Studies investigating the effect of the low FODMAP diet on the microbiota and microbiota metabolites
| Reference | Study design | Participants | Duration (weeks) | Microbiota | Microbiota metabolite | ||
| Method | Findings | Method | Findings | ||||
| Mclntosh et al 42 | Dietary advice RCT (single blind) | Rome III IBS LFD n=19 HFD n=18 | 3 | 16S rRNA sequencing (Illumina) | Microbiota: Increased richness of Actinobacteria, Firmicutes, Clostridiales in LFD versus HFD No difference in α-diversity or β-diversity after LFD versus baseline but higher richness in LFD versus HFD Increased abundance of Clostridiales family XIII Incertae sedis spp. and Porphyromonas spp. in LFD versus baseline Decreased abundance of Propionibacteriaceae, Bifidobacteria in LFD versus baseline | MS | No difference in urinary metabolomic profile at baseline in LFD versus HFD but separation after intervention Three metabolites (histamine, p-hydroxybenzoic acid and azelaic acid) discriminated groups Metabolite concentrations correlated with abundance of various taxa |
| Halmos et al 44 | Feeding RCT, crossover (single blind) | Rome III IBS and healthy LFD versus typical diet IBS n=27 Healthy n=6 | 3 | qPCR | Lower absolute abundance of Bifidobacteria, Faecalibacterium prausnitzii, Clostridium cluster IV in LFD versus typical diet and baseline Lower relative abundance Akkermansia muciniphila in LFD versus typical diet Lower total bacteria in LFD versus baseline Greater diversity Clostridium cluster XIV in LFD versus typical diet and baseline | GLC | No difference in total or individual stool SCFAs in LFD versus typical and baseline |
| Valeur et al 47 | Dietary advice uncontrolled trial (unblind) | Rome III IBS n=63 | 4 | – | – | GLC | Lower total stool SCFAs, acetate, butyrate versus baseline |
| Staudacher et al 49 | Dietary advice RCT (single blind) | Rome III IBS LFD n=51 Sham n=53 | 4 | qPCR | Lower abundance of Bifidobacteria in LFD versus sham | GLC | Lower stool acetate concentration in LFD versus control |
| Staudacher et al 50 | Dietary advice RCT (unblind) | Rome III IBS LFD n=19 Habitual diet n=22 | 4 | FISH | Lower absolute and relative abundance of Bifidobacteria in LFD versus habitual No difference in total abundance of other groups, for example, F. prausnitzii | GLC | No difference in total or individual stool SCFAs in LFD versus habitual |
| Chumpitazi et al 76 | Dietary advice uncontrolled trial (unblind) | Paediatric Rome III n=12 | 1 | 454 pyrosequencing | No difference in α-diversity after LFD No changes in distribution of taxa | UPLC/MS GC/MS | A number of stool metabolites (L-urobilin) associated with response to LFD |
All differences reported are significant (p<0.05).
FISH, fluorescence in situ hybridisation; GC/MS, gas chromatography mass spectroscopy; GLC, gas liquid chromatography; HFD, high FODMAP diet; low FODMAP diet; MS, mass spectrometry; qPCR, quantitative PCR; RCT, randomised controlled trial; SCFA, short-chain fatty acid; UPLC/MS, ultraperformance liquid chromatography tandem mass spectroscopy.