Research suggests that microbiota in our gut could have the power to influence more than just our physical health….
Anyone who has seen a yogurt ad has probably got this: probiotics – the good bacteria in yogurt – are good for our gut health and immune system. But what you probably haven’t heard much about is how these bacteria could also affect our minds.
Earlier studies have shown how the brain can send signals to our gut. If we are stressed, anxious or depressed, it often translates to how our gastrointestinal tract behaves. But recent studies have been looking into whether the signals can also travel the other way
Prebiotics: Food for thought?
A recent study, published in Psychopharmacology, investigated whether prebiotics, AKA a special ‘food’ for the good bacteria already in our gut, can affect our mood. They looked at anxiety in particular, which is closely related to the stress hormone cortisol.
According to their findings, feeding the microbiota in our digestive tract does appear to have a positive effect on our mood.
Psychologists have long heralded that our mental well-being strongly affects our physical health- for instance, when stress and other emotions cause a myriad of digestive issues.
However, the thought that the bacteria in our gut can have an effect on our mind has become a very interesting question in the field.
Probiotics: Researchers weigh in
Dr. Emeran Mayer, a gastroenterologist and neuroscientist at the University of California, Los Angeles (UCLA) and Dr. Kirsten Tillisch, an associate professor of medicine at UCLA’s David Geffen School of Medicine, set out to clarify the effects of probiotics on mood.
Their study, involving healthy women, found that those who regularly ate yogurt containing beneficial bacteria found in probiotics, altered brain function.
“I’m always by profession a skeptic,” says Dr. Emeran Mayer says, appreciating that the idea is not going to be a pill easily swallowed by everyone. “But I do believe that our gut microbes affect what goes on in our brains.”
After feeding the women yogurt containing probiotics, the researchers scanned their brains using an MRI. The researchers found that the parts of the brain involved in anxiety weren’t so active after the probiotics. They also found more activity in parts of the brain related to cognition i.e. learning and experiences.
Another gut feeling
Another study in the Netherlands found that probiotics could help to overcome sad moods or even prevent depression. The triple blind placebo-controlled and randomized pre-and post- assessment trial revealed that after four weeks of taking a multi-species probiotic, participants had a significant reduction in their overall reactivity or negativity to sad thoughts. Pointedly, the group taking probiotics experienced reduced obsessive and aggressive thoughts when they were put into a sad mood.
The authors were not able to determine how probiotics helped overcome sadness, but according to Time, theorized that the bacteria in the gut helped to reduce intestinal inflammation or raised Tryptophan, an amino acid associated with Serotonin-the “feel good” neurotransmitter of the brain responsible for stable moods.
Body and mind: A two- way street
So it seems as though it’s not only our minds that can stress our gut – the gut seems to stress us right back.
“Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut,” Kirsten Tillisch says. “Our study shows that the gut-brain connection is a two-way street.”
To the eye ‘you are what you eat’ has taken on a whole new meaning.