What goes on in your gut is a miracle of interdependence and biochemical magic, as the trillions of microbes in your gastrointestinal system work together (in the best of situations) to digest your food and thereby help regulate the health of your immune system, the metabolism of glucose and nutrients, and the functioning of all your organ systems, including your brain.

A recent lab study published in the journal Brain Behavior and Immunity shows how gut-dwelling Lactobacilli, found in probiotics as well as in fermented dairy products like yogurt and kefir, may help protect you from depression and anxiety, and increase your happiness.

The bacteria seem to upgrade your immune system so that you avoid intestinal inflammation and disruption of neurotransmitters that influence your mood.

The researchers also found that when you're chronically stressed, Lactobacilli in the gut declines, increasing your vulnerability to emotional distress.

This reinforces previous findings in clinical trials and animal research that identified Lactobacillus as a psychobiotic (one that affects your psychology). And a study in Frontiers in Behavioral Neuroscience found that taking probiotic supplements along with SSRIs for depression was superior to taking the antidepressant alone.  

If you're stressed, or feeling blue or anxious, consider taking a lactobacillus and bifidobacterial probiotic daily (ask your doctor first).

You can also enjoy a low-fat yogurt smoothie or a salad with a lemon kefir dressing. Combine them with prebiotic foods that nurture the lactobacilli: asparagus, onions, garlic, soybeans, Jerusalem artichokes, and whole grains.