By far, the most common complaint I hear from patients is that they are tired. There are lots of reasons for fatigue in modern life. Many people work long hours or commute long distances. For parents and caregivers, the balance between work and family time can be overwhelming. Finding great sleep quality can be challenging, especially during time of stress, transition, grief and hormonal changes.

Medical conditions including depression, allergies, hypothyroidism, autoimmune disease and infectious diseases cause fatigue. There are treatments for any one of these medical conditions that can be successful and are worth pursuing.

As a Naturopathic Doctor, I spend a lot of time looking for the underlying cause of dis-ease and how the health of the whole patient can improve, rather than working on an individual symptom. The first place I start is with the diet and health of the GI tract.

A balanced diet, rich in plant based food, healthy proteins and good fats, supports gut health and a balanced mix of beneficial bacteria. In addition to diet changes, I often suggest use of a high quality probiotic, such as Nutrivee’s Advanced Probiotic Formula. The first thing people notice when they make these adjustments is that their energy has improved and they feel less tired.


Mood disorders such as depression are complicated and difficult to resolve. Medications can be helpful, even life saving to people suffering from Major Depressive Disorders, but for people with less severe depression, the results of treatment with medication can be mixed or disappointing.[1] These medications can come with unpleasant side effects, blurring the definition of successful treatment.

Medications focus their action on the neurotransmitters in the brain. The exact way some of the best-known antidepressant medications work is unknown, but many of them manipulate how much serotonin is available to the brain. Serotonin is a neurotransmitter in the brain associated with happiness, anxiety and mood.

Beyond the Brain

Some really interesting research is pointing to areas outside the brain as important to regaining brain health and wellbeing. Inflammation throughout the body, oxidative stress and adrenal fatigue are all known to increase depression. We may think of these as different problems, but they all have an important center in common- the GI tract.

If the bacteria normally housed in the gut are found in the blood stream, as happens in leaky gut, the body must work to remedy the situation. The person will have more inflammation as the body responds to the bacteria traveling throughout the body, more oxidative stress as the result of fighting this bacteria and more mood symptoms, including depression, in response to the stress. Bringing the gut flora back into healthy balance improves depression and even seems to reduce the risk of the most serious type of depression, Major Depressive Disorders. This imbalanced gut flora is where we can take action and change not only the mood, but overall health as well[2].

Gut health and antidepressant medication

Antidepressant medications that should improve the availability of serotonin in the brain don’t always work well for people. This usually leads the practitioner to suggest a new medication or a cocktail composed of different medications, each with its own side effects. These therapies can be successful, but none of them fully address the underlying problem[3].

Recent research has taught us more about exactly how a healthy gut microbiome may actually help depression itself,[4] and possibly even help antidepressant medications work better.

Tryptophan, an amino acid that is needed to make serotonin, comes from food like spinach, eggs, and turkey[5]. A large amount of tryptophan is stored in the GI tract. Although tryptophan is essential to making serotonin, we used to think of this store as different from the serotonin found in the brain.

New research shows that a healthy strain of E. Coli called E. Coli Nissle 1917 is needed to convert tryptophan to serotonin,[6] and the work of this friendly bacteria increases serotonin levels in the GI tract, and throughout the body.[7] This is the first time the specific way in which the gut bacteria affect the neurotransmitters has been demonstrated.

Because a healthy gut microbiome can increase the pool of serotonin available in the body, it may help the antidepressant medication work better by giving it more serotonin to adjust.

Fatigue and the GI tract

Depression causes significant fatigue, and being too tired to participate fully in life activities can look like depression, but fatigue is not always the result of depression. Anyone who has had a bad cold or the flu knows that immune activity can be exhausting!

While it may be less dramatic than the fatigue felt briefly during an infectious illness, the chronic immune stimulation that comes from autoimmune disease or chronic illness is well known to cause fatigue as well.

Lots of conditions cause fatigue, such as hypothyroidism, multiple sclerosis, scleroderma, systemic lupus erythematosus, chronic fatigue syndrome, autoimmune hepatitis… and many more. It has been the task of modern medicine so far to tackle each disease individually, with a different treatment plan for each one. That has led to brilliant advances in medications, but there remains an opportunity to consider what these conditions have in common.

