The researchers believe that encapsulating the probiotic bacteria in a protective biocompatible material shell of alginate will prevent the probiotics from being killed by the antibiotics. Should the combination be shown to be successful in future testing it may be incorporated into wound dressings to help heal infected chronic wounds. Alginates were chosen as they are already being used in dressings for chronic wounds, and alginate has also been found to be a component of biofilms that clusters of bacteria form to protect themselves from antibiotics.
The commercially available probiotic Bio-K+ was chosen to be encapsulated that contains three strains of Lactobacillus bacteria that are known to kill methicillin resistant Staphylococcus aureus. Mechanisms by which this happens is not known, it is possible that the pathogens are susceptible to lactic acid produced by the probiotics; or the probiotics secret antimicrobial peptides or other protein that kill the pathogens or disrupt their ability to form biofilms.
Tobramycin was chosen to be delivered along with the probiotics as it effectively kills Pseudomonas aeruginosa commonly found in wound infections. Exposing Staphylococcus aureus and Pseudomonas aeruginosa growing together in a lab dish to the combination was observed to wipe out all of the pathogenic bacteria. Trials without the probiotics being encapsulated failed as the antibiotics killed the probiotics allowing the MRSA bacteria to survive. When using one of the combination’s components individually the pathogens were not able to be eradicated completely.
The alginate and probiotic used are both FDA approved. The researchers believe that probiotics may help to improve wound treatments in the future, with their work expanding the application of possibilities of probiotics.
A study in 2016 showed that coating probiotic with alginate layers and chitosan helped protect them from being broken down in the gastrointestinal tract, which may help develop methods to treat disease or improve digestion with orally delivered probiotics. Probiotics may also be used in applications to help replenish gut microbiome after treatment with antibiotics.
