Have you been taking probiotics? Different strains of these live bacteria have been shown to help improve lots of different conditions, prevent antibiotic associated diarrhea, improve digestive function, ease constipation and now…to boost your mood?

An exciting & emerging class of probiotics are called psychobiotics, ‘live organisms that, when ingested in adequate amounts, produce a health benefit in patients suffering from psychiatric illness’.

How could bacteria impact brain function?

How is it possible that a probiotic can influence your brain or mental health?

Introducing: the ‘Vagus Nerve’, otherwise known as the ‘gut-brain highway’ running from the brain down into the digestive tract,. 

Turns out that there are a few other specific mechanisms through which psychobiotics could work their magic:

-Improving Gut Barrier Function (which can help prevent unwelcome peptides and compounds from getting through the intestinal wall into the bloodstream)

-Immune activation and modulation of inflammatory cytokines (inflammatory molecules have become increasingly blamed for depressive symptoms)

-Directly producing GABA, an inhibitory (calming) brain chemical

-Metabolizing tryptophan, the precursor to serotonin and melatonin

Looking at the Evidence

Let’s look at an example of a study where specific probiotic strains helped to improve mood, stress & aggression:

Over four weeks, 20 study participants were provided with 2g of freeze dried powder containing Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, L. Casei W56, Lactobacillus salivarious W24, and Lactococcus lactis (W19 and W58). Those who had received the 4-week probiotic intervention experienced less cognitive reactivity to depression, including less aggression and ruminative thoughts (source).

Pretty amazing, right?

What happens in our gut doesn’t stay in our guts-the gut-brain axis is real!