For example, hyocholic acid (HCA) species have been identified as a biomarker for metabolic disorders, and microbial‐derived hyodeoxycholic acid (HDCA) has been shown to alleviate nonalcoholic fatty liver disease via farnesoid X receptor (Fxr) and peroxisome proliferator‐activated receptors α (Pparα) [10, 11, 12]. The gene discussed is NR1H4; the disease is metabolic disease.