•SCFAs (acetate, propionate, butyrate): provide energy for intestinal epithelial cells; regulate immunity and metabolism via GPR41/GPR43 activation and HDAC inhibition (103, 104) •Enhances gut barrier function, reduces LPS translocation, alleviates systemic inflammation (105) •High hPDI shows positive effects in preventing coronary heart disease. The gene discussed is FFAR3; the disease is coronary artery disorder.