Medical food: Fermented uji, mursik, busaa curb infections

Mursik, a drink of choice in the Rift Valley, especially among the Kalenjin. [Christopher Kipsang, Standard]

Fermented foods have various unintended health benefits, including curbing infections, according to digestive health specialists.

Fermented foods include yoghurt, traditional fermented porridge, mursik and traditional brews like busaa. Such foods can alter the makeup of bacteria, viruses and fungi along the intestinal tract (gut microbiome), thus preventing symptoms like diarrhea.

Dr Eric Murunga, a gastroenterologist, says these “good bacteria compete with the bad bacteria for nutrients, and this helps reduce the kind that can cause diseases.”

Researchers at the Stanford School of Medicine have indeed linked the influence of diet on gut microbes and immune status after observing 36 adults on a 10-week diet of either fermented or high-fiber foods.  

One group was fed on plenty of yoghurt, fermented cottage cheese, Kimchi (a Korean side dish from fermented cabbage or radish), Kombucha (a type of fermented tea) and kefir while the other group ate beans, fruits, vegetables, whole grains and nuts. 

The research findings published in the 2021 edition of the journal, Cell, revealed that the more fermented foods people ate, the greater the number of microbial species that sprouted in their guts.

 In contrast, there was no such change in the high-fiber group.

Dr Murunga explains that fermented foods enhance the lining of the intestine, and this “inhibits the likelihood of infection breaking through the lining and going inside the body.”

A healthy diet, coupled with a good digestive system, ensures free flow of food thus creating a conducive environment for healthy bacteria to thrive.

However, dispensing with healthy vegetables can induce constipation, affecting the flow of food “which in turn, can disrupt the good bacteria and alter the microbiome,” says Dr Murunga.

Fermentation process occurs when bacteria and yeast break down sugars, enhancing food preservation, and fermented foods also boost the number of beneficial bacteria (probiotics) in the gut.

A 2008 study in the International Journal of Food Microbiology found that fermented Maasai milk, ‘Kule naoto,’ contains probiotics which improve digestion and immunity.

Traditional fermented foods were found to be more beneficial than commercial ones which gastroenterologist, Dr Christopher Opio, says are marketed to exploit gullible buyers.

Another beneficial food is fermented pearl millet dough from Mbeere, Kenya, according a 2010 study published in Beneficial Microbes Journal.

The makeup of any person’s microbiome is influenced by many factors, including genes, health conditions and medications like antibiotics, but a person’s gut microbiome can be destabilised by environmental factors, dietary patterns and medication which according to Dr Opio, includes prolonged usage of antibiotics which can destroy both the good and bad bacteria.

Dr Murunga says surgery in the digestive system affects how food flows and “this disrupted flow can favour the growth of harmful bacteria over the good ones” besides certain conditions like diabetes destabilising the gut’s microbiome.

Something else: Fermented foods may not work for everyone as some might suffer gas and bloating besides being a recipe for food poisoning when poorly handled. Some cereals may also have aflatoxins which “can cause cancer if not processed well,” adds Dr Opio.