A study from Champalimaud Centre for the Unknown in Lisbon, Portugal and Monash University, Australia, led by Carlos Ribeiro, had led neuroscientist in showing that gut bacteria has an effect on animals food preference. Researchers have identified two species of bacteria that impact their dietary decisions.
It is a fact that nutrients and a community of bacteria, which is called a microbiome, resides inside the stomach and impacts health and eating. However, being able to control behavior is a big leap which is what this new study shows.
According to Scientific American, the two species of bacteria that are responsible for this phenomenon is the Acetobacter and Lactobacillus. Both of these are used in fermentation and are known as probiotic or good bacteria.
The experiment was done using a Drosophila melanogaster, species of a fruit fly. This model organism allowed the scientists to analyze the interaction of diet and microbes and effect of these on food preference.
The scientists found out that as the flies are deprived with amino-acids, they prefer more protein-rich food. They also found out that two specific species of bacteria could suppress the increased appetite for protein in flies that were fed food lacking essential amino acids.
Another study from Javier Bravo at University College Cork discovered that feeding a mouse with Lactobacillus rhamnosus, bacteria commonly found in dairy products, changed the signaling chemical levels in the rodent's brain. The results also showed that behaviors that are connected to stress, depression, and anxiety were reduced, as reported by National Geographic.
With this new discovery, how are bacteria from the gut able to affect the brain in altering appetite? The truth is, it doesn't really affect the brain directly. The gut bacteria induced some metabolic changes that act directly on the brain and the body.
This discovery however, is not to be expected to be the same for humans. A fly has five main bacterial species, humans, on the other hand, have hundreds. This highlights the importance of using simple animal models to gain insights into factors that may be crucial for human health.
