ABSTRACT
In Positive Health Science, we recommend a combined approach to health and disease prevention (or management) that takes mind, body, social and environmental worlds into account. We seek balance between these bio-psycho-social and environmental interfaces and adopt a growth mindset in the process. We humans live in complex environments both without and within. Along with other humans and domesticated animals, we are surrounded by communities of flora and fauna that include plants, fungi, single-celled organisms, viruses and varied animal species, depending on our geographical location, climate and social environment (biomes). Emerging research is describing the potential importance of this interplay for human mental and physical health. Certain bacterial species found within the gut microbiome can deliver mental health benefits to the host. These bacteria are called psychobiotics by virtue of their capacity to initiate the production of neurotransmitters, immune system-related chemical messengers (cytokines), psychotropic hormones (serotonin) and short-chain fatty acids (e.g. butyrate). Psychobiotics can be found in fermented food (probiotics) like sauerkraut or can be maintained in the gut by eating prebiotic whole foods that contain fibre (cabbage, onions, and bananas). Although the science is emerging, it remains unclear how these bacteria serve to regulate human mood and mental health. Experimentation with faecal microbiome transplant (FMT) from healthy mammals (rodents and humans) to sick recipients, prebiotic and probiotic-rich diets, as well as related supplements (e.g., inulin) have all shown promise as potential therapies for mental health conditions, chronic infections and irritable bowel syndrome (IBS). However, the jury remains out.
Unhealthy lifestyles, including the Western diet, can damage the gut microbiome which in turn can have negative consequences for our mood. Chronic stress in particular can inhibit functioning psychobiotics in the gut, leading to a negative feedback loop that further alters mood. Positive psychology interventions that cultivate optimism, gratitude and a growth mindset, coupled with a healthy lifestyle might have a role to play in stabilising the microbiome and contributing to overall wellbeing.
