We must look inward to treat chronic diseases such as cancer, obesity and autoimmune disorders, according to a biologist from Oregon State University-Cascades. That is, to our guts.

The paper is published in the Quarterly Review of Biology.

The human ecosystem

Inside every man and woman are trillions of bacterial cells that perform valuable functions essential to the healthy operation of the human body. Over a thousand different species live in the human gut alone.

While the average person might think of microbes as agents of disease, gut microbes in fact perform a number of functions that are beneficial to the body’s health, from producing fatty acids and vitamins to controlling blood sugar and weight, reducing inflammation, and improving psychological health.

Dysbiosis, or imbalance, of these gut microbes can lead to many kinds of chronic diseases, including cancer, obesity, and various autoimmune disorders.

In this way, the human body can be considered an ecosystem — a flourishing community of thousands of interacting organisms.

“Individual humans can be considered an ecosystem based on recent discoveries of the roles played by human microbes in immunity, digestion, body mass index, and psychology,” said Matthew Orr, an assistant professor in the College of Science at OSU-Cascades and lead author of the paper. “Ninety percent of the cells in our bodies are microbes, 99 percent of the genes are microbial genes, and together our microbiome weighs about the same as our brain.”

Restoration ecology approach

Orr and his colleagues, Deborah Young, an OSU-Cascades biology major, and Kathryn Kocurek, a physician at Fall Creek Internal Medicine in Bend, Oregon, offer an approach to disease treatment based on the application of principles of “restoration ecology” to human health. That means that fighting disease must start with generating healthy symbiosis of gut microbes as a basis for treatment.

Ecological restoration is the practice of assisting the recovery of ecosystems that have been damaged by human action. The researchers note that just as human actions and technological and cultural advances have damaged the natural environment, the application of advances in Western medicine — particularly antibiotics — has also damaged species within the human body.

There are two major strategies in restoring ecosystems: passive and active restoration.

Passive restoration involves removing the harmful agents from an ecosystem and allowing the ecosystem to recover on its own.

Active restoration involves the direct intervention of ecologists and implementation of management techniques. This could mean planting seeds or manipulating the natural environment to assist the recovery of the ecosystem.

An important principle of restoration ecology is, active restoration only occurs after passive techniques are attempted and the harmful agents are removed from the ecosystem. This is called establishing a passive platform. Without doing so, active restoration is likely to fail.

These same concepts, the researchers contend, can be applied to the human body’s ecosystem. Effective disease treatment requires the establishment of a healthy microbial ecosystem.

The application of principles of restoration ecology highlights major failings in Western medicine in disease treatment, according to Orr.

“One failing is that Western doctors do not emphasize diet sufficiently,” he said. “Diet has fundamental effects on human gut microbes, which means it has fundamental effects on immunity, digestion, BMI, and behavior. In restoration ecology, it is important to remove sources of ecosystem disturbance before trying other interventions. If poor diet is a fundamental source of disturbance, then diet should be improved before intervening further.”

Another failing is that Western medicine also tends to overlook the responsibility of the patient in maintaining their own health. This means a patient must do more than simply take a pill or self-inject a pharmaceutical. Orr believes that fighting disease must involve a mutual patient-doctor relationship in which the patient and doctor are equally involved. So, patients are responsible for changing their diet and working to make themselves healthy.

Another weakness with Western medicine is that it often takes too broad an approach.

“Finally, Western medicine too often bins patients under catch-all diagnoses that are broadly descriptive but may mask numerous sources of causality,” said Orr. “Ecosystems are very complex, and it is difficult to treat them with a one-size-fits-all approach. Restoration ecologists have learned that each system needs to be approached and understood individually or a project may fail. More attention needs to be paid to individuality in medicine, and this is starting to happen with the advent of personalized medicine.”

The inspiration

Orr was inspired to investigate the relationship between microbial symbiosis and disease by his own experience fighting Crohn’s disease, which he contracted after picking up gut pathogens while researching ant communities in South America.

“I was diagnosed with Crohn’s disease and put on a monoclonal antibody inhibitor for life,” he said in a statement. “Except that I cleaned up my diet, stopped getting the gut irritation, cut out the monoclonal antibody inhibitor, and my symptoms are gone. Two doctors overturned the Crohn’s diagnosis in writing.”

The experience demonstrated firsthand the value of diet and establishing healthy microbial communities in fighting diseases.

“All of that inspired me to think about ways that my knowledge of restoration ecology might help to guide physicians away from treating and misdiagnosing other people the way that they had treated and misdiagnosed me,” he said in a statement.