created random forest and logistic regression prediction models based on patient's gut microbiome metagenomics data, faecal calprotectin (FCal), human beta defensin 2 (HBD2) and chromogranin A (CgA) to distinguish Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) in a non‐invasive way, which aim to reduce the number of endoscopies needed (Gacesa et al., 2021). Here, CHGA is linked to irritable bowel syndrome.