Table 2.

Factors associated with modern lifestyle that is potentially associated with alterations of the gut microbiota.

Modern lifestyle

Often live in an urban setting, surrounded by concrete Increased urbanization and migration to urban areas Birth in a hospital; increasing rate of cesarean delivery Small family size Sanitation of living spaces: environment colonized by resistant microorganisms (including resistant bacteria, fungi, and acari) Antibiotic usage early in life Frequent body wash with hot water and soap Low rate of Helicobacter pylori colonization Decline in endemic parasitism Food conserved by refrigeration Consumption of processed foods and food additives Increased pollution in developing nations

Traditional lifestyle

Vaginal delivery at home Large family size, crowding Livingin a rural setting in contact with soil microorganisms Ancestral colonization of the living environment No antibiotics in infant life Limited access to hot water and soap High rate of Helicobacter pylori colonization Parasitic worms common Food conserved by microbial fermentation Consumption of natural foods