Evidence is growing that Greek yoghurt doesn’t only make us fat, but also happy.
Gut and brain team up
For several years researchers have had strong evidence for a close functional connection between gut and brain function. They called it the gut-brain-axis. The gut or more precisely the bacterial flora in the gut communicates with the brain on a biochemical level. Thus, a healthy gut can support mental wellbeing. In the same way our emotional state is capable of influencing gut function. If something disturbs this bi-directional communication, it can result in physical and mental impairment. One example is the increased release of the stress hormone cortisol. Cortisol is produced by the adrenal gland and increases the permeability of the gut for certain pathogenic bacteria. This is known as the ‘leaky gut’ response. As patients with depression often show higher stress hormone levels, their gut allows entry to harmful bacteria that can impact digestion. In previous studies researchers tested the effects of probiotics on mice. The mice didn’t only have lower cortisol but also higher serotonin levels. Serotonin is a neurotransmitter sending positive impulses to the brain. The gut flora boosted by the intake of probiotics increases the production of a precursor of serotonin. Although the researchers haven’t found evidence of this effect in humans yet, it appears that brain and gut work hand in hand towards the wellbeing of the entire organism.
Yoghurt versus tablets
Another very handy advantage of probiotics compared to standard antidepressants is its lack of side effects. However, many questions around probiotics remain. For instance, the researchers are still unsure about the most efficient way to deliver probiotics. Although cheese, yoghurt and milk contain lactobacilli, these can be damaged during heating processes applied to the product. Probiotics are commercially available as tablets, capsules and powders that also undergo a destructive heating process. As a result, researchers recommend freeze-dried formulations as the most promising option as only freeze-drying doesn’t harm the bacteria.
All about fat?
The Singaporean researchers who conducted the review study uncovered an interesting effect between low and high fat yoghurt in one of the publications Low fat yoghurt seemed to worsen the mental health state of the patients, while high fat version appeared to lift patients’ moods. Thus, the scientists pointed out that more research is needed to answer questions around the beneficial bacteria in the higher fat yoghurt.
Source: