Probiotic powder ameliorates colorectal cancer by regulating Bifidobacterium animalis, Clostridium cocleatum, and immune cell composition

Luteolin Alleviates Ulcerative Colitis in Mice by Modulating Gut Microbiota and Plasma Metabolism

BACKGROUND/OBJECTIVES

Ulcerative colitis (UC) is a chronic and easily recurrent inflammatory bowel disease. The gut microbiota and plasma metabolites play pivotal roles in the development and progression of UC. Therefore, therapeutic strategies targeting the intestinal flora or plasma metabolites offer promising avenues for the treatment of UC. Luteolin (Lut), originating from a variety of vegetables and fruits, has attracted attention for its potent anti-inflammatory properties and potential to modulate intestinal flora.

METHODS

The therapeutic efficacy of Lut was evaluated in an established dextran sodium sulfate (DSS)-induced colitis mice model. The clinical symptoms were analyzed, and biological samples were collected for microscopic examination and the evaluation of the epithelial barrier function, microbiome, and metabolomics.

RESULTS

The findings revealed that Lut administration at a dose of 25 mg/kg significantly ameliorated systemic UC symptoms in mice, effectively reduced the systemic inflammatory response, and significantly repaired colonic barrier function. Furthermore, Lut supplementation mitigated gut microbiota dysbiosis in a UC murine model, increasing the abundance of Muribaculaceae, Rikenella, and Prevotellaceae while decreasing Escherichia_Shigella and Bacteroides levels. These alterations in gut microbiota also influenced plasma metabolism, significantly increasing phosphatidylcholine (PC), 6'-Deamino- 6'-hydroxyneomycin C, and gamma-L-glutamyl-butyrosine B levels and decreasing Motapizone and Arachidoyl-Ethanolamide (AEA) levels.

CONCLUSIONS

This study reveals that Lut supplementation modulates intestinal inflammation by restoring the gut microbiota community structure, thereby altering the synthesis of inflammation-related metabolites. Lut is a potential nutritional supplement with anti-inflammatory properties and offers a novel alternative for UC intervention and mitigation. In addition, further studies are needed to ascertain whether specific microbial communities or metabolites can mediate the recovery from UC.

Effect of colorectal cancer stem cells on the development and metastasis of colorectal cancer

The relevant mechanism of tumor-associated macrophages (TAMs) in the treatment of colorectal cancer patients with immune checkpoint inhibitors (ICIs) is discussed, and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies. As a class of drugs widely used in clinical tumor immunotherapy, ICIs can act on regulatory molecules on cells that play an inhibitory role - immune checkpoints - and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system. The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly. The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs. ICIs can regulate the phenotypic function of TAMs, and TAMs can also affect the tolerance of colorectal cancer to ICI therapy. TAMs play an important role in ICI resistance, and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

Lactobacillus plantarum Ameliorates Colorectal Cancer by Ameliorating the Intestinal Barrier through the CLA-PPAR-γ Axis

Colorectal cancer (CRC) is the third-largest cancer worldwide. Lactobacillus can regulate the intestinal barrier and gut microbiota. However, the mechanisms of Lactobacillus that alleviate CRC remained unknown. This study aimed to explore the regulatory effect of Lactobacillus plantarum on CRC and its potential mechanism. CCFM8661 treatment significantly ameliorated CRC compared with phosphate-buffered solution (PBS) treatment in ApcMin/+ mice. In addition, conjugated linoleic acid (CLA) was proved to be the key metabolite for CCFM8661 in ameliorating CRC by molecular biology techniques. Peroxisome proliferator-activated receptor γ (PPAR-γ) was proved to be the key receptor in ameliorating CRC by inhibitor intervention experiments. Moreover, supplementation with CCFM8661 ameliorated CRC by producing CLA to inhibit NF-κB pathway and pro-inflammatory cytokines, up-regulate ZO-1, Claudin-1, and MUC2, and promote tumor cell apoptosis in a PPAR-γ-dependent manner. Metagenomic analysis showed that CCFM8661 treatment significantly increased Odoribacter splanchnicus, which could ameliorate CRC by repairing the intestinal barrier. Clinical results showed that intestinal CLA, butyric acid, PPAR-γ, and Lactobacillus were significantly decreased in CRC patients, and these indicators were significantly negatively correlated with CRC. CCFM8661 alleviated CRC by ameliorating the intestinal barrier through the CLA-PPAR-γ axis. These results will promote the development of dietary probiotic supplements for CRC.

