The 1975 movie "Muhammad Ali: Skill, Brains, and Guts" sums up the artful relationship that exists between the mind and the digestive system — and how, when they're working together, you're likely looking at a champion performance, whether you're the greatest boxer of all time or an ordinary Joe or Jane just trying to stay healthy.

The brain-gut connection is a north-south expressway that links emotions like anxiety and stress to stomach and gut problems and can turn digestive woes into emotional turmoil.

That’s because your gut contains the enteric nervous system (ENS), which is made up of two thin layers of more than 100 million nerve cells that line your gastrointestinal tract.

While the ENS cannot design a spaceship like your brain-based central nervous system (CNS) can, disruption in the gut does send signals to your CNS that trigger emotional and cognitive changes.

That's why a study in the journal BMJ Nutrition, Prevention & Health on the effect of probiotics on depression is so interesting.

Researchers published a review of 12 studies and found that eating probiotic-nurturing prebiotics (fermented foods like sauerkraut and vegetables like artichokes) and taking a probiotic improves symptoms of depression — maybe by reducing inflammation that alters brain function.

Probiotics alone and in combination with prebiotics were effective; prebiotics by themselves weren't helpful.

So whether you're feeling blue or your guts are in turmoil, give prebiotics and probiotics a try. We favor probiotics that make it through your stomach acid, such as Digestive Advantage, Trubiotics, and Culturelle.