The microbiome in MSFriday, October 04, 2013, 17:05 - 17:25
The application of quantitative metagenomics to elucidate the gut microbiome of the adultO. Borbye Pedersen (Copenhagen, DK)
Rapid progress in establishing catalogues of gut microbial genomes and genes has opened for possibilities to explore how our other genome - the collective genome of the trillions of commensal microbes inhabiting our intestinal tract, the gut microbiome - influences biological processes of the host, including development and maintenance of the immune system and metabolic functions. Recently we have been involved in the EC 7th Framework-sponsored consortium, Metagenomics of the Human Intestinal Tract, with the aim to define the gut microbiota composition and functional potential in a population sample of adult people. By mapping of a large number of sequencing reads from stool DNA onto the reference catalogue (quantitative metagenomics) in a population sample of 123 non-obese and 169 obese Danish individuals we found two groups of individuals who differ by the number of gut microbial genes and thus gut bacterial richness. They harbour known and previously unknown bacterial species at different proportions; individuals with a low bacterial richness (23% of the population) are characterized by more marked overall adiposity, insulin resistance and dyslipidaemia and a more pronounced inflammatory phenotype when compared with high bacterial richness individuals. The obese individuals among the former also gain more weight over time. The microbiota of people with reduced bacterial richness is featured by a reduction of butyrate-producing bacteria, increased mucus degradation potential, reduced hydrogen and methane production potential combined with an increased H2S formation potential, and an increase of the potential to manage oxidative stress. Only a few bacterial species are sufficient to distinguish between individuals with high and low bacterial richness, and even between lean and obese. Our classifications based on variation in the gut microbiome identify subsets of individuals in the general adult population of whites who may be at increased risk of progressing to adiposity-associated co-morbidities.
I declare no conflicts of interest.