Bacteriocins as alternatives to antibiotics for gut health

Paul Ross, APC Microbiome Ireland, University College Cork.

There is an increasing need to develop non-antibiotic (and non-chemical) approaches whereby microbiomes (human, animal and food) can be modified in a positive manner from a compositional perspective.  At APC Microbiome Ireland, we are adopting a number of strategies to influence the gut and skin microbiome composition and functionality towards improved health outcomes.  These include the use of bacteriocins or the strains which produce them (live biotherapeutics) to kill and outcompete undesirable and/or pathogenic organisms.  In addition, the ability to produce bacteriocins may offer a competitive advantage to introduced strains thereby improving persistence and/or dominance.  We have isolated a battery of strains which produce novel bacteriocins including thuricin produced by Bacillus thuringensis, actifensins produced by Actinomyces species, homicin produced by coagulase-negative staphylococci and naturalling-occurring variants of nisin produced by various organisms.  In addition, we have generated a large range of nisin variants with improved properties such as improved activity, bioavailability or activity against Gram negative bacteria.  We believe that the development of such pharmabiotics will allow the sculpting of microbiome composition in a precise way to deliver improved functionality for food and health applications.