Gut Microbiota Dysbiosis Drives the Development of Colorectal Cancer

Association between metabolic dysfunction-associated steatotic liver disease and risk of colorectal cancer or colorectal adenoma: an updated meta-analysis of cohort studies

Background and aims

In recent years, the relationship between metabolic dysfunction-associated steatotic liver disease (MASLD) and colorectal cancer (CRC) or colorectal adenoma (CRA) has gained widespread attention. Previous meta-analyses on this subject either incorporated numerous cross-sectional studies, which were susceptible to bias, or concentrated solely on a restricted number of cohort studies. Moreover, with the release of a substantial number of high-quality cohort studies on this subject in the past two years, the findings continue to be debated and contradictory. Therefore, we conducted an updated systematic review and meta-analysis of cohort studies to quantitatively evaluate the magnitude of the association between them.

Methods

Comprehensive searches of PubMed, Web of Science, and Embase were conducted without language restrictions from the time of their creation up to December, 2023. The pooled hazard ratios (HRs) with 95% confidence interval (CIs) were calculated by the generic inverse variance based on the random-effects model. Moreover, subgroup and sensitivity analyses were performed.

Results

A total of 15 cohort studies were analyzed in this meta-analysis, which included 9,958,412 participants. The meta-analysis of 13 cohort studies showed that MASLD was linked to a higher risk of CRC (HR=1.25, 95% CI: 1.15-1.36, P < 0.00001). Additionally, further subgroup analysis indicated that the combined HR remained consistent regardless of the study location, nomenclature of fatty liver disease (FLD), confirmation methods for FLD, sample size, follow-up time, and study quality. Furthermore, the meta-analysis of four cohort studies demonstrated that MASLD was correlated with an increased risk of CRA (HR=1.38, 95% CI: 1.17-1.64, P = 0.0002). The sensitivity analysis results further validated the robustness of the aboved findings.

Conclusion

The results of our meta-analysis indicated that MASLD was associated with an increased risk of incident CRC/CRA. In the future, it is necessary to conduct more prospective cohort studies to thoroughly assess potential confounding factors, particularly in individuals from Europe and North America. Furthermore, related mechanism studies should be conducted to enhance our understanding of the link between MASLD and CRC/CRA.

Systematic review registration

Open Science Framework registries (https://osf.io/m3p9k).

Emerging importance of stool preservation methods in OMICS studies with special focus on cancer biology

The intricate consortium of microorganisms in the human gut plays a crucial role in different physiological functions. The complex known-unknown elements of the gut microbiome are perplexing and the absence of standardized procedures for collecting and preserving samples has hindered continuous research in comprehending it. The technological bias produced because of lack of standard protocols has affected the reproducibility of results. The complex nature of diseases like colorectal cancer, gastric cancer, hepatocellular carcinoma and breast cancer require a thorough understanding of its etiology for an efficient and timely diagnosis. The designated protocols for collection and preservation of stool specimens have great variance, hence generate inconsistencies in OMICS studies. Due to the complications associated to the nature of sample, it is important to preserve the sample to be studied later in a laboratory or to be used in the future research purpose. Stool preservation is gaining importance due to the increased use of treatment options like fecal microbiota transplantation to cure conditions like recurrent Clostridium difficile infections and for OMICS studies including metagenomics, metabolomics and culturomics. This review provides an insight into the importance of omics studies for the identification and development of novel biomarkers for quick and noninvasive diagnosis of various diseases.

Colonization of the gut mucosa of colorectal cancer patients by pathogenic mucosa-associated Escherichia coli strains

Some strains of Escherichia coli are known to be involved in the pathogenesis of colorectal cancer (CRC). The aim of current study was to compare the general characteristics of the E. coli from CRC patients and healthy participants. A total of 96 biopsy samples from 48 CRC patients and 48 healthy participants, were studied. The clonality of the E. coli isolates was analyzed by Enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) method. The strains were tested by PCR to determine the prevalence of different virulence factors. According to the results of ERIC-PCR analysis, (from the 860 E. coli isolates) 60 strains from CRC patients and 41 strains from healthy controls were identified. Interestingly, the majority of the strains of both groups were in the same cluster. Enteropathogenic E. coli (EPEC) was detected significantly more often in CRC patients (21.6 %) than in healthy participants (2.4 %) (p < 0.05). The Enteroaggregative E. coli (EAEC) was found in 18.33 % of the strains of CRC patients. However, other pathotypes were not found in the E. coli strains of both groups. Furthermore, all the studied genes encoding for virulence factors seemed to be more prevalent in the strains belonging to CRC patients. Among the virulence genes, the statistical difference regarding the frequency of fuyA, chuA, vat, papC, hlyA and cnf1 genes was found significant (p < 0.05). In conclusion, E. coli strains that carry extraintestinal pathogenic E. coli (ExPEC) and diarrheagenic E. coli (DEC) multiple virulence factors colonize the gut mucosa of CRC patients.

Single-Cell Profiling Reveals the Impact of Genetic Alterations on the Differentiation of Inflammation-Induced Murine Colon Tumors

Genetic mutations and chronic inflammation of the colon contribute to the development of colorectal cancer (CRC). Using a murine model of inflammation-induced colon tumorigenesis, we determined how genetic mutations alter colon tumor cell differentiation. Inflammation induced by enterotoxigenic Bacteroides fragilis (ETBF) colonization of multiple intestinal neoplasia (MinApcΔ716/+) mice triggers loss of heterozygosity of Apc causing colon tumor formation. Here, we report that the addition of BRAFV600E mutation (BRAFF-V600ELgr5tm1(Cre/ERT2)CleMinApcΔ716/+, BLM) or knocking out Msh2 (Msh2LoxP/LoxPVil1-creMinApcΔ716/+, MSH2KO) in the Min model altered colon tumor differentiation. Using single-cell RNA sequencing, we uncovered the differences between BLM, Min, and MSH2KO tumors at a single-cell resolution. BLM tumors showed an increase in differentiated tumor epithelial cell lineages and a reduction in the tumor stem cell population. Interestingly, the tumor stem cell population of BLM tumors had revival colon stem cell characteristics with low WNT signaling and an increase in RevCSC marker gene expression. In contrast, MSH2KO tumors were characterized by an increased tumor stem cell population that had higher WNT signaling activity compared to Min tumors. Furthermore, overall BLM tumors had higher expression of transcription factors that drive differentiation, such as Cdx2, than Min tumors. Using RNA velocity, we identified additional potential regulators of BLM tumor differentiation such as NDRG1. The role of CDX2 and NDRG1 as putative regulators for BLM tumor cell differentiation was verified using organoids derived from BLM tumors. Our results demonstrate the critical connections between genetic mutations and cell differentiation in inflammation-induced colon tumorigenesis. Understanding such roles will deepen our understanding of inflammation-associated colon cancer.

