2019 Volume 69 Issue 1-4 Pages 108-118
It has been reported that an association between gut microbiota and obesity, and changes in the composition of gut microbiota have been reported with aging. The aim of this study is clarify the relationship between obesity and gut microbiota as a function of age. Furthermore, the impact of lifestyle factors（alcoholic drink and smoking） on gut microbiota were discussed. Fecal samples from 1082 healthy Japanese adults aged 19‒90 years who participated in the Iwaki Health Promotion Project in 2014 were analyzed by using 16S rDNA gene-targeted sequencing. The participants were stratified into six age groups: ≤39, 40‒49, 50‒59, 60‒69, 70‒79 and ≥ 80. The participants with a body mass index（BMI） of < 25 kg/m² were classified as non-obese, and those with a BMI of ≥ 25 kg/m² were classified as obese. Changes in the composition of gut microbiota with age were different between the obese and non-obese groups. Bacterial diversity decreased with age at the phylum level, however, this diversity was not observed at the class level. The abundances of certain gut microbiota, such as Bacteroidetes and Firmicutes, were different between the obese and non-obese groups. There were no significant differences in alcoholic and smoking habits. Bacterial diversity was different with age between the obese and non-obese group. The composition of Bacteroidetes and Firmicutes changed with increasing age in the obese group.
