Title : From microbiota to medicine: Therapeutic promise of lactiplantibacillus plantarum derived postbiotics for cardiovascular health
Abstract:
Postbiotics, defined as bioactive metabolites produced by probiotics that confer health benefits, have increasingly attracted attention owing to their antioxidant, antimicrobial, and immunomodulatory properties. These attributes render them promising candidates for the prevention and management of cardiovascular diseases (CVDs), which are frequently associated with chronic inflammation and oxidative stress. Therefore, this study aimed to evaluate the efficacy of postbiotics derived from Lactiplantibacillus plantarum EIR/IF-1 (NCBI GenBank Accession Number: OP810909.1), previously isolated from the fecal microbiota of a breastfed infant, as bioactive agents for targeting CVDs. Postbiotics were obtained through centrifugation, sterile filtration, freezing, and lyophilization from the bacterial culture supernatant. The antibacterial efficacy of postbiotics against Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 was demonstrated using agar well diffusion and microtiter plate assays. Moreover, the impact of postbiotics on MRSA cell viability was evaluated via live/dead bacterial staining observed under fluorescence microscopy. The total phenolic and flavonoid content of the postbiotics was quantified spectrophotometrically, while their overall antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. To evaluate immunomodulatory effects, the H9c2 rat cardiomyoblast cell line (ATCC CRL-1446), widely used in cardiovascular research due to its skeletal muscle-like properties, was employed. Non-cytotoxic postbiotic concentrations were determined by MTT assay. Subsequently, lipopolysaccharide (LPS) derived from Escherichia coli O111:B4 was used as a positive control to stimulate immune-related pathways, and the immunomodulatory effects of postbiotics on LPS-stimulated H9c2 cells were assessed by quantitative real-time PCR (qRT-PCR). Additionally, the expression of the collagen type I gene (COL1A1) was also analyzed via qRT-PCR and confirmed by immunofluorescence microscopy. The results revealed strong antimicrobial activity against MRSA, with an inhibition zone of 19?±?1.4?mm and a minimum inhibitory concentration (MIC) of 20?mg/mL. Fluorescence microscopy further confirmed the postbiotics’ effects on MRSA cell viability. At the MIC-10 dose, postbiotics scavenged 88.65% of DPPH radicals, improved H9c2 cell viability, and significantly upregulated gene expression levels—1.67-fold for IL-6, 1.85-fold for IL-1β, 1.25-fold for TNF-α, and 2.13-fold for NF-κB. Furthermore, a 2.11-fold increase in COL1A1 gene expression was observed following postbiotic treatment. Collectively, these findings indicate that postbiotics may support cardiovascular health by modulating inflammatory responses and promoting extracellular matrix synthesis. Nevertheless, further in vivo studies are necessary to validate these effects and to explore their broader therapeutic applications in cardiovascular medicine.
