From: bovinity.webs.com/kefircancertherapy.htm
Renewed interest in Kefir occurred in the West in the nineteenth century. Perhaps the best known researcher on Kefir is an international Nobel Prize winner (1908) Russian professor Elie Metchnikoff. Professor Mechnikoff considered Kefir a natural and a most effective means of combating intestinal infections, intoxications, and putrefactions. In his opinion good health and longevity could be attributed to the constant use of Kefir. Mechnikoff had proved in a scientific manner that the bacteria contained in Kefir would be of value in promoting the improvement and longevity of the human life if this form of fermented milk were brought into general use. Since then Kefir attained a considerable usage in Europe and is being extensively produced there.
Contribution of Each Microorganism
Leuconostoc Cremoris
Produces lactic and acetic acid.
Produces acetyl-methyl carbinol and diacetyl, two aromatic agents of Kefir.
Lactobacillus Plantarum
Exhibits antagonistic activity against Listeria monocytogenes.
Produces plantaricin, a bacteriocin inhibiting microorganisms which cause spoilage.
Strong producer of lactic acid. Tolerates high concentrations of bile salts. Aheres to intestinal mucosa.
Lactobacillus Casei
Produces L (+) lactic acid. Produces large quantity of lactic acid.
Colonizes intestinal tract. Adheres to intestinal mucosa.
Creates a favorable environment for the desirable microbial balance. Limits intestinal putrefaction, thus controlling production of toxins and their noxious effects upon vital organs and body cells. Inhibits pathogenic bacteria and prevents diseases caused by intestinal infections. Limits lactose intolerance. Contributes to immunity.
Streptococcus Lactis
Produces L (+) lactic acid. Produces large quantity of lactic acid. Partially hydrolyses milk proteins. Increases digestibility of milk. Improves stomachal digestion. Inhibits harmful microorganisms. Produces bacteriolysins.
Strepococcus Cremoris
Has the same properties of Streptococcus Lactis. Is more resistant moreover to phages then Streptococcus Lactis. Increase desirable flavor of Kefir.
Streptococcus Diacelilactis
Has the same properties of Streptococcus Lactis. Produces acetyl-methyl and CO2. Diacetyl is a characteristic aroma of Kefir.