Probiotics and Antimicrobial Proteins最新文献

Antibiotics are frequently used in livestock, aquaculture, and poultry, resulting in their accumulation in these animals and the surrounding environment. This contamination can present health risks to humans. Research on the harmful effects of antibiotics, especially their potential to disrupt hormones in the male reproductive system, is still in its early phases. This study investigated the impact of exposure to the antibiotic amoxicillin (AMO) on male reproductive health. The aim is to shed light on the potential dangers antibiotics pose to male reproductive health and to emphasize how Bacillus clausii may help protect against the toxic effects of AMO. The study included four groups treated via gavage: control animals, a supplemented group receiving B. clausii (1.25 ml, 1 × 10^9 CFU per mouse per day), a group treated with AMO at 30 mg/kg daily, and a fourth group that received AMO and B. clausii. After 45 days of treatment, blood samples were collected to assess serum activities of superoxide dismutase and catalase and levels of reduced glutathione, malondialdehyde, and testosterone. Testicular tissue samples were analyzed for mechanistic target of rapamycin (mTOR) gene expression and histological changes. This study demonstrates that exposure to AMO negatively impacts male reproductive health by increasing oxidative stress, reducing testosterone levels, causing testicular damage, and downregulating the mTOR expression level. However, supplementation with B. clausii mitigates these harmful effects, likely due to its antioxidant properties. The probiotic reduced oxidative stress markers, improved testosterone levels, and alleviated testicular lesions, thereby upregulating the mTOR expression level, which suggests its potential protective role against antibiotic-induced toxicity.

Turmeric, referred to as "Golden Spice of India," belongs to Zingiberaceae family is cultivated in South-eastern and North-eastern regions of India, where it displays the regional diversity. In this study, turmeric rhizomes of Curcuma longa (yellow turmeric) from the South-eastern India and Curcuma caesia (black turmeric) from North-eastern India were collected. Proteins from these rhizome samples were extracted by using four different pH based buffer systems. The sequentially purified peptide filtrates obtained through ultrafiltration with 10 kDa and 3 kDa cut off membranes were quantified and assessed for their antioxidant potential by FRAP, NOS, DPPH and ABTS assays. The results showed that the highest antioxidant activities were observed in the Phosphate (pH 7.0) and Tris-HCl (pH 8.0) buffers. Further analysis of the 3 kDa filtrates from both turmeric samples by using HPLC confirmed the presence of peptides, which were subsequently identified by MALDI-TOF MS. The peptides identified in this study exhibited the promising bioactive potential based on their sequences and showed the less cleaving potential evaluated by insilico peptideCutter analysis. Future research will focus on validating these activities through comprehensive experimental approaches, including cell-based antioxidant, mechanistic studies, and antimicrobial evaluations. Such investigations will be essential to confirm their biological relevance and to determine its suitability for nutraceutical applications.

Developing novel probiotics can help in preventing livestock diarrhea and associated intestinal diseases. Lactic acid bacteria (LAB) are symbiotic intestinal bacteria, which contribute to gastrointestinal tract health. An LAB strain, designated L. johnsonii RS-7, was isolated from the feces of healthy adult pigs and was resistant to acidic conditions and bile salts. In vitro evaluation showed significant antioxidant and anti-inflammatory properties, suggesting its potential application in alleviating intestinal inflammation. An artificially induced colitis model was established in mice to investigate the efficacy of L. johnsonii RS-7. Results indicated that mice administered water containing 3% DSS developed pronounced colitis symptoms, characterized by weight loss, elevated disease activity index, shortened colon length, microvilli shedding, tight junction disruption, reduced goblet cell counts, suppression of anti-inflammatory cytokines, activation of pro-inflammatory cytokines and the TLR4/MyD88/NF-κB signaling pathway, and impaired gut microbiota diversity. These suggest that oral administration of L. johnsonii RS-7 significantly alleviated colitis symptoms. In summary, L. johnsonii RS-7 acted as a probiotic by inhibiting activation of the TLR4/MyD88/NF-κB pathway.

