Bacteria that naturally reside in the gut are important for health, but recent studies consistently show that a modern lifestyle depletes the gut's collection of microbes.
How lifestyle affects the diversity of this gut "microbiome" is unclear, but an analysis of the gut microbiomes of Papua New Guinean and US residents in Cell Reports now suggests that western lifestyle may diminish the variety of bacteria in the gastrointestinal tract by limiting their ability to be transmitted among humans.
"There are several aspects of western lifestyle that have been hypothesized to alter the gut microbiome and decrease diversity," explains senior author Jens Walter of the University of Alberta Department of Agricultural, Food & Nutritional Science. "These include diet, sanitation, and clinical practices such as antibiotic use and caesarean sections, but we lack a conceptual understanding of how our microbiomes are altered."
The research team found that Papua New Guineans have microbiomes with greater bacterial diversity, lower inter-individual variation, and vastly different compositional profiles compared with US residents. US residents lacked approximately 50 bacterial types that belonged to the core microbiome in Papua New Guineans.
The information obtained in this study has implications for human health, given that microbiome alterations associated with westernization might contribute to increases in noncommunicable chronic diseases occurring in industrialized countries. The investigators noted the importance of caution when questioning specific modern lifestyle practices, though, because overall, health and life expectancy is higher in westernized societies.