Metagenomics and metabolomics to investigate the effect of Amygdalus mongolica oil on intestinal microbiota and serum metabolites in rats

Background: Renal fibrosis (RF) is an inevitable consequence of multiple manifestations of progressive chronic kidney diseases (CKDs). Mechanism of Amygdalus mongolica (Maxim.) in the treatment of RF needs further investigation.

Purpose: The study further investigated the potential mechanism of A. mongolica in the treatment of RF.

Methods: A rat model of RF was induced by unilateral ureteral obstruction (UUO), followed by treatment with varying dosages of A. mongolica oil for 4 weeks. Body weight was measured weekly. We detected serum levels of interleukin (IL)-6, IL-1β, type Ⅲ procollagen (Col-Ⅲ), type IV collagen (Col-Ⅳ), laminin (LN), hyaluronidase (HA), and tissue levels of albumin (ALB), blood urea nitrogen (BUN), creatinine (Cre), superoxide dismutase (SOD), malondialdehyde (MDA), and hydroxyproline (HYP). Shotgun metagenomics analyzed the composition of the intestinal microbiota. High-performance liquid chromatography coupled with a quadrupole-exactive mass spectrometer (HPLC-Q-Exactive-MS) monitored changes in metabolite levels in serum and gut. Multiple reaction monitoring-mass spectrometry (MRM-MS) determined the levels of amino acids in serum.

Results: A. mongolica oil significantly alleviated indicators related to RF (p < 0.05). A. mongolica oil reduced the ratio of Firmicutes to Bacteroidetes and restored the balance of intestinal microbiota in rats with RF. A. mongolica oil modulated levels of metabolites in gut content and serum. It regulated 11 metabolic pathways including arachidonic acid metabolism. Targeted metabolomics of amino acids showed that 17 amino acids were significantly changed by A. mongolica oil, including L-glycine, L-serine and L-glutamine.

Conclusion: A. mongolica oil regulates intestinal microbiota and metabolites, restoring amino acid metabolism to treat RF.