BioMed Research International / 2018 / Article / Tab 1

Review Article

Gut Microbial Changes, Interactions, and Their Implications on Human Lifecycle: An Ageing Perspective

Table 1

Changes in the gut microbiota in the healthy ageing (natural, non-antibiotic treated).

Study details Sample detailsMethodsChangesRef

Comparative study = 30
(i) Rural (high fibre diet) = 15 median age 84
(ii) Urban (low fibre diet) = 15 median age 68
Culture based
(i) Rural: High in Bifidobacteria, Bacilli and mainly Clostridium perfringens
(ii) Urban: Low Bifidobacterium adolescentis and Fusobacterium mortiferum strains

Analysis of gut microbiota = 616S rRNA gene sequencing, culture-based(i) Bacteroides, Gamma-Proteobacteria and Clostridium IV, IX, XIVa dominated[14]

Characterization of jejunal, ileal, caecal and rectosigmoidal colonic microbiota = 3
(i) Colon autopsy samples
16S rRNA gene sequencing(i) Jejunal and Ileal microbiota: streptococci, lactobacilli, Gammaproteobacteria, the Enterococcus group and the Bacteroides
(ii) Caecum: Bacteroides, Clostridium
(iii) Sigmoid-colon: C. coccoides group, the C. leptum subgroup, the Bacteroidetes group, Gammaproteobacteria, the Bifidobacterium, streptococci and lactobacilli groups

= 230
(i) Sweden, adults (SA) = 20, elderly (SE) = 40
(ii) Germany (GA), adults = 23, elderly (GA) = 38
(iii) France, adults (FA) = 22, elderly (FE) = 27
(iv) Italy, adults (IA) = 30, elderly (IE) = 40
FISH and flow cytometry(i) SA: Eubacterium rectale-Clostridium coccoides low in number High Lactobacillus-enterococcus group in both SA and SE
(ii) GE: Eu., rectale-C. coccoides cluster higher
(iii) FA: low levels of Bacteroides-Prevotella group. Low levels of bifidobacteria trend in FE
(iv) IA & IE: lowest levels of Lactobacillus-enterococcus group. High Bifidobacterium group
(v) High enterobacteria levels in all countries in the elderly

Observational study = 249
(i) Infants = 150, age 1 to 12 months;
(ii) Adults = 54, age 25 to 35 years;
(iii) Elderly = 45, age 80 to 82 years.
16S rRNA gene sequencing and FISH analysis(i) Akkermansia muciniphila is present and colonizes the intestinal tract in early life and develops within a year to a level close to that observed in healthy adults[17]

Comparative assessment of faecal microbiota = 62
(i) Infants, = 21, age 3 weeks to 10 months
(ii) Adults, = 21, age 25 to 45 years
(iii) Elderly, = 20, age 70 to 90 years
qPCR and 16S rRNA gene sequencingFirmicutes to Bacteroidetes ratios (in log10):
(i) Infants: 0.4
(ii) Adults: 10.9
(iii) Elderly: 0.6

Comparative analysis = 84
(i) Adults = 20, age 25 to 40 years;
(ii) Elderly = 22, age 63 to 76 years;
(iii) Centenarians = 21, age 99 to 104 years.
16S rRNA gene sequencing(i) Adults and Elderly: Bacteroidetes and Firmicutes dominant; low levels of Actinobacteria, and Proteobacteria
(ii) Centenarians: High levels of Proteobacteria; decrease in Clostridium cluster XIVa, an increase in Bacillus species

sorted by year of publication; FISH: fluorescence in situ hybridization.