Researchers at Emory University used mouse models to study how a high-fat diet affects the gut–brain connection. Germ-free mice ate Paigen’s Diet, a high-fat Western-like diet, for nine days. After this short period, scientists saw changes in the gut microbiome and higher intestinal permeability, often called a "leaky gut".
The leaky gut allowed live bacteria to travel from the intestine to the brain along the vagus nerve, the nerve that links the gut and brain. In one test, researchers gave mice antibiotics for three days and then added engineered, barcoded bacteria. When mice ate the high-fat diet, the special bacteria were later found in the vagus nerve and in the brain.
Difficult words
- microbiome — All tiny organisms that live in the gut
- permeability — How easily substances pass through tissue
- leaky gut — Condition when the intestine lets things pass
- vagus nerve — The nerve that connects the gut and brain
- antibiotics — Medicines that kill or stop bacteria growth
- engineer — To change something by design or modificationengineered
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think a short change in diet can change gut bacteria? Why or why not?
- Would you be worried if bacteria could reach the brain? Explain briefly.
- How do you think antibiotics can change the gut microbiome?
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