Antimicrobial potentiality of D-tagatose and Lactobacillus spp. synbiotic preparation

Sohini Roy, AK Samanta, A Dhali, AP Kolte, Jayaram C

Statement of the Problem: The issue of anitimicrobial resistance is a global threat to human, animal and environmental health. Pre, pro and synbiotics are emerging as an important alternative of antibiotics. Synbiotics are more efficient because of the combined effect of prebiotics and probiotics. The objective of this study was to evaluate the antimicrobial potentiality of D-tagatose and Lactobacilli as a synbiotic. Methodology & Theoretical Orientation: Batch culture fermentation was carried out with four Lactobacillus spp. (L. rhamnosus GG, L. casei, L. acidophilus and L. fermentum) and two pathogenic bacteria (E. coli and S. typhimurium) in presence of D-tagatose, Fructooligosaccharides and D-glucose as carbon sources. Based on D-tagatose utilization ability, two lactobacilli (L. rhamnosus GG and L. casei) were used in liquid co-culture assay to investigate the anti-microbial efficacy against selected pathogens. The agar diffusion bioassay was used to screen the anti-microbial activity of the cell free culture supernatant (CFCS) of the Lactobacillus spp. in grown presence of D-tagatose. Findings: Our results showed that all the selected Lactobacillii spp. were able to utilize D-tagatose, but the tested pathogens were failed to utilize it as carbon source. The highest growth was demonstrated by L. rhamnosus GG and L. casei after 24h. In co-culture assay, the presence of D-tagatose with selected lactobacilli was shown to inhibit both the pathogens (E. coli and S. typhimurium) completely (Fig.1 and Fig. 2). The anti-microbial activity by the CFCS was attributed by lowering of pH due to the production of lactic acid and short chain fatty acids. Conclusion & Significance: D-tagatose in combination with L. rhamnosus GG or L. casei can be used to develop a potential synbiotic supplement. The antimicrobial efficacy of the symbiotic preparation could be used in replacing the antimicrobial therapy in prevention or treatment of bacterial infections.