The effect of prebiotics on bacteriocin production and gut adhesion potential of Lysinibacillus sphaericus DY13 and Bacillus clausii DY14

Probiotics are living microorganisms which when administrated adequately, confer benefits to hosts. In order to estimate the probiotic potential of these microorganisms, it is necessary to assess their health benefits, efficacy, and safety. This study was aimed to evaluate gut adhesion capacity of Lysinibacillus sphaericus DY13 and Bacillus clausii DY14 strains which were previously isolated from healthy human milk, and to assess the effects of natural and commercial prebiotics on bacteriocin production by these two strains.
Material & L. sphaericus DY13 and B. clausii DY14 isolates were evaluated for tolerating the artificial gastrointestinal conditions. Moreover, isolates were examined for auto-aggregation, co-aggregation, and cell surface hydrophobicity properties. The prebiotic effect of mannitol, sorbitol, garlic, onion and honey on the enhancement of bacteriocin production against Escherichia coli, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus was also evaluated.
Compared to the control, auto-aggregation potential of DY13 and DY14 was found to be decreased by 4%. Both isolates have demonstrated preeminent auto-aggregation potential. The hydrophobicity percentage of DY13 and DY14 isolates typically ranged between 51-52.7% and 59.1-66.1%, respectively. Comparing the effect of selected prebiotics on bacterial isolates growth and bacteriocin production revealed that honey is the best source to improve the growth of bacterial strain, and also to stimulate bacteriocin production.
Due to considerable adhesion potential of both selected strains, they can be applied as suitable and efficient probiotics, along with honey as prebiotic.