Why should I add probiotics to my diet?

Probiotics are live microorganisms that benefit the host in which they live. They can aid in digestion, and normalize the intestinal flora.  There are currently many studies being done to look at the use of probiotics in preventing the symptoms for IBS (Irritable Bowel Syndrome), IBD (Inflammatory Bowel Disease) as well as some other chronic diseases.  The most common probiotic is the lactobacillus strain and it is found in raw milk (unpasteurized), most yogurts, as a dietary supplement, or in Kombuchas (fermented teas.)

A Little History....
Just for a little background, in the beginning of the 20th century, it was presumed that the bacteria that is in our guts (totally normal and appropriate) can cause toxins when we breakdown certain foods, like proteins (they are called proteolytic bacteria).  This process, diet and body depending, can build up a lot of toxins in the gut an cause various stomach discomforts like bloating, gas, diarrhea, constipation, etc. So, a Russian scientist at the Pasteur Institute in Paris, who had noticed a link between long life span (completely observational in his hometown in rural Russia)and drinking fermented milk (AKA sour milk), started drinking it himself, and found that he felt much healthier.  After that, he started to test it on friends and patients, and it became a widely followed trend in Europe and MD's even prescribed it to patients as a treatment for stomach ailments.  They found that the lactic-acid bacteria helped to change the pH in the intestine and prevented the proteolytic bacteria from having damaging effects.  In 1989 Roy Fuller defined probiotics as "A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance." And thus, the modern studies of probiotics on health really began!

Why are they so good for me?
All of the modern research on probiotics is very new and hasn't had the full battery of testing including randomized control trials (the gold standard in research!) Lactobacillus has been shown to prevent antibiotic associated diarrhea and is being studied for its usefulness in other diseases.
Lactose Intolerance: The strain of bacteria turns lactose into lactic acid, so you are able to tolerate more lactose than you would have.  For example, eat some yogurt before eating ice cream (or pizza with cheese) and you won't get the normal response that you usually get. It is being tested to see how many different strains of bacteria aid in this process.
Lowering Cholesterol: In animal studies the addition of probiotics has shown to increase the breakdown of bile (which is stored in the gallbladder and released into the stomach when you ingest food) in the stomach before it gets reabsorbed; when bile is re-absorbed it is in the form of cholesterol. It needs MUCH more human testing.
Lowering Blood Pressure: A few small studies have shown that fermented milk with certain strains of probiotics can break down and create these peptides, which are similar to proteins in chemical nature but smaller, and they can have similar effects to certain blood pressure lowering medications (specifically ACE inhibitors). It needs larger studies to be performed.
Strengthening immune system and prevent Infection: Some studies have been performed and it has shown that they can reduce respiratory infections, by increasing the number of "killer" cells that attack pathogens (viruses and bacteria that we are exposed to) and can decrease cavities in children.  As well, induction of probiotics in your diet has been studied as far as decreasing the severity of rotavirus and shortening symptoms, along with preventing altogether. (rotavirus is a highly contagious virus that causes usually stomach issues like diarrhea along with fevers and it is very common among children.)
AND, probiotic use is still being studied (very promising) in the areas of: colon cancer prevention, IBS, IBD, eczema, reducing inflammation (generalized in the body), improving absorption, in relief of UTI and bacterial vaginosis, and the decrease of ulcers during stress.

Any side effects?
You are introducing live bacteria to your system, so immunocompromised people (due to illness or medications taken) should probably not add probiotics to your diet.  As well, you need to be very careful with the very young and the elderly; babies immune systems are not fully developed, and I am generalizing when I say "elderly", but for the most part, older adults have other chronic medical issues which puts their immune system under strain and they are considered immunocompromised.  Also, as I've stated a billion times, full side effects aren't known because more studies are needed to find out the short and long term effects of probiotic use.  One study did show that children under six months of age that were given doses of various probiotics had much higher rates of food allergies/sensitivities!

Best Sources of probiotics:
Yogurts, pickles (naturally fermented- not with vinegar), miso, kimchi (pickled cabbage), Kefir (fermented milk), buttermilk, raw milk, raw or aged cheeses, kombuchas, and probiotic supplements that can be added to a smoothie, for example, or other foods.
Oral Supplements:
A few of them are align, culturelle, phillips, jarrow, and nature made brands.  You can find them at basically any pharmacy, grocery store, or health food/vitamin store.

Personally, I am a huge believer in probiotics even though some of the data is weak.  I eat only raw dairy products and try to eat foods that are high in probiotics whenever I can.  I did used to take supplements, but I don't think they are absorbed as well, and you need to ingest them regularly to see their effects, and I am HORRIBLE with taking supplements; I always forget, which is why I just eat a healthy diet!  So the choice is up to you, and if you do have medical issues I would discuss with your HCP if probiotics are right for you.  If you are healthy, the choice is yours if you want to wait for more studies to come out or not!

Yours in Good Health
B