Studies on Anti-Hypertensive Peptides in Milk Fermented with Lactobacillus helveticus

Milk fermented by Lactobacillus helveticus, a lactic acid bacterium with potent proteolytic activity, had an antihypertensive effect in animal model studies. During the culture process, the biogenic peptides valyl-prolyl-proline and isoleucyl-prolyl-proline were derived from milk protein. These two peptides have been shown to have an inhibitory effect on angiotensin-converting enzyme, which converts angiotensin I to angiotensin II, a strong vasoconstrictor. Pre-clinical and in vitro studies suggest that a portion of the orally ingested dose of these peptides can be absorbed in the intact form from the gastrointestinal tract, can inhibit the tissue renin-angiotensin system, and can produce significant reductions in blood pressure. In clinical studies, fermented milk containing biologically active peptides significantly decreased systolic and diastolic blood pressure in hypertensive subjects. In contrast, no significant effect on blood pressure was observed in normotensives. Based on these observations, it is possible that fermented milk containing valyl-prolyl-proline and isoleucyl-prolyl-proline which could provide a non-pharmacological approach to the management of hypertension. This report reviews a series of studies on antihypertensive peptides in milk fermented with Lactobacillus helveticus and also describes the results of clinical trials including the latest information.