Traditionally fermented milk can lower cholesterol and even prevent cancer.

These health benefits were discovered by Dr. Maina, a Food Microbiologist from the Department of Food Science at Jomo Kenyatta University of Agriculture and technology.

Maina analysed Kule naoto, a traditionally fermented milk by the Maasai community of Kenya. He published his ground-breaking findings in International Journal of Food Microbiology in 2008, a globally respected journal.

‘The cancer and cholesterol lowering properties of traditionally fermented milk are accrued from the probiotic bacteria’ says Dr. Maina. ‘Probiotic bacteria, if present in food, provide health promoting benefits to the consumer’ he adds.

In the last two decades, science has recognised and embraced probiotics as beneficial to human health. This led to coining of the term ‘probiotic’ or pro-life to describe all micro-organisms including bacteria that promote health.

Broadly speaking, probiotic bacteria are living micro-organisms, which upon ingestion in certain numbers; exert health benefits to the consumer.

At the beginning of the 20th century, A Russian bacteriologist Eli Metchnikoff was the first to give a scientific explanation for the beneficial effects of bacteria present in fermented milk.

He attributed the good health and longevity of the Bulgarians to their consumption of large amounts of fermented milk, called yahourth. In 1908 Eli Metchnikoff postulated his ‘longevity-without-aging’ theory.

The principle of his theory was that the lactic acid bacteria found in fermented milk resulted in the displacement of toxin producing bacteria normally present in the intestines resulting in prolonged life.

What is lactic acid bacteria?

Lactic acid bacteria is a group of bacteria that cause milk to coagulate during fermentation.

Milk has an important sugar called lactose. The term lactic acid bacteria is derived from the fact that these bacteria feed on the lactose, breaking it down to lactic acid; which is released into the milk.

Essentially, these bacteria produce lactic acid as the main end-product of carbohydrate breakdown.

Accumulation of high amounts of lactic acid in the milk increases the acidity of milk (lowering pH) which prompts protein to coagulate forming a thick consistency.

How does ‘live lactic acid bacteria’ find their way into milk

There are two processes of making fermented milk, either spontaneously or controlled fermentation.

It is obvious that fresh milk turns sour if left to stand for a long at high temperatures.

In spontaneous fermentation, milk is put in a container and left for 2-5 days. During this period bacteria grow in the milk. These bacteria feed on lactose and other nutrients in milk.

The end product of lactose breakdown is lactic acid which adds flavour, increases the acidity of the milk and cause it to coagulate. Generally, coagulated milk is viewed as having gone bad.

On the hand, in controlled fermentation, specific strains of bacteria are added to the milk which is stored under controlled conditions (usually 30- 40 °C) for a certain number of hours for fermentation to occur. This is the method used to produce fermented milk commonly referred to as ‘Mala’ .

The controlled fermentation gave birth to a category of fermented milk products called yoghurt. Yoghurt is produced with a specific type of bacteria called ‘yoghurt culture’. Yoghurt culture is available commercially, mostly, in freeze-dried form.

How do the Maasai ferment their milk?

According to earlier work published by Maina in the International Journal of Food Microbiology in 2004, the Kule naoto is spontaneously fermented from raw cow’s milk in custom-made, treated gourds.

The milk and gourd pre-treatment includes addition of fresh cow’s blood and rubbing the gourd’s interior with a burnt stick from the tree; Olea Africana.

The gourd containing the milk is stored in warm place for a few days until the milk ferments.

Health benefits

Read health benefits of traditionally fermented milk in the next article which is part 2 of this.