SINGAPORE — The importance of the gut to physical health is well known. Now, an emerging field of research has found that the trillions of microorganisms living in the digestive tract, known as gut microbiota, can communicate with the brain too.
Tweaking this gut microbial balance through the use of a new class of probiotics known as psychobiotics, for instance, could tip it in favour of better mental health, some experts believe.
Psychobiotics are “a game changer” that could potentially provide new treatments for conditions such as depression, Parkinson’s disease and autism, said Professor Tsai Ying-Chieh of the Institute of Biochemistry and Molecular Biology of National Yang-Ming University in Taiwan at the Vitafoods Asia conference held here earlier this month.
The effect, according to experts, could occur though several pathways, including the nervous system — the spinal cord or the vagus nerve, which connects the brain to the digestive tract — small molecules produced by gut microbes, as well as through the immune system and hormones within the gut.
“This concept surfaced only in the past five to six years. Before that, nobody would believe that your gut microbiota could influence your brain,” Prof Tsai told TODAY on the sidelines of the conference.
Findings from preliminary research have been promising. In studies on animals, Prof Tsai and his team found a novel psychobiotics strain, known as Lactobacillus plantarum PS128, could alter the brain chemistry of mice, such as by raising dopamine levels.
Dopamine is a chemical messenger that transmits signals between brain cells and lowers stress hormones and depression-like behaviour.
Low levels of dopamine are linked to low mood, depression, as well as neurological conditions such as Parkinson’s disease and attention deficit hyperactivity disorder. Elevated levels of stress hormones in the long term can interfere with learning, memory and may lower immunity, said Prof Tsai.
Lactobacillus plantarum PS128, extracted from a Taiwanese traditional fermented mustard, has been tested on humans. This year, Prof Tsai and his team wrapped up a study involving 80 boys aged seven to 15 and diagnosed with autism spectrum disorder. The study was placebo-controlled and double-blind, where participants and researchers did not know which participants belonged in the test or the control groups.
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Prof Tsai said his team observed “improvements in symptoms such as…