Analysis of peptide production by Lactobacillus species and evaluation of their antihypertensive and immunomodulatory activities

Abstract

Cardiovascular disease (CVD) is the leading cause of death among Canadian adults. Research has demonstrated an inverse relationship between the consumption of fermented dairy products and a decreased risk of CVD due to lactic acid bacteria used in the fermentation process which liberate small bioactive peptides from larger milk proteins (eg. casein). We observed that supplementation with 0.1% casein significantly increased the growth rate of L. helveticus R0389 and L. rhamnosus R0011 and increased the ACE-inhibitory activity of their secreted peptide fractions. Peptide-containing supernatants of L. rhamnosus R0011 show comparable ACE inhibition to known antihypertensive peptides, VPP and IPP. Supernatants of milk ferments induced the production of the regulatory cytokine, IL-10, by THP-1 monocytes. Novel antihypertensive and immunomodulatory activities of individually synthesized peptides were also reported. By investigating the relationship between these bioactive properties, we can improve upon the use of probiotic organisms to confer maximal health benefits to Canadians.