassified Negativibacillus was negatively associated with AMPK activation. Importantly, LP.P101 modified the compositions of the serum metabolites. The potential biomarker stercobilinogen was positively correlated with AMPK activation and negatively associated with lipid accumulation. This work confirmed that LP.P101 attenuated alcohol-induced hepatic lipid accumulation in mice through AMPK activation, and the alterations in gut microbiota and metabolites may play a significant role on AMPK activation.

Mycotoxins like aflatoxins pose a significant threat to the health of both people and animals because of their deadly effects. This study aimed to investigate the potential of Lactobacillus strains in reducing the toxicity caused by aflatoxins in mice receiving a diet contaminated with aflatoxins. The mice were split up into various treatment groups, including a control group, an aflatoxin-treated group, and groups treated with the aflatoxin-contaminated diet along with Lactobacillus strains. Various parameters, including liver enzymes, blood parameters, malondialdehyde (MDA) levels, morphometric analysis of ileum, and gene expression, were analyzed to assess the effectiveness of the Lactobacillus strains in mitigating aflatoxins toxicity. Results showed that mice in the aflatoxin-treated group had increased MDA levels, indicating oxidative stress. Alternatively, the Lactobacillus cocktail treatment group showed a decreasing trend in MDA levels, suggesting a reduction in lipid peroxidation. The morphometric analysis of ileum tissue demonstrated that the Lactobacillus-treated group exhibited improved structural integrity compared to the aflatoxin-treated group. Additionally, gene expression analysis revealed that the Lactobacillus treatment attenuated the downregulation of SOD gene expression and mitigated the upregulation of iNOS gene expression induced by aflatoxins. These findings suggest that Lactobacillus strains have the potential to reduce aflatoxin-induced toxicity by alleviating oxidative stress, preserving intestinal tissue integrity, and modulating gene expression associated with antioxidant defense and inflammation. This study provides evidence for the beneficial effects of Lactobacillus strains in reducing aflatoxin toxicity in mice. The findings obtained may contribute to the development of preventive or therapeutic strategies against mycotoxin-induced toxicity.

The increase in the prevalence of asthma, particularly in urban communities, has encouraged investigations into preventive strategies. The hygiene theory proposes that early exposure to infections and unhygienic conditions during childhood influences immune system development, potentially protecting against allergic diseases. The mechanisms involved are related to alterations in the intestinal microbiota, such as with probiotics. This study aimed to evaluate the preventive effect of Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Bifidobacterium animalis ssp. lactis, administered isolated or in combination, at various concentrations, on asthma in an animal model. Mice received two concentrations (1 × 10⁹ and 1 × 10¹⁰ CFU/ml) of three probiotics, isolated and in combination, over 26 consecutive days, initiating 10 days before sensitizing and challenging with ovalbumin. In vivo bronchial hyperresponsiveness and airway and lung inflammation were assessed. The administration of L. paracasei, L. rhamnosus, and B. animalis spp. lactis in different concentrations, isolated or in combination, did not reduce hyperresponsiveness and airway and lung inflammation. As probiotic effects are strain and dose-dependents, specific studies are necessary to assess the effect of different probiotic strains, doses, and regimes.

