腸内フローラ研究からみた日本人とアジア人の健康

抄録

　Asia differs substantially among and within its regions populated by diverse ethnic groups with different cultures and unique diets. Asian Microbiome Project, which is a consortium research project participated by ten Asian countries, is investigating on the gut microbiome diversity which may link with these diverse diets. Thus far, we found country-specific features as well as enterotype-like global variations in the Asian microbiomes. Notably, Japanese have unique features such as less alpha- and beta-diversities, low abundance of potentially pathogenic bacteria groups and high abundance of Bifidobacterium. This may reflect unique Japanese life and dietary styles. Regarding enterotypes, majority of southeast Asian populations carry the Prevotella-type (P-type) in reflection of high consumption of rice. However, a cross-sectional study on the gut microbiota of school-age children on Leyte island in Philippines showed the enterotype-shift from P-type to Bacteroides/Bifidobacterium-type (BB-type), which associated with dietary Westernization. Another cross-sectional study on Thai children further indicated decrease of short chain fatty acid concentration in the feces of children in urban city, who consumed much less vegetables compared with children in rural city. Altogether, although Asian people have evolved their gut microbiomes in association with their unique diets, current urbanization hampers their structure and function. It warrants further studies on the impact of altered gut microbiomes on the health of Asian people.