Wednesday, August 4, 2010: 8:40 AM
336, David L Lawrence Convention Center
Background/Question/Methods: The application of ecology to human health is a concept becoming more widespread in clinical research. As more human diseases appear to have microbial community components, the application of niche-based assembly models or neutral-based assembly models may have relevance to human health. More treatments strive for changes in microbial communities within humans, and an understanding of the assembly of these within-human communities may be useful to the design of methodologies and interpretation of treatment. It has been suggested by others that many bacterial communities exhibit a distribution consistent with neutral birth-death-migration processes. To the best of our knowledge, there has been no previous application of neutral community models to the bacterial communities found at the many habitats within the human body. Using a model developed by Sloan et al, we examine if bacterial communities found inside the human body exhibit a distribution consistent with neutral or niche-based community models. Each dataset used was generated by extracting bacterial community DNA and cloning and sequencing the 16s rDNA gene to identify the bacteria present. We apply this model to two sets of data, both of communities of bacteria detected in the mouth of healthy humans. (1) a dataset of 10 individuals, each sample defined at the level of the individual person, and (2) a dataset of three individuals, each sample defined at the level of the individual teeth, and analyzed separately for each person sampled.
Results/Conclusions The dataset of ten subjects generally conforms well to a distribution consistent with a neutral community model at the level corresponding to species, with support for a niche-based model at the level of genus. The dataset examining three mouths in greater detail demonstrates slightly different patterns for the individual patients sampled, with both niche-based and neutral models having support. This variability may be indicative of different forces acting within different people’s bodies, or in different types of communities. These differences also emphasize the questions of level of analysis in communities that must be sampled using molecular methods. In addition, there are individual taxa identified which are outliers to the general distribution. These taxa may be of interest in therapeutic uses- for instance as targets of therapy or diagnostic tests. Analysis continues of these datasets and those from other areas of the human body.
Results/Conclusions The dataset of ten subjects generally conforms well to a distribution consistent with a neutral community model at the level corresponding to species, with support for a niche-based model at the level of genus. The dataset examining three mouths in greater detail demonstrates slightly different patterns for the individual patients sampled, with both niche-based and neutral models having support. This variability may be indicative of different forces acting within different people’s bodies, or in different types of communities. These differences also emphasize the questions of level of analysis in communities that must be sampled using molecular methods. In addition, there are individual taxa identified which are outliers to the general distribution. These taxa may be of interest in therapeutic uses- for instance as targets of therapy or diagnostic tests. Analysis continues of these datasets and those from other areas of the human body.