WHAT ARE PROBIOTICS?

Time for breakfast? Help yourself to a plate of hot steaming idlis, dosas or uttappams and dahi. These are not only nutritious but are safe, highly acceptable and packed with health benefits that are both protect ive and therapeutic against a wide range of disorders. They are all fermented foods i.e. they are subjected to the action of micro-organisms for a few hours causing desirable alterations in food quality. The process also preserves and predigests the food.

The bacteria that cause these changes are called "Probiotic bacteria". They are not destroyed by the acid in the stomach or by the enzymes in the intestinal tract.


Normally bacteria are considered harmful; but probiotic are good ones responsible for a variety of health benefits. Probiotics and probiotic foods have been used both as therapeutic and preventive supplements for many ailments including GI disturbances and cancers.

The two most recognised ones are lactobacillus and bifidobacteria. The probiotic bacteria found in yogurt belong to the streptococcus and the lactobacillus strains.

Those food ingredients that can promote the growth of probiotics are referred to as "prebiotics". These are not digested by the intestinal tract but stimulate the activity and growth of selective beneficial bacteria in the colon. Cereals like wheat, pulses including soya, onion, garlic, leek, banana and even tomatoes are prebiotics.

A food that is both prebiotic and probiotic is called "synbiotic". This combination can have a beneficial effect on the host by increasing the survival of the probiotics in the intestinal tract.

India probably has the most diverse variety of fermented foods — Idli, Dosa, Dhokla, Khaman, Batura, Kulcha and the traditional dahi. The commonest probiotic foods are fermented dairy products such as yogurt and buttermilk. Sauerkraut or pickled cabbage is an example of a fermented food widely consumed in the West.

Our digestive system contains many millions of bacteria. In a normal intestine there are some 500 different species. They are important for many health functions including those concerned with the digestive system and immunity.


These are mainly the good bacteria and there is a balance between the desirable and the pathogenic bacteria. However, use of antibiotics, a poor diet, alcohol, stress and other reasons can reduce the healthy bacteria and upset this balance.

An adequate intake of probiotic foods helps the desirable bacteria colonise the colon. Antibiotics are the biggest culprit, killing both the probiotic and the disease-causing bacteria. This is why a doctor recommends curds or probiotic supplements with antibiotic treatment.

Probiotics are involved in synthesising and enhancing the bioavailability of some nutrients.
Nutritional benefits

Fermenting the foods produces certain nutrients like an increase in the Bcomplex (folic acid and vitamin B12) and vitamin K. Probiotics also produce short-chain fatty acids, an important energy source for the colon. Some amino acids, growth factors, antioxidants and antimicrobial factors are also produced. Fermentation also destroys certain anti-nutrients like phytates and oxalates that interfere with the absorption of minerals like iron and calcium.

People with lactose intolerance are unable to digest lactose, the milk sugar, leading to bloating, flatulence and abdominal pain and diarrhoea. Consumption of fermented dairy products such as dahi and lassi helps in such cases because the bacteria produce the enzymes necessary to break down lactose. Probiotics also reduce intolerance symptoms such as diarrhoea.

Fermented foods, especially dairy foods, contain certain strains of bacteria that promote the health of the gastrointestinal tract. Prebiotics have also been studied for their beneficial gastrointestinal effects. A synbiotic combination is the best.

Probiotic bacteria prevent the proliferation of the pathogenic (disease-causing) micro-organisms in the gastrointestinal tract. When are ingested orally, such as through fermented foods, they produce antibiotic substances in the intestine, which can destroy the pathogens and also deprive pathogens of nutrients necessary for their growth. Probiotics can also enhance the immunity to microbial pathogens and thus exclude pathogens from the gut.

The microbes in most fermented foods are sensitive to heat and are destroyed by pasteurisation or processing. Some may be destroyed when cooked, which means that when you make idli or dosa it may not necessarily contain all the probiotic organisms originally present in the batter. A cup of yogurt will contain more live beneficial microflora than a cooked fermented product. Fermented dairy products are, therefore, a preferred delivery vehicle for probiotics.

Today probiotics are available as dietary supplements and are used to prevent and treat certain illnesses and also support good health. They provide higher levels of the beneficial bacteria than fermented foods.

Routine therapeutic interventions with probiotic strains may well become a reality soon. It is, however, wise to take them only under the guidance of a doctor. In the meantime go ahead with the fermented foods. They are totally safe and you can have them as much as you can. The fresher the product, the higher the count of good bacteria.

Are probiotic supplements safe? In most cases, yes. In some rare cases, a few side effects such as bloating of the stomach have been reported. However they are not recommended for persons with low immune status, premature infants or neonates.
Other benefits

There is enough evidence to show that administration of selected micro-organisms like lactobacillus is beneficial both in the prevention and treatment of certain intestinal and, perhaps vaginal, infections.

Probiotics may help reduce risk of rotavirus-induced diarrhoea and diarrhoea associated with intake of antibiotics and help treat infantile and, to a smaller extent, adult gastroenteritis.

They may be useful in treating constipation; specific strains of Lactobacilli may suppress the growth of and displace Helicobacter Pylori, which is associated with peptic ulcers.

Some studies suggest that prebiotics improve calcium and magnesium absorption from the human intestine. This may be associated with a change in peak bone density and mineral bone mass and a reduction in osteoporosis. Probiotics are useful in treating food allergy and inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease.

Some probiotic bacteria can break the milk protein casein into smaller units and provide relief from allergic manifestations such as intestinal inflammation. They may also prevent and possibly treat allergic conditions like eczema and allergic dermatitis.

Studies on infants have shown probiotic bacteria help increase Immunoglubulin (compounds that confer the ability to fight infections) levels.

Fermentation of milk is reported to produce certain peptides (chains of amino acids) that inhibit an enzyme which tends to increase blood pressure. Studies on humans indicate that fermented milk could help lower blood pressure when used on a daily basis.


Although the evidence is weak, some studies have reported a modest reduction in cholesterol levels after consumption of fermented milk products for two to four weeks.

Animal experiments have shown that probiotic bacteria reduce the risk of colon cancer. Some epidemiological studies suggest that consumption of fermented dairy products may have some protective effect against cancer of the large colon. Regular consumption of thayir sadam may be a simple way to lower the incidence of colon tumours.

Probiotics may be useful in preventing alcohol-induced liver damage, a common condition in many societies. Studies from Johns Hopkins Hospital in the United States suggest that orally administered probiotics could be superior to the conventional therapy in the treatment of hepatic encephalopathy, a common and dreaded complication of liver disease.