Table 4.
Overview of human studies that demonstrate an association between obesity and compositional dysbiosis of the intestinal microbiota determined with culture-independent methods
| Study material | Population | Analytical methods | Key findings | References |
|---|---|---|---|---|
| Faeces (3 time points) |
12 Obese individuals (on diet) 2 Normal-weight individuals |
Clone library sequencing (16S) |
Obese individuals compared with lean: ↓ Bacteriodetes ↑ Firmicutes |
Ley et al. (2006) |
| Faeces (3 time points) | 19 Obese individuals (on diet) |
FISH GC |
Obese individuals on diet of decreased carbohydrate intake: ↓ Roseburia ↓ Eubacterium rectale subgroup of cluster XIVa ↓ bifidobacteria |
Duncan et al. (2007)* |
| Faeces (2 time points) |
18 Obese pregnant women 36 Normal-weight pregnant women |
FISH/flow cytometry qPCR |
Overweighed pregnant women: ↑ Bacteroides ↑ Clostridium ↑ Staphylococcus |
Collado et al. (2008b)# |
| Faeces (3 time points) |
23 Overweight/obese individuals (on diet) 14 Non-obese individuals |
FISH |
During weight-loss diet: ↔ Bacteriodetes ↓ butyrate-producing Firmicutes |
Duncan et al. (2008)* |
| Faeces (2 time points) |
25 Overweight/obese children 24 Normal-weight children (prospective study) |
FISH/flow cytometry qPCR |
Intestinal microbiota during infancy preceding overweight during childhood: ↓ bifidobacteria ↑ Staphylococcus aureus |
Kalliomäki et al. (2008) |
| Faeces |
20 Obese individuals 9 Individuals with anorexia nervosa 20 Normal-weight individuals |
qPCR |
Obese individuals: ↓ Bacteriodetes ↑ Lactobacillus Anorexic individuals: ↑ Methanobrevibacter smithii |
Armougom et al. (2009) |
| Faeces (2 time points) | 39 Overweight/obese adolescents (on diet and physical activity) | FISH/flow cytometry |
Obese individuals: ↑ C. histolyticum ↑ E. rectale-C. coccoides Upon calorie restricted diet: ↓ C. histolyticum ↓ C. lituseburense ↓ E. rectale-C. coccoides ↑ Bacteroides-Prevotella group |
Nadal et al. (2009)† |
| Faeces (2 time points) | 36 Overweight/obese adolescents (on diet and physical activity) | qPCR |
Obese adolescents on diet with a high weight-loss: ↑ Total bacteria ↑ B. fragilis group ↑ C. leptum group ↑ B. catenulatum group ↓ C. coccoides group ↓ Lactobacillus group |
Santacruz et al. (2009)† |
| Faeces (2 time points) |
31 Monozygotic twin pairs 23 Dizygotic twin pairs 46 Mothers of twin pairs |
Sanger sequencing (16S) 454 FLX titanium sequencing (metagenome) |
Most obesity-associated genes are from: Actinobacteria Firmicutes Most lean-enriched genes are from Bacteroidetes |
Turnbaugh et al. (2009) |
| Faeces |
3 Obese individuals 3 Individuals with a gastric-bypass 3 Normal-weight individuals |
Clone library sequencing (16S) 454 FLX titanium sequencing (16S) qPCR |
Obese individuals: ↑ H2-producing Prevotellaceae ↑ H2-utilizing methanogenic Archaea |
Zhang et al. (2009) |
| Faeces |
15 Obese Indian adolescents 13 Non-obese Indian adolescents |
qPCR |
Obese children: ↔ Bacteroides-Prevotella ↔ Bifidobacterium ↔ L. acidophilus ↔ E. rectale ↑ F. prausnitzii |
Balamurugan et al. (2010) |
| Faeces (2 time points) |
16 Infants of overweight women 26 Infants of normal-weight women |
FISH/flow cytometry qPCR |
Infants of overweight mothers: ↑ Bacteroides ↑ Staphylococcus |
Collado et al. (2010)# |
| Faeces |
33 Obese individuals 35 Overweight individuals 30 Normal-weight individuals |
qPCR GC |
Obese individuals compared with lean: ↑ Bacteriodetes ↓ Firmicutes |
Schwiertz et al. (2010) |
| Faeces |
16 Overweight pregnant women 34 Normal-weight pregnant women |
qPCR |
Overweight pregnant women: ↓ Bifidobacterium ↓ Bacteroides ↑ Staphylococcus ↑ Enterobacteriaceae ↑ E. coli |
Santacruz et al. (2010) |
All studies have used the body mass index (BMI) to define normal weight, overweight and obesity. Studies that have used subjects from the same cohort are indicated by *, # and †
FISH fluorescence in situ hybridisation, GC gas chromatography, qPCR quantitative polymerase chain reaction