The diet of each tribe studied played a critical role in shaping their gut microbiomes. The Sabar, Bhutia, and Mech tribes have diets that are deeply connected to their environment and traditional practices. Each tribe's diet not only supports their lifestyle but also ensures the preservation of specific gut bacterial species, which is less prevalent in urban individuals.
The Sabar tribe's diet consists primarily of rice, pulses, various leaves, and occasional small animals like rats and snakes. Fish, a key source of protein, is often caught from nearby water bodies. These natural food sources maintain the tribe’s diet devoid of modern processed foods, preserving their gut microbiota in a more ancestral state. This unique diet provides essential nutrients during lean crop seasons or when natural disasters strike, ensuring food security. Some of their food habits also include the regular consumption of alcoholic beverages and tea liquor (tea without sugar and milk), which have a distinct impact on their gut bacteria composition.
The Bhutia tribe's diet is rooted in small-scale farming, livestock raising, and the cultivation of fruits and vegetables. Their diet is rich in meat, fermented dairy products, and locally brewed alcohol. The Bhutia's gut microbiome is rich in a diversity of microbes that come from their consumption of fermented products and dairy, as well as their reliance on fresh produce and natural resources. This traditional Mongolian diet fosters gut bacteria known to support high levels of metabolism.
The Mech tribe, like the Bhutia, follows a diet based on natural produce and hunting. Their diet includes rice, dairy products, fruits, vegetables, and a variety of meats, such as quail and frog, harvested from the local forests. This fresh, natural diet maintains their gut bacterial diversity and health. The tribe’s gut microbiome is enriched in beneficial microbes due to the consumption of minimally processed food, which contrasts with the bacterial profiles observed in urban subjects.
Urban subjects, in comparison, have a diet rich in processed foods, which affects their gut bacterial profiles by reducing diversity. Processed food consumption has been linked to increased gut inflammation and the prevalence of bacterial strains associated with negative health outcomes, such as obesity and irritable bowel syndrome (IBS). This sharp contrast between the tribal and urban diets highlights the profound impact that diet has on gut bacteria composition and, by extension, health.