RESUMO
Objective To analyze the diversity of intestinal microecology in different healthy age groups and explore the relationship between age and the composition of intestinal microflora.MethodsFecal samples were collected from the children,adult and elderly groups.The main intestinal microflora were cultured and quantified,and the qualitative and quantitative changes in the level of category were determined by fluorescence quantitative PCR.The Bifidobacteria/Enterobacteriaceae (B/E) ratio reflexing intestinal colonization resistance was also calculated.Results The germiculture of fecal samples indicated that the counts of Bifidobacteria and Lactobacillus (P＜0.01 and P＜0.05,respectively) were significantly lower in the adult and aged groups than in children group.The number of Bacteriodes and Enterobacteriaceae in the elderly group were higher than in the children and the adult groups (all P＜0.01).The counts of Enterococcus were increased in the adult and the aged groups (P＜0.05 and P＜0.01) compared with the children group,and were higher in the aged group than in the adult group (P＜0.05).The B/E ratio was significantly decreased in the aged group (0.88-±-0.13) as compared with the children (1.15±0.15) and the adult groups ( 1.01± 0.20) ( both P ＜ 0.01).The diversities of Bifidobacteria,Bacteriodes,Enterobacteriaceae and B/E ratio by fluorescent quantification PCR were consistent with the results by germiculture technology.The diversity of Lactobacillus (P＜0.01) between the children and the aged groups as well as between the children group and the adult group significantly improved (P＜0.01 and P＜0.05 ) in PCR compared with the germiculture technology. ConclusionsThe numbers of intestinal Bifidobacterium and Lactobacillus are decreased with lower colonization resistance,while the numbers of Bacteriodes,Enterobacteriaceae and Enterococcus are increased with aging.