Why does our tummy growl when we think of food or have ‘butterflies’ when we are nervous, whereas an upset tummy causes anxiousness or a bloated tummy brings your mood down?
There is a link between the gut and the brain, known as the gut-brain axis. This intimate bi-directional link is the result of the enteric nervous system (ENS) – a collection of the nervous system or neurons found in the gut.
Our gut is also home to millions of microorganisms called gut microbiota. It plays an important role in digestive health and the immune system but also can influence the brain.
Probiotics And The Brain
According to Universiti Kebangsaan Malaysia (PPUKM) Hospital Canselor Tuanku Muhriz consultant physician and gastroenterologist, Assoc Prof Dr Raja Affendi Raja Ali, the gut-brain bi-directional axis interaction is complex.
Furthermore, there is a link between probiotics and the gut-brain axis, as it has been found that gut microbiota can influence or be influenced by the brain.
Emerging researches show the gut produces a variety of hormones, neurotransmitters and immunological factors, which ‘communicate’ with the brain. Variations in gut microbiota would have an effect on mental state such as anxiety or depressive disorders.
A study in 2015 found that gut microbiota interacts with the central nervous system by regulating brain chemistry and disturbances of a normal gut microbiota could be restored with probiotics.
Another study in 2017 on patients with major depressive disorder found probiotic supplementation helped improve their symptoms. Other studies include stress and psychiatric disorders may have an effect on the body’s gut microbiota by causing changes in its composition, richness and diversity.
“The gut-brain axis boasts a complex ‘communication system’ that helps ensure the gut works optimally. To function in harmony, a balanced gut microbiota of 85% good bacteria versus 15% bad bacteria in the gut is important,” he says.
Probiotics, the ‘good bacteria’ have the potential to be used as treatment or prevention of various mental illnesses. Currently, probiotics are proven beneficial in maintaining a healthy gut microbiota balance for optimal digestive health.
Local Research Shows Digestive Health Benefit
Citing a recent probiotics research by PPUKM, Assoc Prof Dr Raja Affendi, as the principal investigator remarks, “Daily probiotics improved our research subjects’ digestive health in several aspects of the digestive system and immunity.”
PPUKM research results at a glance:
♦ 96% of research subjects reported improvements in constipation symptoms
♦ 45% of research subjects spent less than 10 minutes in the toilet
♦ 36% of research subjects had lesser straining when going to toilet
♦ 31% of research subjects experienced much softer stools
♦ 33% faster food digestion time (or intestinal transit time) from 20-45 hours and reduced by 5-15 hours
♦ 73% of research subjects with irritable bowel syndrome (IBS) had reduction of pro-inflammatory cytokines, thus enhancing the immunity
Maintaining Digestive Health For Peace Of Mind
Probiotic-rich food is recommended as a regular part of our diet. These include fermented food products such as cultured milk drinks, tempeh, kimchi, yoghurt, and tapai pulut.
“You have to constantly replenish the good bacteria in your gut to maintain a healthy balance in your gut microbiota,” Assoc Prof Dr Raja Affendi said.
“Fruits, vegetables, whole grains and legumes have dietary fibres, known as prebiotics. They are food for probiotics and should be part of your diet to regulate bowel movement, increase stool bulk, lower the risk of digestive problems.”
“Thanks to the outcome of our research, we know with certainty that probiotics are beneficial for IBS patients and some aspects of immunity as well. However, we also feel that more can be done to explore the link between probiotics and other areas of health, including mental health that may perhaps lead to a breakthrough one day. It would be good to discover how probiotics, together with good healthy lifestyle habits, can benefit our mental health,” he concludes.