How AQUACILIN-LB 625 works Amoxycillin + Clavulanic Acid + Lactobacillus is a combination of three medicines: Amoxycillin , Clavulanic Acid and Lactobacillus. Amoxycillin is an antibiotic. It works by preventing the formation of the bacterial protective covering which is essential for the survival of bacteria. Clavulanic Acid is a beta-lactamase inhibitor which reduces resistance and enhances the activity of Amoxycillin against bacteria. This treats your infection, but may upset your digestive system by killing healthy gut bacteria as well. Lactobacillus is added to restore the balance of healthy bacteria..