We use these milk samples for clinical and research purposes. They can help us understand evolutionary trends in mammals, because the nutritional composition of milk can be similar among animals that are related. For example, we’ve learned that animals in the superorder Xenarthra — sloths, armadillos and anteaters — all have high protein milks. We can also analyze a milk sample and create a similar formula to feed a baby animal. Cincinnati Zoo’s baby hippo Fiona is perhaps the most famous recipient of a formula that we helped create.
It’s great to be able to provide supplemental milk when an animal mom can’t, but there’s still so much more to learn about what’s in milk and why. In fact, we’re working with the Zoo’s genetics lab to learn about the microbiomes found in milks.
A microbiome is a community of bacteria that exists in a specific area. Remember, not all bacteria is bad. For example, humans have a gut microbiome which is very important for our digestive health. To determine which microbes are present in a sample of milk, we use DNA sequencing.
DNA sequencing is the process of identifying the sequence of nucleotide bases in a piece of DNA. Think of these as the chemical building blocks that make up a piece of DNA (the order of those building blocks is a sequence). Once we’ve sequenced DNA from a milk sample, we can use a series of data analyses and reference databases to interpret those strings of nucleotides and match them with a microbial taxon (or group).
For a long time, scientists didn’t have the resources to efficiently and accurately analyze the world of microbial communities. DNA sequencing was a long and tedious process, because technology only allowed scientists to read one section of DNA at a time. Now, geneticists can sequence an entire genome (an organism’s complete set of DNA) all at once. This easier and remarkably faster method of sequencing DNA makes studying milk microbiomes much more achievable.