Probiotic Supplementation in Pregnancy Reduces the Risk of Anxiety and Depression

Though the evidence of the role of diet and the gut in the development of psychological disorders is established and growing, the majority of the research has either been epidemiological (observations of large groups of people – these do not show causality) or animals trials (show the mechanisms but might not completely translate to humans). At the end of all of these papers the authors remark that more high-quality human trials are required to draw firmer conclusions. Earlier in the year we had the publication of the SMILES Trial, a study that showed a cause and effect relationship between poor diet and depression and now a new paper provides more good evidence of the role of probiotics and the gut microbiome on mental health. Even more interesting is that this was not even the main aim of the research.

Researchers in New Zealand set up a trial to see whether giving pregnant women probiotics would affect their children’s risk of developing eczema. Eczema is an inflammatory skin condition and the gut microbiome plays an essential role in regulating inflammation. A baby’s gut microbiome is seeded at birth during its transit through the birth canal, or from skin contact after delivery by caesarean section. In the study 423 pregnant women were randomly assigned to two groups. One group received a daily supplement of a strain of bacteria called Lactobacillus rhamnosus (HN001). The other group received an identical looking/tasting placebo. The women took the supplement/placebo from the moment they enrolled until their child was born, and from birth until 6 months if the mother was breastfeeding. Information about the women’s mental state was taken at baseline (14-16 weeks pregnant), when the child was 6 months and 12 months old. They found a strong effect of the probiotic. The women who had taken the supplement (and none of the women knew whether they were taking the active supplement or the placebo) were much less likely to experience depression and anxiety after the birth of their children.  

The researchers report that between 10%-15% of women experience post-partum (post-natal) depression, which can impair the development of a strong bond between mother and infant, creating psychological and physical health risks for both. Medication options for breastfeeding women are limited because of the risk that the medication would be ingested by the baby in breast milk. In addition, it is practically difficult for women to access psychological or psychosocial interventions on top of the demands of a new baby. Further, some women feel reluctant to ask for help because they feel ashamed or guilty that they should feel so unhappy following the birth of their baby. Clearly then, the development of accessible and effective treatments is essential. There are many questions still to be answered about what a probiotic treatment might look like. This trial looked at only one strain and it might be that others of a combination are important too. We also need to know how long treatment should last and what the dose should be. But this well-designed study adds to the evidence of the role and importance of gut health in mental health and of taking the health of the whole body in to consideration when looking to treat mental health problems.

Reference

Effect of Lactobacillus rhamnosus HN001 in Pregnancy on Postpartum Symptoms of Depression and Anxiety: A Randomised Double-blind Placebo-controlled Trial. DOI: 10.1016/j.ebiom.2017.09.013

Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review

Many by now will be familiar with the term ‘friendly bacteria’, referring to the vast population of bacteria in the digestive tract. This population of microbes (the microbiome) play an important role in maintaining our digestive health and many people consume yogurt and other fermented milk drinks to promote gut health. Increasingly research is showing us that the gut microbiome has a significant effect on our mental as well as physical health.

To gain a better overview of the current status of research in this area a systemic review of random controlled trials was conducted and published in the Journal of Neurogastroenterology & Motility. The researchers reviewed 25 animal and 15 human trials. Of the studies involving human participants just over half described significant effects of probiotics on central nervous system function and an intake of probiotics for four weeks appeared to be the threshold for noticeable effects. In the human trials the most common bacterial strains tested were Bifidobacterium longum, B. breve, B. infantis, Lactobacillus helveticus, L. rhamnosus, L. plantarum, and L. casei, all of which are present in fermented foods such as yogurt, kefir and traditional (unpasteurised) sauerkraut.

Looking at both the animal models and human trials the results of this review indicated that probiotics were an effective intervention for a range of mental health disorders including anxiety, depression, Obsessive Compulsive Disorder (OCD) and memory function. A number of potential mechanisms were identified:

• Reduced cortisol (stress hormone) levels

• Reduced inflammation.