Immunomodulation aspects of gut microbiome-related interventional strategies in colorectal cancer

Colorectal cancer (CRC), the third most common cancer worldwide, develops mainly due to the accumulation of genetic and epigenetic changes over many years. Substantial evidence suggests that gut microbiota plays a significant role in the initiation, progression, and control of CRC, depending on the balance between beneficial and pathogenic microorganisms. Nonetheless, gut microbiota composition by regulating the host immune response may either promote or inhibit CRC. Thus, modification of gut microbiota potentially impacts clinical outcomes of immunotherapy. Previous studies have indicated that therapeutic strategies such as probiotics, prebiotics, and postbiotics enhance the intestinal immune system and improve the efficacy of immunotherapeutic agents, potentially serving as a complementary strategy in cancer immunotherapy. This review discusses the role of the gut microbiota in the onset and development of CRC in relation to the immune response. Additionally, we focus on the effect of strategies manipulating gut microbiome on the immune response and efficacy of immunotherapy against CRC. We demonstrate that manipulation of gut microbiome can enhance immune response and outcomes of immunotherapy through downregulating Treg cells and other immunosuppressive cells while improving the function of T cells within the tumor; however, further research, especially clinical trials, are needed to evaluate its efficacy in cancer treatment.

Scutellaria baicalensis Georgi alleviates Clostridium difficile associated diarrhea and its modulatory effects on the gut microbiota

The growing incidence of Clostridium difficile associated diarrhea (CDAD) underscores the urgency for potent treatments. This research delves into the therapeutic potential of Scutellaria baicalensis Georgi (Lamiaceae) root (SR) in addressing CDAD and its influence on gut microbiota. Using a CDAD mouse model and fidaxomicin as a control, SR's impact was measured through diarrhea symptoms, colonic histopathology, and C. difficile toxin levels. Employing the PacBio platform, 16S rRNA full-length gene sequencing analyzed the gut microbial composition and the effect of SR. Results revealed SR considerably alleviated diarrhea during treatment and restoration phases, with a marked decrease in colonic inflammation. C. difficile toxin levels dropped significantly with SR treatment (P < 0.001). While SR didn't augment gut microbiota's overall abundance, it enhanced its diversity. It restored levels of Proteobacteria and Bacteroidetes, reduced Akkermansia spp. and Enterococcus spp. proportions, and modulated specific bacterial species' abundance. In essence, SR effectively mitigates CDAD symptoms, curtails inflammatory reactions, and beneficially restructures gut microbiota, suggesting its potential in advanced CDAD clinical intervention.

The role of CD8+ T-cells in colorectal cancer immunotherapy

Immunotherapy has been an advanced and effective approach to treating various types of solid tumors in recent years, and the most successful strategy is immune checkpoint inhibitors (ICIs), which have shown beneficial effects in patients with colorectal cancer (CRC). Drug resistance to ICIs is usually associated with CD8+ T-cells targeting tumor antigens; thus, CD8+ T-cells play an important role in immunotherapy. Unfortunately, Under continuous antigen stimulation, tumor microenvironment(TME), hypoxia and other problems it leads to insufficient infiltration of CD8+ T-cells, low efficacy and mechanism exhaustion, which have become obstacles to immunotherapy. Thus, this article describes the relationship between CRC and the immune system, focuses on the process of CD8+ T-cells production, activation, transport, killing, and exhaustion, and expounds on related mechanisms leading to CD8+ T-cells exhaustion. Finally, this article summarizes the latest strategies and methods in recent years, focusing on improving the infiltration, efficacy, and exhaustion of CD8+ T-cells, which may help to overcome the barriers to immunotherapy.

Exploring potential causal associations between autoimmune diseases and colorectal cancer using bidirectional Mendelian randomization

Several observational studies have revealed an association between autoimmune diseases (AIDs) and colorectal cancer (CRC), although their causal association remained controversial. Therefore, our study used a two-sample Mendelian randomization (MR) analysis to verify the causal association between AIDs and CRC. We employed three common MR approaches, including inverse variance weighted (IVW), weighted median, and MR-Egger methods, to assess the causal association between type 1 diabetes (T1D), systemic lupus erythematosus, rheumatoid arthritis, psoriasis, multiple sclerosis, juvenile idiopathic arthritis, celiac disease, and primary sclerosing cholangitis (PSC) and CRC. The reverse MR analysis was performed to assess the possibility of reverse causation. To evaluate the validity of the analysis, we also performed sensitivity analysis, such as the heterogeneity test, the horizontal pleiotropy test, and the leave-one-out sensitivity analysis, and validated the results in the validation cohort. Our results showed that genetically predicted T1D was nominally associated with a lower risk of CRC (IVW OR = 0.965, 95% CI = 0.939-0.992, P = 0.012). However, genetic susceptibility to psoriasis nominally increased the risk of CRC (IVW OR = 1.026, 95% CI = 1.002-1.050, P = 0.037). Genetically predicted PSC had a significant causal effect on the increasing risk of CRC (IVW OR = 1.038, 95% CI = 1.016-1.060, P = 5.85 × 10-4). Furthermore, the MR analysis between PSC and the CRC validation cohort indicated consistent results. We found no causal association between genetically predicted other five AIDs and CRC (P > 0.05). The results of reverse MR analysis showed that genetically predicted CRC had no causal effect on T1D, psoriasis, and PSC (P > 0.05). The sensitivity analysis demonstrated that the results of the MR analysis were reliable. Our findings help to understand the causal association between AIDs and CRC, which deserves further investigation.