Integrated metabolomics and 16S rDNA sequencing to investigate the mechanism of immune-enhancing effect of health Tonic oral liquid

Health Tonic oral liquid (HT) is a popular functional food in China and is used to enhance host immune response. However, its mechanisms of action are still poorly understood. In this work, we combined ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS) serum metabolomics with 16S rDNA sequencing to evaluate the effects of HT on metabolomics profiling and microbial community signatures. Short-chain fatty acids (SCFAs) contents in fecal were quantified through gas chromatography-mass spectrometry (GC–MS). Results indicated that HT use leads to a significant increase in IgG, IgM and IgA. Thirty-four metabolites were identified and quantified using metabolomics, most were aromatic amino acids and metabolites involved in glucose metabolism. HT intervention significantly increased the abundance of Alloprevotella, which may contribute to intestinal barrier integrity and inflammatory response inhabitation. Most SCFAs were highly expressed following HT intake. In summary, HT use maintains glucose and lipid metabolism balance, promotes high expressions of beneficial bacteria, and exerts promising immunomodulatory effects.