Many people are familiar with the term “bad” gut bacteria, but recently “good” microorganisms, including probiotics, have been making headlines. A team of researchers from Malaysia explain how kefir – a popular fermented milk drink – may hold some key ingredients for the production of nutraceuticals.
By Mohd Akmal Azhar
The term probiotics originates from the Greek word ‘probios’ which means ‘for life’. In 2001, a joint expert group from the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) defined probiotics as living microorganisms that provide numerous health benefits if consumed in sufficient amounts. They can be found in some yoghurts, cheese, dairy products such as milk or kefir, kimchi and other fermented foods.
How do probiotics work?
The complex community of microorganisms in our gut is called the gut flora or microbiota. In fact, our gut contains hundreds of different types of microorganisms. Not all of these microorganisms are beneficial though. Some studies state that an unbalanced gut flora, which contains too many “bad” and not enough “good” microorganisms, causes an unhealthy diet and is linked to numerous diseases.
Probiotics can help correct this balance in several ways, for example by restoring beneficial bacteria in the body after an antibiotic treatment.
Criteria for good probiotics
An effective probiotic must meet certain criteria, such as being safe, viable and able to survive in the gastrointestinal tract. In addition, it needs to display antimicrobial activity against pathogenic bacteria and to be able to stick to the intestinal wall. Each isolated, potentially probiotic strain is scrutinized for these main criteria. Lastly and most importantly, scientists have to verify the probiotic’s safety for human consumption using taxonomic classification, human trials and genome sequencing.
In a recent study, published in the International Journal of Food Engineering, researcher Mohd Akmal Azhar and co-workers from the University of Malaysia, Pahang evaluated the probiotic potential of yeast strains isolated from kefir – a popular fermented milk drink. Their aim was to evaluate the yeasts’ potential for use in the preparation of nutraceutical products (food with medical health benefits).
Yeasts are a large and diverse group of macroscopic, single-celled organisms that belong to the kingdom of fungi. In the course of the study, the Malaysian researchers managed to identify four dominant yeast strains in kefir: Saccharomyces boulardii, Kazachstania unispora, Kodamaea ohmeri and Saccharomyces cerevisiae.
The study showed that the strains were able to survive in the acidic pH of the human stomach and intestines whilst growing well at human body temperature. They also demonstrated antimicrobial activity against some foodborne pathogens and resistance to common antibiotics like penicillin.
According to Azhar and colleagues, the isolated yeasts from kefir show “excellent potential” for probiotic use in various products and food supplements. More studies are now needed to investigate how well the yeasts stick to the intestinal wall.
Read the original article here: