Assessment of microbial diversity in the distal gut of Filipino children of different nutritional status through rDNA analysis

As one of the countries still plagued by malnutrition and since one of the millenium development goals (MDGs) is to reduce child mortality, this study addresses malnutrition through profiling of the gut microbiota of nourished and malnourished Filipino children. Archival DNA samples extracted from stool of 2-11 year-old children were used to amplify the ribosomal DNA (rDNA) of bacteria and archaea. (16S rDNA) and eukarya (18S rDNA). The amplified rDNA were subjected to denaturing gradient gel electrophoresis (DGGE) to come up with a gut microbial community profile. In the analysis of the DGGE profile of the nourished, moderately malnourished and severely malnourished subjects using Sorensen's index of similarity, there is high diversity among the three groups, which means that different microorganisms characterize different nutritional states. In terms of gut bacterial diversity, there is greater species richness in the severely malnourished group compared to the nourished group, which implies that dominance of certain bacterial phylotypes is lost in the malnourished state due to the need for mutual beneficence among different members of the community since there are limited resources to partake of. In archaea and micro-eukaryae, there is greater species richness in the moderately malnourished group, but this significantly declines in the severely malnourished group, which implies that the poor environmental condition causes the proliferation of archaea and the emergence of micro eukaryal enteropathogens. The decline of archaea and micro-eukarya richness in the severely malnourished group may have been influenced by the increase in bacterial diversity and the atrophy or deterioration of the distal gut lining where the microorganisms thrive. These findings provide additional information on what could be taking place in the distal gut microbial community in different nutritional states, as well as open up new directions in studying gut microbial community dynamics in different nutritional states.