IHMC Meeting At Hangzhou 2013 : First Day

The GMFH team was at the International Human Microbiome Consortium meeting at Hangzhou in China co-chaired by Pr Lanjuan Li and Pr Dusko Ehrlich. Here under, we report the most interesting talks related to gut microbiota and health. During the opening ceremony, Pr Lanjuan Li announced that the event gathered some 2000 delegates from 20 countries and Pr Ehrlich expressed his hope that the congress would help look forward for cutting edge science.

 

On the first talk, Pr Lanjuan Lipresented her work regarding association between Livers cirrhosis and gut microbiota. Changes occur mainly on Bifidobacterium composition while microbial diversity increases. The main function from the gut microbiota is also altered like cellulase and pectinase gene which decrease for patient. The bacterial enrichment could come from oral microbiota.

 

Dusko Ehrlich reminded us that the gut microbiota is the first pool of immune cells and the 2nd for neuronal cells. He explained MetaHIT’s success through the establishment of the human gut microbiota gene catalog and the enterotypes discovery. In the second part of his talk, he presented evidence that genetic markers have a modest discriminative value for obesity and metabolic disease but in the two last articles published in Nature in 2013, gut metagenomics enabled to define a set markers which allows us to classify obese and lean people. He also mentioned that the gene richness was associated with metabolic markers. Using the the gene richness, he showed that North Americans and Chinese patients have less diversity than European patients, a difference that may find an explanation with sampling protocol issue.

 

George Weinstock made a presentation on how gut metagenomics could be used as diagnostic tools. For example, it is very straight forward to measure microbial richness and metagenomics tools could be set up in hospital. Nevertheless, viruses have also to be taken into account as they are key players in human health together with bacteria. Pathogens relative abundance could be easily targeted using 16S rRNA gene analysis. Another step is to develop test around genotype variation of bacterial strain and to connect this to serotype, antibiotic resistant. In collaboration with Peer Bork’s group, they published the first study which set up the framework aiming to get genotype variation from metagenomics data.

 

Matthieu Almeida stared his presentation by saying that 70% of the gut microbiota is difficult to cultivate. Because of that, it is difficult to sequence their genome. He tried using metagenomics data to reconstruct uncultivable strain genome using the co-abundance of genes across patients. This helped notably to establish dependencies between bacterial species and small units enriched in virulence genes or bacteriophages for example. More surprisingly, Oscillibacter is dependent on Ruminococcus and Pseudoflavonifractor and it was seen to be linked to Vitamin B12 biosynthesis.

 

To conclude this first day, Rob Knight presented how successful science could be crowd sourced. His project “American gut” , which is close to the my.microbes initiative. Instead of using full metagenome sequencing, they chose 16S rRNA sequencing, which is a cheaper solution. In spite of potential risks, samples were sent without refrigeration. With more than 1,200 participants, the “American gut” project already gathers valuable data across a wide demographic age range.

GMFH Editing Team
GMFH Editing Team