The Telegraph
Sunday , May 4 , 2014
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Microbe link to malnutrition

New Delhi, May 3: Indian scientists have discovered previously unknown links between microbe populations in the gut and malnutrition, putting together jigsaw puzzles by using sequences of genetic material extracted from faecal samples of children.

The scientists, collaborating out of institutions in Calcutta, New Delhi and Pune, have found that the abundance of certain disease-causing bacteria rises while populations of friendly bacteria appear depleted in malnourished children.

The researchers studied the so-called gut microbiomes of 20 children in varying nutritional states selected from a village in Bengal’s Birbhum district and a site for a long-term health and demographic study funded by the state government.

“No one has so far looked at gut microbiomes with respect to malnutrition in India in this detail,” said Gopinath Balkrish Nair, the director of the Translational Health Science and Technology Institute (THSTI), Faridabad (Haryana), who led the study.

Nair and his colleagues observed a progressive increase in the abundance of potentially harmful bacteria such as Escherichia, Streptococcus and Shigella and a progressive decrease in the abundance of friendly bacteria such as Roseburia, Butyrivibrio, or Faecalibacterium with decreasing nutritional status of the children. The scientists have described their findings in a paper that appeared in the journal PLOS One on April 25.

“Among malnourished children, we see this pattern where pathogenic (disease-causing) bacteria dominate and friendly bacteria are depleted,” Nair told The Telegraph. “These changes in microbes’ abundance may be contributing to the malnutrition processes.”

The study, a collaboration between the THSTI, the Institute of Postgraduate Medical Education and Research, Calcutta, and the Tata Consultancy Services (TCS) Innovation Labs, Pune, was aimed at investigating the role of microbes in malnutrition.

“Most studies on malnutrition in India have been focused on the lack of good diet and its consequences,” said Abhijit Chowdhury, professor of hepatology at the IPGMER, Calcutta, and a collaborator. “We’re examining another biological component of malnutrition.”

Their findings suggest that the guts of children with severe malnutrition are populated by two “opposing” groups of microbes — one group can cause disease or inflammation, while the other group helps in digestive processes and counters inflammation.

Earlier independent studies have shown that the bacteria Roseburia and Butyrivibrio help improve the absorption of carbohydrates while both Roseburia and Faecalibacterium have anti-inflammatory action.

“If our early findings are validated through larger studies, we could think of designing new therapies for severe malnutrition,” Chowdhury told The Telegraph. “We could try to increase the abundance of friendly bacteria.”

A team of computational biologists at the TCS Innovation Lab put together the gut microbiomes from sequences of genetic material extracted from the faecal samples of the children by using a set of algorithms developed in-house.

“The gut has thousands of bacteria,” said Sharmila Mande, a senior computational biologist and a team member. “The task was to computationally use fragments of thousands of bacterial genomes to determine the abundances of those bacteria.”