Summary of studies associating faecal microbiota profiles with frailty
| Ref. (country of study cohort) | Young adults | Elderly | Determination of frailty | 16S rRNA approach | Main findings with increased frailty | ||
| Nr. | Age range (years) | Nr. | Age range (years) | ||||
| van Tongeren72(The Netherlands) | 23 | 70–100 | Groningen Frailty Indicator | FISH | ↓lactobacilli/Enterococcus group | ||
| ↓Bacteroides/Prevotella group | |||||||
| ↓Faecalibacterium prausnitzii | |||||||
| ↑Enterobacteriaceae | |||||||
| Claesson77 (Ireland) | 13 | 28–46 | 178 | 64–102 | Barthel Index and Functional Independence Measure | Pyrosequencing | ↓Ruminococcus CAG, ↓Prevotella |
| ↓Oscillibacter CAG | |||||||
| ↑Bacteroides CAG | |||||||
| O’Toole56 (Ireland) | 282 | 64–102 | Barthel Index and Functional Independence Measure | Pyrosequencing | ↓Alpha diversity | ||
| Jeffery60 (Ireland) | 13 | 28–46 | 371 | 64–102 | Barthel Index and Functional Independence Measure | Pyrosequencing | ↓Alpha diversity |
| ↑Alpha diversity | |||||||
| Ticinesi61 (Italy) | 76 multimorbid | 71–97 | Rockwood Frailty Index | Illumina MiSeq | ≈ Microbial richness | ||
| ↑Unclassified member of Clostridiaceae 1 family | |||||||
| 25 | 65–87 | ↑Unclassified member of Lachnospiraceae family | |||||
| ↑Oscillospira, ↑Peptococcus, ↑Porphyromonas | |||||||
| ↑Fonticella, ↑Prevotella | |||||||
| Jackson53 (UK) | 728 (42–86)* | Rockwood Frailty Index | Illumina MiSeq | ↓Microbial diversity and richness | |||
| ↓A subset of Lachnospiraceae OTUs | |||||||
| ↓Faecalibacterium, ↓Faecalibacterium prausnitzii | |||||||
| ↑Eubacterium,↑Eggerthella, ↑Eubacterium dolichum | |||||||
| ↑Eggerthella lenta, ↑13 Enterobacteriaceae OTUs | |||||||
| Maffei55 (USA) | 85 (43–79)* | 34-item frailty index | Illumina MiSeq | ↓Microbial richness | |||
| ↓Paraprevotella, ↓Sutterella | |||||||
| ↓Rikenellaceae family OTU | |||||||
| ↑Coprobacillu, ↑Dialister | |||||||
| ↑TM7 candidate-phylum OTU | |||||||
*Studies did not report on the definition of young adult, elderly and centenarian.
Nr, number of subjects; CAG, coabundance groups; FISH, fluorescence in situ hybridisation; OTU, operational taxonomic unit; increased Barthel index indicates decreased frailty; increased functional independence measure indicates decreased frailty; ↓, significant decrease; ↑, significant increase; ≈, not significantly different.