Senior author Jens Walter from the University of Alberta in Canada said, "There are several aspects of western lifestyle that have been hypothesized to alter the gut microbiome and decrease diversity. 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."
Researchers compared the fecal bacteria of adults from two rural, non-industrialized regions in Papua New Guinea with those of the US residents. They found that Papua New Guineans have microbiomes with greater bacterial diversity, lower inter-individual variation, and vastly different compositional profiles compared with the US residents. Bacterial dispersal, or the ability of bacteria to move from individual to individual, appeared to be the dominant process that shapes the collection of gut bacteria in residents of Papua New Guinea but not those in the US residents.
Walter said, "These findings suggest that lifestyle practices that reduce bacterial dispersal, specifically sanitation and drinking water treatment, might be an important cause of microbiome alterations." However, the researchers noted the importance of caution when questioning specific modern lifestyle practices, though, because overall, health and life expectancy is higher in westernized societies.
The study is published in the Cell Reports.