Probiotics and Mood

New and exciting research is revealing a strong connection between our mood and the various bacteria that live within our intestines. This is certainly a sobering notion. Think of it: the bacteria living within the digestive system are, to some degree, involved in determining whether we are happy, sad, anxious or even depressed.

In a new study published in the peer-reviewed journal Brain, Behavior and Immunity, researchers in the Netherlands explored the idea that changing the array of bacteria in the gut by giving a multispecies probiotic supplement could have an effect on mood. The study provided the probiotic to 20 healthy individuals, none of whom had a mood disorder, over a four week period. A similar group of 20 individuals received a placebo over the same period. At the conclusion of the study, both groups underwent an evaluation to determine their reactivity, in terms of cognitive function, to sad mood. This is a fairly standard research tool that assesses depression.

The researchers demonstrated a significant reduction in the degree change, in terms of cognitive reactivity, to sad mood in the group receiving the probiotic in comparison to a placebo. These results and others provide significant evidence that the intake of probiotics may help reduce negative thoughts associated with sad mood. Probiotics supplementation warrants further research as a potential preventive strategy for depression.

The exact mechanisms that relate improvement in mood to the consumption of probiotics were not specifically presented in this data, but what we do know is that the gut bacteria regulate several factors that do influence our state of mind. First, the microbiota living within the intestines play a large role in creating the various neurotransmitters that have a significant effect on mood, and these include chemicals like serotonin and dopamine. Second, the gut bacteria regulate the level of inflammation throughout the body and including the brain. The chemical messengers of this process, cytokines, are known to be significantly involved in mood and how we perceive the world around us.

But what is unique about this research is that it is interventional. This means that rather than observing how differences in gut bacteria may relate to mood, this research actually made a change in the array of organisms living within the test subjects and then observed the changes in mood as described above. Imagine that, giving bacteria to treat mood disorders!

Some Probiotic Foods to Improve Mood
• Fatty fish: Omega-3 fatty acids are a group of essential fats that you must obtain through your diet because your body can’t produce them on its own. Fatty fish like salmon and albacore tuna are rich in two types of omega-3s — docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) — that are linked to lower levels of depression.
• Dark chocolate: Chocolate is rich in many mood-boosting compounds. Its sugar may improve mood since it’s a quick source of fuel for your brain. Furthermore, it may release a cascade of feel-good compounds, such as caffeine, theobromine, and N-acylethanolamine — a substance chemically similar to cannabinoids that has been linked to improved mood.
• Fermented foods: Fermented foods, which include kimchi, yogurt, kefir, kombucha, and sauerkraut, may improve gut health and mood. The fermentation process allows live bacteria to thrive in foods that are then able to convert sugars into alcohol and acids.
• Bananas: Bananas may help turn a frown upside down. They’re high in vitamin B6, which helps synthesize feel-good neurotransmitters like dopamine and serotonin.
• Berries: Curiously, eating more fruits and vegetables is linked to lower rates of depression. Although the mechanism isn’t clear, a diet rich in antioxidants may help manage inflammation associated with depression and other mood disorders.
• Beans and lentils: In addition to being high in fiber and plant-based protein, beans and lentils are full of feel-good nutrients. They’re an excellent source of B vitamins, which help improve mood by increasing levels of neurotransmitters like serotonin, dopamine, norepinephrine, and gamma aminobutyric acid (GABA), all of which are important for regulating mood.

For Further Reading:
•Healthline.com discusses the relationship between probiotics and your brain, mood, and gut at the article: https://www.healthline.com/health/probiotics-for-brain-and-memory
•Harvard Health Publishing has published an article "Probiotics may help boost mood and cognitive function". The online article is found at: https://www.health.harvard.edu/mind-and-mood/probiotics-may-help-boost-mood-and-cognitive-function
• "Can Probiotics Improve Your Mood?", an article published John Hopkins Medical, can be found at https://www.hopkinsmedicine.org/health/wellness-and-prevention/can-probiotics-improve-your-mood