Depression: A new role for probiotics in nutritional psychiatry?

By Tim Cutcliffe

- Last updated on GMT

© gettyimages
© gettyimages

Related tags Probiotics Depression Selective serotonin reuptake inhibitor

The possibility that probiotics could be a new tool in fighting depression is gaining increasing attention in nutritional psychiatry, says Caroline Wallace ahead of her talk at the IPA World Congress + Probiota 2018 next month.

“Probiotics as a novel therapeutic in a clinical sample of depressed patients”​ is the title of a presentation by Canadian Ph.D student Caroline Wallace during the forthcoming IPAWC + Probiota in held in Barcelona. 

NutraIngredients caught up with Wallace recently to get a sneak preview of the key issues and challenges facing researchers in this area, as well as topics she would be addressing in the talk.

Although difficult to identify the single most important issue, a key motivator for the development of probiotics as a treatment for depression is that “the treatments that we have right now are not treating the illness, they are treating the symptoms,”​ suggested Wallace.

“One of probiotics’ potential big benefits would be getting at the underlying mechanism of the disorder that is causing the symptoms instead of just putting a Band-Aid on, which is kind of what I think of antidepressants doing,” ​she added.

Another challenge facing scientists right now is that, although the area is growing, there is not "not enough research being done in clinical samples. Most of the research that has been done looking at mood symptoms has been done in individuals who present without any mood disorder.”

As part of her address, Wallace will present an overview of the research to date.

“It's really important that the next steps are focused on looking at this in clinical populations with rigorousrandomised controlled trials (RCTs) and also looking at an underlying mechanism."

Wallace will explore this in more detail, together with other theories about mechanisms that underpin the impact of probiotics on depression.

Probiota 2018 - SQUARE

IPA World Congress + Probiota 2018​​

The rapidly evolving universe of probiotics, prebiotics and the microbiome will be discussed in-depth at the upcoming IPA World Congress + Probiota 2018​ in Barcelona on February 7-9.

From microbiome advances, to start-up game changers, market stats, crucial clinical science and regulatory knowledge, this is a congressional must-have.

Will you be joining your peers in one of Europe’s great cities?

Pilot study

Wallace is also looking forward to presenting the results of a pilot study, which she recently conducted, evaluating the efficacy, safety and tolerability of probiotic supplements on symptoms of depression in treatment-naïve patients. Regarding the choice of trial population, Wallace explained:

“We wanted to look at a sample that was early on in their depression and more of a mild-to- moderate depression. So it is a clinically relevant, but not a treatment- resistant or chronic or severe depression, because that's not really the population who we feel would benefit from probiotics," ​she said, hinting at another exciting upcoming research project.


Topics of research that may influence the effectiveness of probiotics as a depression treatment include dose, duration of treatment and which species or strains to use.

Wallace will be reviewing the data on dosage and length of treatment, which show widely varying results in these parameters.

The identification of effective probiotic species and/or strains and the single versus multi-strain debate are also important questions, she suggests.  

Wallace will be highlighting a couple of strains that have shown promise in their effect on the gut-brain axis in animal trials. Knowledge of this aspect will continue to evolve in the near future, but evidence to-date already suggests that strains are function-specific.

“In a lot of the research that has been done in human populations, the strains vary very widely, but it really should be known that different strains have different functions,” ​commented Wallace.

“It is important to follow all avenues and tease out which of the strains have an effect and which don’t.”

Depression – a heterogeneous disorder

Another important characteristic of depression is that rather than being a single condition, it has many different components and symptoms including effects on mood, stress/ anxiety and cognition.

It is important that “We don’t look at depression as one whole, but that we see it as many parts. And it’s important to tease those parts out when we are looking at treatments,”​ Wallace emphasises.

“In our analysis, we have broken it down by symptom groupings, so I will present some data on that,” ​she added.

Big picture

Wallace is very passionate about improving people’s mental health using probiotics, though the research is still in its early stages. She also emphasised the importance of having a robust scientific basis behind eventual treatments.

“It’s really important that the information that’s out there for people is evidence based and not ahead of the research.

"The potential of using probiotics to alleviate depressive symptoms translates into an accessible lifestyle modification that improves our mental health.

“That could be really revolutionary for some people, even people who don't necessarily have a clinical diagnosis of depression, but who present with subclinical symptoms of depression.”

For those who do not wish to go onto antidepressants, a simple change in diet or the addition of a supplement could really be of benefit, she proposes.

Probiotics could also be important in population segments where use of pharmaceutical anti-depressants are unsuitable, she suggests. This includes those aged under 18-years, (in whom certain Selective Serotonin Reuptake Inhibitors (SSRIs) have been known to induce or worsen suicidal thoughts) and pregnant or lactating women.

Finally, Wallace suggests that using a supplement might help those who fear seeking treatment or medication because of the stigma surrounding the issue

“Another area of interest for me and why I think this research is important is because in people who do present with clinical depression there is so much stigma around the disorder and so much stigma around antidepressant medication.

“If they can take a supplement which they can buy over the counter at a drug store, this might not be so stigmatising to them,”​ she concludes. 



Related news

Show more

Related products

show more

Harness the power of algae for omega-3 innovation

Harness the power of algae for omega-3 innovation

Content provided by dsm-firmenich | 08-May-2024 | Insight Guide

Algal-sourced omega-3s have limitless potential, able to scale to meet the needs of our planet’s population with twice the potency – naturally – and all...

HRB probiotics in the HMO era

HRB probiotics in the HMO era

Content provided by Morinaga Milk Industry Co., Ltd. | 29-Apr-2024 | White Paper

Discover the science behind human-residential bifidobacteria (HRB) probiotics and their superior benefits for infants.

Related suppliers

Follow us


View more