Nursing is especially good for a baby's "microbiome". But here's how to help good bacteria flourish whether you breastfeed or bottle-feed.

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Mixed race mother nursing newborn baby
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There's a ton of buzz lately about the "microbiome"—the trillions of bacteria living in and on the body—and how it shapes health. These bacteria, especially the bacteria found in the gut, may affect immunity and influence the risk for obesity, allergies, asthma, and certain diseases like type 1 diabetes.

Breast milk has a big impact on a baby's microbiome for the better because it contains beneficial bacteria. But it may also matter how babies are fed. According to research from Children's Hospital Research Institute of Manitoba in Canada, milk directly from the breast may offer better bacteria composition than pumped breast milk.

What could explain the difference? It could be that some of the good bacteria are transferred from the baby's mouth into the breast then back out again during nursing, says researcher Meghan Azad, PhD, an assistant professor of Pediatrics and Child Health at the University of Manitoba. This "bacteria backwash" doesn't happen unless the baby is at the breast. Babies are also exposed to bacteria on the skin of the mother's breast when they're nursing. On the flipside, improperly sterilized pumps could cause bacteria from the pump to displace some of the beneficial bacteria in the breast milk.

But the reality is, pumping is the only way some mothers are able to provide breast milk to their babies. "In many cases, pumping is what allows moms to keep breastfeeding, which is awesome. We do not intend to imply that pumping is bad," says Azad. "Pumped milk still contains many beneficial components for the baby and the microbiome." This includes special carbohydrates in breast milk that act as food for good bacteria in the gut. Azad says future research will hopefully pinpoint ways to express, store, and feed pumped breast milk that don't disrupt the healthy bacteria.

She also adds that this research underscores the importance of breastfeeding and the need for more policies and support for women who want to breastfeed.

If you can't or don't want to breastfeed, there are still ways you can help keep your baby's microbiome healthy:

Provide plenty of skin-to-skin contact. Good bacteria from your skin can transfer to your baby's body when you're snuggling and kissing, and this can positively impact his microbiome.

Avoid overcleaning. Yes, there's an impulse to sanitize everything that comes into contact with your baby, but there are risks for wiping out all bacteria too. Some exposure to bacteria is a good thing.

Don't discount pets. A furry friend in the family may help boost the health of your child's microbiome. Research shows that kids exposed to family pets have lower rates of allergies and even obesity.

Use antibiotics with care. Antibiotics wipe out both bad and good bacteria. Some antibiotic use may be absolutely necessary (and lifesaving!), but trust your child's doctor when she says antibiotics won't help in certain cases, such as with common viruses.

To learn more about your child's gut microbiome, watch this quick video.

Sally Kuzemchak, MS, RD, is a registered dietitian, educator, and mom of two who blogs at Real Mom Nutrition. She is the author of The 101 Healthiest Foods For Kids. She also collaborated with Cooking Light on Dinnertime Survival Guide, a cookbook for busy families. You can follow her on Facebook, Twitter, Pinterest, and Instagram. In her spare time, she loads and unloads the dishwasher. Then she loads it again.