The emerging new connection between the gut microbiome and the brain.

By Nathan Jeffery, ND, BSc.

It is now well accepted that certain good bacteria can be extremely useful for digestive problems like irritable bowel syndrome (IBS) or to recover after antibiotics. We also know that healthy gut bacteria can provide us with important micronutrients like vitamin K. Recently there has been some interesting research indicating that the good bacteria in our gut can benefit our mind. In the clinical setting people regularly report that when they take probiotics or recover from digestive problems they feel more mentally alert and clear.

There are many ways good bacteria could influence our mind. A dysfunctional gut lining can produce inflammation which could contribute to fatigue and low mood. It is well known that micro-nutrients like B12, other B vitamins and folate also influence our mind. A healthy gut is critical for the absorption of these nutrients. Altering the gut microbiome is a critical step to repairing a dysfunctional gut lining. Bacteria also produce chemical messengers that may be absorbed into our body. They may produce GABA, serotonin or peptide based chemical messengers. It is thought that these chemical messengers may stimulate particular regions of the brain through the vagus nerve. Some researchers had found that those who took probiotics, showed changes in blood flow to regions of the brain involving emotion and sensation.

The health applications of probiotics may also be species specific. Bifidobacterium longum NCC3001 species was recently found to decrease depression scores and limbic system activity in those with IBS.

The therapeutic applications for probiotics are continuing to expand. We expect to see new information on the roles of probiotics in our bodies and applications for health purposes in the very near future. As the research unfolds, we will keep updated and share this fascinating information.


Consumption of Fermented Milk Product With Probiotic Modulates Brain Activity. Tillisch, Kirsten et al. Gastroenterology , Volume 144 , Issue 7 , 1394 - 1401.e4

Probiotic Bifidobacterium longum NCC3001 Reduces Depression Scores and Alters Brain Activity: a Pilot Study in Patients With Irritable Bowel Syndrome. Pinto-Sanchez, Maria Ines et al. Gastroenterology , Volume 0 , Issue 0,