Analysis of Infant Intestinal Microbiota by Various Kinds of Molecular Approaches

-Toward Large Scale Epidemiological Investigations Correlating Allergy Development with Intestinal Microbiota-

Abstract

There is considerable evidence that the development of intestinal microbiota in early life has a great influence on the development of the immune system, and it is important to trace changes in the intestinal microbiota of allergy patients, whose number has been increasing recently. However, since lifestyle and genetic factors also affect allergy development, a large scale epidemiological investigation is required to realize the precise correlation between allergy and intestinal microbiota. Therefore, it is indispensable to establish a high-throughput analytical system for fecal microbial composition. In this review, various kinds of molecular methods are compared with regards to fitness for the epidemiological investigation. DGGE and T-RFLP are quite efficient for a rapid diversity assessment of infant intestinal bacterial community structure even though they are limited to only dominant bacteria. Real-time quantitative PCR is promising for much more sensitive and accurate quantitation of the target bacteria. Random sequencing of 16S rDNA clone libraries allows precise identification with high accuracy and could be applied to the microbial composition analysis with a decrease in the sequencing cost. Microarray analysis allows high-throughput diversity assessment which could be applied to these kinds of epidemiological studies instead of DGGE and T-RFLP in the near future.