Probiotics linked to a reduction in negative feelings, offering potential advantages for mental health

Research by Katerina Johnson and Laura Steenbergen published in the journal NPJ mental health research shows that taking probiotics can help reduce negative feelings. They also studied people who benefit the most from these “good” bacteria.

Probiotics are “good” bacteria in the form of drinks or tablets that you can buy in the supermarket and that you will also find in foods such as yogurts, fermented cheese and sauerkraut. There is an increasing interest in the possibility that probiotics improve not only intestinal health but also mental health.

“The intestinal-end connection provides various ways through which bacteria in the intestine can influence our feeling and we comport, including via the vagus nerve, the immune system and the hormones,” explains Johnson.

Daily mood reports

While animal studies have already found promising effects of probiotics on the brain and behavior, human studies have given inconsistent results. Johnson and Steenbergen therefore used a combination of methods to grasp how probiotics could influence the ability to regulate our emotions and affect our moods. They understood psychological questionnaires, daily mood relationships and computer tasks that test how people treat emotions.

The study was conducted in young healthy adults who took a probiotic daily (containing bacteria such as lactobacillus and bifidobacterium).

This is the first study to use daily mood relationships to assess the effects of probiotics. This clearly shows that probiotics can reduce negative feelings compared to a placebo. This could mean a reduction in feelings such as anxiety, stress, fatigue or depressive trends.

“It is striking that by simply asking participants how they felt each day, we could detect the beneficial effects of the probiotics on the mood,” said Steenbergen. “On the other hand, standard psychological questionnaires that are common in this area were not sensitive enough to recover these changes.”

No antidepressant substitute

The researchers discovered that it took about two weeks for the probiotics to improve negative feelings. It takes almost the same time for antidepressants to work, but while antidepressants tend to reduce the negative and positive mood, the results have shown that probiotics only reduce negative mood.

This could be a possible advantage, although researchers point out that probiotics should not be considered an antidepressant substitute.

Who would benefit most from probiotics?

When the researchers observed the decrease in negative feelings, they wanted to explore if they could predict that would benefit most from the probiotics. “We found that various traits, including a propensity for risk avoidance, were associated with a greater effect of mood probiotics,” said Johnson.

In addition, researchers have found evidence that probiotics can affect the way participants deal with emotional signals. Participants who received probiotics were slightly more precise to recognize facial expressions.

Probiotics could be used in a targeted manner in the future

Many questions remain unanswered about the operation exactly of probiotics and their long -term effects. “Perhaps that in the future, probiotics could be used in a targeted way as an early intervention to reduce the risk of negative feelings that progress towards mental health conditions such as depression, although more research is necessary to confirm it,” explains Steenbergen.

Johnson and Steenbergen hope that their results will also encourage other mental health researchers to include simple daily mood measures in their studies. As they conclude in their article, “to try to delimit the complexity of the human brain and emotion, we cannot lose sight of the evidence. Sometimes, the simplest questions reveal the most significant answers.”