Changes in the intestinal microbiota from adulthood through to old age.

The human intestinal microbiota comprises a complex community whose composition has been resolved in fine detail by recent culture-independent methodologies. The adult intestinal microbiota is stable within individuals, and individual specific when examined at high resolution. Infants and older persons, however, represent stages of life in which the microbiota is in flux. Since changes in the intestinal microbiota are associated with certain diseases or health issues, we have examined the composition and function of the intestinal microbiota in 500 subjects over 65 years of age in Ireland. Medical, biochemical and immunological parameters were measured for all subjects. Faecal microbiota was measured by amplicon pyrosequencing. The data revealed significant inter-individual variation, especially in the proportions of some major bacterial phyla, and significant differences in the microbiota compared with younger adults. These data support the notion of modulating the intestinal microbiota of older people to promote enhanced nutrition utilization and to improve general health.