A gluten-free diet (GFD) is commonly adopted as an effective treatment for celiac disease, and is often followed to alleviate GI complaints. While we know there is an important link between diet and the gut microbiome, how a switch to a GFD affect the human gut microbiome is largely unknown. Twenty one healthy human volunteers followed a GFD for four weeks. Researchers collected stool samples from each at baseline, four during the GFD period, and four when they returned to their habitual diet (HD). They determined microbiome profiles using 16S rRNA sequencing, then processed the samples for taxonomic and imputed functional composition. They also measured six gut health related biomarkers in all samples. Inter-individual variation in the gut microbiota remained stable during the short term GFD intervention. A number of taxon-specific differences were seen during the GDF: the most striking shift was seen for the family Veillonellaceae (class Clostridia), which was significantly reduced during the intervention. Seven other taxa also showed significant changes; the majority of them known to play a role in starch metabolism. Stronger differences in pathway activities were seen: 21 predicted pathway activity scores showed significant association to the diet change. Strong relation between the predicted activity of pathways and biomarker measurements were observed. Researchers concluded that GFD changes the gut microbiome composition and alters the activity of microbial pathways.
Bonder MJ, et al. The influence of a short-term gluten-free diet on the human gut microbiome. Genome Med. 2016 Apr 21;8(1):45. doi: 10.1186/s13073-016-0295-y.