Gut Microbes and Anxiety: Singapore Scientists Unveil Potential Probiotic Mental Health Breakthrough - Video

Could the key to easing anxiety be hidden in our gut? Scientists from Duke-NUS Medical School and the National Neuroscience Institute have discovered a crucial connection between gut microbes and anxiety-related behaviour.

Microbial metabolites– specifically indoles–play a direct role in regulating brain activity linked to anxiety, reveals a recent research published in EMBO Molecular Medicine.

The prevalence of mental health disorders has been rising over the years.

The aim of the research was to investigate the role microbes play in anxious behaviour. In pre-clinical studies, the scientists observed that in a germ-free environment, those which were not exposed to live microbes, showed significantly more anxiety-related behaviour than those with typical resident live microbes.

Further investigation revealed that the increased anxiety was associated with heightened activity in a brain region involved in processing emotions such as fear and anxiety, the basolateral amygdala (BLA). This was further identified to be related to specialised proteins within brain cells known as the calcium dependent SK2 channels, associated with anxiety behaviour. In conditions when the body and brain are exposed to live microbe metabolites, the SK2 channels act like a clutch, thus preventing neurons from becoming overly excited and firing too frequently.

Associate Professor Shawn Je from Duke-NUS’ Neuroscience and Behavioural Disorders Programme and one of the lead authors, explained:

“Our findings reveal the specific and intricate neural process that link microbes to mental health. Those without any live microbes showed higher levels of anxious behavior than those with live bacteria. Essentially, the lack of these microbes disrupted the way their brains functioned, particularly in areas that control fear and anxiety, leading to anxious behavior."

The team now hopes to explore clinical trials to determine whether indole-based probiotics or supplements can be effectively used in humans as a natural anxiety treatment. If successful, this could mark the beginning of a new era in mental health care—one where gut microbes help keep our minds at ease.

Ref: Yu W, Xiao Y et al. Microbial metabolites tune amygdala neuronal hyperexcitability and anxiety-linked behaviors. EMBO Mol Med (2025); https://doi.org/10.1038/s44321-024-00179-y