The gut microbiome comprises the collective genome of the trillions of 
microorganisms residing in our gastrointestinal ecosystem. The interaction 
between the host and its gut microbiome is a complex relationship whose 
manipulation could prove critical to preventing or treating not only various gut 
disorders, like irritable bowel syndrome (IBS) and ulcerative colitis (UC), but 
also central nervous system (CNS) disorders, such as Alzheimer's and Parkinson's 
diseases. The purpose of this review is to summarize what is known about the gut 
microbiome, how it is connected to the development of disease and to identify 
the bacterial and biochemical targets that should be the focus of future 
research. Understanding the mechanisms behind the activity and proliferation of 
the gut microbiome will provide us new insights that may pave the way for novel 
therapeutic strategies.