Do we need to take probiotic supplements?

Q.  I've been reading a fair amount about probiotics. What are your opinion of them? Should people be taking them to stay healthy or does a good, healthy diet keep all the good bacteria in our gut anyway?

A.  The healthy, human gut contains millions of beneficial bacteria.  it's a symbiotic relationship: Our intestines make a good habitat for the bacteria, and in return they help us digest our food, crowd out harmful bacteria (such as food-borne pathogens), strengthen the gut's immune response, and even manufacture certain nutrients, such as vitamins B12 and K.   Antibiotics, chronic illness, or a diet high in sugar or processed foods can disrupt the natural flora of the intestinal tract and create health problems such as indigestion, constipation, yeast overgrowth, and lowered immune function.

The traditional source for beneficial bacteria are fermented foods, which are made by culturing fresh foods like milk or vegetables with live bacteria (usually a lactobacillus). Almost every food culture features some sort of fermented food, such as miso, yogurt, kefir, fresh cheese, sauerkraut, kim-chee, etc. Traditionally, these foods would be eaten daily, in part, to keep the gut well-stocked with beneficial bacteria. (For a while, sauerkraut was even being bandied about as a treatment for bird flu!)

In today's pasteurized world, live cultures are a bit harder to come by.  (Pasteurization kills both good and bad bacteria.) In our commercial food supply, yogurt is probably the primary source of probiotic bacteria, providing that the label specifies that the product contains "live" cultures or organisms.    Homemade yogurt, cheese, and traditionally prepared sauerkraut and kim-chee are others. (Most commercial sauerkraut is fermented and then pasteurized, which kills the bacteria.)

In my opinion, healthy people who regularly eat yogurt or other cultured foods don't need to take a regular probiotic supplement.  Personally, I will take a probiotic supplement following a course of antibiotics (to recolonize my quasi-sterilized digestive tract) or as a precautionary measure if traveling to regions where dysentary is a risk.  People with digestive disorders such as colitis, IBS, Crohn's disease, food allergies, chronic constipation, or ulcers, might also benefit from probiotic therapy. 

If you do decide to take a probiotic supplement, this is not a time to bargain shop. These living organisms are very sensitive to temperature, light, and pH.  If not properly handled, probiotic supplements may contain few active organisms by the time they reach the shelf. Be sure to check the expiration date on the package.   

One particular bacterial strain, called lactobacillus GG (or LGG) has a wealth of clinical research documenting its stability and potency in supplement form and its effectiveness in a variety of digestive disorders. You can buy it under the tradename "Culturelle." Recently, Dannon started adding LGG to several new yogurt products that are being marketed as "functional foods," or foods that have medicinal benefit. 

If you're a do-it-yourself-er and are interested in making your own fermented foods, this website is a good starting place: Fermentation is Fun.