The Guts Of A Caterpillar Do Not Contain Many Microbes That Seem Necessary

All living things possess an environment within their guts that host several different types of microbes. This environment is called a microbiome. Humans, for example, have billions of bacteria living within their guts. So do spiders and insects. Termites are known for their unique gut microbes. These microbes can break down tough cellulose in wood and plant matter. The bacteria in the guts of animals helps digest food, aids in metabolism, and serves many more necessary bodily functions. However, researchers have recently learned that caterpillars do not possess a wealth of digestive bacteria, and they are still not exactly sure as to why. But there are some plausible ideas that have yet to be tested. However, researchers are already beginning to suspect that microbiomes are not necessary for all of the world’s animal life.

Caterpillars have been found to possess very few bacteria and fungi within their digestive systems. Even the bacteria and fungi that does exist within caterpillar guts does not seem to have a purpose other than for the development of disease. Researchers are considering the idea that caterpillars may not need microbes. This is an entirely new thought among physiologists since it has been held as scientifically true that all animals possess their own unique microbiomes.

Tobin Hammer, a doctoral candidate in CU Boulder’s Department of Ecology and Evolutionary Biology, had always assumed that all living organisms possessed a microbiome, so he decided to investigate the microbiome of a caterpillar. Amazingly, Hammer found that caterpillars had fifty thousand fewer gut microbes than other animals. The caterpillar is of the well known species Lepidoptera, which includes one hundred and eighty thousand different types of butterflies and moths.

DNA analysis on caterpillars revealed that the microbes present in the guts of a caterpillar were the same as the microbes found on a leaf. Therefore, it is possible that a caterpillar’s microbiome contains microbes that exist in the outside environment, and the caterpillar simply ingests the microbes. However, most animals have microbiomes that are composed of microbes that are distinct from any sort of microbes within the surrounding environment. Maybe microbes only have negative effects on a caterpillar’s physiology, such as disease development. In any case there is more research to be conducted on this topic, but one thing is for sure, caterpillars develop in a way that is wholly unique and different from other animals.

Do you think that the gut bacteria that allows caterpillars to digest food is similar to our own digestive gut bacteria?