Mysuru: Indians love curd for its distinct flavour and its rather friendly disposition to their tummies. It has live and friendly bacteria that help in digestion, absorbing useful vitamins and fighting not-so friendly microbes that invade our guts.
Indian scientists found one more reason for us to fall in love with curd all over again! Curd made of milk from a pure Indian cow breed can be more beneficial as it contains several useful bacterial species that can fight Aflatoxin B1, the lead culprit for stomach ache. Researchers say curd prepared from the milk of Malnad Gidda cow can soak in Aflatoxin B1 from ingested foods.
Aflatoxin is a harmful toxin found in moldy food. It is secreted by a mold called Aspergillus that infects grains such as wheat and nuts such as peanuts. Consuming such mold-infested foods could upset our health, and the effects could vary from a mild stomach ache to cancer in case of severe and long-term ingestion. Though there is a variety of aflatoxin, Aflatoxin B1 or AFB1 is the most common cause of food poisoning.
“Our study focused on isolating potential health-promoting probiotic bacteria. Malnad Gidda cow is native of a place typically rich in medicinal plants. Obviously its milk would be medicinally important,” Dr Gayatri Devaraja, lead author of the study, said.
The team collected 34 samples of curd from three districts of Karnataka and searched them for the presence of Lactobacillus, the good bacterium. All these samples were made using Malnad Gidda, a dwarf variety of cow. A total of 34 strains of Lactobacillus were obtained from these curd samples. When scientists tried to identify the bacterial types they found that four were different from the rest in terms of food intake and DNA.
These characteristics point out to a type of lactobacillus known as Lactobacillus fermentum. Subsequently, the researchers found that all these four strains of L. fermentum could reduce the growth of other unfriendly microbes such as Staphyllococcus aureus, Escherichia coli and Pseudomonas aeruginosa.
There were studies that showed that some types of Lactobacillus could bind Aflatoxin in the guts. So, the researchers set upon testing these four Lactobacillus fermentus too. Dividing them into several groups, they tested each group for its ability to absorb aflatoxin. They deliberately added AFB1 to the bacterial growth medium. After 12 hours, the amount of AFB1 found in the growth medium was measured. In the culture medium where there were no bacteria, almost the entire amount of AFB1 could be recovered, whereas the test tubes added with both bacterium and AFB1, only about one-fourth of the toxin remained.
In other words, the bacteria efficiently absorbed nearly 75 per cent of all the aflatoxin added. “This is the first time that Lactobacillus fermentum is found in the milk of Malnad Gidda cows,” says
Devaraja. It is not, however, unique to the cows, but is one among the several strains of lactobacillus found, she explained.
The lactobacillus isolate from the curd of Malnad Gidda cows also showed other beneficial probiotic properties such as competing with other bacteria and reducing their growth, secreting bacteriocin which kills other bacteria, and a high survival in bile juice. This is important because tolerating high concentration of bile salt assures its survival in the hostile environment of the intestine. In other words, Malnad Gidda curd has all qualities of a good probiotic. This study was jointly conducted by the researchers from University of Davanagere, IIT-Mumbai, and CSIR-Central Food Technological Research Institute (CFTRI), Mysuru.
The research findings were published in Probiotics and Antimicrobial Proteins journal. The research team included S Sunil Kumara and Gayathri Devaraj from University of Davanagere; Dr G Venkateswaran from CSIR-Central Food Technological Research Institute; and Ambika Vasisht and P Hariprasad from IIT-Mumbai.
(India Science Wire)