|Photo: Stephanie Diani|
Humans and the microbes we host have co-evolved over millennia, and we are only now beginning to understand the significant role this relationship plays in the balance between health and disease. Think of us as a microbial consortium, a “superorganism” inhabited by an estimated 100-trillion microbes, mainly bacteria that outnumber the cells of our own making by a factor of 10. Collectively, these are called the microbiota.
At UCLA, we are in the early stages of launching a concerted effort to understand the effects of our microbiota, and we are working toward creating the UCLA Microbiome Center to explore the full gamut — from basic science to clinical applications — of microbiomes, so that, ultimately, we can use this knowledge to help treat chronic conditions, infections and even cancer.
An example of this would be the role of microbiota in the mysterious link between diet and obesity. At this time, more than one-third of adults in the U.S. are obese, and the physical and financial toll is enormous. Obesity brings with it increased risk of heart disease, stroke and certain kinds of cancer, and according to some studies, the condition and its associated complications carry a price tag that exceeds $190 billion a year. There is mounting evidence that an unhealthy diet, and other factors, including host genetics and lifestyle, can result in an imbalance in the microbiota that leads to increased intestinal permeability, low-grade inflammation and a poorly understood cascade that ultimately leads to weight gain and associated conditions.
But obesity is only one area being explored in the field of microbiomes. Faculty in the David Geffen School of Medicine at UCLA (DGSOM) have found evidence that bacteria ingested in food can affect brain function; they also have observed that women who regularly consume beneficial bacteria known as probiotics through yogurt showed altered brain function. Other DGSOM investigators have discovered that specific types of bacteria that live in the gut are major contributors to lymphoma, a cancer of the white blood cells, and that small molecules produced by bacteria in the intestinal tract can affect our immune systems, the liver and the brain. Clinically, we are offering fecal transplantation from healthy donors to treat infections that are caused by overuse of antibiotics, particularly C. difficile infections.
This brave new world of microbiota may lead to applications that someday will provide better ways to manage infections during transplantation; the development of antibiotics that kill pathogens but don’t harm beneficial microbes; evidence-based deployment of probiotics and prebiotics for managing obesity, metabolic disorders, allergies, autoimmunity and other disorders; and microbiome-based diagnostics and therapeutics.
What needs to happen now, and what we are undertaking at UCLA, is rigorous science that moves from animal models to human studies and moves the field from correlation to causality. We in the David Geffen School of Medicine at UCLA and UCLA Health System are shaping this future.
A. Eugene Washington, MD, MSc
Vice Chancellor, UCLA Health Sciences
Dean, David Geffen School of Medicine at UCLA
Gerald S. Levey, MD, Endowed Chair