Metabolite characterization of probiotic Enterococcus Faecium for targeting Salmonella Entrica gut bacteria causing...

Gastroenteritis is a prevalent digestive disorder that contributes to significant morbidity worldwide, often caused by pathogenic bacteria. Probiotics are increasingly recognized for their therapeutic potential in treating gastrointestinal diseases due to their beneficial effects on gut health. This study aimed to explore the antimicrobial, antioxidant, anti-diabetic, and anti-inflammatory properties of Enterococcus faecium metabolites, isolated from a milk sample, against Salmonella enterica. The bacterial strains were isolated using the streak plate method and molecularly characterized, with Enterococcus faecium showing 93.79% sequence similarity and Salmonella enterica showing 96.97% similarity in 16S rRNA sequencing. Metabolites of Enterococcus faecium were extracted using solvents such as ethanol, methanol, n-butanol, and ethyl acetate, resulting in 14 bioactive compounds, including lactic acid, acetic acid, and indole. Antimicrobial activity was evaluated via the disc diffusion method, revealing a dose-dependent increase in the zone of inhibition, reaching 20 mm at 100 µg/mL against Salmonella enterica. Antioxidant activity, assessed using the DPPH assay, exhibited a maximum scavenging rate of 99.8% at 550 µg/mL, while anti-diabetic activity showed 84.66% inhibition of alpha-amylase at 500 µg/mL. The anti-inflammatory activity demonstrated 99% inhibition of protein denaturation at the same concentration. No hemolytic activity was observed at lower concentrations, with the maximum hemolysis of 90% occurring at 250 µg/mL. In conclusion, Enterococcus faecium metabolites exhibited significant in vitro antimicrobial, antioxidant, anti-diabetic, and anti-inflammatory activities, indicating their promise as candidates for further investigation in the context of Salmonella enterica-induced gastroenteritis and related metabolic disorders. Future studies should focus on further clinical applications of these metabolites.