Tag Archives: genes

Why does yogurt aid digestion?


I’ve always wondered why probiotic yogurt was good for you. Yes, it aids digestions, as many clinical studies have shown, but exactly why has never been explained to my satisfaction. Until recently, that is.

According to a story reported in The Scientist last fall, “The bacteria found in some fermented dairy products, such as yogurt, may alter gene expression in human gut microbes…”

Probiotic yogurtOne of the results of the study that surprised me was that eating yogurt did not significantly alter the existing population of your gut microbes. Food microbiologist, David Mills, is quoted saying, “To assume that you could eat a yogurt and numerically challenge what’s in your gut is kind of like dumping a gallon of Kool-Aid in your swimming pool and expecting it to change color.” As someone who swears by the benefits of eating yogurt, especially when on vacation in foreign countries like Mexico, I have always assumed gut populations needed rebuilding when foreign food and water challenged and reduced it. Perhaps not, it seems now. I still believe that one of the reasons we never get sick in Mexico is because we eat yogurt daily. But why?

…probiotic bacteria changed the expression of gut microbe genes encoding key metabolic enzymes, such as those involved in the catabolism of sugars called xylooligosaccharides, which are found in many fruits and vegetables. …[probiotic] organisms are capable of altering the metabolic properties of a human microbial community…

Seems like some recombinant DNA action happening here. Pretty fascinating stuff. A story from Live Science includes this:

Studies have shown that probiotics, such as those found in yogurt, can help with certain intestinal issues, such as irritable bowel syndrome. Recent research suggests that ingesting probiotics may even affect our behavior and could someday treat depression.

Affect behaviour? That’s food for thought… imagine instead of buying yogurt for its flavour, you’d buy it for its mood-altering effects. Replace strawberry and peach with happy and optimistic?