Fouad Boumezbeur
#mfh2010 Microbes For Health - session 4 will be the last session of this meeting and will be focused on "Dysbiosis, Pathology and Intervention" - David A. Relman, Ph.D., Stanford University, Stanford, USA - Unrest at home : Perturbation and Stability of the Human Gut Microbiota
benefits from microbiota : food digestion, nutrition, xenobiotic processing, energy harvest, ... - Fouad Boumezbeur
what is the most important sources of variation in community composition, function? - Fouad Boumezbeur
what are the rules of "assembly" ? (deterministic vs stochastic factors) - Fouad Boumezbeur
site-specific distributions of bacterial phyla in healthy humans : see Dethlefsen L. et al., Nature 2007 - Fouad Boumezbeur
distal gut species/strains over the course of 10 months? : ~1600-2000 (Dethlefsen, 2010) - Fouad Boumezbeur
but few phyla - Fouad Boumezbeur
D. Relman address the question of the boundary of self (distinct "inside-outside" habitat boundary) and establishment of this boundary - Fouad Boumezbeur
looking for a strategy to design probiotics for dolphins (marine mammals) - Fouad Boumezbeur
see works of Venn-Watson, Carlin and Jensen, SSC San Diego - Fouad Boumezbeur
8 see-lions and 20 dolphins were subjects of this study - Fouad Boumezbeur
combined data found exclusively in water/fish show a huge diversity (~1600 OTU) - Fouad Boumezbeur
very distinct microbiota from the water/fish one are found in the oral cavity and in the gut of these mammals - Fouad Boumezbeur
most abundant OTU in water : Pelagibacter ubique, but 1/21,429 sequence in marine mammals (sea lion mouth) - Fouad Boumezbeur
Ecological boundaries : presence of areas of transition - Fouad Boumezbeur
sources of variation in patterns of diversity : space, individual, health status, host genetics, environment features, ... - Fouad Boumezbeur
signs of resistance to perturbations ? alternative stable states, disturbance and loss of resilience : see Folke et al., Ann Rev Ecol Evol Syst 200 - Fouad Boumezbeur
perturbation can be seen as a natural feature of all ecosystems, or as a tool ('pulse' vs 'press') - Fouad Boumezbeur
see Dethlefsen et al., PLoS Biology 2008 and Dethlefsen and Relman, PNAS 2010 for the design of the study - Fouad Boumezbeur
12 healthy subjects who had no antibiotics during the previous year, pulse perturbation - Fouad Boumezbeur
during ~300 days, 16S rRNA analysis of samples taken at intervals of a few days was conducting, followed by a study of the temporal autocorrelation within subjects of abundance of identified OTUs - Fouad Boumezbeur
diversity over time : a drop after administrating Ciprofloxacine - Fouad Boumezbeur
with a resilience of Faecalibacterium but not for Roseburia (both are butyrate-producers) - Fouad Boumezbeur