Baby Microbiomes: Christi Investigates

Let’s give a warm welcome to Christine Preston, a post-doc from UC Berkeley who is now part of the uBiome family. She’s here to help us better understand the current state of research on the microbiome. Thanks Christi!

Hello to the uBiome community!ChristiPreston

When Alexandra asked me if I wanted to do a blog post I jumped to say yes. While I am a scientist, I don’t really know much about microbiology, so I figured I could use this space to share some of the cool research I’m learning about.

And trust me; there is LOTS of amazing knowledge out there about our microbiomes!

Earlier this week I realized I didn’t know much about the beginnings of the human microbiome, so in the spirit of fresh starts I decided to start there. It didn’t surprise me to learn that infants and adults have different microbiomes, however HOW babies get their microbiome, and how infant microbiomes changes during the first few years of life is fascinating. I’ve linked to some articles below that I found especially exciting.

The first thing I learned is that newborn infants probably do not have much of a microbiome before they are born. In fact, a baby’s microbiome is ‘seeded’ by their mother during birth, and researchers can actually tell the difference between babies that are born vaginally and babies that are born by a caesarian section based on their microbiome (1)!

Babies that are born vaginally have microbiomes comparable to their mother’s vagina, with high levels of Lactobacillus and Prevotella bacteria. Babies born by C-section have microbiomes with high levels of the bacteria that hang out on their mother’s skin; specifically Staphylococcus, Corynebacterium and Propionibacterium bacteria. Other groups have looked at whether birth method has a long term-effect on the bacteria in the microbiome of the infants, and find differences in the microbiomes of babies born by C-section versus vaginal births for months (2) or possibly years (3) after birth.

Another major area of research is how the infant microbiome changes as babies grow. There is TONS of research on this, however one study I found especially intriguing was a report that looked at how bacteria species in the gut of a single baby changed over the first 2½ years of his life (4).

This group found that as the baby aged, the bacterial diversity in his gut increased — diversity being generally a good thing in the gut. They also found that some major life changes for the baby affected the bacteria species in his gut, with big changes in bacteria species occurring when the baby was sick, started on solid food, and given antibiotics.

Shortly after the baby was started on solid foods like peas, his gut levels of Bacteroidetes increased. Bacteroidetes are involved in breaking down plant food. The researchers also estimated that a baby’s gut microbiome starts to look like that of an adult around 3 years old.

Stay tuned for more microbiome investigations as I dig and learn more. See you soon!