Gut dysbacteriosis is closely related to various intestinal and extraintestinal diseases. Fecal microbiota transplantation (FMT) is a biological therapy that entails transferring the gut microbiota from healthy individuals to patients in order to reconstruct the intestinal microflora in the latter. It has been proved to be an effective treatment for recurrent Clostridium difficile infection. Studies show that the gut microbiota plays an important role in the pathophysiology of neurological and psychiatric disorders through the microbiota-gut-brain axis. Therefore, reconstruction of the healthy gut microbiota is a promising new strategy for treating cerebral diseases. We have reviewed the latest research on the role of gut microbiota in different nervous system diseases as well as FMT in the context of its application in neurological, psychiatric, and other nervous system-related diseases (Parkinsons disease, Alzheimers disease, multiple sclerosis, epilepsy, autism spectrum disorder, bipolar disorder, hepatic encephalopathy, neuropathic pain, etc.).

Background: Plant-derived exosome-like nanoparticles (PELNs) have received widespread attention in treating ulcerative colitis (UC). However, the role of Houttuynia cordata-derived exosome-like nanoparticles (HELNs) in UC remains unclear. This study aims to evaluate the efficacy of HELNs in treating colitis in mice and investigate its potential mechanisms. Methods: HELNs were isolated from H. cordata for characterization, and their safety and stability were evaluated. A dextran sulfate sodium (DSS)-induced colitis mouse model was utilized to assess the therapeutic potential of HELNs in UC. In vivo, imaging and flow cytometry were utilized to investigate the targeting effect of HELNs on inflamed colonic sites and their modulation of the immune environment. RNA-seq analysis and molecular docking were performed to identify potential pathways recruited by HELNs. Guided by transcriptomic findings, NLRP3^−/− mice were used in conjunction with Western blotting, qPCR, immunofluorescence, and other techniques to verify that HELNs alleviated DSS-induced colitis by inhibiting NLRP3/NOD-like receptor signaling pathways. Lastly, the impact of HELNs on the gut microbiota was investigated through 16S rRNA sequencing. Results: HELNs significantly reduced the severity of DSS-induced colitis in mice, alleviating colitis symptoms and histopathological damage. Furthermore, HELNs can specifically target inflamed colon tissue, regulate the immune environment, and decrease inflammation. RNA-seq analysis, coupled with the use of NLRP3^−/− mice, demonstrated that HELNs inhibited the NLRP3/NOD-like receptor signaling pathways. Lastly, HELNs balanced the gut microbiota composition in mice with colitis, decreasing the abundance of harmful bacteria and increasing the abundance of beneficial bacteria in the intestinal tract of these mice. Conclusion: In summary, HELNs exhibit the potential to protect the colon from DSS-induced damage by inhibiting the NLRP3/NOD-like receptor signaling pathway and modulating the gut microbiota, presenting a promising therapeutic option for the management of UC.

As an important intestinal microorganism, Odoribacter splanchnicus frequently appears in high-throughput sequencing analyses, although pure culture research on this microorganism is not as advanced. It is widely present in the mammalian gut and is closely associated with the health status of the host and the incidence of various diseases. In recent years, changes in the abundance of O. splanchnicus have been found to be positively or negatively correlated with health issues, such as obesity, metabolic syndrome, diabetes, and intestinal inflammation. It may exhibit a dual protective or promotional role in specific diseases. Thus, it may play an important role in regulating host metabolism, immune response, and intestinal homeostasis. Additional research has revealed that O. splanchnicus can synthesize various metabolites, especially short-chain fatty acids (SCFAs), which play a key role in promoting intestinal health, enhancing energy metabolism, improving insulin resistance, and regulating immune responses in the host. Therefore, O. splanchnicus is a strong candidate for “next-generation probiotics”, and its potential probiotic function provides novel ideas for the development of functional foods and the prevention and treatment of metabolic and intestinal inflammatory diseases. These findings can help develop new biological treatment strategies and optimize health management plans.

The ability to regulate the gut environment has resulted in remarkable great breakthroughs in the treatment of several diseases. Several studies have found that the regulation of the gut environment might provide relief from the symptoms of benign prostatic hyperplasia. However, the correlation between the gut microenvironment and the colon and prostate glands is still unknown. We found that ulcerative colitis (UC) induced an increase in prostate volumes that could be reversed by sodium butyrate (NaB) and fecal microbiota transplantation (FMT). The mechanism by which UC induced changes in the prostate gland was examined via RNA-Seq. The results show that the expression level of GPER was significantly lower in the prostate gland of UC mices than in normal mices. The expression of GPER could be increased via treatment with NaB or FMT. We found that prostate tissues exhibited higher butryic acid levels after they were treated with NaB or FMT. In experiments conducted in vitro, NaB or the fecal filtrate (FF) from healthy mice up-regulated of the expression of GPER, inhibited cell growth, and induced apoptosis in BPH-1 cells. These changes could be alleviated by treatment with the G15 or in GPER-silenced cells.

As double membrane-encapsulated nanovesicles (30-150 nm), exosomes (Exos) shuttle between different cells to mediate intercellular communication and transport active cargoes of paracrine factors. The anti-inflammatory and immunomodulatory activities of mesenchymal stem cell (MSC)-derived Exos (MSC-Exos) provide a rationale for novel cell-free therapies for inflammatory bowel disease (IBD). Growing evidence has shown that MSC-Exos can be a potential candidate for treating IBD. In the present review, we summarized the most critical advances in the properties of MSC-Exos, provided the research progress of MSC-Exos in treating IBD, and discussed the molecular mechanisms underlying these effects. Collectively, MSC-Exos had great potential for cell-free therapy in IBD. However, further studies are required to understand the full dimensions of the complex Exo system and how to optimize its effects.