• Improved immune function

It is also feasible that some of the known metabolites of the microbiome such as GABA, an inhibitory neurotransmitter, might play a role either via the vagus nerve or more directly by crossing the blood-brain barrier. Whilst the review is generally positive the researchers called for further studies to be conducted with human participants in order to be able to draw firmer conclusions on the promising role of probiotics on mental diseases.

Reference:

Wang, H., Lee, I., Braun, C. & Enck, P. (2016). Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review. Journal of Neurogastroenterology & Motility, 22, 589-605.

Mental Health Awareness Week – Special Focus on Depression (Probiotics)

Just last week the NHS reported a study stating that there was insufficient evidence that probiotics were beneficial for healthy people. The trials analysed so far had not been well enough designed to be sure.

“Given the limitations of the studies – including the variety of probiotics examined – it is not possible to conclude with certainty that all probiotics are ineffective.

Absence of good-quality evidence is not evidence of there being no effect. Better-designed studies may yet find some benefit from taking probiotics.”

However, there is certainly some good evidence that particular probiotics do have a beneficial effect on depression, particularly where that depression is associated with cellular inflammation. Inflammation is the body’s immune response to illness or injury; the swelling around a cut or a bruise is part of this process. But inflammation also happens within and around the cell in response to other non-injury factors such as poor diet, prolonged stress or an imbalance of bacteria in the gut. Inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease are commonly associated with psychological and behavioural changes such as lack of energy or interest, loss of appetite, loss of appetite; and depression. This consistent relationship between inflammation and depression has led to the inflammation theory of depression; that is to say that for some sufferers inflammation may be contributing to the severity of their depressive symptoms.

A well-designed study of petrochemical workers published in 2015 showed that probiotic yogurt and supplements significantly improved scores of depression and anxiety. I have reported elsewhere that probiotics have been shown to alleviate the negative thoughts associated with low mood. A more recent controlled study showed that eight weeks of probiotic supplementation was associated with a significant reduction on depression scores in patients with a diagnosis of Major Depressive Disorder. It is thought that part of the mechanism underlying this effect are the by-products of the bacteria’s metabolism. When breaking down food in the gut (particularly fibre) gut bacteria produce a number of metabolites, many of them beneficial to the human body such as vitamin K and some B vitamins. They also produce short-chain fatty acids. One of these, butyric acid, in a potent anti-inflammatory. It also forms part of a neurotransmitter called GABA, which has a calming, tranquilizing effect on the brain.

There are a lot of probiotic products on the market and it can be difficult to know which is likely to be the most effective. There is very good research data supporting the anti-inflammatory properties of a highly concentrated probiotic supplement called VSL#3 in a number of different diseases. Whilst not necessarily a recommendation, this is the product that I use as well as ensuring regular consumption of fermented and high fibre foods.

http://www.nhs.uk/news/2016/05May/Pages/No-evidence-probiotics-are-beneficial-for-healthy-adults.aspx

Mohammadi, A. A., Jazayeri, S., Khosravi-Darani, K., Mohammadpour, N., Asemi, Z., Adab, Z., Djalali, M., Tehrai-Doost, M., Hosseini, M. & Eghtesadi, S. (2015). The effects of probiotics on mental health and hypothalamic–pituitary–adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers. Nutritional Neuroscience. Published online April 16th.

Laura Steenbergen, Roberta Sellaro, Saskia van Hemert, Jos A. Bosch, and Lorenza S. Colzato. 2015. A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain, Behavior, and Immunity, 48, 258-264.

Akkasheh, G., Kashani-Poor, Z., Tajabadi-Ebrahimi, M., Jafari, P., Akbari, H., Taghizadeh, M., Memarzadeh, M. R., Asemi, Z., & Esmaillzadeh, A. (2016). Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Nutrition, 32, 315-20.

D'Mello, C., Ronaghan, N., Zaheer, R., Dicay, M., Le, T., MacNaughton, W. K., Surrette, M. G. & Swain, M. G. (2015) Probiotics Improve Inflammation-Associated Sickness Behavior by Altering Communication between the Peripheral Immune System and the Brain. Journal of Neuroscience, 35, 10821-18030.

