What your gut is telling you

Even cooking oil can influence the microbes that live within us

Millions of microorganisms that live inside the human gut play a critical role in not just metabolising food but also in maintaining overall health. The type and composition of gut bacteria depend on where we live and what we eat. For example, a study of gut bacteria among groups of Indians has shown that they vastly differ from those found among western populations and even depend on multiple factors such as exposure to pollution and the cooking medium.

The India focus

Human microbiome (colonies of bacteria) plays a key role in digestion, fat metabolism, ensuring resistance to infection and boosting human immunity against diseases. They are linked to a variety of human conditions ranging from obesity to anxiety and even one’s armpit smell. Thus, a study of the dynamics of microbiomes could help scientists understand/treat various conditions/diseases.

The new study, on the nature and composition of gut microbiomes of healthy Indians, has shown interesting trends. It was done among healthy individuals living in Ballabhgarh near Faridabad, Haryana, and Leh in the Ladakh region of Jammu and Kashmir; the findings have been published in the journal,

Scientific Reports . The samples from Ballabgarh were categorised into rural and urban as there are different food habits/patterns of living. Faecal samples were analysed to document gut bacteria.

The findings

It was found that the gut microbiome of Indians are generally dominated by Firmicutes bacteria followed by Bacteroidetes, Actinobacteria, Proteobacteria, Spirochetes, Verrucomicrobia and Fusobacteria. There was marked variation in the functional compositions of microbiomes in the sample populations from the two regions. Variation was also seen between rural and urban areas as well as between plains and high altitude areas.

The study also suggests a link between the use of cooking oil and an abundance of specific microorganisms. For example, Collinsella was abundant in the gut of individuals who consumed ghee. Pseudomonas, which is associated with dairy products, was largely lacking in the Leh population probably because they don’t much consume dairy products. However, people here had a significantly higher concentration of bacteria like Faecalibacterium and Lachnospiraceae, which have anti-inflammatory functions.

The gut microbiomes from Ballabhgarh were found to have an abundance of genes which play an active role in the degradation of xenobiotic substances (carcinogens, pollutants, drugs and pesticides). This could be as a result of high exposure to industrial or agricultural chemicals such as fertilizers and pesticides. This means that in addition to food, environmental exposure plays a role in shaping our gut microbiome.

“Gram-positive bacteria (Fermicutes) are in more abundance in Indian microbiome. This is in sharp contrast to the earlier belief, according to which Gram-negative bacteria dominated the gut of Indians,” said Dr. Bhabatosh Das, lead researcher of the study. Gram positive and Gram negative are two broad categories of bacteria based on the difference in their cell walls.

Road ahead

“This research could open up possibilities of new interventions such as faecal transplantation in future to counter diseases such as Inflammatory bowel disease and Clostridium difficile infection, where antibiotics are proving to be less effective,” added Dr. Das.

The study was funded by the Department of Biotechnology and the Department of Science and Technology (DST)-UK India Education Research Initiative. — India Science Wire