A perspective on the human microbiome and therapeutic opportunities

Advances made in high throughput DNA sequencing have revealed that the human body is home to a vast array of microbes collectively referred to as the microbiome. Bacteria, fungi, protozoans, mammalian viruses and bacterial viruses are all members of the microbiome. The microbial communities profoundly contribute to the architecture and function of their habitat. Microbial metabolites are also known to have an effect on distant organs, with the brain being a good example via the phenomenon known as the gut-brain-axis. The human gut indeed is the most densely populated microbial habitat with densities around a trillion microbes, mainly bacteria, per gram of colonic content and will be the focus of the presentation. It is now generally accepted that on a cell-to-cell basis microbes outnumber human cells by a factor of 10. Therefore, it is estimated that there are around 100 times as many genes in microbial aggregates as there are in the human genome. Therefore, mining the human bacterial gut flora could lead to the discovery of novel therapeutics, such as antimicrobial agents and signaling molecules. These molecules play a role in maintaining the peaceful coexistence between the commensal gut microbiota. Other therapeutics of interest are probiotics and prebiotics because they may have the ability to restore dysbiosis of the gut microbiome to a healthy and functional state. There is indeed growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of intestinal disorders, for instance, irritable bowel syndrome, and other disorders, such as allergy and obesity.