Impact of healthy aging on active bacterial assemblages throughout the gastrointestinal tract

Gut Microbes. 2021 Jan-Dec;13(1):1966261. doi: 10.1080/19490976.2021.1966261.

Abstract

The adaption of gut microbiota (GM) throughout human life is a key factor in maintaining health. Interventions to restore a healthy GM composition may have the potential to improve health and disease outcomes in the elderly. We performed a comprehensive characterization of changes in the luminal and mucosa-associated microbiota composition in elderly compared with younger healthy individuals. Samples from saliva and feces, and biopsies from the upper and lower gastrointestinal tract (UGIT, LGIT), were collected from 59 asymptomatic individuals grouped by age: 40-55, 56-70, and 71-85 years). All underwent anthropometric, geriatric, and nutritional assessment. RNA was extracted and reverse-transcribed into complementary DNA; the V1-V2 regions of 16S ribosomal RNA genes were amplified and sequenced. Abundances of the taxa in all taxonomic ranks in each sample type were used to construct sample-similarity matrices by the Bray-Curtis algorithm. Significant differences between defined groups were assessed by analysis of similarity. The bacterial community showed strong interindividual variations and a clear distinction between samples from UGIT, LGIT, and feces. While in saliva some taxa were affected by aging, this number was considerably greater in UGIT and was subsequently higher in LGIT. Unexpectedly, aging scarcely influenced the bacterial community of feces over the age range of 40-85 years. The development of interventions to preserve and restore human health with increased age by establishing a healthy gut microbiome should not rely solely on data from fecal analysis, as the intestinal mucosa is affected by more significant changes, which differ from those observed in fecal analyses.

Keywords: Healthy aging; gut microbiota; microbiome; nutrition; physical fitness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aging*
  • Bacteria / classification*
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • DNA, Bacterial / genetics
  • Feces / microbiology
  • Female
  • Gastrointestinal Microbiome / physiology*
  • Host Microbial Interactions / physiology*
  • Humans
  • Intestinal Mucosa / microbiology*
  • Male
  • Middle Aged
  • Probiotics / analysis
  • Prospective Studies
  • RNA, Ribosomal, 16S / genetics
  • Saliva / microbiology

Substances

  • DNA, Bacterial
  • RNA, Ribosomal, 16S

Grants and funding

This study was primarily performed and funded in the context of the EMGASTA project (DRKS-ID: DRKS00009737) and received partial support from the LILIFE project. Both projects are carried out within the research group “Autonomie im Alter” of Saxony-Anhalt, Germany, and are supported by the European Commission through the “European Funds of regional development” (EFRE) as well as by the regional Ministry of Economy, Science and Digitalization. This study was also supported by the Helmholtz Association’s Initiative on Aging and Metabolic Programming (AMPro).“European Funds of regional development” (EFRE);“European Funds of regional development” (EFRE);European Commission through the “European Funds of regional development” (EFRE);