How Your Gut Affects Your Mood

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We already know that eating well is fundamental to our overall health and well-being, but in recent years, research has shown that there is constant dialogue between our brain and gut. More specifically, it indicates that the bacteria teeming in our gut – collectively known as the microbiome – influences our behaviour.

We speak to functional medicine coach Dr Cheryl Kam MBBS BSc (London), FACNEM (Aus) to learn more about the connection between the gut and brain, and how we can enhance it to improve our mood and mind-set.

The Gut-Brain Axis

If you’ve felt butterflies in your stomach or ever had to make a gut-wrenching decision, it’s likely you’re getting signals from your second brain – otherwise known as your gut.

“Historically and intuitively, we’ve always found clues in linguistics and knowledge,” Dr Kam tells us. "And now, modern science has been able to bring it down to the anatomical and molecular level with testing and science experience, to tell you that yes, this is actually true. It’s more connected than we think.”

Researchers have surmised that a lesser known nervous system in our gut communicates with our brain, meaning the brain, gut and hormones related to stress and anxiety are all linked. This bidirectional line of communication happens by way of the vagus nerve, one of the biggest nerves in the body.


How stress affects the gut

That churn-y tummy and the urge to run to the loo when you get nervous? It’s one of the more palpable connections experienced by a lot of people. Stress activates the flight-or-fight response in your central nervous system, and this can affect your digestive system in various ways. For instance, it can make your gut more permeable to bacteria.

“People suffering from irritable bowel syndrome (IBS) tend to be more aware of this phenomenon,” says Dr Kam. “When they’re more stressed, they’ll have more bouts of diarrhoea or they might get constipated, depending on the subtype of IBS.”

It happens the other way round, too. Those with gastrointestinal problems often experience anxiety, stress and depression; reciprocally, these negative feelings exacerbate gut issues.

In the most obvious cases, someone who is down with gastroenteritis (food poisoning), or or bowel infection may also suffer from short-term depression.

“You’re not really going to have the brain ability to do anything, your mood is going to be down for various reasons not just from the gut but from the lack of energy and dehydration."


Diet plays a major role in how we feel

According to Dr Kam, if your diet is chronically low in iron and zinc, and there's nutrient debt, you’re going to experience fatigue, energy loss and low mood. As this goes on chronically, your body’s hormones won’t function as well; your gut digestion slows down and begins to lose its ability to absorb nutrients. Processed foods, or foods that contain toxins like pesticides, drugs and antibiotics, won't do your gut any favours, either.

“They exert an effect on the microbiome and kill off, or won’t nurture good bacteria,” she explains. "There’s a chance of bacteria overgrowing, and you’ll begin to have digestive problem, which then causes anxiety."

Keep in mind that over 90% of serotonin i.e. the happy hormone, is produced in the gut, as well as mood-boosting dopamine so if gut bacteria is thrown off balance, this inextricably affects our mood.

Dr Kam says that it’s also about the whole process, and not just the actual food itself; for example, having a well-presented meal with friends.

“It can first of all, raise your immunity,” she says. “When you’re enjoying yourself more, people have found higher levels of IgA immune cells in the saliva. When you’re eating your meal and it doesn’t look so pretty, you’re not going to have the same kind of enjoyment and feedback."

*IgA (Immunoglobulin A) is a protein that fights infection.


Probiotics may help – to an extent

“Using probiotic is a very simplistic approach, in my opinion, although it can help and I do use it in my healing protocol,” says Dr Kam.

If you're after general probiotics, she recommends looking for one that contains 10-20 billion CFUs (colony forming units). Choose a good quality probiotic that has been proven to have the live organism up until its expiration date.

She adds that it's essential for people suffering from specific gut issues like IBS, small intestinal bowel overgrowth or malabsorption, to work with a functional medicine doctor to plan and strategise a healing plan.

A lot of people have issues that arise from lifetime long problems. “We need to fix the foundation first before we do any kind of probiotic or gut eradication work, and even elimination diets," she says.

"We’re trying to reverse 20, 30 or 40 years of effects on the gut. You can’t expect probiotics to be able to do that."

There isn’t a probiotic for improving mood specifically, either. If someone was aiming to do that, Dr Kam says she would first examine their nutrient intake, then hormones and adaptogens; followed by the nervous system and calming agents, and finally, spend six to 12 month fixing the gut.

“Without the first few steps, the fourth is not going to create results.”


The bottomline: Food first

"For the everyday person, they could take a general formula if they wish, and if they find it works on them, then very nice, they’ve stumbled upon something that works for them," says Dr Kam. "But I believe a lot of this can be done naturally with food products such as kefir, home-made yoghurt, sauerkraut and kimchi."

In addition to fermented foods, she says a diverse diet and getting whole food nutrients, especially fibre, are key.

“There is no point having probiotics and not having fibre for them to thrive on,” she says. “You’d be reliant on the probiotics, which never really get seeded and colonise the way it would, if you fed it a lot of food (fibre) and allowed it to multiply until it gives you the results you need."

Like prebiotics, fibre promotes the growth of the good bacteria present in the lower portion of the digestive tract, which consequently aids in digestive balance.


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