A recent study published in Biological Research investigates the impact of a high-fat diet (HFD) on gut microbiome diversity and its subsequent effects on the expression of brainstem serotonergic genes associated with anxiety-related symptoms. Study: High-fat diet, microbiome-gut-brain axis signaling, and anxiety-like behavior in male rats . Image Credit: beauty-box / Shutterstock.
com Previous animal studies have shown that HFD-induced obesity increases neuroinflammation and anxiety-related behaviors. Although the underlying mechanisms responsible for the effects of a HFD on anxiety-related defensive behavioral responses are not completely understood, a strong link with modified microbiome-gut-brain (MGB) axis signaling has been established. HFD modifies the microbial diversity, composition, and abundance of the gut microbiome.
These alterations invariably influence an individual’s innate immunity, cognitive function, and inflammation state, thereby increasing their risk of disease. An imbalanced gut microbiome, which is also referred to as gut dysbiosis, alters brain serotonergic signaling. The serotonergic system regulates an individual’s emotional state and promotes anxiety-like defensive behavioral responses.
In the brain, the dorsal raphe nucleus (DR) is the key source of serotonin. Previous studies have shown that serotonergic neuron activation in the caudal region of the dorsal raphe nucleus (DRC) and dorsal part of the dorsal raphe nucleus (DRD) induces anxiety-li.