This study investigated the beneficial effects of probiotic Bifidobacterium animalis TISTR 2591 on the regulation of blood glucose and its possible mechanisms in a rat model of type 2 diabetes. The type 2 diabetic-Sprague Dawley rats were established by the combination of a high-fat diet and a low dose of streptozotocin. After 4 weeks of treatment with 2 × 10⁸ CFU/ml of B. animalis TISTR 2591, fasting blood glucose (FBG), oral glucose tolerance, serum insulin, and pancreatic and hepatic histopathology were determined. Liver lipid accumulation, glycogen content, and gluconeogenic protein expression were evaluated. Oxidative stress and inflammatory status were determined. B. animalis TISTR 2591 significantly reduced FBG levels and improved glucose tolerance and serum insulin in the diabetic rats. Structural damage of the pancreas and liver was ameliorated in the B. animalis TISTR 2591-treated diabetic rats. In addition, significant decreases in hepatic fat accumulation, glycogen content, and phosphoenolpyruvate carboxykinase-1 protein expression were found in the diabetic rats treated with B. animalis TISTR 2591. The diabetic rats showed a significant reduction of inflammation following B. animalis TISTR 2591 supplementation, as demonstrated by decreasing hepatic NF-κB protein expression and serum and liver TNF-α levels. The B. animalis TISTR 2591 significantly decreased MDA levels and increased antioxidant SOD and GPx activities in the diabetic rats. In conclusion, B. animalis TISTR 2591 was shown to be effective in controlling glucose homeostasis and improving glucose tolerance in the diabetic rats. These beneficial activities were attributed to reducing oxidative and inflammatory status and modulating hepatic glucose metabolism.

Food waste has been a global issue with 2.5 billion tons generated globally in 2021. Approximately 46% of the food waste is contributed by fruit and vegetable waste. Due to improper waste handling, these fruit by-products have a negative impact on the environment through soil and water pollution, the greenhouse effect, global warming, and eutrophication. However, research has shown the potential to reuse fruit waste in various applications for sustainability owing to their high source of valuable components and potential health benefits. In recent years, researchers have also explored the potential of reutilizing fruit waste as a prebiotic. Hence, literatures from the past 10 years has been critically analyzed and presented in this review. This review focused on the potential of fruit waste as a prebiotic for probiotic and gastrointestinal microorganisms and its food applications. The nutritional composition and bioactive compounds of the fruit wastes had been introduced to reflect their potential as prebiotics. Moreover, the increase in bioactive compounds and bioactivities in probiotics with the presence of fruit wastes has been reviewed. The impact of fruit by-products on the growth of the probiotic and its survivability in food matrices as compared to established prebiotic and the absence of prebiotics have also been extensively discussed in this review. This review also highlighted some of the factors that might contribute to the negative effect of fruit waste on probiotics. The safety concerns and future prospects of reutilizing fruit wastes for food applications have been emphasized. The review article is beneficial for researchers exploring fruit wastes as prebiotics and industrialists who are interested in incorporating fruit wastes as an added-value ingredient for food applications.

The primary goals of this work are to explore the potential of probiotic lactic acid bacteria's (LAB) mucin/mucus layer thickening properties and to identify anti-obesity candidate strains that improve appropriate habitat for use with the Akkermansia group population in the future. The HT-29 cell binding, antimicrobial properties, adhesion to the mucin/mucus layer, growth in the presence of mucin, stability during in vitro gastrointestinal (GI) conditions, biofilm formation, and mucin/mucus thickness increment abilities were all assessed for artisanal LAB strains. Sixteen LAB strains out of 40 were chosen for further analysis based on their ability to withstand GI conditions. Thirteen strains remained viable in simulated intestinal fluid, while most showed high viability in gastric juice simulation. Furthermore, 35.9-65.4% of those 16 bacteria adhered to the mucin layer. Besides, different lactate levels were produced, and Streptococcus thermophilus UIN9 exhibited the highest biofilm development. In the HT-29 cell culture, the highest mucin levels were 333.87 µg/mL with O. AK8 at 50 mM lactate, 313.38 µg/mL with Lactobacillus acidophilus NRRL-B 1910 with initial mucin, and 311.41 µg/mL with Lacticaseibacillus casei NRRL-B 441 with initial mucin and 50 mM lactate. Nine LAB strains have been proposed as anti-obesity candidates, with olive isolates of Lactiplantibacillus plantarum being particularly important due to their ability to avoid mucin sugar consumption. Probiotic LAB's attachment to the colonic mucosa and its ability to stimulate HT-29 cells to secrete mucus are critical mechanisms that may support the development of Akkermansia.