Research into in the microbiome is suggesting that the gut is pivotal for the entire body’s health. When a healthy gut flora is present and able to convert tryptophan to serotonin, the serotonin acts locally to improve digestive function. It works to balance the immune system too.

Serotonin and stress

Serotonin helps regulate stress by balancing the hypothalamus-pituitary-adrenal axis, which refers to the feedback loop that helps the brain know when to ask for more or less activity from the adrenal glands.[8] This axis regulates the response to stressors in daily life, from the pressure to meet a deadline to how we respond to dangerous situations. It also balances the immune system to break cycles of inflammation. When the gut bacteria are balanced, they send signals to the brain that make the response to stress less extreme and therefore less damaging to the body. When there is dysbiosis, or an imbalance in the gut flora, inflammation continues to rise.

There is a marker for inflammation that is measured frequently in chronic disease, called the C-reactive protein, or CRP. CRP is made by the liver and released into the bloodstream when the body is in crisis. It is not specific to one disease; CRP will be elevated whether the inflammation is caused by MS or arthritis.

Studies have shown that species of Bifidobacteria work to lower CRP. One such study showed that while this general marker was lower in diseases that cause very different symptoms: psoriasis, ulcerative colitis and chronic fatigue syndrome, the specific immune cells that were also altered were different for each condition[9]. In other words, in addition to lowering the inflammation itself, the probiotic balanced each patient’s immune system in the way that was most helpful to their own disease process.

Slowly, medicine is starting to look for commonalities across disease. Many more details will be found over time, but for now, many of the secrets of great energy and immune balance appear to include great gut health.



[2] Slyepchenko A, Maes M, Jacka FN, Köhler CA, Barichello T, McIntyre RS, Berk M,

Grande I, Foster JA, Vieta E, Carvalho AF. Gut Microbiota, Bacterial

Translocation, and Interactions with Diet: Pathophysiological Links between Major

Depressive Disorder and Non-Communicable Medical Comorbidities. Psychother

Psychosom. 2017;86(1):31-46. Epub 2016 Nov 25. PubMed PMID: 27884012.


[4] Wallace CJK, Milev R. The effects of probiotics on depressive symptoms in humans: a systematic review. Annals of General Psychiatry. 2017;16:14. doi:10.1186/s12991-017-0138-2.


[6] Nzakizwanayo J, Dedi C, Standen G, Macfarlane WM, Patel BA, Jones BV. Escherichia coli Nissle 1917 enhances bioavailability of serotonin in gut tissues through modulation of synthesis and clearance. Scientific Reports. 2015;5:17324. doi:10.1038/srep17324.

[7] Clarke G, Grenham S, Scully P, Fitzgerald P, Moloney RD, Shanahan F, Dinan TG, Cryan JF. The microbiome-gut-brain axis during early life regulates the hippocampal serotonergic system in a sex-dependent manner. Mol Psychiatry. 2013 Jun; 18(6):666-73.

[8] Sarkar A, Lehto SM, Harty S, Dinan TG, Cryan JF, Burnet PWJ. Psychobiotics and the Manipulation of Bacteria–Gut–Brain Signals. Trends in Neurosciences. 2016;39(11):763-781. doi:10.1016/j.tins.2016.09.002.

[9] Mazidi M, Rezaie P, Ferns GA, Vatanparast H. Impact of Probiotic Administration on Serum C-Reactive Protein Concentrations: Systematic Review and Meta-Analysis of Randomized Control Trials. Nutrients. 2017;9(1):20. doi:10.3390/nu9010020.

To all Nutrivee customers. Nutrivee has now been rebranded to 'Vibranelle'. PLEASE NOTE: Our Advanced Prebiotic is still the exact same formula from the same manufacturer. Our Advanced Probiotic formula has changed and is now manufactured by the same manufacturer as our Advanced Prebiotic. Please purchase through our Amazon store here

Dr Keri Layton

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