BACKGROUND: Post-cardiac surgery anxiety or depression (PCPAD) is a common neuropsychiatric complication following cardiovascular interventional procedures, which significantly increases the risk of adverse cardiovascular events and long-term mortality. Existing treatment strategies have limitations, and clinical needs remain unmet. The gut-brain axis (GBA) serves as a core network regulating neuroimmune and endocrine responses, and its imbalance involves key links such as intestinal flora dysbiosis and neuroimmune crosstalk disorders. It is closely related to the pathogenesis of this complication, providing a novel perspective for targeted interventions.
OBJECTIVE: This review aims to systematically clarify the mechanism of GBA in PCPAD, comprehensively explore therapeutic strategies targeting this axis, and focus on the intervention value and application potential of natural products.
METHODS: The study was designed and conducted in strict accordance with the PRISMA 2020 guidelines. Relevant literatures were searched from PubMed, Web of Science Core Collection, ScienceDirect, Embase, Cochrane Library, and CNKI databases from their inception to December 2025. Literatures focusing on GBA-related mechanisms of PCPAD or investigating the mechanisms and clinical applications of natural products targeting GBA for PCPAD treatment were included. Conference abstracts, case reports, duplicate publications, and other ineligible literatures were excluded. Through quality control strategies including double independent screening and verification, priority inclusion of high-credibility evidence, and data cross-validation, 168 eligible literatures were finally included. The composition and functions of GBA, its imbalance mechanisms, and the basic and clinical evidence of natural product-based interventions were systematically analyzed.
RESULTS: Studies have shown that GBA imbalance is the core pathogenesis of PCPAD, among which the inflammatory cascade initiated by intestinal flora dysbiosis, abnormal activation of the neuroendocrine axis, disorder of immune-nerve crosstalk, and abnormal gene and epigenetic regulation are key pathological links. In summary, GBA imbalance, especially gut microbiota dysbiosis and neuroimmune interactions, plays a critical role in the pathogenesis of PCPAD. Natural products (including traditional Chinese medicine (TCM) monomers, TCM compound prescriptions, patented TCM drugs, and natural products from other plant sources worldwide) can exert therapeutic effects by synergistically regulating GBA homeostasis through multiple targets. Specifically, they include increasing the abundance of beneficial bacteria such as Bifidobacterium and Lactobacillus, promoting the production of anti-inflammatory metabolites such as short-chain fatty acids, repairing intestinal barrier function, inhibiting pro-inflammatory pathways such as NF-κB and NLRP3 inflammasome, and regulating the levels of neurotransmitters and neurotrophic factors such as 5-HT and BDNF. Basic and clinical studies have confirmed that these natural products have high biocompatibility and low toxic side effects, and are compatible with the safe medication needs of patients during the organ function recovery period after cardiac surgery. Several natural products have been proven to modulate GBA dysfunction, with potential for clinical therapeutic application.
CONCLUSIONS: This review systematically elucidates a new paradigm of precise intervention for PCPAD via natural products that regulate GBA through multiple targets, addressing the limitation of traditional single-target therapies and providing a low-cost, easily promotable solution for clinical translation. Additionally, natural product-based interventions offer a novel approach for treating post-cardiac surgery complications. In the future, it is necessary to further conduct large-sample, multicenter clinical trials to clarify their mechanisms of action and standardized dosage regimens, strengthen toxicological research, facilitate the translation from basic research to clinical practice, and provide more precise therapeutic strategies for patients.
