Microbiota, Environment, and Diet
We are grateful for the interest in our article regarding the intestinal microbiota of children living in different environmental conditions (1). Other studies have compared the intestinal microbiota among children in different countries (2–4). Our study, however, takes a novel and unique approach, where the groups compared are residents of the same city. The intestinal microbial composition of children living in a favela, near a sanitary landfill, differ significantly from that of children of high socioeconomic status having adequate hygienic-sanitary conditions. The term “slum” has no universal definition (5,6). According to the State of the World's Cities Report, 2006/2007 (7) “a slum household is a group of individuals living under the same roof in an urban area who lack ≥1 of the following 5 conditions: durable housing, sufficient living area, access to improved water, access to sanitation and secure tenure.” Thus, the children belonging to the low socioeconomic group, in our study, reside in slums as they fulfill these criteria. This is a cross-sectional study, similar to those performed in communities (3) or in small groups of patients with an underlying disease (8). It was not designed to investigate the temporal variations of microbiota. However, this theme may be the subject of future projects. Furthermore, the association between certain types of diet and the profile of intestinal microbiota is difficult to establish, as various factors seem to influence this relation. We are currently analyzing possible correlations between our collected dietary data and the intestinal microbiota.