We’ve come to realize that as walking sacks of bacteria, the tiny microogranisms living in our gut actually have quite a lot of control over us. But the bacteria themselves are in turn influenced by what we feed them, and it seems that the hormones naturally present in the plants we eat may be influencing our gut microbes.
Just like animals, plants produce a whole array of hormones that help them develop and survive. Hormones are involved in all aspects of how the plants grow, from whether or not they reach for the Sun or tunnel into the dirt to whether they ripen their fruit or give up the ghost. Now, however, it seems that these molecules may also be influencing the bacteria in our gut, and therefore our health.
A new opinion article, published in Trends in Plant Science, details how plant hormones may be doing this. It turns out that not only are humans and bacteria able to perceive these plant-derived molecules, but in some cases, they are able to produce their own mimics of them.
For example, plants produce a hormone known as abscisic acid (ABA) in response to drought, but this is also produced in mammals and is thought to have an anti-inflammatory role and to regulate glucose uptake. This, therefore, raises the possibility that a diet of plants high in ABA could be used to help treat diabetes. But there are a whole host of other plant hormone-bacteria-human relationships that we are yet to understand, and could provide a novel way to treat diseases from obesity to cancer.
The question, however, of why the hormones in plants may influence the bacteria in our gut, or even the cells in our own body, is not quite understood. One possibility may be that the molecule structure of the hormones have a similar shape to other metabolites in animals, including us.
But equally, it might be more intimate a relationship, and that humans and plants have in effect co-evolved together over millennia. “We have evolved in an environment including plants and microbes while consuming plant hormones,” says Emilie Chanclud. “We have IAA and ABA in our body, and even if we don't know where they come from, we may have evolved ways to respond to them over time.”
What’s certain is that there is much we still don’t know about our gut and how the microorganisms that call it home may be pulling the strings.