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Book Excerpt: 'Looking Out for Number Two' (Harper Wave, 2017)

Dr. Bryan Vartabedian's new book outlines "the ins and outs" of infant digestion. (Image credit: Book cover courtesy of Harper Wave, an imprint of HarperCollins Publishers)

In "Looking Out for Number Two," pediatric gastroenterologist Dr. Bryan Vartabedian offers a reassuring (and humorous) perspective on the mysterious effluvia that infants produce. Vartabedian describes "the ins and outs" of infant digestion in exhaustive detail, describing the range of by-products that emerge from both ends of a baby. He addresses long-standing myths about digestive health and poop, and introduces the latest scientific discoveries that are informing how researchers understand the role played by bacteria in a baby's gut health. Below is an excerpt of "Looking Out for Number Two: A Slightly Irreverent Guide to Poo, Gas, and Other Things That Come Out of Your Baby" (Harper Wave, 2017). 

After a baby’s milk disappears, we don’t give it much thought until it reappears on the other end. While your baby may seem like something of a black box, what happens between when milk goes in and when it comes out is huge. The transformation of milk into poo is the result of a perfectly tuned system of nutrient and fluid extraction. A lot more is going on in there than you think.

Here are some things to keep in mind about the magic of your baby’s intestinal tract:

1. It’s the ultimate source of nutrition. That is . . . after the placenta. Before birth the placenta gives your baby all the nutrients she needs. After delivery, the gut takes center stage to replace what your placenta was doing.

2. It’s part of the immune system. The gut plays a key role in the development of a healthy immune system. In fact, most of a baby’s immune cells are in her intestines.

3. It’s a hormone factory. It may sound surprising, but the process of digestion is under heavy hormonal control. Depending on what your baby eats, the tummy hormones released will vary. Gut hormones shape things like hunger, fullness, and how hard the gallbladder squeezes.

4. It holds on to fluids and minerals. The intestines are key to holding on to liquid to meet a baby’s basic fluid needs.

5. It’s home to the microbiome. As we’ll learn, the bugs found within the intestinal tract play a key role in helping a baby adapt to a world full of foreign things.

6. It has its own brain. There may be some truth to the accusation of having your brains in your arse. The intestines are home to a vast network of nerves rivaling those found in even the spinal cord. This enteric brain, as it’s called, is critical to digestion and the elimination of the stuff we don’t need.

7. It’s a work in progress. Your baby’s gut goes through several months of growth and development as it adjusts to the new outside world and all its nutrients. 

Want more? Read our Q&A with "Looking Out for Number Two" author, Dr. Bryan Vartabedian.

Original article on Live Science.

Mindy Weisberger
Mindy Weisberger

Mindy Weisberger is a Live Science senior writer covering a general beat that includes climate change, paleontology, weird animal behavior, and space. Mindy holds an M.F.A. in Film from Columbia University; prior to Live Science she produced, wrote and directed media for the American Museum of Natural History in New York City. Her videos about dinosaurs, astrophysics, biodiversity and evolution appear in museums and science centers worldwide, earning awards such as the CINE Golden Eagle and the Communicator Award of Excellence. Her writing has also appeared in Scientific American, The Washington Post and How It Works Magazine.