Anti-depressants are now the most widely-used prescription drug in many countries Photo: AFP/File

Gut feeling: Study links depression to digestive bacteria

By Patrick GALEY

Bacteria in the gut may affect our mental well-being and could be linked to depression, researchers said, after conducting the largest study of its kind so far.

The World Health Organization says an estimated 300 million people suffer from depression, and there are known links between a patient's physical and mental health.

Scientists in Belgium now believe that a wide range of gut bacteria can produce chemicals that significantly impact the brain, including several microorganisms linked -- positively or negatively -- to mental health.

The experiment, known as the Flemish Gut Flora Project, examined depression data and stool samples from more than 1,000 people and found that two types of bacteria were "consistently depleted" in those who suffered from depression. This held true even if patients were on anti-depressants.

Scientists' understanding of how the gut and brain are linked is in its early stages, and the researchers acknowledged that their findings, published in the journal Nature Microbiology, could be considered controversial.

"The notion that microbial metabolites can interact with our brain -- and thus behavior and feelings -- is intriguing," said lead researcher Jeroen Raes, from the department of Microbiology and Immunology at KU Leuven University.

"Until now, most of the studies were or in mice or in small-scale human studies, with mixed and contradictory results," he told AFP.

The team repeated the study on 1,063 people from the Netherlands and a third group of clinically depressed patients in Belgium, and got similar results.

Raes stressed, however, that while the experiment showed a clear link between the levels of certain bacteria in the gut and an individual's mental well-being, that didn't mean that one thing directly caused the other.

The two microbe groups, coprococcus and dialister, are know to have anti-inflammatory properties.

"We also know that neuro-inflammation is important in depression. So, our hypothesis is that somehow these two are linked," said Raes.

Depression -- a treatable but debilitating condition that affects how an individual behaves and feels -- is sometimes referred to as a "silent epidemic", and is a major driver of the some 800,000 suicides that occur each year worldwide.

Anti-depressants are now the most common prescribed drug in many countries and Raes said his team's research could pave the way for new, smarter treatments for the illness.

"I really think there is a future in this: using cocktails of human-derived bacteria as treatment –- bugs as drugs, as they say," he said.

The team behind the research studied the genomes of more than 500 types of gut bacteria and analyzed their ability to produce a set of neuroactive compounds -- chemicals shown to affect brain function.

They found several that could produce compounds linked to a variety of mental processes.

Raes said recent technological and medical advances had allowed researchers to zero in on the gut when looking into possible causes of mental health issues.

"The field went for the obvious diseases first -– obesity, diabetes, colon cancer, irritable bowl syndrome," he said.

"But then evidence started coming in from animal studies," he added. "The last few years, the gut-brain axis field really exploded. It's really, really exciting at the moment."

© 2019 AFP

©2019 GPlusMedia Inc.

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I got a gut feeling that these pills are a scam.

1 ( +1 / -0 )

Theres a lot of truth to this. Most people don’t realise that most of their immune system is in their gut.

2 ( +2 / -0 )

I have recently wondered if diet sodas with the artificial sweeteners have some effect on gut bacteria that could be linked to the extraordinary obesity in the US. I avoid the stuff...

3 ( +3 / -0 )

The gut is supposed to be like a second brain and is connected to the brain via the vagus nerve, which is sort of like a superhighway between the body and brain. If there is an imbalance in the gut with 'bad' bacteria and fungi like candida crowding out the beneficial bacteria then you start to have health issues. Depression is only one of these problems.

Candida overgrowth in the gut, for example, can cause what's known as leaky gut, which leads to allergies, foggy thinking, chronic athletes foot and on and on as the blood becomes contaminated with toxins from the fungi.

To cut a long story short it can be treated thru diet, stress management, probiotics, exercise and natural supplements etc. Detoxing and having amalgams replaced with non-metal fillings will also go a long way to getting the gut bacteria back into balance.

There's an easy (but rough) test to check whether a person has candida; do a search on "candida, spit test".

Anyway I'm not a doctor and only know about this stuff because I've been dealing with a gut problem for the last 20 years or so - now mostly cleared up and manageable. The doctors I originally went to had no idea what was causing my symptoms and the solution was to prescribe ointment, steroids or some pill which were mostly worthless and possibly even contributed to the problem.

I have recently wondered if diet sodas with the artificial sweeteners have some effect on gut bacteria

Spot on. Same goes for a diet high in carbs as well.

2 ( +2 / -0 )

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