Bacteria in Your Food: Sometimes It's Good

After the peanuts-and-salmonella problem (and tomatoes before that, and spinach before that), you'd think food manufacturers would be taking extraordinary measures to keep bacteria out of food. But a growing number of companies are intentionally, and legally, putting them in. And what they're doing is good for you.

See, certain bacteria are beneficial, especially for your immune and digestive systems, and probably your heart, too (although not the bacteria that enter food from questionable processing conditions).

Probiotics, the good bacteria in foods like some yogurts and cheeses, kefir, and probiotic supplements, may even help reverse certain ills of aging. The idea is hardly new: Back in the 19th century, immunologist Elie Metchnikoff believed that good bacteria were what helped Bulgarian peasants, who drank loads of lactobacillus-rich fermented milk, live so long.

Now, you don't have to be a Bulgarian peasant or drink fermented milk to reap these health-enhancing benefits, since many products now contain various probiotics. And each different type boasts a unique way to boost your health. So while Lactobacillus bulgaricus can make it easier to digest lactose, you may need L. johnsonii to ward off an ulcer.

Here's what they can (and can't) do to help you feel and be younger:

• Promote a healthy digestive system. Your gastrointestinal (GI) tract is one giant immune organ, serving as a defense against viruses, fungi, some bacteria, and foreign invaders (including things kids swallow accidentally, like ear pods). And it's crammed with bacteria, both good and bad. Not to gross you out, but more than 500 species of bugs (10 trillion in toto -- yes, 10 trillion) live in your digestive system right now. Your mission: Make sure the good guys outnumber the bad. Downing bugs such as L. casei, L. bulgaricus, and L. acidophilus helps beef up your immune system by reducing inflammation and stomping out invaders.

• Ease lactose intolerance. Does drinking milk translate to a major case of gas? Try snacking on yogurt with live cultures, such as L. bulgaricus and S. thermophilus. They can help break down lactose, the sugar in milk that's at the root of your discomfort. Just check the label to see that your yogurt contains these.

• Speed up food processing inside you. Some yogurt contains the live bacterium B. animalis DN-173 010. It reduces transit time (how long it takes food to pass through your system) by 21%. Other probiotics, like the spore-forming Bacillus coagulans (found in products such as Digestive Advantage and Sustenex) may do substantially better.

Consider them for:

• Preventing an ulcer. Probiotics in yogurt with live cultures may keep H. pylori, the bacteria behind many ulcers, from sticking to your intestinal walls. People who eat yogurt or take spore probiotics just once a week reduce their chances of having H. pylori in their stomachs by 43%.

• Avoiding a urinary tract infection (UTI). Women with chronic UTIs often harbor lower-than-normal amounts of lactobacillus. That weakens their ability to fight off the bacteria that cause painful urinary tract infections. A handful of studies hint that probiotics may even provide relief.

• Ease antibiotic side effects. Antibiotics can wipe out both the good and the bad bacteria in your gut. Result? Gas, stomach pain, and a nasty case of the runs for nearly 25% of people who take antibiotics. A recent analysis looked at more than 25 studies to see if probiotics could lessen the toll. More than half the studies supported countering antibiotics with probiotics. Again, we like spore-forming Digestive Advantage and Sustenex; their good bacteria survive better than yogurt's in the stomach's harsh acidic environment, so the probiotics are still alive and kicking by the time they get to your intestines.

• Improving IBS (irritable bowel syndrome) symptoms. Got IBS? If you do, you're likely uncomfortable and either running to the bathroom or chronically constipated. Live bifidobacterium, or spore-formers, or even magnesium may help.

Skip probiotics if your immune system is weakened, you are about to have surgery, or you are recovering from surgery. After all, we're still talking bacteria here. If you're sick, you may not want to introduce more bugs into your system.

Bottom line: While much of the research on these beneficial bugs is still emerging, there's no downside to gulping them down if you're basically healthy. But they don't live inside you for long. To get maximum benefits, down them daily. Just check that the strain you need is actually in your yogurt, fermented milk drink, cereal, or supplement.