S100A9 and inflammatory bowel disease: For example, Lehmann et al. [15] observed higher abundances of calprotectin (protein S100-A9) in the feces of patients with inflammatory bowel disease, and Biemann et al. (2021) [16] showed that obese patients possess a systemic inflammation, higher abundances of protein S100-A9, and increased abundance of the family Thermotogaceae.