Parvimonas micra can translocate from the subgingival sulcus of the human oral cavity to colorectal adenocarcinoma

Oral and intestinal samples from a cohort of 93 colorectal cancer (CRC) patients and 30 healthy controls (non-CRC) were collected for microbiome analysis. Saliva (28 non-CRC and 94 CRC), feces (30 non-CRC and 97 CRC), subgingival fluid (20 CRC), and tumor tissue samples (20 CRC) were used for 16S metabarcoding and/or RNA sequencing (RNAseq) approaches. A differential analysis of the abundance, performed with the ANCOM-BC package, adjusting the P-values by the Holm-Bonferroni method, revealed that Parvimonas was significantly over-represented in feces from CRC patients (P-value < 0.001) compared to healthy controls. A total of 11 Parvimonas micra isolates were obtained from the oral cavity and adenocarcinoma of CRC patients. Genome analysis identified a pair of isolates from the same patient that shared 99.2% identity, demonstrating that P. micra can translocate from the subgingival cavity to the gut. The data suggest that P. micra could migrate in a synergistic consortium with other periodontal bacteria. Metatranscriptomics confirmed that oral bacteria were more active in tumor than in non-neoplastic tissues. We suggest that P. micra could be considered as a CRC biomarker detected in non-invasive samples such as feces.

Fusobacteria alterations are associated with colorectal cancer liver metastasis and a poor prognosis

Liver metastasis is a major cause of mortality in patients with advanced stages of colorectal cancer (CRC). The gut microbiota has been demonstrated to influence the progression of liver diseases, potentially providing novel perspectives for diagnosis, treatment and research. However, the gut microbial characteristics in CRC with liver metastasis (LM) and with no liver metastasis (NLM) have not yet been fully established. In the present study, high-throughput 16S RNA sequencing technology was employed, in order to examine the gut microbial richness and composition in patients with CRC with LM or NLM. A discovery cohort (cohort 2; LM=18; NLM=36) and a validation cohort (cohort 3; LM=13; NLM=41) were established using fresh feces. In addition, primary carcinoma tissue samples were also analyzed (LM=8 and NLM=10) as a supplementary discovery cohort (cohort 1). The findings of the present study indicated that the intestinal microbiota richness and diversity were increased in the LM group as compared to the NLM group. A significant difference was observed in species composition between the LM and NLM group. In the two discovery cohorts with two different samples, the dominant phyla were consistent, but varied at lower taxonomic levels. Phylum Fusobacteria presented consistent and significant enrichment in LM group in both discovery cohorts. Furthermore, with the application of a random forest model and receiver operator characteristic curve analysis, Fusobacteria was identified as a potential biomarker for LM. Moreover, Fusobacteria was also a poor prognosis factor for survival. Importantly, the findings were reconfirmed in the validation cohort. On the whole, the findings of the present study demonstrated that CRC with LM and NLM exhibit distinct gut microbiota characteristics. Fusobacteria detection thus has potential for use in predicting LM and a poor prognosis of patients with CRC.

The multispecies microbial cluster of Fusobacterium, Parvimonas, Bacteroides and Faecalibacterium as a precision biomarker for colorectal cancer diagnosis

The incidence of colorectal cancer (CRC) has increased worldwide, and early diagnosis is crucial to reduce mortality rates. Therefore, new noninvasive biomarkers for CRC are required. Recent studies have revealed an imbalance in the oral and gut microbiomes of patients with CRC, as well as impaired gut vascular barrier function. In the present study, the microbiomes of saliva, crevicular fluid, feces, and non-neoplastic and tumor intestinal tissue samples of 93 CRC patients and 30 healthy individuals without digestive disorders (non-CRC) were analyzed by 16S rRNA metabarcoding procedures. The data revealed that Parvimonas, Fusobacterium, and Bacteroides fragilis were significantly over-represented in stool samples of CRC patients, whereas Faecalibacterium and Blautia were significantly over-abundant in the non-CRC group. Moreover, the tumor samples were enriched in well-known periodontal anaerobes, including Fusobacterium, Parvimonas, Peptostreptococcus, Porphyromonas, and Prevotella. Co-occurrence patterns of these oral microorganisms were observed in the subgingival pocket and in the tumor tissues of CRC patients, where they also correlated with other gut microbes, such as Hungatella. This study provides new evidence that oral pathobionts, normally located in subgingival pockets, can migrate to the colon and probably aggregate with aerobic bacteria, forming synergistic consortia. Furthermore, we suggest that the group composed of Fusobacterium, Parvimonas, Bacteroides, and Faecalibacterium could be used to design an excellent noninvasive fecal test for the early diagnosis of CRC. The combination of these four genera would significantly improve the reliability of a discriminatory test with respect to others that use a single species as a unique CRC biomarker.

