The human gastrointestinal tract (GIT) harbors trillions of microbial cells that play important role in the digestion of complex dietary polysaccharides by providing enzymatic functions that are not encoded in our own genome. In addition, the gut microbiota contributes significantly in the synthesis of vitamins, neurotransmitters, signaling molecules and other metabolites, which are the key components of human health. The microbiota living inside the GIT can modulate cytokine production, host immunity, and development of gut-associated lymphoid tissues. People living in different countries have different gut microbiota and several functions including diet, environment, antibiotics, and host genetics could play critical role in shaping community structure of the GIT microbial ecosystem. However, in spite of immense variety, our understanding on the microbial diversity and genomic repertoires of the microbiota inhabiting the GIT of healthy Indians are limited. Considering the distinct environment, ethnicity, food habits and unique socio-economic culture, the researchers in Translational Health Science and Technology Institute (THSTI) anticipated that microbiome research on Indian population, investigating specific hitherto unexplored sub-populations, has unique opportunity.
The team analyzed the GIT microbiome of 84 healthy Indians living in the sea level rural and urban sites comprised 29 villages and 27 urban wards in Ballabhgarh block in Faridabad district of Haryana and high altitude Leh, which is a district of Ladakh, the highest plateau of the Indian state of Jammu and Kashmir. The microbiome analysis was done by adopting culture independent Next Generation Sequencing (NGS) technology.
The present study, for the first time, reveals that the gut microbiome of healthy Indians (vegetarians, non-vegetarians and eggetarians in dietary habit) is dominated by Firmicutes (62%), followed by Bacteroidetes (24%), Actinobacteria (5.2%) and Proteobacteria (4.2%) with prevalent and dominant members of Prevotella, Bacteroides, Faecalibacterium, Roseburia, Ruminococcus, and Collinsella. A total of 54 core bacterial genera were detected across the three distinct communities. Detail analysis reveals that the gut bacterial composition displayed specific signatures and was observed to be influenced by the topographical location and dietary intake of the individuals. The gut microbiome of individuals living in Leh was observed to be significantly similar with a high representation of Bacteroidetes and low abundance of Proteobacteria. In contrast, the gut microbiome of individuals living in Ballabhgarh areas harbored higher number of Firmicutes and Proteobacteria and is enriched with microbial xenobiotic degradation pathways. The rural community residing in sea level Ballabhgarh areas has unique microbiome characterized not only by a higher diversity, but also a higher degree of interindividual homogeneity.
Translational Opportunity: The findings of the present study will be of immense use for clinicians working on Faecal Microbial Transplantation (FMT) as a therapy for Inflammatory Bowel Disease (IBD). It was reported that the success of FMT in the treatment of IBD widely vary depending on the donors. This study clearly tells us about the interindividual heterogeneity (Beta diversity) of gut microbiome among the healthy subjects. Highest heterogeneity was observed among individuals living in the urban areas compared to rural areas. The immediate translational benefit of this study is to select ideal donor for FMT. It is believed that the people living in the rural areas could be best donor to increase the therapeutic success of FMT.