Probiotics for depression

Meet the psychobiotics

The right strain and level of probiotics can enable you to handle stress better, lift mood and help lower depression and anxiety.

That’s the conclusion from a randomised trial published in Nutrition and a series of articles published in Biological Psychiatry. The results were sufficiently convincing for the authors to coin the term pyschobiotics.

We certainly know that there is a direct connection between the health of the gut and improvements in a number of conditions. Probiotics are able to improve digestive health, boost immune function, help treat candida and thrush and cut the risk of stomach upsets during foreign travel.

How do probiotics act on the brain to become psychobiotics?

Although the improvements in mood are real, researchers are still not completely sure what the mechanisms are. There are three ways in which probiotics could be reducing stress, acting as anti-depressants and boosting mood.

1. Probiotics can create new neurotransmitters

First, we know that gut bacteria can create neurotransmitters like acetylcholine, GABA and serotonin. Low levels of serotonin are associated with increased risk of sleep problems and depression – although they are not apparently the direct cause. Adequate levels of serotonin, however, are definitely linked to happiness and positivity.

We also know that low levels of acetylcholine in the brain are linked to increased risk of Alzheimer’s.

2. Probiotics can help restore the stress response system

Secondly, psycho-biotics can help restore the body’s stress response system.

This is quite complicated, but essentially the hypothalamus and pituitary glands should work in concert to create hormones that create enough blood sugar to bring the body back to a normal unstressed state. Certain probiotics can help ensure this happens.

3. Probiotics have a positive anti-inflammatory effect

The third way in which psychobiotics can reduce depression and stress is via their anti-inflammatory effect. Chronic inflammation is now recognised as the key driver of many diseases, including heart disease and stroke. It is one of the major underlying causes of depression and cognitive impairments including dementia.

All this explains why leading clinics are beginning to treat patients who have depression and even psychological disorders with probiotics – alongside conventional therapies.

Study reports patients "significantly less depressed" after probiotic treatment

A double blind trial (the gold standard in clinical research) was conducted on 40 patients with severe depression, allocated either a placebo or probiotics.

After 8 weeks, the patients who received the probiotic supplements were ‘significantly less depressed’.

Even better, their inflammation levels were lower – as measured by CRP scores – they had lower insulin levels and reduced insulin resistance. Each of these positive outcomes is important for overall health and especially beneficial for diabetics.

There was a significant further benefit – they experienced a sizeable increase in their glutathione levels.

The 'master anti-oxidant' glutathione

Glutathione is a simple molecule that you produce internally, but production normally declines with age.

Glutathione has been called the master anti-oxidant – it counteracts free radical (oxidative) damage to cells. Free radical damage is recognised to be a major element in accelerated ageing and age-related illness.

Indeed, glutathione researcher Dr Mark Hyman states:

“I have come to realize that our ability to produce and maintain a high level of glutathione is critical to recovery from nearly all chronic illness — and to preventing disease and maintaining optimal health and performance.”

A combination of health-positive effects

Lowered depression, lowered inflammation, lowered insulin levels and higher glutathione levels is a very powerful combination of health-positive outcomes. And this study is supported by others in which depression was reduced and mood boosted – see references.

So what are the strains involved in these studies?

Which probiotics can help depression?

Analysing 7 studies on the effect of probiotics in reducing depression and stress and in improving mood, the following strains seems to be effective. The level appears to be 6 – 10 billion CFUs (Colony Forming Units) a day.

  • Lactobacillus acidophilus
  • Bifidobacterium bifidum
  • Lactobacillus casei
  • Bifidobacterium longum
  • Lactobacillus helveticus
  • Lactobacillus plantarum
  • Lactobacillus rhamnosus
  • Bacillus coagulans

There is also evidence that prebiotics – the food for probiotics – can act as regulators of both mood and brain function.

Match the probiotic strain to the condition

A recent edition of University Health News stated that

“The benefits of probiotics extend far beyond digestion; the question is not whether you should be taking probiotics, but which probiotics, how many and how often.”

Having reviewed the clinical evidence, they recommend the following well researched strains – ideally in combination:

Lactobacillus rhamnosus

Helps prevent diarrhoea, ease IBS and reduce respiratory tract infections (colds) in children.

Level: As much as 10 billion CFUs per day. Try for 30 days.

Lactobacillus plantarum

Helps reduce the frequency and intensity of abdominal pain in conditions like IBS.

Level: 10 billion a day.

Bifidobacterium lactis

Regularises bowel movements and improves immune function.

Level: 7-10 billion a day.

Bacillus coagulans

An especially hardy strain that is shown to be effective in relieving abdominal pain and improving the absorption of nutrients.

Lactobacillus acidophilus

Effective in treating candida overgrowth.

The different probiotic names can be confusing, but you can find a helpful report on probiotics at

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Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Ghodarz Akkasheh M.D. et al; Nutrition. Volume 32, Issue 3, March 2016, Pages 315-320

Probiotics for treatment of acute diarrhoea in children: randomised clinical trial of five different preparations. Canani RB et al; BMJ. 2007 Aug 18;335(7615):340. Epub 2007 Aug 9.

Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. Philippe Ducrotté et al; World J Gastroenterol. 2012 Aug 14; 18(30): 4012–4018.

Enhancement of immunity in the elderly by dietary supplementation with the probiotic Bifidobacterium lactis HN019. Harsharnjit S Gill, Kay J Rutherfurd, Martin L Cross, Pramod K Gopal;  The American Journal of Clinical Nutrition. Volume 74, Issue 6, 1 December 2001