Obesity may be one of several health conditions and diseases where the human microbiome can be harnessed for diagnostic and therapeutic uses

Microbiologists could soon be the front lines in the nation’s fight against obesity and possibly other chronic diseases. New research underway at Vanderbilt University could lead to a host of new clinical laboratory tests that use engineered microbes.

This research is revealing how the human microbiome can be the source of new biomarkers for diagnostic tests and therapeutic drugs. In fact, early research findings point to the possibility that pathologists and clinical laboratories may eventually use the human microbiome in their daily work.

Engineering Bacteria to Battle Obesity

The human microbiome has remained largely unstudied. One reason why this is true is that it has been difficult to recreate, in the laboratory, the optimal conditions to allow these microbes to grow and thrive just as they do in the human body. However, as researchers continue to make new discoveries about this community of micro-organisms, there is optimism that elements of the human microbiome can be used to develop novel medical laboratory tests.

For example, Sean Davies, PhD, Principle Investigator in Davies Lab at Vanderbilt University, is working “to develop novel and highly sustainable therapeutic interventions for chronic diseases in order to improve human health.” Among those interventions are engineered microbes that can be injected, and which then grow in the body to perform specific functions.

Recently, Davies and his team tested their idea with a microbe that may someday be used to help reduce obesity. In an article on the MIT Technology Review website, Davies said that some people, “overeat because they’re not getting a ‘full’ signal,” and that his team has engineered a bacterium that suppresses appetite by secreting a compound that the intestine usually releases to signal fullness.

To test the modified bacteria, the Davies Lab researchers placed it in the water of half of a group of mice being fed a high-fat diet. Those who received the bacteria gained 15% less weight than those who did not receive it.

Sean Davies, PhD, and his team engineered bacteria that could help treat obesity and other chronic diseases. (Photo copyright: Vanderbilt University.)

Sean Davies, PhD, and his team engineered bacteria that could help treat obesity and other chronic diseases. (Photo copyright: Vanderbilt University.)

Ancient History and Future Study

Ingesting living organisms to improve health, particularly digestive health, is not a new idea. Probiotics have been popular for the last couple of decades. Hippocrates said, “All disease begins in the gut,” and the study of the human microbiome seems to be supporting those ancient words.

The human microbiome is defined by the American Society for Microbiology as “the collection of trillions of microbes living in and on the human body.”

The National Institutes of Health (NIH) is funding the Human Microbiome Project, which is one of several international projects seeking to learn more about the effect of microbes on physiology, pathology, immunity, nutrition, and more.

Targeted Therapies Using Micro-Organisms a Revenue Stream for Clinical Labs

The study into the human microbiome combined with the study of synthetic biology may open even more doors for the development of future therapies involving micro-organisms that are designed for specific purposes. At the Synthetic Biology Group at MIT, which is lead by Timothy Lu, MD, PhD, researchers are bringing together living materials, electrical engineering, and computer science to create tools to treat infectious diseases and amyloid-associated conditions, as well as applications involving nanotechnology.

Might Jenny Craig Counselors One Day Use Microbiome-based Medical Lab Tests?

An array of chronic conditions could be treated using targeted therapies involving micro-organisms. Its application could even extend beyond the medical setting. Once this technology is ready for prime time, diet and weight-loss companies such as Jenny Craig and NutriSystem could offer such clinical laboratory tests to their customers in order to provide the tailored microbiome therapy, combined with their proprietary nutritional products. Since health insurance would not be paying for the testing, particularly in the early development of this diagnostic/therapeutic approach, this could be a cash-paying source of lab tests for medical laboratories and microbiology labs.

Timothy Lu, MD, PhD, works to combine living materials, electrical engineering, and computer science to find therapies and treatments for specific conditions for the Synthetic Biology Group at MIT. (Photo copyright: Massachusetts Institute of Technology.)

Timothy Lu, MD, PhD, works to combine living materials, electrical engineering, and computer science to find therapies and treatments for specific conditions for the Synthetic Biology Group at MIT. (Photo copyright: Massachusetts Institute of Technology.)

Risks and Obstacles

Although such lines of research are thrilling to the imagination there are obstacles. One problem researchers must overcome is that many living micro-organisms are too delicate to survive digestion. This is one reason that Davies and his team at Vanderbilt are working to develop modified microbes that can be injected. Some scientists, however, believe it will be challenging to develop engineered bacteria that can thrive once injected.

Charles Elson III, MD, professor of gastroenterology at the University of Alabama Birmingham School of Medicine (UAB) and a collaborative investigator in the Mucosal HIV and Immunobiology Center (MHIC) at UAB said in the MIT Technology Review article that “the resident organisms in the gut will fight them off,” and that engineered bacteria would require “no competition” from other bacteria in the gut for such a therapy to work “long term.”

Charles Elson III, MD, says that one big challenge is creating bacteria that can thrive in the human gut. (Photo copyright: University of Alabama Birmingham School of Medicine.)

Charles Elson III, MD, says that one big challenge is creating bacteria that can thrive in the human gut. (Photo copyright: University of Alabama Birmingham School of Medicine.)

An additional potential risk is that of accidental ingestion. If a person with a medical condition mistakenly ingested an appetite-suppression microbe, the result could be fatal. The Vanderbilt researchers are working on a couple of methods, such as a “genetic kill switch,” that could prevent such accidents. The larger challenge, though, is simply that scientists don’t yet know enough about how the human microbiome functions.

The big projects such as the Human Microbiome Project at the NIH, as well as those at individual labs such as Vanderbilt and MIT, are advancing the understanding of how these micro-organisms function. It may well be that engineered bacteria to help obesity is only the beginning of what clinical laboratory scientists can do with a clearer understanding of how the human microbiome impacts health and well being.

—Dava Stewart

Related Information:

Microbes Engineered to Prevent Obesity

Why Your Gut Microbiome Could Hold the Key to Solving the Obesity Epidemic

Obesity and the Gut Microbiome: Striving for Causality

Effort to Map Human Microbiome Will Generate Useful New Clinical Lab Tests for Pathologists

Cornell Researchers Identify Gut Microbes that May Help Some People Remain Thin; Findings Could Result in Clinical Laboratory Tests to Analyze the Microbiomes of Individuals

Expanding Knowledge about the Human Microbiome Will Lead to New Clinical Pathology Laboratory Tests

Get the Poop on Organisms Living in Your Gut with a New Consumer Laboratory Test Offered by American Gut and uBiome

At the University of Michigan, Research Study Indicates How Composition of Gut Microbiome May Serve as Complementary, Noninvasive Screening Tool for Colon Cancer

Mayo Clinic and Whole Biome Announce Collaboration to Research the Role of the Human Microbiome in Women’s Diseases Using Unique Medical Laboratory Tests