Your Baby’s Microbiome

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What’s living in your baby’s belly can make a big difference.

All humans have trillions of bacteria living inside our bodies, creating what scientists call a microbiome. We actually have 10 times more bacteria in our bodies than we do cells. Microbiomes affect many different systems in our body, and can have an influence on whether or not you develop autoimmune problems such as diabetes, rheumatoid arthritis or muscular dystrophy. Researchers are also starting to understand how the microbiome affects mood, memory and learning.

The bacteria of our microbiomes are with us from birth, or possibly even before. While it was long-held that healthy babies were born sterile, only exposed to bacteria during birth, recent research has found germ colonies in the amniotic fluid and within a baby's first bowel movement, before a first meal.

Major bacteria colonization happens during birth. However, not all babies develop the same amounts of the same bacteria at consistent times. Babies delivered vaginally are exposed to completely different bacteria than those delivered via cesarean section. During the first year of life, approximately 1,000 different species of bacteria begin to grow.

Building a Better Biome?

Research into the microbiome is ongoing and relatively new in the scientific world, but science is already finding how small differences can make a huge difference in a baby's biome.

A new study published in the journal Microbiome examined one particular bacterium, Bifidobacterium. This species prevents infections by making the gut slightly more acidic, keeping harmful bacteria from growing. The study found that changes on one gene, passed from mother to baby through breastfeeding, can change how much Bifidobacterium is inside a baby's gut and when the bacterium begins to grow.

An earlier study found that probioticsor supplements of good gut bacteriacan actually reduce crying from babies with colic and constipation.

As research in this area continues and we learn what specific microbes are introduced to babies in specific places, we may be able to supplement bacteria and prevent illnesses starting at birth.

When to Stay and When to Go

If you think your infant is ill, its always best to seek medical help. However, if you aren't sure whether or not to go to the urgent care or emergency facility closest to you or wait until your pediatricians office is open, use these guidelines to help.

Does your baby have a fever? Newborns younger than two months should see a doctor if his or her temperature is 100.4 degrees Fahrenheit or higher, as should children older than two months with fevers of 102 degrees. A fever can be a sign of infection.

Is your baby breathing normally? Slow, rapid, irregular or no breathing is cause for concern.

Is your baby crying differently? While all babies cry from time to time, a baby that is inconsolably crying (despite being fed and having a diaper changed) may be sick.

Is your baby alert? Changes in sleeping patterns, difficulty waking a baby or sleeping more than usual can all be signs of trouble.

Is your baby eating normally? Feeding patterns may vary naturally in a newborn, but sudden loss of appetite, sweating or difficulty feeding, or frequent vomiting or bowel movements after eating can indicate a problem.

Schedule doctor visits for your child online at! Day or night, schedule appointments for next day and beyond with pediatricians Alan Brown, M.D., or Bird Gilmartin, M.D., here.

Drs. Brown and Gilmartin are members of the medical staff at Evanston Regional Hospital.