The contamination of food with Listeria monocytogenes threatens food safety and human health, and developing a novel, green, and safe antimicrobial substance will offer a new food preservation strategy. FengycinA-M3 is a novel lipid peptide with low cytotoxicity and resistance and has effective antibacterial activity against L. monocytogenes with a minimum inhibitory concentration (MIC) of 4 µg/mL. Further combined transcriptomics and proteomics analysis yielded 20 differentially expressed genes (DEGs). The MICs of the combined use of FengycinA-M3 and Cefalexin on L. monocytogenes were further determined as FengycinA-M3 (2 µg/mL) and Cefalexin (8 µg/mL) using the checkerboard method. In addition, FengycinA-M3 was found to play a role in delaying pork deterioration. This study explored the inhibitory effect of FengycinA-M3 on L. monocytogenes and its mechanism of action. FengycinA-M3 interacted with penicillin-binding protein 2B on the cell membrane of L. monocytogenes, destroying the permeability of the membrane, causing cell membrane rupture, thereby inhibiting the growth of L. monocytogenes. Overall, FengycinA-M3 is a promising candidate for preventing the emergence and spread of L. monocytogenes with potential applications in food processing.

Host defense antimicrobial peptides (AMPs) are recognized candidates to develop a new generation of peptide antibiotics. While high hydrophobicity can be deployed in peptides for eliminating Gram-positive bacteria, high cationicity is usually observed in AMPs against Gram-negative pathogen. This study investigates how the sequence distribution of basic amino acids affects peptide activity. For this purpose, we utilized human cathelicidin LL-37 as a template and designed four highly selective ultrashort peptides with similar length, net charge, and hydrophobic content. LL-10 + , RK-9 + , KR-8 + , and RIK-10 + showed similar activity against methicillin-resistant Staphylococcus aureus in vitro and comparable antibiofilm efficacy in a murine wound model. However, these peptides showed clear activity differences against Gram-negative pathogens with RIK-10 + (i.e., LL-37mini2) being the strongest and LL-10 + the weakest. To understand this activity difference, we characterized peptide toxicity; the effects of salts, pH, and serum on peptide activity; and the mechanism of action and determined the membrane-bound helical structure for RIK-10 + by two-dimensional NMR spectroscopy. By writing an R program, we generated charge density plots for these peptides and uncovered the importance of the N-terminal high-density basic charges for antimicrobial potency. To validate this finding, we reversed the sequences of two peptides. Interestingly, sequence reversal weakened the activity of RIK-10 + but increased the activity of LL-10 + especially against Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Those more active peptides with high cationicity at the N-terminus are also more hydrophobic based on HPLC retention times. A database search found numerous natural sequences that arrange basic amino acids primarily at the N-terminus. Combined, this study not only obtained novel peptide leads but also discovered one useful strategy for designing novel antimicrobials to control drug-resistant Gram-negative pathogens.

Probiotics are pivotal in maintaining or restoring the balance of human intestinal microbiota, a crucial factor in mitigating diseases and preserving the host's health. Exploration into Bacteroides spp. reveals substantial promise in their development as next-generation probiotics due to their profound interaction with host immune cells and capability to regulate the microbiome's metabolism by significantly impacting metabolite production. These beneficial bacteria exhibit potential in ameliorating various health issues such as intestinal disorders, cardiovascular diseases, behavioral disorders, and even cancer. Though it's important to note that a high percentage of them are as well opportunistic pathogens, posing risks under certain conditions. Studies highlight their role in modifying immune responses and improving health conditions by regulating lymphocytes, controlling metabolism, and preventing inflammation and cancer. The safety and efficacy of Bacteroides strains are currently under scrutiny by the European Commission for authorization in food processing, marking a significant step towards their commercialization. The recent advancements in bacterial isolation and sequencing methodologies, coupled with the integration of Metagenome-Assembled Genomes (MAGs) binning from metagenomics data, continue to unveil the potential of Bacteroides spp., aiding in the broader understanding and application of these novel probiotics in health and disease management.