The Gut-Brain Connection: Can Probiotics Affect Your Mood?

The Gut-Brain Connection: Can Probiotics Affect Your Mood?

5 minute read

Once a cultural taboo, gut health became a hot topic somewhere around the 2010s (as if someone suddenly decided it was cool to discuss the workings of our gastrointestinal system). However, our language has always reflected the significance of the gut on a very visceral level. Have you ever been sick to your stomach? Or perhaps you've had a strong gut feeling about what’s coming next? When was the last time you felt butterflies in your stomach? These and many more expressions indicate that the gut (not just our brains or hearts) holds the key to our feelings.


What Is Gut Microbiome?

Trillions of tiny living organisms—cells, viruses, bacteria, and fungi—inhabiting our mouth, colon, and everything in between (stomach, small and large intestine) make an ecosystem of its own. These microorganisms (microbes) in our gastrointestinal tract form an entity called the microbiome, which weighs between 1-3% of our body mass. There are no two identical microbiomes in the world. Yes, your gut makes you unique.


Why Is Everyone Talking About Gut Health?

A healthy, happy, and diverse (gut loves diversity) microbiome ecosystem has been linked to long-term health, including:

  • food digestion and nutrient absorption
  • vitamin synthesis
  • robust immune system
  • cardio-vascular health
  • protection from harmful bacteria
  • mood, cognition, anxiety, and pain regulation

Gut flora imbalance has been linked to:

  • auto-immune diseases
  • weight gain
  • diabetes
  • neurodegenerative diseases (like Alzheimer's)
  • emotional issues (anxiety and depression)


Your Gut and Brain Are Talking

Some scientists refer to the gut microbiome as the 'Second Brain'. Though unable to perform cognitive functions (like thinking or deciding to write a novel), the gut microbiome communicates with our Big Brain by the brain-gut axis. Think of it as an expressway between our gastrointestinal tract and brain, used for a sophisticated exchange of hormones, chemicals, and neural activity. A direct line of communication. An intimate, two-way conversation—messages and information travel from the gut to the brain and the other way around (a prominent role in this exchange is played by the vagus nerve).

The Second Brain (also known as the enteric nervous system) contains roughly 100 million neurons and over 30 neurotransmitters (molecules used by the nervous system to send information chemically). One of them is serotonin, known commonly as the “happiness hormone” or “feel-good chemical." Serotonin is a potent mood, sleep, and social function regulator. Estimation is that 90% of serotonin is produced in the gut. Other neurotransmitters made by the gut (GABA, norepinephrine, acetylcholine) also play a prominent role in mood, motivation, reward, anxiety, and concentration. Because of the two-way brain-gut conversation continuously taking place, changes in the gut microbiome cause changes in the brain, mood, and behavior.


You Are What You Eat

Remember what we said earlier about gut-loving diversity? It goes for both diversity in types of microorganisms in a healthy gut and our diet. The more diverse the diet, the more diverse the gut. The more diverse the gut, the happier the gut. So, it’s not just about the calories and macro and micronutrients. We must aim for variety in our eating habits. Antibiotics, stress, and illnesses wipe out our good bacteria.

Luckily, there is one aspect of our life we can control. Our diet. It is the single most contributing factor to our gut health. The gut reacts to dietary changes surprisingly quickly: three or four days from introducing a massive change in how we eat. So, what should we be eating? There’s no clear-cut answer to this question.


Should You Be Chugging Kombucha?

Each person’s microbiome is unique, so every gut will respond differently to what we feed it. An excellent way to go about it is to observe how you feel after consuming a particular food. Do you feel energetic or sluggish?Do you feel happier and ready to work after eating something or do you suffer from brain fog? Do you have digestive issues or feel physically uncomfortable? Keeping track of these sensations over time will reveal what foods to keep and what to cut out. A good rule of thumb is staying away from processed foods and filling your plate with whole foods instead.

Many products promising to take good care of your gut are being launched, but you can go old-school. Go for a plate full of plant-based food sources of different colours. Fiber doesn’t just support regular bowel movement; it is also super gut-friendly and microbiome bacteria thrive when fed fiber. Our typical Western diet makes it challenging to get in the daily recommended fiber amount (25 grams for women, 38 grams for men). So, conscious decisions and some planning are required.

Prebiotics became a bit of a buzzword in recent years. They are merely dietary fiber that your gut bacteria love to eat, and that helps them grow. Probiotics are the gut fuel. Garlic, onions, shiitake mushrooms, asparagus, bananas, leeks, oats, and spinach are some common prebiotics in homes worldwide.


The bottom line

Your gut affects your mood, motivation, reward system, and concentration. Trillions of tiny living organisms are inhabiting your gut, and that’s a good thing. You want that neighbourhood to stay diverse and vibrant, as the largest factory of feel-good chemicals is located right there. To support your gut, feed it with fiber (plenty of fruits and veggies of different colours). Eating the same-old-same-old won’t do it long-term. Diversity is key when talking about gut health.


Read more:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6282467/

https://pubmed.ncbi.nlm.nih.gov/31530002/

https://www.sciencemag.org/news/2019/02/evidence-mounts-gut-bacteria-can-influence-mood-prevent-depression

https://www.nature.com/articles/nrn3346

https://www.scientificamerican.com/article/the-guts-microbiome-changes-diet/

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