MHM Magazine

Is it possible that the idiom “listen to your gut instinct” carries old wisdom forgotten by modern generations? Did the humans of yesteryear understand the body and how it works better than we do? Is there scientific evidence that the gut can “dictate” to your brain? Let's explore. The gut-brain axis (GBA) is complex neuro-endocrine system consisting of: • The gut microbiome • The hypothalamic pituitary axis (HPA) • The central nervous system (CNS) • The peripheral nervous system (PNS) consisting of the autonomic and somatic nervous system (ANS, SNS) • The enteric nervous system The gut microbiome It’s estimated that more than 50% of your cells don’t contain your DNA but are in fact protozoa, fungi and bacteria which are collectively called “MICROBIOTA”. The majority of the microbiota are found in the gut and hence termed gut microbiota or gut microbiome. New research reveals that the gut microbiome talks to your brain and influences mood, energy levels, cognition, memory and sleep. Such research includes mice studies using a cohort of germ free (non-colonized gut) mice vs cohort of normal (colonized gut) mice. Each cohort was placed in the same maze; colonised mice showed natural curiosity, were quick, eager learners, and remembered where in the maze they’d been, compared to non-colonised mice who lacked curiosity and eagerness to learn and were quick to forget where in the maze they’d been. In addition, a further study between the two cohorts showed that the non- colonised mice lacked the normal distress/anxious behavior compared to the colonised mice when separated from their mother. Fascinatingly, when the non- colonised mice were colonised (with gut microbiomes appropriate for their species), their behaviour changed to that of the “normal” mice. Some research has been able to transfer information from mice studies to humans. Gut microbiome from human twins were transferred to mice with the following results: Gut microbiome from the obese twin transferred to mice caused obesity in the mice, whilst gut microbiome transferred from the thin twin to mice caused mice to remain thin/ lose weight. The mice diet was kept the same across chohorts. Another fascinating study involving all non-colonised mice, showed that when gut microbiome from a depressed human was transferred to mice, the mice displayed depressive behaviour e.g., losing hope when trapped in a water tank and quick to stop swimming, whilst gut microbiome from non- depressed person transferred to mice showed the mice persevered to swim longer and fought to stay alive. By Dr Aneshree Moodley Psychiatrist Cape Town THE GUT- BRAIN AXIS: ARE WE BEING CONTROLLED BY OUR GUT INSTINCT? MHM | 2024 | Volume 11 | Issue 2 | THE GUT- BRAIN AXIS: Are we being controlled by our GUT instinct? MHM 14 | MENTAL HEALTH MATTERS | 2024 | Issue 2 H