Composition, variability, and temporal stability of the intestinal microbiota of the elderly

Abstract

Alterations in the human intestinal microbiota are linked to conditions including inflammatory bowel disease, irritable bowel syndrome, and obesity. The microbiota also undergoes substantial changes at the extremes of life, in infants and older people, the ramifications of which are still being explored. We applied pyrosequencing of over 40,000 16S rRNA gene V4 region amplicons per subject to characterize the fecal microbiota in 161 subjects aged 65 y and older and 9 younger control subjects. The microbiota of each individual subject constituted a unique profile that was separable from all others. In 68% of the individuals, the microbiota was dominated by phylum Bacteroides, with an average proportion of 57% across all 161 baseline samples. Phylum Firmicutes had an average proportion of 40%. The proportions of some phyla and genera associated with disease or health also varied dramatically, including Proteobacteria, Actinobacteria, and Faecalibacteria. The core microbiota of elderly subjects was distinct from that previously established for younger adults, with a greater proportion of Bacteroides spp. and distinct abundance patterns of Clostridium groups. Analyses of 26 fecal microbiota datasets from 3-month follow-up samples indicated that in 85% of the subjects, the microbiota composition was more like the corresponding time-0 sample than any other dataset. We conclude that the fecal microbiota of the elderly shows temporal stability over limited time in the majority of subjects but is characterized by unusual phylum proportions and extreme variability.

Modulation of the gut microbiota by prebiotic fibres and bacteriocins

“…In the adulthood of healthy humans, the gut ecosystem is in a homeostatic equilibrium with temporal balance between different microbial groups, epithelial tissue of the intestine and the immune system of the host [21,23]. However, after approximately 65 years of age, the composition of the gut microbiota alters, with high interindividual variability, which is probably due to the physiological changes in the intestines that affect food digestion and absorption, and immune function [24]. Another possible reason for this alteration in gut microbiota is the frailty or health status of the host during ageing; however, it is still not clear whether the changes in microbiota are correlative with or causative for the poor health status during ageing [25].…”

Human gut microbiota: does diet matter?

“…Interest, as well as the number of studies, in the GI microbiota of elderly people has grown as life expectancy in the Western world has rapidly increased. The elderly have been reported to have relatively stable microbiota (93)(94)(95) . However, the microbiota of the elderly has been reported to be more diverse and to contain partly different core microbiota as compared with younger adults (93,94,96,97) .…”

“…The elderly have been reported to have relatively stable microbiota (93)(94)(95) . However, the microbiota of the elderly has been reported to be more diverse and to contain partly different core microbiota as compared with younger adults (93,94,96,97) . Moreover, inter-individual variation is greater in elderly people as compared with younger adults (2,94,98) .…”

Integration of ‘omics’ data in aging research: from biomarkers to systems biology

“…It has a huge influence on many biological processes such as immune response, metabolism and disease (Zhu et al ., 2010; Grice & Segre, 2012). While the microbiome seems to be relatively stable during adulthood, it changes significantly in later life (Guigoz et al ., 2008; Biagi et al ., 2010; Claesson et al ., 2011). Biagi et al .…”