Western diet fats may push gut bacteria into the brain via the vagus nerve

A study from Emory University in mice shows that a high-fat Western-style diet increases gut permeability, allowing live gut bacteria to travel through the vagus nerve into the brain, which could help explain links between diet and neurological conditions; the movement was tracked using an engineered barcoded bacterium, occurred without bacteria appearing in the blood, and returning to a normal diet reduced brain bacterial load, suggesting reversibility.