In this study, we aimed to develop a novel antimicrobial peptide (AMP) design strategy via a localization-based motif combination approach to target Gram-negative and Gram-positive pathogenic bacteria. Peptide sequences with high inhibitory activity against Escherichia coli and Staphylococcus aureus were extracted from Database of Antimicrobial Activity and Structure of Peptides (DBAASP) to form two separate datasets for Gram-negative and Gram-positive bacteria, respectively. The peptide sequences in the datasets were segmented into three fragments based on their N-terminal, C-terminal, and central positions, and their statistical significance was scored. The top-scoring fragments were assembled based on their segment-specific positions to generate candidate peptides. The several properties of the candidate peptides were predicted in silico, and the peptides exhibiting the highest antibacterial activity against Gram-positive and Gram-negative bacteria were selected for subsequent synthetic production. The peptides showed membrane deformation effects against the target bacterial strains, and their minimum inhibitory concentration (MIC) values were determined to be between 4 and 16 µg/mL for Gram-negative strains and 4-128 µg/mL for Gram-positive strains. The maximum therapeutic index of the peptides varied between 86 and 129, and their docking scores were found to be higher than known antimicrobial agents, such as nisin and polymyxin B. These results suggest that the designed peptides may serve as effective agents against pathogenic bacteria, including drug-resistant strains, and represent a promising alternative to traditional antibiotics.

Acute hypoxia stress poses a significant challenge in aquaculture, not only compromising gut health but also resulting in substantial economic losses. Using an integrated multi-omics approach, this study demonstrates that hypoxia severely disrupts the intestinal function of yellow catfish (Pelteobagrus fulvidraco), specifically manifesting as phospholipid metabolism disorders, inhibited fatty acid β-oxidation, reduced short-chain fatty acid (SCFA) synthesis, imbalanced gut microbiota (e.g., decreased levels of beneficial lactic acid bacteria Lactococcus and Clostridium sensu stricto 1), and downregulation of detoxification pathways mediated by cytochrome P450. Building upon the previously isolated and identified high-yield SCFA-producing probiotic Clostridium butyricum B3 from yellow catfish in early work, this research further investigated the efficacy and mechanisms of B3 supplementation in mitigating hypoxia-induced intestinal barrier damage in yellow catfish. The results indicated that the supplementation of C. butyricum B3, particularly at a dose of 3.0 × 10⁷ CFU/g, significantly reduced histological damage, enhanced the expression of key tight junction proteins (such as ZO-1 and Claudin), and modulated hypoxia-inducible factor signaling pathways (including HIF-1α, FIH, and PHD). Furthermore, the application of C. butyricum B3 restored microbial ecological balance by promoting the growth of beneficial bacteria like Cetobacterium and inhibiting potential pathogens such as Acinetobacter. In conclusion, these findings underscore the potential of C. butyricum B3 as a novel probiotic strategy for enhancing fish hypoxia tolerance and maintaining intestinal integrity, offering valuable insights for sustainable aquaculture practices.

Per- and polyfluoroalkyl substances (PFAS) are highly persistent environmental contaminants that pose a significant threat to ecosystems and human health due to their exceptional chemical stability and resistance to degradation. Conventional remediation methods-such as activated carbon adsorption, ion exchange, and advanced oxidation-primarily transfer PFAS between phases rather than achieving complete mineralization, resulting in the generation of secondary waste. Microbial bioremediation has emerged as a promising, sustainable strategy. Several bacteria, fungi, and cyanobacteria can transform or defluorinate PFAS under environmentally relevant conditions, yielding less fluorinated intermediates. Enzymatic studies have identified oxygenases and reductive dehalogenases as key catalysts in the cleavage of C-F bonds. Moreover, recent evidence indicates that the gut microbiota can adsorb and sequester PFAS, facilitating fecal elimination and reducing systemic toxicity. Advances in synthetic biology now enable the engineering of microbial systems, including probiotic strains, with enhanced PFAS uptake and degradation capabilities. However, significant challenges remain; current microbial pathways primarily act through partial transformation rather than complete mineralization, often accumulating stable fluorinated intermediates. True mineralization is constrained by low enzymatic efficiency, narrow substrate specificity, and the difficulty of translating laboratory success to complex environmental matrices. This review critically synthesizes current progress in microbial and probiotic bioremediation of PFAS, emphasizing enzymatic mechanisms, microbial pathways, and integration with conventional treatment systems. By engaging with these limitations alongside promising advances, we provide a balanced assessment of the feasibility of microbial and engineered probiotic approaches, highlighting knowledge gaps and future directions for developing safe, scalable detoxification technologies.