Exposure to Microcystin-LR Promotes Colorectal Cancer Progression by Altering Gut Microbiota and Associated Metabolites in APCmin/+ Mice

Microcystins (MCs), toxins generated by cyanobacteria, feature microcystin-LR (MC-LR) as one of the most prevalent and toxic variants in aquatic environments. MC-LR not only causes environmental problems but also presents a substantial risk to human health. This study aimed to investigate the impact of MC-LR on APCmin/+ mice, considered as an ideal animal model for intestinal tumors. We administered 40 µg/kg MC-LR to mice by gavage for 8 weeks, followed by histopathological examination, microbial diversity and metabolomics analysis. The mice exposed to MC-LR exhibited a significant promotion in colorectal cancer progression and impaired intestinal barrier function in the APCmin/+ mice compared with the control. Gut microbial dysbiosis was observed in the MC-LR-exposed mice, manifesting a notable alteration in the structure of the gut microbiota. This included the enrichment of Marvinbryantia, Gordonibacter and Family_XIII_AD3011_group and reductions in Faecalibaculum and Lachnoclostridium. Metabolomics analysis revealed increased bile acid (BA) metabolites in the intestinal contents of the mice exposed to MC-LR, particularly taurocholic acid (TCA), alpha-muricholic acid (α-MCA), 3-dehydrocholic acid (3-DHCA), 7-ketodeoxycholic acid (7-KDCA) and 12-ketodeoxycholic acid (12-KDCA). Moreover, we found that Marvinbryantia and Family_XIII_AD3011_group showed the strongest positive correlation with taurocholic acid (TCA) in the mice exposed to MC-LR. These findings provide new insights into the roles and mechanisms of MC-LR in susceptible populations, providing a basis for guiding values of MC-LR in drinking water.

Sishen Pill and its active phytochemicals in treating inflammatory bowel disease and colon cancer: an overview

The incidence of inflammatory bowel disease (IBD) and the associated risk of colon cancer are increasing globally. Traditional Chinese medicine (TCM) treatment has unique advantages. The Sishen Pill, a common Chinese patented drug used to treat abdominal pain and diarrhea, consists mainly of Psoraleae Fructus, Myristicae Semen, Euodiae Fructus, and Schisandra Chinensis. Modern research has confirmed that Sishen Pill and its active secondary metabolites, such as psoralen, myristicin, evodiamine, and schisandrin, can improve intestinal inflammation and exert antitumor pharmacological effects. Common mechanisms in treating IBD and colon cancer mainly include regulating inflammation-related signaling pathways such as nuclear factor-kappa B, mitogen-activated protein kinase, phosphatidylinositol 3-kinase, NOD-like receptor heat protein domain-related protein 3, and wingless-type MMTV integration site family; NF-E2-related factor 2 and hypoxia-inducible factor 1α to inhibit oxidative stress; mitochondrial autophagy and endoplasmic reticulum stress; intestinal immune cell differentiation and function through the Janus kinase/signal transducer and activator of transcription pathway; and improving the gut microbiota and intestinal barrier. Overall, existing evidence suggests the potential of the Sishen pill to improve IBD and suppress inflammation-to-cancer transformation. However, large-scale randomized controlled clinical studies and research on the safety of these clinical applications are urgently required.

Association between the gut microbiota, inflammatory factors, and colorectal cancer: evidence from Mendelian randomization analysis

Background

Colorectal cancer (CRC) is one of the most common malignant tumors primarily affecting individuals over the age of 50 years. Recent studies have suggested that the dysbiosis of the gut microbiota, a community of microorganisms in the human gut, is closely associated with the occurrence and development of CRC. Additionally, inflammatory factors (IFs) have also been reported to play a significant role in the development of CRC. However, the causal relationships between the gut microbiota, IFs, and CRC remain unclear.

Methods

In this study, we performed Mendelian randomization (MR) analysis using publicly available genome-wide association study (GWAS) data to explore the causal relationship between the gut microbiota, IFs, and CRC. The gut microbiota GWAS data were obtained from the MiBioGen study, while the IFs GWAS data were derived from the comprehensive analysis of three independent cohorts. Causal relationship analysis was conducted using appropriate instrumental variables (IVs) and statistical models.

Results

MR analysis of the gut microbiota and CRC revealed a negative correlation between the Lachnospiraceae species in the gut and CRC risk, while a positive correlation was observed between Porphyromonadaceae species, Lachnospiraceae UCG010 genus, Lachnospira genus, and Sellimonas genus in the gut, and CRC risk. Additionally, we observed a causal relationship between IL-10 and CRC risk. These findings suggest that the dysbiosis of the gut microbiota might be associated with an increased risk of CRC and that specific bacterial groups may play a crucial role in the occurrence and development of CRC.

Conclusion

Using MR analysis, this study revealed the causal relationships between the gut microbiota, IFs, and CRC. The negative correlation between the Lachnospiraceae species in the gut and CRC risk, as well as the causal relationship between IL-10 and CRC, provide important clues for the potential roles of gut microbiota regulation and inflammatory factor control in the prevention and treatment of CRC.

Unlocking the secrets: exploring the influence of the aryl hydrocarbon receptor and microbiome on cancer development

Gut microbiota regulates various aspects of human physiology by producing metabolites, metabolizing enzymes, and toxins. Many studies have linked microbiota with human health and altered microbiome configurations with the occurrence of several diseases, including cancer. Accumulating evidence suggests that the microbiome can influence the initiation and progression of several cancers. Moreover, some microbiotas of the gut and oral cavity have been reported to infect tumors, initiate metastasis, and promote the spread of cancer to distant organs, thereby influencing the clinical outcome of cancer patients. The gut microbiome has recently been reported to interact with environmental factors such as diet and exposure to environmental toxicants. Exposure to environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) induces a shift in the gut microbiome metabolic pathways, favoring a proinflammatory microenvironment. In addition, other studies have also correlated cancer incidence with exposure to PAHs. PAHs are known to induce organ carcinogenesis through activating a ligand-activated transcriptional factor termed the aryl hydrocarbon receptor (AhR), which metabolizes PAHs to highly reactive carcinogenic intermediates. However, the crosstalk between AhR and the microbiome in mediating carcinogenesis is poorly reviewed. This review aims to discuss the role of exposure to environmental pollutants and activation of AhR on microbiome-associated cancer progression and explore the underlying molecular mechanisms involved in cancer development.

