The human body is host to trillions of microorganisms, yet little is known about their impact on human health. Oklahoma State University Center for Health Sciences scientist Gerwald Koehler, Ph.D., is researching how the tiny organisms that live in the digestive tract affect the central nervous system.
“I am specifically interested in microbes that live in the intestine because that is where the majority of bacteria reside,” said Koehler, associate professor of microbiology at OSU-CHS. “Different types of bacteria interact with our immune system and even with our central nervous system in different ways and some can have detrimental effects on our health.”
Microorganisms in the gastrointestinal tract help digest food by breaking down proteins, lipids and carbohydrates into nutrients that can be easily absorbed by the human body. The specific types and numbers of these bacteria are unique to each person, resulting in differing influences on an individual’s health and risk of disease.
“The neurons in our intestine are connected to our brain,” Koehler said. “It is conceivable that these microorganisms can utilize these neurons to communicate with the brain and that the brain can communicate back.”
Determining the types of microorganisms that reside in the intestine has been problematic due to scientists’ inability to grow the majority of these microbes in a laboratory. In recent years, however, researchers have developed new methods to identify these microbes and discern their function in the digestive system.
Koehler and other OSU-CHS researchers also are investigating claims that probiotics, which are considered good bacteria, can improve digestive and overall health.
“There are a lot of claims out there that probiotics are beneficial, but research to understand the mechanisms of how probiotics work on a molecular level is limited,” Koehler said. “We are attempting to put some scientific research behind probiotics claims.”
Some of the health benefits attributed to probiotics by proponents include help with weight loss, boosting the immune system and reducing the incidence of colds, allergies, urinary tract infections and eczema. Others argue that probiotics provide relief for conditions ranging from irritable bowel syndrome to high cholesterol.
Koehler is hopeful that the research will produce a better understanding of how microbes in the digestive system function so that medical treatments can be developed to prevent or mitigate certain diseases, such as irritable bowel syndrome and ulcerative colitis. Some microbes might even be beneficial beyond the intestine by communicating in positive ways with the central nervous system.
He has previously published research papers on microbial pathogens and the ability of beneficial bacteria to suppress fungal pathogens.
To learn more about Koehler’s research on how microorganisms in the digestive system affect human health, visit the OSU-CHS Research Spotlight website.