09/02/2017
This week we saw the promotion of a new study by Australia's very own Deakin University highlighting the connection of a healthy diet (Mediterranean style) and depression. ( See link)
http://www.abc.net.au/news/2017-01-31/mediterranean-diet-can-help-in-fight-against-depression-study/8224522
Whilst I can say that I am hearing about digestive issues such as bloating, food intolerances , SIBO and IBS more and more these days, many are wondering how can my gut impact my mental health ?
Reports on the study did highlight how it was the consumption of a variety of vitamins and nutrients that supported a positive state of mind, however the crucial point of our gut microbiota was slightly overlooked. Through the next few posts I will break down; the connection of the brain-gut axis, contributing factors to dysbiosis and eubiosis and ultimately how to give your gut the support it needs.
Often stressors in our daily life are a contributing factor to how well one can manage their mental health, exacerbating the symptoms one experiences. Ever felt so nervous or stressed you can't eat? Or maybe the opposite, where only a sugar or caffeine hit will pick you up? You get bloated and have an overall sense of discomfort?
A complex known as the BRAIN-GUT AXIS allows us to understand how diet can have influence on stress management and our wellbeing.
In order to understand the Brain- Gut Axis we must go back all the way to birth. Scientists have identified that the gut and brain originate from the same tissue found in the embryo and whilst the position of the brain and gut clearly part ways they remain connected via the Vagus nerve. This link acts as a 2 way street for communication between the gut's own nervous system, the enteric nervous system [ENS], and brain ( via central nervous system [CNS]) , particularly alerting the brain via neurons, hormones and chemicals to when our gut microbiota may be threatened or jeopordized. The main responses between out brain and gut are highlighted in the simplified image.
The ENS has a main influence on neurotransmitters ( chemical messengers to our brain) which ultimately impact our response to stress, anxiety, mood and behavior. Mood disorders have been linked to the downfall in the expression of brain derived neurotrophic factor (BDNF) in regions of the brain associated with controlling emotion, memory and learning. Depletions of BDNF contribute to a loss of structure and function, ultimately impacting our ability to cope with stress. Consequently neurotransmitter availability and uptake may require intervention and a boost via anti-depressant medication (e.g. selective serotonin reuptake inhibitors). It is hypothesized that microbiota can influence the production of serotonin ( our natural mood booster) via our gut, giving hope to new research and interventions.
Stress particularly can stimulate signalling molecules by immune cells, neurons and endocrine cells that act on the gut.
The CNS influences our gut, controlling our natural digestive responses such as motility, secretion of digestive juices ( e.g. bile and hydrochloric acid), nutrient delivery and microbial balance.
Microbial balance is a crucial point to note as it is a lack of diversity or overgrowth of the wrong types of bacteria in our gut that have demonstrated to contribute to a number of conditions that go beyond gastrointestinal disorders. It is through a weak intestinal barrier integrity and chronic gastrointestinal inflammation that nutrient uptake is negatively affected, contributing to overall systemic inflammation.
Studies have now shown links of gut microbiota composition to inflammatory diseases, pain and obesity.
It is through our feeding habits and diet as described in the Deakin study, that the diversity of our gut microbiota can develop, in addition to specific functional foods and supplements (e.g. probiotics) to support the beneficial bacteria we need to assist with stress and our overall wellbeing. Look out for my next post on how to promote and protect your gut!
