[BojanaL]

Microorganisms in food fermentation

People realized long time ago that microorganisms could improve nutritional value of the food they are eating. Some types of food that is consumed today have a hundreds or thousands year long tradition. Evidences (like excavated jars…) suggest that some fermented beverages were produced in Babylon 5000 years BC while milk fermentation started a bit “later”, around 3000 BC. Fermentation is one of the oldest methods used for food preservation. List of food that could be processed and improved by microorganisms is long as well as the list of beneficial effects fermented food has on our health.

Fermentation process increases nutritional value of the food by increasing the level of proteins, vitamins, amino-acids, essential fatty acids…It also increases food digestibility. Typical example is lactose intolerance that prevents many people from drinking milk. Microorganisms used in milk fermentation digest lactose and decrease it to the level that could be safely consumed even with lactose intolerant people. Bacterial enzymatic hydrolysis can enhance intestinal bioavailability of the fat and proteins. Disorders like constipation, irritable bowel syndrome, yeast infections and some kind of allergies could be prevented or decreased with well balanced gut microflora.

Here’s the list of some less known fermented products and their effect on the health:

Kefir is popular in Eastern European and Middle Eastern countries. This is easily digested alcoholic milk beverage that could improve immune response and is often given to immune-compromised patients like those suffering from AIDS, herpes or cancer.

Koumiss is Caucasus derived fermented dairy product used in the treatment of pulmonary tuberculosis.

Natto is fermented soybean products. This sticky meal, rich in protein, is popular in Asian kitchen and it’s believed that it prevents brain hemorrhage. Due to increased level of vitamin K2, it’s used to prevent osteoporosis in older people.

Indonesian tempeh is fermented soybean product that reduces cholesterol levels. Level of niacin and riboflavin in the tempeh could be increased with Rhizopus oligosporus starter culture.

Chinese douche is another soybean product that is effective in lowering high blood pressure.

Kimchi is Korean fermented dish that could be produced in hundreds of ways using 4 main ingredients: napa cabbage, radish, scallion, or cucumber. This meal is famous for its health benefits. It’s used to prevent constipation and colon cancer. It produces anti-stress effect, decreases cholesterol level, ameliorates depression, and prevents osteoarthritis, liver disease, obesity and atherosclerosis.

Gundruk is result of green vegetable fermentation while Sinki is fermented radish tap-root product. These Nepal derived dishes are used to prevent cancer as they contain large amounts of anti-cancerogenous substances such as lactic acids, vitamin C, carotene and fibers.

Bhaati jaanr extract is Himalayan fermented rice food-beverage that increases the strength in women after childbirth. Kodo ko jaanr is fermented finger millet product that could serve the same purpose due to high energy value.

Here are some of the most famous probiotics and their effect on the human health:

Bifidobacteria species reduce incidence of neonatal necrotizing enterocolitis.

Enterococcus faecium can decrease duration of acute diarrhea resulting from gastroenteritis.

Lactobacillus strains can ameliorate pouchitis, improve lactose digestion, decrease diarrhoea in lactose intolerant individuals or in individuals with short-bowel syndrome and improve mucosal immune function and mucin secretion.

Lactobacillus acidophilus can decrease diarrhea in patients receiving pelvic irradiation; decrease polyps, adenomas and colon cancer in experimental animals; prevent urogenital infection induced by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa; lower serum cholesterol levels.

Lactobacillus plantarum can prevent diarrhea; reduce inflammation, pain and constipation in inflammatory bowel disease; decrease bloating and flatulence; L. plantarum produces positive effect on immunity in HIV+ children.

Lactobacillus reuteri can shorten the duration of acute gastroenteritis as well as acute diarrhea.

Lactobacillus rhamnosus can enhance cellular immunity.

Lactobacillus salivarius can suppress and eradicate Helicobacter pylori in tissue cultures and animal models by lactic acid secretion.

Bacteroides species can decrease chronic colitis, gastritis and arthritis.

Saccharomyces boulardii (yeast) can reduce recurrence of Clostridium difficile diarrhea and decrease risk of antibiotic-associated diarrhea; S. boulardii can shorten duration of acute gastroenteritis and prevents functional diarrhea in irritable bowel syndrome.

Unfortunately, consumption of fermented food is repressed by modern life style and growing popularity of the fast food. It’s a shame; fermented food is not just tasty but extremely healthy and important for our well being.