Fermented Milk: For the Gut and the Brain

Andrea Fabry

Andrea Fabry › Andrea is a former journalist, a radio host, and the mother of nine children. She is ...


Consuming fermented milk products such as kefir and yogurt not only helps digestion, it also impacts our brain function.

A University of Southern California study has found that women who consume fermented milk with probiotics show marked changes in their brain activity.

Researchers at UCLA’s David Geffen School of Medicine divided 36 healthy women into three groups. One group was given the fermented milk product with probiotic (FMPP) twice daily for four weeks. Another group was given a non-fermented milk product, and the third group was given nothing. The study included MRI testing before and after the four-week period.

The study’s conclusion?

Four weeks’ intake of a FMPP by healthy women affected activity of brain regions that control central processing of emotion and sensation.

While further study is needed to show a definitive connection between fermented milk and elevated mood, the study validates the vital connection between the gut and the brain.

Sour milk products have been used for centuries to improve vitality and health. Hippocrates, the father of medicine, used liquid whey—or serum, as he called it—to strengthen immune resistance.

Kefir, a fermented milk product derived from globules of bacteria and yeast known as “grains,” has a long history in Eastern Europe, Russia, and the Middle East. The word “kefir” is derived from the Turkish word “keif,” which means “good feeling.” An apt description for what fermented milk does for your entire body.

In the early 20th century, Nobel Prize recipient Eli Metchnikoff suggested that yogurt contributed to the longevity of Bulgarians, noting their average lifespan of 87 years. His “theory of longevity by yogurt” hypothesized that the consumption of live lactic acid bacteria in yogurt suppressed the multiplication of putrefactive bacteria in the large intestine.

The dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in our bodies and to replace the harmful microbes by useful microbes.

(Metchnikoff, 1907)

Why not consider adding some useful microbes to your diet? Be sure to look for the term “live cultures” when purchasing. The yellowish liquid on the top of the yogurt is the liquid whey. You might even try your hand at making your own fermented milk products. Yogurt strains like Viili and Matsoni are cultured at room temperature, eliminating the need for a yogurt maker. Cultures for Health offers an abundance of yogurt starters.

Homemade kefir contains a wide variety of strains, including the four strains of probiotic used in the UCLA study (Bifidobacterium animalis, Streptococcus thermophiles, Lactobacillus bulgaricus, and Lactococcus lactis). Once you have your starter grains, also available at Cultures for Health, you can culture your milk for years to come.

For step-by-step directions, see HandPicked Nation’s article “How to Make Kefir.”