BR 07-1 DEVELOPMENT OF THE CELL MICROARRAY FOR HIGH-THROUGHPUT ANALYSIS OF GUT MICROBIOTA.

The human intestine contains a massive and complex microbial community called gut microbiota. A typical human carries 100 trillion microbes in his/her body which is 10 times greater than the number of their host cells, i.e. whole number of human cells. A combined microbial genome constituting gut microbiota is well excess our own human genome. The microbial composition of gut microbiotata and its role on diseases became a booming area of research, presenting a new paradigm of opportunities for modern medicines. Recent evidences showed that gut microbiota acts as a very important determining factor for the development of almost all complex diseases such as primary hypertension, obesity, depression, diabetes, autism, asthma, bowl diseases, rheumatic arthritis, systemic lupus erythematosus, Crohn's disease, Parkinson's disease, Alzheimer's disease, epilepsy, schizophrenia, etc. In spite of the significant role of gut microbiota in the development of complex diseases, the elucidation of the mechanistic pathway on the development of complex diseases by gut microbiota is not moving forward as expected. Current methods to identify alteration of gut microbiota in patients and healthy controls are basically based on the metagenomic sequencings of DNA samples extracted from feces by using next-generation sequencing machines. Although the metagenomic sequencing approaches proved association of gut microbiota with various complex diseases, those methods failed to accurately pinpoint the etiological agents in gut microbiota for complex diseases. The metagenomic sequencing approaches are not only difficult to identify the etiological agent of complex diseases at species level but also difficult to use, requiring complex bioinformatic analyses, and expensive. To overcome the current challenges in analysis of gut microbiota, we developed a novel cell microarray to analyze the constituent microbial organisms of gut microbiota very accurately and fast by using a drop of blood. The cell microarray contains all of the known individual microbial organisms constituting gut microbiota. We proved by using Rheumatoid arthritis (RA) cases that the cell microarray is much more accurately and faster than the current metagenomic sequencing approaches in analyzing gut microbiota. The cell microarray was hybridized with the serums of healthy people and RA patients. Based on the binding affinity of serum immunoglobin with the spots of bacterial cultures on the cell microarray, our results clearly indicated that the serum of RA patients have significantly less response to gut bacterial species than those of healthy control. It was also able to detect the microbial species playing a causative role for RA and the microbial species playing a protective role to RA. This result suggests that, the cell microarray developed here is an effective, less expensive, and rapid identification method for analyzing gut microbiota. We believe that the cell microarray can be used to various clinical blood samples, including hypertension, to elucidate the etiological microbial species of gut microbiota which play causative roles for complex diseases or protective roles to the complex disease.