Probiotics can aid depressive disorder in people unresponsive to antidepressants

A recent study funded by King's College London, the NHS Foundation Trust and National Institute for Health and Care Research (NIHR) shows the effectiveness of probiotics in depressive disorders along with antidepressant medicines.

The study used 14 strains of bacteria as a probiotic blend which helped in depressive disorder treatments when used alongside antidepressants.

The King's College London scientists did an eight-week long pilot study on 50 people of the age group 18 to 55 years. It's a double randomised placebo-controlled clinical study where the participants were given either a placebo or a multistrain probiotic with eight billion colony-forming units capacity per day along with their regular antidepressant medicine.

The study was done with a random sample of people taken from primary and secondary care services in London. The researchers collected the data between September 2019 to May 2022 and then analysed it between July-Semptember 2022.

The researchers gave 24 of them probiotics and 25 were given a placebo. A recorded 80 per cent of the people in the study were female which meant 39 participants were women. The mean age of the participants was 31.7 years.

After eight weeks the result showed an improvement in mood in the participants who had taken probiotics over those who had the placebo. Only eight per cent had attrition.

Attrition was observed in one candidate from the probiotic group and three candidates from the placebo group. The 97.2 per cent of participants adhered to the intervention and the positive effect seen in them left no side effects.

Gut health can enhance mood

The result highlights a critical link between gut health and mental health, showing how what we eat can affect our moods. It shows how probiotics can influence and enhance a person's mood over a long period of time like eight weeks. This suggests that the enhanced gut health improved by the presence of beneficial bacteria supplied by the probiotics could be used as a tool for mood lifting and bettering the mental health of people.

The researchers involved in the study see a ray of hope in this study, one that needs larger trials.

This is the first time the effects of probiotics in enhancing the mental health of clinically depressed people have been studied in the Western world. The result showed positive improvements in many anxiety and depression scores among these people suffering from depressive disorders.

This study done by researchers at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) of King's College London was published in JAMA Psychiatry on June 14, 2023.

Why is this crucial?

Depressive disorders are often associated with binge eating and other such unhealthy eating habits. Also, there is growing evidence regarding the gut microbiota's role in enhancing brain activities including mood regulation.

The gut microbiota is a unique blend of microorganisms in our gut or intestine. These are mostly beneficial bacteria which help in digestion and other processes and can be replenished by probiotics.

Now this study has given us insight into how gut microbiota affects your mood swings and how we can use probiotics to better people's mental health and reduce depression and anxiety, which is often seen in people with depressive disorders. This gives us an idea of how mood can be regulated using probiotics.

Although in the course of this eight-week trial, both the placebo and the probiotics group showed signs of improvement. The extent of it was greater in the probiotic group in the middle of the study.

So, from the fourth week onwards the probiotics team made greater progress than the placebo team. This sealed the deal for the probiotics in that it wasn't a one-off effect but a sustained bacterial community change in the gut.

One of the researchers involved in the study, Professor James Stone of Sussex Medical School, underlined how important this study was as most antidepressants have partial effects on people. So, probiotics provide an opportunity to enhance and support antidepressants in the treatment.

Another scientist from King's College Dr. Viktoriya Nikolova, reiterated this when he said that this is a crucial step in understanding the role of probiotics in mental health.

Close to five per cent of adults have depression and a considerable number of them don't respond to standard treatments, according to WHO. In such a scenario, the results of this study present a new way.