Exploring the gut-brain connection for insights into multiple sclerosis

May 9, 2016
Immunofluorescence imaging of human brain tissue generated from an active lesion from an individual with multiple sclerosis shows astrocytes (blue), the Aryl hydrocarbon receptor (red) and the phosphorylated Signal transducer and activator of transcription 1 (green). Credit: Image courtesy of Jorge Ivan Alvarez, Assistant Professor at the Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

New research by investigators at Brigham and Women's Hospital (BWH) suggests that bacteria living in the gut may remotely influence the activity of cells in the brain that are involved in controlling inflammation and neurodegeneration. Using pre-clinical models for multiple sclerosis (MS) and samples from MS patients, the team found evidence that changes in diet and gut flora may influence astrocytes in the brain, and, consequently, neurodegeneration, pointing to potential therapeutic targets. The team's results are published this week in Nature Medicine.

"For the first time, we've been able to identify that food has some sort of remote control over central nervous system inflammation," said corresponding author Francisco Quintana, PhD, an investigator in the Ann Romney Center for Neurologic Diseases at BWH. "What we eat influences the ability of bacteria in our gut to produce , some of which are capable of traveling all the way to the brain. This opens up an area that's largely been unknown until now: how the gut controls brain inflammation."

Previous investigations have suggested a connection between the and brain inflammation, but how the two are linked and how diet and microbial products influence this connection has remained largely unknown. To explore this connection further, Quintana and colleagues performed genome-wide transcriptional analyses on astrocytes—star-shaped cells that reside in the brain and spinal cord - in a mouse model of MS, identifying a molecular pathway involved in inflammation. They found that molecules derived from dietary tryptophan (an amino acid famously found in turkey and other foods) act on this pathway, and that when more of these molecules are present, astrocytes were able to limit . In blood samples from MS patients, the team found decreased levels of these tryptophan-derived molecules.

"Deficits in the , deficits in the diet or deficits in the ability to uptake these products from the gut flora or transport them from the gut—any of these may lead to deficits that contribute to disease progression," said Quintana.

The research team plans to investigate this pathway and the role of diet in future studies to determine if the new findings can be translated into targets for therapeutic intervention and biomarkers for diagnosing and detecting the advancement of disease.

Explore further: Probiotics protect mice from estrogen deficiency-related bone loss

More information: Veit Rothhammer et al, Type I interferons and microbial metabolites of tryptophan modulate astrocyte activity and central nervous system inflammation via the aryl hydrocarbon receptor, Nature Medicine (2016). DOI: 10.1038/nm.4106

Related Stories

You are what you eat: How gut bacteria affect brain health

January 22, 2015

The hundred trillion bacteria living in an adult human—mostly in the intestines, making up the gut microbiome—have a significant impact on behavior and brain health. The many ways gut bacteria can impact normal brain ...

Microbial cooperation in the intestine

April 25, 2016

The human intestine is home to a dense and diverse ecosystem of microbes, but little is known about how the abundant bacteria in our gut interact with each other. In a new study published in Nature this week, Brigham and ...

Recommended for you

Bioelectricity new weapon to fight dangerous infection

May 26, 2017

Changing the natural electrical signaling that exists in cells outside the nervous system can improve resistance to life-threatening bacterial infections, according to new research from Tufts University biologists. The researchers ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.