Metabolic Interaction Between Host and the Gut Microbiota During High-Fat Diet-Induced Colorectal Cancer

Colorectal cancer (CRC) is the second-highest cause of cancer-associated mortality among both men and women worldwide. One of the risk factors for CRC is obesity, which is correlated with a high-fat diet prevalent in Western dietary habits. The association between an obesogenic high-fat diet and CRC has been established for several decades; however, the mechanisms by which a high-fat diet increases the risk of CRC remain unclear. Recent studies indicate that gut microbiota strongly influence the pathogenesis of both high-fat diet-induced obesity and CRC. The gut microbiota is composed of hundreds of bacterial species, some of which are implicated in CRC. In particular, the expansion of facultative anaerobic Enterobacteriaceae, which is considered a microbial signature of intestinal microbiota functional imbalance (dysbiosis), is associated with both high-fat diet-induced obesity and CRC. Here, we review the interaction between the gut microbiome and its metabolic byproducts in the context of colorectal cancer (CRC) during high-fat diet-induced obesity. In addition, we will cover how a high-fat diet can drive the expansion of genotoxin-producing Escherichia coli by altering intestinal epithelial cell metabolism during gut inflammation conditions.

Microbiomes in pancreatic cancer can be an accomplice or a weapon

Recently, several investigations have linked the microbiome to pancreatic cancer progression. It is critical to reveal the role of different microbiomes in the occurrence, development, and treatment of pancreatic cancer. The current review summarizes the various microbiota types in pancreatic cancer while updating and supplementing the mechanisms of the representative gut, pancreatic, and oral microbiota, and their metabolites during its pathogenesis and therapeutic intervention. Several novel strategies have been introduced based on the tumor-associated microbiome to optimize the early diagnosis and prognosis of pancreatic cancer. The pros and cons involving different microbiomes in treating pancreatic cancer are discussed. The microbiome-related clinical trials for pancreatic cancer theranostics are outlined. This convergence of cutting-edge knowledge will provide feasible ideas for developing innovative therapies against pancreatic cancer.

The Evolving Microbiome of Dental Caries

Dental caries is a significant oral and public health problem worldwide, especially in low-income populations. The risk of dental caries increases with frequent intake of dietary carbohydrates, including sugars, leading to increased acidity and disruption of the symbiotic diverse and complex microbial community of health. Excess acid production leads to a dysbiotic shift in the bacterial biofilm composition, demineralization of tooth structure, and cavities. Highly acidic and acid-tolerant species associated with caries include Streptococcus mutans, Lactobacillus, Actinomyces, Bifidobacterium, and Scardovia species. The differences in microbiotas depend on tooth site, extent of carious lesions, and rate of disease progression. Metagenomics and metatranscriptomics not only reveal the structure and genetic potential of the caries-associated microbiome, but, more importantly, capture the genetic makeup of the metabolically active microbiome in lesion sites. Due to its multifactorial nature, caries has been difficult to prevent. The use of topical fluoride has had a significant impact on reducing caries in clinical settings, but the approach is costly; the results are less sustainable for high-caries-risk individuals, especially children. Developing treatment regimens that specifically target S. mutans and other acidogenic bacteria, such as using nanoparticles, show promise in altering the cariogenic microbiome, thereby combatting the disease.

Synbiotics as potent functional food: recent updates on therapeutic potential and mechanistic insight

Synbiotics are the specific mixtures of prebiotics with probiotics intended to give health benefits to the host by stabilizing and supporting the gut microbiota.The prebiotic substance used in the synbiotics selectively favors the growth and metabolite production of probiotics. Gut microbiome dysbiosis may lead to generation and progression of various chronic diseases. Synbiotics act synergistically to modulate the gut ecosystem for improvement of metabolic health of the host. Probiotics have been found promising against various diseases being safer, effective, as an alternative or combinatorial therapy. Specific combinations of probiotics with suitable prebiotic substrate as synbiotics, may be the more effective therapeutic agents that can provide all benefits of probiotics as well as prebiotics. Though, effective combinations, dosage, mechanism of action, safety, cost effectiveness and other clinical investigations are required to be established along with other relevant aspects. Synbiotics have the potential to be functional food of importance in future. Present review summarizes the mechanistic overview of synbiotics related to gut microbiota, therapeutic potential and promising health benefits for human illnesses according to the available literature. In present scenario, synbiotics are more promising future alternatives as therapeutics to maintain healthy microbiota inside the host gut which directly affects the onset or development ofrelated disorders or diseases.

Commensal microbiota-derived metabolite agmatine triggers inflammation to promote colorectal tumorigenesis

Colorectal cancer (CRC), a malignant tumor worldwide, is associated with gut microbiota. The influence of gut microbe-derived metabolites on CRC has attracted a lot of attention. However, the role of immunity mediated by commensal microbiota-derived metabolites in tumorigenesis of CRC is not intensively explored. Here we monitored the gut microbial dysbiosis in CRC mouse model (ApcMin/+ model) without dietary and pharmacological intervention, followed by characterized of metabolites enriched in CRC model mice. Profound changes of gut microbiome (bacteriome) were observed during intestinal disorders. Metabolomic profiling indicated that agmatine, derived from the gut bacteria i.e. Blautia, Odoribacter, Alistipes and Paraprevotella, could interact with Rnf128 to suppress the Rnf128-mediated ubiquitination of β-catenin to further upregulate the downstream targets of β-catenin including Cyclin D1, Lgr5, CD44 and C-myc, thus activating Wnt signaling. The activated Wnt signaling pathway promoted dysplasia of intestinal cells and inflammatory infiltration of lymphocytes via inducing the upregulation of pro-inflammatory cytokines (IL-6 and TNF-α) and downregulation of anti-inflammatory cytokine (IL-10), thereby contributing to colorectal carcinogenesis. Therefore, our study presented novel insights into the roles and mechanisms of gut microbiota in pathogenesis of CRC.

