You may have heard of the microbiome, the community of microbes that lives in our gastrointestinal tract, as it is getting a lot of research attention since genetic techniques advanced in recent years. That gave researchers the power to assess what species were living in our guts and how they were influencing our health. It turns out that they are having a huge impact, and while that is not surprising, it has been interesting to find that they may also be affect our moods and behaviors.
The phenomenon even has a name - the gut-brain axis. There are nerves that go directly from your gut, which has an extensive nervous system of its own, to your brain. The brain is protected from the rest of the body by the blood-brain barrier, so it had been simply assumed that microbes in the gut had no effect on the brain. But the microbes actually end up producing an effect that does transmit to the brain, through the molecules they release. The video discusses a breakthrough researchers made in that area which showed how microbes in the gut did indeed cause a reaction in the brain, although it's still not known exactly how that happens, and additional research has indicated that the relationship is quite complex.
Scientists have gone on to show that transplanting the microbiome of one mouse into another can induce behavioral changes, which is explained well in the video. Check it out to learn more about this interesting new research, and how it is performed.