GI highlights from the literature
- Mairi H McLean, Education editor
Dietary influences on the gut microbiome
▶ Wu GD, Chen J, Hoffman C, et al. Linking long-term dietary patterns with gut microbial enterotypes. Science 2011;334:105–8.
Mounting evidence suggests that the gut microbiota may influence the development of human diseases such as autoimmunity, obesity, and inflammatory bowel disease. Diet may serve as a modifiable factor that can influence the composition of the host microbiome. Wu et al recently reported findings of a cross sectional study of 98 healthy volunteers investigating dietary influences on the gut microbiota. Short-term and long-term dietary intake was assessed by the use of food frequency questionnaires. Massively parallel sequencing of 16S ribosomal bacterial DNA sequences was performed on DNA isolated from stool samples. Gut bacterial populations were clustered into ‘enterotypes’, largely as a result of the relationship between the two dominant bacterial genera. Enterotype was associated with long-term, but not short-term, nutrient intake. There was a significant association between the Bacteroides enterotype and consumption of animal protein and saturated fat. The Prevotella enterotype was, in contrast, associated with vegetarian, carbohydrate-based diets. In a controlled-feeding experiment, 10 subjects were randomised to receive either a high-fat/low-fibre diet, or a low-fat/high-fibre diet. Stool samples were then collected over 10 days. Interestingly, changes in the gut microbiome occurred rapidly but were small in comparison to the magnitude of inter-individual variability. No stable switching between enterotypes occurred. Whether gut enterotype is associated with specific disease predisposition in humans remains to be seen. If such associations exist, stable modification of enterotype may represent a prophylactic or therapeutic target in clinical practice.
Is multiple sclerosis a disease of the gastrointestinal microbiota?
▶ K Berer, M Mues, M Koutrolos, et al. Commensal microbiota and myelin autoantigen cooperate to trigger autoimmune demyelination. Nature. Published Online First: 26 October 2011. doi:10.1038/nature10554.
Berer et al investigate multiple sclerosis (MS) in a mouse model of experimental autoimmune encephalomyelitis …