Prevalence of Pentatrichomonas hominis in foxes and raccoon dogs and changes in the gut microbiota of infected female foxes in the Hebei and Henan Provinces in China

Pentatrichomonas hominis (P. hominis) is a zoonotic parasite that affects a wide range of hosts, causing gastrointestinal diseases. The present study aimed to evaluate the prevalence of P. hominis among caged foxes and raccoon dogs and the effect of P. hominis on the gut microbiota in female foxes. A total of 893 fresh fecal samples were collected from the Hebei and Henan Provinces in China. P. hominis was screened based on 18S rRNA gene expression via nested PCR. The difference in the gut microbiota between nine P. hominis-positive and nine P. hominis-negative samples was investigated by 16S rRNA gene sequencing. The total prevalence of P. hominis infection in foxes and raccoon dogs was 31.7% (283/893). The prevalence rates of P. hominis infection were 28.2% (88/312) and 33.6% (195/581) in foxes and raccoon dogs, respectively. Phylogenetic analysis revealed that all P. hominis strains detected in foxes and raccoon dogs in the present study were the zoonotic genotype CC1. Moreover, compared with those in the P. hominis-negative group, the diversity of the gut microbiota in the P. hominis-positive group was lower, and the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidetes (F/B) in the P. hominis-positive group were lower than those in the P. hominis-negative group. We speculate that these differences may be due to indigestion and diarrhea in infected female foxes. Overall, the present study evaluated the prevalence of P. hominis in foxes and raccoon dogs in the Henan and Hebei Provinces and revealed that P. hominis infection interrupted the diversity of the gut microbiota in female foxes.

Single-cell profiling reveals the impact of genetic alterations on the differentiation of inflammation-induced colon tumors

Genetic mutations and chronic inflammation of the colon contribute to the development of colorectal cancer (CRC). Using a murine model of inflammation-induced colon tumorigenesis, we determined how genetic mutations alter colon tumor cell differentiation. Inflammation induced by enterotoxigenic Bacteroides fragilis (ETBF) colonization of multiple intestinal neoplasia (Min ApcΔ716/+ ) mice triggers loss of heterozygosity of Apc causing colon tumor formation. Here, we report that the addition of BRAF V600E mutation ( BRAF FV600E Lgr5 tm1(Cre/ERT2)Cle Min ApcΔ716/+ , BLM) or knocking out Msh2 ( Msh2 LoxP/LoxP Vil1-cre Min ApcΔ716/+ , MSH2KO) in the Min model altered colon tumor differentiation. Using single cell RNA-sequencing, we uncovered the differences between BLM, Min, and MSH2KO tumors at a single cell resolution. BLM tumors showed an increase in differentiated tumor epithelial cell lineages and a reduction in the stem cell population. In contrast, MSH2KO tumors were characterized by an increased stem cell population that had higher WNT signaling activity compared to Min tumors. Additionally, comparative analysis of single-cell transcriptomics revealed that BLM tumors had higher expression of transcription factors that drive differentiation, such as Cdx2, than Min tumors. Using RNA velocity, we were able to identify additional potential regulators of BLM tumor differentiation such as NDRG1. The role of CDX2 and NDRG1 as putative regulators for BLM tumor cell differentiation was verified using organoids derived from BLM tumors. Our results demonstrate the critical connections between genetic mutations and cell differentiation in inflammation-induced colon tumorigenesis. Understanding such roles will deepen our understanding of inflammation-associated colon cancer.

The role of intermittent fasting and the ketogenic diet in cancer disease: can they replace the Mediterranean diet?

The prevalence of cancer is rising globally, and it is the second leading cause of death. Nutrition has an important influence on the risk of developing cancer. Moreover, changes in the gut microbiota are connected to the risk of developing cancer and are critical for sustaining immunity. Various studies have shown that intermittent fasting, ketogenic diet, and the Mediterranean diet are effective therapies in changing the intestinal microbiota, the prevention of cancer, and the improvement of tolerance to treatment in cancer patients. Although there is not enough evidence to show that the ketogenic diet is effective in changing the intestinal microbiota in a manner that could prevent cancer, intermittent fasting and the Mediterranean diet could positively affect composition of intestinal microbiota against cancer. In addition, the ketogenic diet, intermittent fasting, and the Mediterranean diet have the potential to stimulate anticarcinogenic pathways, and they might increase cancer patients' quality of life according to scientific evidence. In this review, we represent and argue recent scientific data on relationship between intermittent fasting, the ketogenic diet, and the Mediterranean diet, intestinal microbiota, cancer prevention and cancer treatment.

Non-Genomic Hallmarks of Aging-The Review

Aging is a natural, gradual, and inevitable process associated with a series of changes at the molecular, cellular, and tissue levels that can lead to an increased risk of many diseases, including cancer. The most significant changes at the genomic level (DNA damage, telomere shortening, epigenetic changes) and non-genomic changes are referred to as hallmarks of aging. The hallmarks of aging and cancer are intertwined. Many studies have focused on genomic hallmarks, but non-genomic hallmarks are also important and may additionally cause genomic damage and increase the expression of genomic hallmarks. Understanding the non-genomic hallmarks of aging and cancer, and how they are intertwined, may lead to the development of approaches that could influence these hallmarks and thus function not only to slow aging but also to prevent cancer. In this review, we focus on non-genomic changes. We discuss cell senescence, disruption of proteostasis, deregualation of nutrient sensing, dysregulation of immune system function, intercellular communication, mitochondrial dysfunction, stem cell exhaustion and dysbiosis.

Exploring the gut microbiota: lifestyle choices, disease associations, and personal genomics

The gut microbiota is a rich and dynamic ecosystem that actively interacts with the human body, playing a significant role in the state of health and disease of the host. Diet, exercise, mental health, and other factors have exhibited the ability to influence the gut bacterial composition, leading to changes that can prevent and improve, or favor and worsen, both intestinal and extra-intestinal conditions. Altered gut microbial states, or 'dysbiosis', associated with conditions and diseases are often characterized by shifts in bacterial abundance and diversity, including an impaired Firmicutes to Bacteroidetes ratio. By understanding the effect of lifestyle on the gut microbiota, personalized advice can be generated to suit each individual profile and foster the adoption of lifestyle changes that can both prevent and ameliorate dysbiosis. The delivery of effective and reliable advice, however, depends not only on the available research and current understanding of the topic, but also on the methods used to assess individuals and to discover the associations, which can introduce bias at multiple stages. The aim of this review is to summarize how human gut microbial variability is defined and what lifestyle choices and diseases have shown association with gut bacterial composition. Furthermore, popular methods to investigate the human gut microbiota are outlined, with a focus on the possible bias caused by the lack of use of standardized methods. Finally, an overview of the current state of personalized advice based on gut microbiota testing is presented, underlining its power and limitations.

