Recently, the interplay of gut microbes and their effects on the body have begun to receive greater attention by the scientific community. In an opinion piece published yesterday in Trends in Plant Science, researchers discuss the role of plants and their hormones in these systems and how they might affect diseases such as cancer, inflammatory and neurological disorders.
Plants produce hormones to control how they grow, age and manage water. When plants are eaten, remnants of these hormones are ingested as well.
One example where these mechanisms may come into play is in the association of gut microbes and dietary factors with inflammatory bowel disease and similar afflictions. The plant hormone abscisic acid (ABA) can worsen inflammation, while another set of hormones, gibberellic acids (GAs), reduce inflammation. Researchers have therefore suggested that synthesis of these hormones in the gut may be related to inflammatory disease. They also believe that GA-rich diets including grains and spinach might be useful for combatting inflammatory disorders.
ABA has also been known to stimulate increased glucose uptake. The researchers thus suggest that consuming ABA-rich fruits and vegetables such as apricots, apples, carrots, and sweet potatoes could help alleviate aspects of diabetes. Another hormone, indolec acetic acid (IAA), has been shown to kill off cancer cells upon exposure to high-energy excited dyes in photodynamic therapy. The researchers believe this is another association that should be further investigated.
The authors also discuss the potential reason for these types of interactions. "The most likely explanation is that plant hormones are structurally related to some metabolites in animals, including humans,” explains senior author Benoît Lacombe of France's Centre National de la Recherche Scientifique. Other potential explanations include co-evolution of plants, animals and their microbiome with our bodies learning to respond to plant hormones over time.
Although, this research is still in its early stages it may someday offer new context for investigating diet, disease and the digestive process.
Image: A diagram of human-plant-microbe interactions mediated by plant hormones. Image courtesy of Chanclud and Lacombe.