By Katie Bohn
The liver, as well as gut bacteria, in humans can alter molecules in food to influence signaling pathways that can activate or deactivate an array of genes, according to a new study led by researchers at Penn State.
The study, which took place in both humans and mice, was published in the Nature journal Communications Biology. When gut bacteria break down the dietary amino acid tryptophan — a protein building block found in common foods, including nuts, cheese and chicken — it produces a molecule, or metabolite, called indole-3-acetic acid (IAA).
The researchers found that the gut bacteria and the liver can chemically attach glycine, an amino acid produced by the body and found in beans and meats, to IAA. Typically, this process, called conjugation, helps make the metabolite water-soluble so the body can safely eliminate it. IAA-glycine, however, may have special characteristics, the researchers said.
IAA is a molecule that can bind to and activate the aryl hydrocarbon (Ah) receptor, a protein that can activate or deactivate other genes. Previous research has shown that the activation of the Ah receptor enhances gut immune function and intestinal barrier integrity, according to Gary H. Perdew, Thomas and Dorothy Willits Hallowell Emeritus Chair in Agricultural Sciences in the College of Agricultural Sciences and lead author of the paper.
Source : psu.edu