Researchers are investigating how gut microbes, including probiotics and postbiotics, may influence mental health and treat conditions like depression and anxiety.
Key facts
- •The human gut contains an estimated 500 million neurons in the enteric nervous system.
- •Microbial neuroscience studies are investigating treatments for depression, anxiety, OCD, and ADHD.
- •Postbiotics are heat-inactivated microbes that can be added to food products.
- •A 2023 study in JAMA Psychiatry explored the use of probiotics for major depression.
- •Research indicates that the effects of postbiotics may wear off once administration stops.
The field of microbial neuroscience is rapidly expanding as scientists explore the gut-brain axis, the bidirectional communication between the digestive tract and the brain. Researchers are investigating whether manipulating gut microbes through probiotics, prebiotics, and postbiotics can help manage psychological disorders. While once met with skepticism, the study of how the gut microbiome influences mental health has gained significant scientific attention over the past decade.
By the numbers
The Gut-Brain Connection
The human digestive tract contains approximately 100 trillion microbial cells representing up to 5,000 species. These microbes communicate with the brain through the vagus nerve, the production of metabolites that cross the blood-brain barrier, and by influencing hormones and the immune system. The enteric nervous system, which controls digestion, contains an estimated 500 million neurons, acting as a 'second brain' that interacts with the central nervous system.
Clinical Research and Interventions
Scientists are moving from observational studies to experimental trials to test the impact of microbial interventions on conditions including depression, anxiety, bipolar disorder, OCD, and ADHD. A 2023 study published in JAMA Psychiatry by researchers at King’s College London and ADM investigated the effects of probiotics on major depression. Other research has shown that both live and heat-treated bacteria can produce similar results in patients with irritable bowel syndrome.
The Role of Postbiotics
Postbiotics, which consist of inactivated microbes, are an emerging area of research. Unlike probiotics, which are live, postbiotics do not require refrigeration and can be added to food or drinks. Studies have indicated that postbiotics can exert biological effects rapidly, with some physiological changes noted within an hour of administration. Research is ongoing to determine the long-term efficacy and mechanisms of these treatments.
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This article was independently rewritten by ManyPress editorial AI from reporting originally published by New Scientist.
