Effects of the Aqueous Extract of <i>Curcuma longa</i> on Pathogenic Gastrointestinal and Probiotic Bacteria

Background: The uncontrolled spread of antibiotic resistance and their low or no efficacy in treating infections caused by multidrug-resistant (MDR) microorganisms has made it urgent to pay more attention to plants, as they are more available and safer natural agents. Curcuma longa, a medical spice, also known as turmeric, has been shown to have high antioxidant, anti-inflammatory, and antimicrobial properties. Objectives: This study aimed to determine the antimicrobial effect of the C. longa extract on six pathogenic bacteria, Pseudomonas aeruginosa, enterohemorrhagic Escherichia coli, Staphylococcus aureus, Salmonella enterica, Streptococcus mutans, and Clostridium difficile, and its positive impact on the growth of two selected probiotic bacteria, Lactobacillus plantarum and Lactobacillus reuteri. Materials and Methods: To evaluate the antibacterial activity of the C. longa extract, the broth dilution method was used, and the minimum inhibitory concentrations of six pathogenic strains underwent evaluation. The prebiotic effect of the extract on two types of lactic acid bacteria (LAB) was also investigated in this study. Results: The results revealed that the C. longa extract had prebiotic properties that could improve the growth of L. plantarum and L. reuteri, and it strongly inhibited the growth of enterohemorrhagic E. coli, P. aeruginosa, S. aureus, C. difficile, and S. mutans. Conclusion: In summary, the C. longa extract has antibacterial properties and prebiotic effects that enhance the growth of beneficial bacteria, making C. longa a suitable candidate for the development of gastrointestinal health.