Gut microbiota of children living in rural south Thailand and urban Singapore.

BACKGROUND: An imbalanced prevalence of allergic diseases occurs in the region of South East Asia. It has been suggested that a change in lifestyle associated with improved hygiene and modernization has altered the composition of human gastrointestinal microbiota, and hence susceptibility to allergy.
METHODS: This cross-sectional study was designed to investigate the differences between fecal microbiota in children living in areas with contrasting socioeconomic development. Fecal samples from 73 young children (age 3.0 +/- 0.5) from rural Thailand and 69 age-matched children from urban Singapore were collected and studied using selective culture. Clinical data were also collected using modified ISAAC questionnaires, aiming to identify the key differences in the demographic as well as clinical features between the two study groups.
RESULTS: The two contrasting populations studied differed significantly in multiple lifestyle factors such as family size, antibiotic use and sources of drinking water in the households. Rural children harbored significantly higher counts of lactic acid bacteria (LAB) [7.1 (6.4, 8.3) vs 6.0 (5.3, 7.0) logCFU/g, p < 0.001)], coliforms [8.9 (7.3, 10.2) vs 6.9 (5.7, 7.7) logCFU/g, p < 0.001)] as well as staphylococci [5.3 (4.8, 6.3) vs 4.3 (3.6, 5.0) logCFU/g, p < 0.001)] than their urban counterparts. However, enterococcal counts did not differ between the two groups. No single lifestyle factor could be identified to have caused such differences.
CONCLUSIONS: Certain fecal microbial counts were higher in rural children compared with urban children in South East Asia. Several contrasting home environmental conditions and practices were also identified. These may serve as a basis for future investigation of lifestyle factors underlying the global gradient of the increasing trends of allergic diseases.