The Dirt on Bacteria

Good "bugs" make for a healthier pregnancy.


Most of the bacteria we encounter do no harm. Many do quite a bit of good. But moms-to-be are often certain that all bacteria are out to get them, thanks to a few bad players like Listeria monocytogenes, sometimes found in unpasteurized soft cheeses, and Salmonella, a potential hazard when meat and eggs are undercooked.

In fact, pregnancy is an excellent time to rethink your attitude toward the more benign microscopic critters who live in, on and around us, says pediatrician Alan Greene, M.D., author of Raising Baby Green: The Earth-Friendly Guide to Pregnancy, Childbirth and Baby Care (Jossey- Bass). "Bacteria help with digestion," he explains. "They help your immune system. They prevent allergies. It's primarily a good relationship."

Scientists researching the role of probiotics—"good" bacteria found in yogurt, kefir and fermented foods like sauerkraut—are discovering that these merry microbes can be particularly healthy for expectant mothers. A Finnish study found that those who took probiotic supplements had lower rates of gestational diabetes, while British researchers found that babies born to women who drank probiotic- fortified milk during pregnancy had half the incidence of eczema as those whose moms drank regular milk.

A New Take on Bacteria

Fine, you may say, eating certain bacteria-rich foods can be good for you. But what about bacteria in the environment—the stuff that makes dirt dirty? Here too, they get a bad rap. German scientists showed that prenatal exposure to environmental microbes may make offspring more resistant to allergies. Their study was done on pregnant mice, but it's additional evidence of what's known as the hygiene hypothesis, a theory that suggests increases in allergies, asthma and autoimmune disease are linked to the modern world's overly clean lifestyle. Research in rural Germany, Switzerland and Austria found that women who worked with farm animals during pregnancy bore children who later had a lower incidence of asthma and hay fever, and that babies who visited stables frequently in their first year developed much less hay fever.

Farm visitors get another advantage: exposure to Mycobacterium vaccae, a soil bacterium with surprising effects on brainpower and mood, at least in lab animals. Scientists at The Sage Colleges in Troy, N.Y., found that mice exposed to M. vaccae navigated a maze in half the time it took other mice, and showed fewer signs of anxiety and stress.

Meanwhile, our all-encompassing prejudice against bacteria subjects us to some potentially dangerous chemicals. A University of Florida study indicates that triclosan, an anti-bacterial chemical found in everything from hand soap to anti-plaque toothpaste, may interfere with an enzyme that's crucial to pregnancy. The enzyme helps metabolize estrogen and move it through the placenta, where it plays a key role in fetal brain development.

Triclocarban, another common anti-bacterial chemical, seems to have endocrine-disrupting properties. Stay safer by avoiding items labeled "anti-bacterial" or "anti-microbial," including personal-care products, cutting boards, towels, shoes, clothing, bedding and highchair trays.

Fortunately, you needn't use anti-bacterial soaps and cleansers to eradicate germs that could make you sick (many are viruses and thus unaffected by anti-bacterial products anyway). Multiple studies have found no significant difference in the bacteria-killing properties of regular and anti-bacterial soaps. For household cleaning, use diluted white vinegar or lemon juice to kill any nasties. "There are so many things that good bacteria can do for pregnant women," Greene says. "We want to be out there supporting them, not fighting them."