Mariman, R., Tielen, F., Koning, F. & Nagelkerken, L. (2014). The probiotic mixture VSL#3 dampens LPS-induced chemokine expression in human dendritic cells by inhibition of STAT-1 phosphorylation. PLoS One, 9: e11567.

Disclaimer

This information is provided for information purposes only and should not be taken as advice or instruction. This information does not replace the advice of your doctor. Please consult an appropriate health professional if you believe you are experiencing a mental or physical health concern. Speak to your GP or a trainer before making any significant changes to your exercise routine.

Probiotic Relieves Anxiety in Chronic Fatigue Syndrome (Pilot Study)

Chronic Fatigue Syndrome (CFS) or Myalgic Encephalopathy (ME) is a complex illness of unknown cause that has both physical and psychological symptoms. The major physical symptom is intense bodily fatigue, which is made worse by bouts of physical or mental exertion and is not relieved by sleep. Muscle and joint pain and bowel conditions such IBS are often also seen. Psychologically, people with a diagnosis of CFS often report feeling depressed and/or anxious and find it hard to concentrate. Although it is not clear what causes CFS there is a strong link to increased markers of inflammation (the body’s immune response to illness or infection) and disturbances in the gut microbiome. This observation is interesting because the gut is the crucible of the immune system and plays an important role in ‘teaching’ the immune system to respond appropriately to pathogens and in distinguishing the body’s own cells from invaders.

In a small but well-designed pilot study, participants with a diagnosis of CFS and comorbid depression and/or anxiety were randomly assigned to two experimental groups. The test group took three sachets a day of a probiotic (Lactobacillus casei Shirota) totalling 24 billion bacteria per day. The control group ingested three sachets of an identical looking placebo product. After eight weeks the patients were reassessed on the depression and anxiety scales.

At the end of the test period not only had there been an increase in the number of Lactobacillus in the patients’ guts but also increased numbers of Bifidobacteria, a different strain of bacteria that is associated with a healthy digestive system. This is noteworthy a) because it indicates that the introduction of one helpful strain can encourage the proliferation of another, b) because CFS patients tend to have low levels of Bifidobateria and c) because some strains of Bifidobacteria are known to improve blood levels of tryptophan, an essential amino acid that is the precursor of serotonin, a neurotransmitter linked to happiness and good mood.

The researchers also found that patients who had been taking the probiotic were significantly less anxious than at the start of the study, a valuable finding considering the significant burden of anxiety in this patient group. Importantly, the probiotic was well tolerated, which means that it did not cause any unwanted or unpleasant side-effects.

Rao, A. V., Bested, A. C., Bealune, T. M., Katzman, M. A., Iorio, C., Berardi, J. M. & Logan, A. C. (2009). A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome. Gut Pathogens, 1:6.

Probiotic Alleviates Stress and Anxiety

We have known for some years now that there is a comorbidity between psychological problems such as depression and anxiety and gastrointestinal disorders. That is to say people who present with these psychological problems often have a gut issue at the same time and vice versa. Recent research that has started to explain some of the processes underlying this relationship and the term given to this connection is the ‘gut-brain axis’. The community of bacteria in the gut is central to the gut-brain axis with the bacteria playing an essential role in nutrient absorption and production, inflammation and immunity amongst many others.

Much of the research into the gut-brain axis is of potential treatments: the researchers are looking to relieve a particular disorder and so the results can often only accurately be applied to groups who suffer from that disorder. However, a recently presented study looked at the effects of probiotic (beneficial bacteria) supplementation on healthy people.

Researchers from Ireland put 22 male participants through a battery of tests to assess their cognitive performance, perceived stress and stress hormone levels before and after a four-week course of a daily supplement of the bacteria Bifidobacteria longum. At the end of the study the participants reported feeling less anxious and stressed, had significantly improved cognition scores and were producing lower levels of stress hormones.