Colon cancer lower in India due to veg-rich diet: IISER study

Colon cancer lower in India due to veg-rich diet: IISER study

Ramendra.Singh@timesgroup.com

Bhopal:22.10.2021

Gut associated problems such as inflammatory bowel disease, colitis, colon cancer and such others have a much lower incidence in India compared to the western countries due to consumption of plant-based diets rich in complex polysaccharides that provide a supportive growth environment for good bacteria in the gut.

Researchers of IISER (Bhopal) in their study have concluded this which was recently published in a prestigious high-impact international publication journal “Biofilms and Microbiomes”. Incidentally, it is the biggest gut metagenome study ever done in the country so far.

The research team was led by Dr Vineet K. Sharma, associate professor, Department of Biological Sciences, IISER Bhopal, and comprised Vishnu Prasoodanan PK, Shruti Mahajan, Dr Ashok K Sharma, Dr Darshan B Dhakan, Dr Abhijit Maji and collaborator Dr Joy Scaria.

Associate professor, Vineet Sharma said that by studying the largest gut metagenome of 200 samples from healthy individuals from six diverse geographical regions of India, the IISER team has shown that the bacterium Prevotella copri is the most abundant in Indian human gut which can constitute upto 70% of the total gut bacteria despite the diversity in the choice of meals, preparation-styles, and usage of spices across India.

“A unique and comprehensive Prevotella Genome Database (PGD) and Prevotella Gene Catalogue (PGC) was constructed in this study by including 2,204 genomes and 2.9 million genes to study this bacterium,” said Dr Sharma. Researchers have also identified the presence of an array of genes encoding plant-polysaccharide metabolising enzymes as clusters in this bacterium. “The other non-western countries that also consume plant-based fibres in diet such as Madagascar, Peru and Tanzania also mimicked the results from India, whereas the western populations (USA, Netherlands, Spain and Italy) consuming diets rich in protein and fat and poor in plant-based fibres had poor abundance of this bacteria,” claimed Dr Sharma.

Another important outcome of this study is the presence of inflammation associated with Prevotella species in western populations possibly due to transmission of Prevotella bacteria from mouth to gut that makes them more susceptible for Prevotella-associated gut inflammatory diseases.

These findings emphasize the role of high fibres for a healthy gut microbiome and provide leads for designing new prebiotics and probiotics for the Indian and western populations.

Samples were collected from six different locations to capture the maximum diversity in the gut metagenome of the Indian sub-population, including Madhya Pradesh, Delhi-NCR , Rajasthan, Maharashtra, Bihar and Kerala.

IISER research is the biggest gut metagenome study ever done in India