Exploring link between gut and brain health

Scientists continue to find evidence that the brain and gastrointestinal tract are closely linked—and that keeping one healthy will benefit the other.

The brain and gut are connected, but the exact nature of that connection is still a mystery. Research suggests, however, that the better we treat our guts, the healthier our brains will be, and vice versa.

Encompassing all the organs that process food, the gut consists of the mouth, esophagus, stomach, pancreas, liver, gallbladder, small intestine, and large intestine, which includes the colon and rectum. Scientists have been studying the gut components to better understand how they may put people at risk for Alzheimer’s disease, multiple sclerosis, Parkinson’s disease, and other neurologic disorders.

“The notion of gastrointestinal health, and thus normal gut flora, may be as old as medicine itself,” says Michael G. Schlossmacher, MD, endowed chair in neurodegeneration at Canada’s Ottawa Hospital Research Institute and co-director of the Parkinson Research Consortium.

Living within the gut are trillions of microorganisms, including bacteria, fungi, protozoa, and viruses. These microbes aid multiple bodily functions, like breaking down food, producing vitamins, responding to pathogens, and helping the body absorb nutrients. The genes that produce these microorganisms—which also live in saliva, skin, and other body parts—and the microorganisms themselves are collectively known as the microbiome. Various factors, including genetics, lifestyle, diet, environmental exposures, and use of antibiotics, likely influence the microbiome’s composition.