Gut Feelings - Workplace Mental Health Institute

Gut Feelings

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Think you’re alone? You’re not. Trillions of microbacteria live in your gastrointestinal system and they are crawling over your skin. These nearinvisible organisms make up your microbiota, and the human environs they inhabit are collectively known as your microbiome.

How do we create that healthy gut biome? What destroys a good biome? How is the gut linked to happiness? What works against good gut health?

According to researchers, several thousands of types of bacteria make up a healthy gut. Each person’s microbiota is unique, and is constantly changing due to diet, environment, behavioural

patterns, and age, among other influences. It is impacted by the type of birth we had. Vaginal borne babies have a different microbiota profile than those born via caesarean section, just as breast fed babies have a different microbiota profile than formula-fed babies. As we age, the number of microbiota species in our microbiome decreases.

There are some unhealthy bacteria, but the majority of micro-organisms in the human microbiome are necessary to create the type of environment that stimulates the production of the neurotransmitter serotonin, essential in moderating mood and sleep.

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The link between the gut and the brain was proposed in a study that reported an impaired stress response in germ-free mice. Other studies using germ-free mice not only supported this link, but also the idea that it reaches into the endocrine, neural, and immune systems. Scientists have recently examined the effect of the microbiome on disorders of the central nervous system, including depression, anxiety, and schizophrenia.

Why is everyone talking about inflammation and leaky gut?

Inflammation of the gastrointestinal tract triggers a response that increases permeability of intestinal walls. This, put simply, means that the processes that are normally contained within the gastrointestinal tract can ‘leak’ out, becoming an unfamiliar invader into the surrounding parts of the human body. This can cause the body to begin to attack the rogue, out-of-bounds molecules.”

Furthermore, during inflammation the presence of certain mobilising factors in the gut (called cytokines) increase the permeability of the blood-brain barrier, impacting brain function and leading to anxiety, depression and memory loss.

What triggers the release of these cytokines? In a word, Endotoxins. These are toxins stored within a bacterial cell that is released when the cell disintegrates. In one study, endotoxin infusions were given to healthy human subjects with no history of depressive disorders. The infusions triggered cytokine release and the subjects began to display classical depressive symptoms.

Cytokines also play a key role in stimulating the central nervous system, in which excessive activity can lead to anxiety and depressive symptoms. The good news is that, in both animal and human studies, probiotics have demonstrated the potential to diminish the hypothalamus, pituitary and adrenal response.

Can the damage from gut inflammation be reversed?

Early studies are promising. Participants in a study suffering from chronic stress were given

During the diagnosis of my auto-immune condition several years ago, my GP predicted, “doctors will be prescribing diets for treatment of autoimmune conditions in ten years”.

a three-week probiotic treatment. Subjects in the bottom third of the elated/depressed scale demonstrated the most improvement with treatment. These patients rated an overall happier mood on daily analogue scales using six dimensions of mood including energetic/ tired, composed/anxious, elated/depressed, clearheaded/muddled, confident/unsure, and agreeable/angry.

In some studies, probiotics were found to have effectively mitigated anxiety and depressive symptoms at a level similar to prescription medications. These findings point to the potential value of a healthy microbiome, particularly the gut microbiota, to assist in the prevention of and recovery from anxiety and depression. Whilst researchers are sharing common findings in relation to healthy gut microbiota, more research is necessary to make conclusions about specific treatments, such as those involving probiotics, at this point.

A systematic review of all the human studies showed the majority do not show any effect of probiotics on mood, stress or symptoms of mental illness.

On the plus side, large studies show us that people who eat a balanced diet with all the usual good stuff (fibre, fresh fruit and vegetables) have lower rates of mental illness as adults and adolescents.

During the diagnosis of my auto-immune condition several years ago, my GP predicted, “doctors will be prescribing diets for treatment of autoimmune conditions in ten years.” The research is yet to be considered and approved by regulatory bodies for prescription purposes. Until that time, there is no harm to come from seeking appropriate guidance from a nutritionist or dietitian in relation to healthy gut biomes.

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