Phospholipids affect host metabolism

There is a complex interaction between phospholipids and intestinal flora, and this interaction can affect host metabolism through multiple pathways, providing a new perspective for understanding host metabolic regulation. The details are as follows:

Effects of Phospholipids on Intestinal Flora

Regulating flora composition: Different types of phospholipids can have different effects on intestinal flora. For example, soybean phospholipids, whose main components include phosphatidylcholine and phosphatidylethanolamine, can be decomposed by intestinal bacteria to produce beneficial substances such as short-chain fatty acids. These substances can promote the growth and reproduction of beneficial bacteria like Bifidobacterium and Lactobacillus, while inhibiting harmful bacteria, thereby optimizing the structure of intestinal flora.

Influencing flora metabolic activity: Phospholipids can serve as metabolic substrates for intestinal flora and participate in their metabolic processes. Studies have found that plasmalogens rich in n-3 polyunsaturated fatty acids can stay in intestinal regions with abundant flora for a long time, regulating intestinal flora and their metabolites. Intestinal flora can metabolize phosphatidylcholine to produce trimethylamine (TMA), which is absorbed by the host and converted into trimethylamine-N-oxide (TMAO) in the liver. TMAO is closely related to the host's lipid metabolism and cardiovascular diseases.

Effects of Intestinal Flora on Phospholipid Metabolism

Participating in phospholipid decomposition: Intestinal microorganisms produce lipases, which can degrade triglycerides and phospholipids into polar groups and free lipids, affecting the metabolic processes and levels of phospholipids in the body.

Influencing phospholipid synthesis: Intestinal flora can also participate in the synthesis of host phospholipids. For example, studies have found that intestinal flora can utilize inulin polysaccharides to synthesize choline, an important raw material for the synthesis of phosphatidylcholine (PC), which further participates in the synthesis of PC and lysophosphatidylcholine (LPC) in multiple host organs.

Pathways by Which Phospholipid-Intestinal Flora Interactions Affect Host Metabolism

Regulating lipid metabolism: The interaction between phospholipids and intestinal flora can regulate host lipid metabolism by affecting bile acid metabolism. For instance, EPA-plasmalogens can regulate intestinal flora, alter bile acid metabolism, and promote the liver to catabolize excess cholesterol into bile acids, which are then excreted through feces. This reduces circulating cholesterol levels and affects the balance of host lipid metabolism.

Affecting energy metabolism: Short-chain fatty acids (such as acetic acid, propionic acid, and butyric acid) produced by the decomposition of phospholipids by intestinal bacteria can be absorbed by the host and participate in energy metabolism. They not only provide energy for the host but also regulate the metabolic activities of adipocytes and hepatocytes, influencing energy storage and consumption.

Regulating immune metabolism: Certain phospholipids synthesized by intestinal flora, such as diacyl phosphatidylethanolamine produced by Akkermansia muciniphila, can activate pattern recognition receptors and inhibit the pro-inflammatory IL-12/IL-23 response in human monocytes. By regulating immune pathways, they affect host metabolism, and changes in inflammatory status can impact the body's glucose and lipid metabolism.

Influencing intestinal barrier function: The interaction between intestinal flora and phospholipids can also affect intestinal barrier function. The phospholipid levels in host cells of germ-free mice are different from those of conventional mice. Changes in membrane phospholipid chemistry can lead to altered intestinal permeability, thereby affecting the absorption of nutrients and the excretion of harmful substances, indirectly influencing host metabolism.