Diet-mediated gut microbial community modulation and signature metabolites as potential biomarkers for early diagnosis, prognosis, prevention and stage-specific treatment of colorectal cancer

BACKGROUND

Over the last decade, studies have shown an increased incidence of colorectal cancer (CRC), particularly early onset colorectal cancer (EOCRC). Researchers have demonstrated that dietary behavior, especially among young adults, influences alterations in the gut microbial community, leading to an increased accumulation of pathogenic gut microbiota and a decrease in beneficial ones. Unfortunately, CRC is likely to be diagnosed at a late stage, increasing CRC-related mortality. However, this alteration in the gut microbiota (gut dysbiosis) can be harnessed as a biomarker for non-invasive diagnosis, prognosis, prevention, and treatment of CRC in an effort to prevent late diagnosis and poor prognosis associated with CRC.

AIM OF REVIEW

This review discusses identification of potential biomarkers by targeting diet-mediated gut dysbiosis for the stage-specific diagnosis, prognosis, treatment, and prevention of CRC. Our findings provide a comprehensive insight into the potential of protumorigenic bacteria (e.g.pathogenic Escherichia coli,enterotoxigenic Bacteroides fragilis and Fusobacterium nucleatum) and their metabolites (e.g., colibactin and B. fragilis toxin) from gut dysbiosis as biomarkers for the diagnosis of CRC.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Collectively, a detailed understanding of the available data from current studies suggests that, further research on quantification of metabolites and stage-specific pathogenic microbial abundance is required for the diagnosis and treatment of CRC based on microbial dysbiosis. Specifically, future studies on faecal samples, from patient with CRC, should be conducted for F. nucleatum among different opportunistic bacteria, given its repeated occurrence in faecal samples and CRC biopsies in numerous studies. Finally, we discuss the potential of faecal microbial transplantation (FMT) as an intervention to restore damaged gut microbiota during CRC treatment and management.

Chemopreventive effect of a milk whey by-product derived from Buffalo (Bubalus bubalis) in protecting from colorectal carcinogenesis

BACKGROUND

Several studies show that natural foods are a source of compounds with anticancer properties that affect the gut microbiota and its metabolites. In the present study, we investigate the effect of a delactosed buffalo milk whey by-product (DMW) on colorectal carcinogenesis.

METHODS

The effect of DMW on colorectal carcinoma (CRC) was investigated in the established mouse model of azoxymethane (AOM)-induced colon carcinoma, which closely resembles the human clinical condition of CRC. The effect of DMW on CRC immortalized cell lines was also evaluated to further identify the antineoplastic mechanism of action.

RESULTS

Pretreatment of AOM-treated mice with DMW significantly (P < 0.05) reduced the percentage of mice bearing both aberrant crypt foci with more than four crypts (which are early precancerous lesions that progress to CRC) and tumors. In addition, DMW completely counteracted the effect of AOM on protein expression of caspase-9, cleaved caspase-3 and poly ADP-ribose polymerase in colonic tissue. Administration of DMW alone (i.e. without AOM) resulted in changes in the composition of the gut microbiota, leading to enrichment or depletion of genera associated with health and disease, respectively. DMW was also able to restore AOM-induced changes in specific genera of the gut microbiota. Specifically, DMW reduced the genera Atopobiaceae, Ruminococcus 1 and Lachnospiraceae XPB1014 and increased the genera Parabacteroides and Candidatus Saccharimonas, which were increased and reduced, respectively, by AOM. Blood levels of butyric acid and cancer diagnostic markers (5-methylcytidine and glycerophosphocholine), which were increased by AOM treatment, were reduced by DMW. Furthermore, DMW exerted cytotoxic effects on two human CRC cell lines (HCT116 and HT29) and these effects were associated with the induction of apoptotic signaling.

CONCLUSIONS

Our results suggest that DMW exerts chemopreventive effects and restores the gut microbiota in AOM-induced CRC, and induces cytotoxic effect on CRC cells. DMW could be an important dietary supplement to support a healthy gut microbiota and reduce the prevalence of CRC in humans. Video Abstract.

[Ulcerative colitis-associated carcinogenesis : An update]

Ulcerative colitis (UC) is a chronic inflammatory bowel disease beginning in the rectum and gradually extending to the right-sided colon and the terminal ileum (backwash-ileitis). Its causes are still not completely understood. Genetic susceptibility, changes in the microbiota and immune response, as well as environmental factors are thought to influence the disease course.Patients with UC are at increased risk of developing colorectal cancer (CRC) when compared to an age-matched normal population. Cancer risk increases with early onset, duration, and extent of the disease, with development of strictures, intraepithelial neoplasia, and concomitant primary sclerosing cholangitis.In contrast to the sporadic adenoma-carcinoma-sequence, UC-related CRC develops through an inflammation-intraepithelial neoplasia-carcinoma-sequence, in which genetic alterations already occur in the inflamed epithelium before the development of intraepithelial neoplasia.This article summarizes the current state of knowledge regarding UC-related carcinogenesis and its possible impact on prevention and therapy.

Gut microbiota of healthy Asians and their discriminative features revealed by metagenomics approach

This study is conducted to identify the microbial architecture and its functional capacity in the Asian population via the whole metagenomics approach. A brief comparison of the Asian countries namely Malaysia, India, China, and Thailand, was conducted, giving a total of 916 taxa under observation. Results show a close representation of the taxonomic diversity in the gut microbiota of Malaysia, India, and China, where Bacteroidetes, Firmicutes, and Actinobacteria were more predominant compared to other phyla. Mainly due to the multi-racial population in Malaysia, which also consists of Malays, Indian, and Chinese, the population tend to share similar dietary preferences, culture, and lifestyle, which are major influences that shapes the structure of the gut microbiota. Moreover, Thailand showed a more distinct diversity in the gut microbiota which was highly dominated by Firmicutes. Meanwhile, functional profiles show 1034 gene families that are common between the four countries. The Malaysia samples are having the most unique gene families with a total of 67,517 gene families, and 51 unique KEGG Orthologs, mainly dominated by the metabolic pathways, followed by microbial metabolism in diverse environments. In conclusion, this study provides some general overview on the structure of the Asian gut microbiota, with some additional highlights on the Malaysian population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03671-3.

