Science Buddies: "Ask an Expert"

Hello!
I'm doing a science project, and wanted to test the effect of coconut oil (specifically MCTs) on metabolism.
I was originally planning on using daphnia as test subjects, but I'm worried that the antibiotic properties of the coconut oil would kill the daphnia before I get any results. I was hoping that planaria would be a better organism to use, but I can't find any information about how antibiotics or coconut oil would affect the planaria other than a few websites about using prescription drugs to kill off aquarium infestations.
I'm hoping it won't be an issue because I still have to figure out how to mix the coconut oil into their food...

Hi Siya,
This is a very interesting question! Don't worry, we will help you figure things out. But first - could you please elaborate a bit more what you mean by metabolism? What exactly do you plan to measure and how would you do that (what test will you use or what instrument would you need)? Even if your ideas are very preliminary, please share whatever you have in mind so we can brainstorm this together!
Best wishes,
MS

Thank you for your response!
I want to test the effect of MCTs (medium chain trigylcerides) on Metabolic Rate. Last year in my science class, I did a lab measuring CO2 emissions of yeast using a probe, and I thought I could use a similar set up and measure metabolism with CO2 emissons.
I'm planning on using planaria and giving them coconut oil, which contains MCTs. My only worry so far is that coconut oil has antibiotic properties, and I don't want to kill my planaria before the experiment ends.

Hi Siya,

Thanks for sharing the details. In my opinion, the reports about the antimicrobial effects of coconut oil are a bit controversial. If you search carefully, you will find reports that debunk this idea. Let's say even if the antimicrobial claim is true, the studies typically show only one or two specific types of bacteria for example, the bacteria that causes acne. So it hasn't really been established that coconut oil had broad spectrum antimicrobial activities.

Also, even if it really kills bacteria, you are planning to use planaria which are actually flatworms from the animal kingdom. I would expect they would be safe from antibacterial compounds. However, it is important to consider that coconut oil is a complex mixture of fats and lipids and planaria do not consume coconut oil in their normal environment. Therefore it is possible that coconut oil could be toxic (at least to some degree) to your experimental animals. The ideal thing to do is to try a range of different concentrations and figure out what concentrations do not kill them. So you can feed them only those non-toxic concentrations to perform your metabolic rate measurements, and then compare them against control animals which have not been exposed to coconut oil.

Optional: It may also be valuable to repeat the experiment in some other experimental animal than just planaria alone. It is important to rule out the fact that any effect you see (in metabolic rate change due to a MCT diet) is specific to the planaria and how they metabolize MCTS. If the phenomenon is a general effect of MCT consumption, then it should also be observable in other species. Are any other animal models compatible with your CO2 probe setup? You could also use yeast.... the point is to see if it happens in more than one species (i.e. conserved phenomenon).

Hope this helps! Let me know if you have additional questions.
MS