Traditional fermentation of raw milk into cheese, creme fraiche, yogurt, lassi and other dairy products is a form of natural preservation with many health benefits. The identities of the micro-organisms that generate medicinal molecules in raw milk dairy products are often known. Lactic acid bacteria are examples of important fermenters. They enrich milk with vitamins and also make small proteins called bacteriocins—antibiotics that work by perforating bacterial cell membranes. One bacteriocin, lacticin 3147, destroys the diarrhea-inducing germ Clostridium difficile. Other important fermenters include strains of Lactobacillus, Propionibacterium, Bifidobacterium, and Enterococcus. These fermenters serve double duty synthesizing conjugated linoleic acid, an anti-clotting and anti-cancer agent. (Curiously, aged cheeses contain less of this acid than cheeses with a short ripening period.)
Moreover, bacteria that could have a hand in improved fermentation are being revealed all the time. One such strain is Lactobacillus helveticus BGRA43 which breaks apart key proteins as it ferments milk such that it imbues the milk with anti-microbial, anti-hypertensive, and immunomodulatory properties.
But in most cases, the enrichment of health-promoting substances was an unintended, and until recently, an unnoticed, side effect of making tasty foodstuffs that last. It isn’t always clear whether the chemicals involved survive digestion in the human gut and go on to do good things around the body. This point needs examining before fermentation science can be used to design healthier dairy products in the future.
See on milkgenomics.org