Probiotic-Derived Bioactive Compounds in Colorectal Cancer Treatment

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and antiproliferative properties. This review provides a classification of postbiotic types and a comprehensive summary of the current state of research on their biological role against CRC. It also describes how their intricate interaction with the gut microbiota regulates the proper function of the intestinal barrier, thus eliminating gut dysbiosis and CRC development. Finally, it discusses the future perspectives in precision-medicine approaches as well as the challenges of their synthesis and optimization of administration in clinical studies.

From Non-Alcoholic Fatty Liver Disease to Liver Cancer: Microbiota and Inflammation as Key Players

It is estimated that 25% of the world's population has non-alcoholic fatty liver disease. This disease can advance to a more severe form, non-alcoholic steatohepatitis (NASH), a disease with a greater probability of progression to cirrhosis and hepatocellular carcinoma (HCC). NASH could be characterized as a necro-inflammatory complication of chronic hepatic steatosis. The combination of factors that lead to NASH and its progression to HCC in the setting of inflammation is not clearly understood. The portal vein is the main route of communication between the intestine and the liver. This allows the transfer of products derived from the intestine to the liver and the hepatic response pathway of bile and antibody secretion to the intestine. The intestinal microbiota performs a fundamental role in the regulation of immune function, but it can undergo changes that alter its functionality. These changes can also contribute to cancer by disrupting the immune system and causing chronic inflammation and immune dysfunction, both of which are implicated in cancer development. In this article, we address the link between inflammation, microbiota and HCC. We also review the different in vitro models, as well as recent clinical trials addressing liver cancer and microbiota.

Association between nonalcoholic fatty liver disease and colorectal cancer: A population-based study

Colorectal cancer (CRC) and nonalcoholic fatty liver disease (NAFLD) have high prevalence rates and place a considerable burden on the health-care industry. The association between both diseases is controversial. Our aim was to examine the association between NAFLD and CRC. Using data extracted from the Taiwan National Health Insurance Research Database (NHIRD) from 2000 to 2015, we enrolled 60 298 patients with NAFLD. Of these, 52,986 met the inclusion criteria. A comparison group was selected using 4-fold propensity score matching by age, sex, and year of index date. The primary outcome was the cumulative incidence of CRC in patients with NAFLD. Over a mean follow-up period of 8.5 years, 160 new cases of CRC were identified. The incidence rate of CRC was higher in the NAFLD group (12.23 per 100,000 person-years) than in the comparison cohort (6.0 per 100,000 person-years). Cox proportional hazards regression analysis revealed that the adjusted hazard ratio (HR) of CRC was 1.259 in the study group (95% confidence interval [CI]: 1.047-1.486, P = .003). Using Kaplan-Meier analysis, we ascertained that the cumulative incidence of CRC was significantly high in the NAFLD group. Patients older than 50 years, with diabetes mellitus (DM), and with chronic liver disease also exhibited a high risk of CRC. NAFLD was associated with a high risk of CRC. CRC occurs more frequently in patients with NAFLD aged between 50 and 59 years and those older than 60 years with comorbidities, including DM and chronic liver disease. Physicians should consider the subsequent risk of CRC when treating patients with NAFLD.

Gut microbiota and ionizing radiation-induced damage: Is there a link?

According to observational findings, ionizing radiation (IR) triggers dysbiosis of the intestinal microbiota, affecting the structural composition, function, and species of the gut microbiome and its metabolites. These modifications can further exacerbate IR-induced damage and amplify proinflammatory immune responses. Conversely, commensal bacteria and favorable metabolites can remodel the IR-disturbed gut microbial structure, promote a balance between anti-inflammatory and proinflammatory mechanisms in the body, and mitigate IR toxicity. The discovery of effective and safe remedies to prevent and treat radiation-induced injuries is vitally needed because of the proliferation of radiation toxicity threats produced by recent radiological public health disasters and increasing medical exposures. This review examines how the gut microbiota and its metabolites are linked to the processes of IR-induced harm. We highlight protective measures based on interventions with gut microbes to optimize the distress caused by IR damage to human health. We offer prospects for research in emerging and promising areas targeting the prevention and treatment of IR-induced damage.

Implication of Obesity and Gut Microbiome Dysbiosis in the Etiology of Colorectal Cancer

The complexity and variety of gut microbiomes within and among individuals have been extensively studied in recent years in connection to human health and diseases. Our growing understanding of the bidirectional communication between metabolic diseases and the gut microbiome has also highlighted the significance of gut microbiome dysbiosis in the genesis and development of obesity-related cancers. Therefore, it is crucial to comprehend the possible role of the gut microbiota in the crosstalk between obesity and colorectal cancer (CRC). Through the induction of gut microbial dysbiosis, gut epithelial barrier impairment, metabolomic dysregulation, chronic inflammation, or dysregulation in energy harvesting, obesity may promote the development of colorectal tumors. It is well known that strategies for cancer prevention and treatment are most effective when combined with a healthy diet, physical activity, and active lifestyle choices. Recent studies also suggest that an improved understanding of the complex linkages between the gut microbiome and various cancers as well as metabolic diseases can potentially improve cancer treatments and overall outcomes. In this context, we herein review and summarize the clinical and experimental evidence supporting the functional role of the gut microbiome in the pathogenesis and progression of CRC concerning obesity and its metabolic correlates, which may pave the way for the development of novel prognostic tools for CRC prevention. Therapeutic approaches for restoring the microbiome homeostasis in conjunction with cancer treatments are also discussed herein.

Molecular methods for colorectal cancer screening: Progress with next-generation sequencing evolution

Currently, colorectal cancer (CRC) represents the third most common malignancy and the second most deadly cancer worldwide, with a higher incidence in developed countries. Like other solid tumors, CRC is a heterogeneous genomic disease in which various alterations, such as point mutations, genomic rearrangements, gene fusions or chromosomal copy number alterations, can contribute to the disease development. However, because of its orderly natural history, easily accessible onset location and high lifetime incidence, CRC is ideally suited for preventive intervention, but the many screening efforts of the last decades have been compromised by performance limitations and low penetrance of the standard screening tools. The advent of next-generation sequencing (NGS) has both facilitated the identification of previously unrecognized CRC features such as its relationship with gut microbial pathogens and revolutionized the speed and throughput of cataloguing CRC-related genomic alterations. Hence, in this review, we summarized the several diagnostic tools used for CRC screening in the past and the present, focusing on recent NGS approaches and their revolutionary role in the identification of novel genomic CRC characteristics, the advancement of understanding the CRC carcinogenesis and the screening of clinically actionable targets for personalized medicine.

In Vitro Fermentation of Edible Mushrooms: Effects on Faecal Microbiota Characteristics of Autistic and Neurotypical Children

Children with autism spectrum disorder (ASD) often suffer gastrointestinal disturbances consistent with gut microbiota (GM) alterations. Treatment with pro/prebiotics may potentially alleviate gut symptoms, but the evidence for prebiotics is scarce. This study aims to evaluate the effects of edible mushrooms (Pleurotus, Basidiomycota) and prebiotic compounds on GM composition and metabolite production in vitro, using faecal samples from autistic and non-autistic children. Specific microbial populations were enumerated after 24 h of fermentation by quantitative PCR, and the metabolic production was determined by gas chromatography. Higher levels of Prevotella spp. and Bifidobacterium spp. were measured in neurotypical children compared to ASD children. A total of 24 h fermentation of Pleurotus eryngii and P. ostreatus mushroom powder increased the levels of Bifidobacterium, while known prebiotics increased the levels of total bacteria and Bacteroides in both groups. Only P. eryngii mushrooms resulted in significantly elevated levels of total bacteria Bacteroides and Feacalibacterium prausnitzii compared to the negative control (NC) in the ASD group. Both mushrooms induced elevated levels of butyrate after 24 h of fermentation, while short-chain fructooligosaccharides induced increased levels of acetate in the ASD group, compared to NC. Overall, this study highlights the positive effect of edible mushrooms on the GM and metabolic activity of children with ASD.

Multifactorial Diseases of the Heart, Kidneys, Lungs, and Liver and Incident Cancer: Epidemiology and Shared Mechanisms

Within the aging population, the frequency of cancer is increasing dramatically. In addition, multiple genetic and environmental factors lead to common multifactorial diseases, including cardiovascular disease, chronic kidney disease, chronic obstructive pulmonary disease, and metabolic-associated fatty liver disease. In recent years, there has been a growing awareness of the connection between cancer and multifactorial diseases, as well as how one can affect the other, resulting in a vicious cycle. Although the exact mechanistic explanations behind this remain to be fully explored, some progress has been made in uncovering the common pathologic mechanisms. In this review, we focus on the nature of the link between cancer and common multifactorial conditions, as well as specific shared mechanisms, some of which may represent either preventive or therapeutic targets. Rather than organ-specific interactions, we herein focus on the shared mechanisms among the multifactorial diseases, which may explain the increased cancer risk. More research on this subject will highlight the significance of developing new drugs that target multiple systems rather than just one disease.

The crosstalk between the gut microbiota and tumor immunity: Implications for cancer progression and treatment outcomes

The gastrointestinal tract is inhabited by trillions of commensal microorganisms that constitute the gut microbiota. As a main metabolic organ, the gut microbiota has co-evolved in a symbiotic relationship with its host, contributing to physiological homeostasis. Recent advances have provided mechanistic insights into the dual role of the gut microbiota in cancer pathogenesis. Particularly, compelling evidence indicates that the gut microbiota exerts regulatory effects on the host immune system to fight against cancer development. Some microbiota-derived metabolites have been suggested as potential activators of antitumor immunity. On the contrary, the disequilibrium of intestinal microbial communities, a condition termed dysbiosis, can induce cancer development. The altered gut microbiota reprograms the hostile tumor microenvironment (TME), thus allowing cancer cells to avoid immunosurvelliance. Furthermore, the gut microbiota has been associated with the effects and complications of cancer therapy given its prominent immunoregulatory properties. Therapeutic measures that aim to manipulate the interplay between the gut microbiota and tumor immunity may bring new breakthroughs in cancer treatment. Herein, we provide a comprehensive update on the evidence for the implication of the gut microbiota in immune-oncology and discuss the fundamental mechanisms underlying the influence of intestinal microbial communities on systemic cancer therapy, in order to provide important clues toward improving treatment outcomes in cancer patients.

Role of Traditional Chinese Medicine Syndrome Type, Gut Microbiome, and Host Immunity in Predicting Early and Advanced Stage Colorectal Cancer

OBJECTIVE

To investigate the role of Traditional Chinese Medicine (TCM) syndrome type, gut microbiome distribution, and host immunity function in predicting the early and advanced clinical stages of colorectal cancer (CRC).

METHODS

A cross-sectional case-control study was performed which included 48 early stage and 48 advanced patients with CRC enrolled from March 2018 to December 2020. 16S rRNA gene sequencing was performed to analyze the gut microbiomes of the patients, while T and B lymphocyte subsets in peripheral blood were assessed using flow cytometry. TCM syndrome type was measured using the spleen deficiency syndrome (SDS) scale.

RESULTS

The abundance levels of Prevotella, Escherichia-Shigella, and Faecalibacterium in the gut microbiota were significantly increased in the advanced group, while Bacteroides was significantly decreased. Phascolarctobacterium was detectable only in the early metaphase group, whereas Alistipes was detectable only in the advanced group. The lymphocyte (P = .006), T helper cell (TH) (P = .002), cytotoxic T cell (TC) (P = .003), double positive T cell (DPT) (P = .02), and total T counts (P = .001) were significantly higher in the early metaphase group than in the advanced metaphase group. Compared with patients with early stage CRC, the advanced group had a higher SDS score. After adjusting for clinical stage, Spearman's correlation analysis showed interactions among gut microbiome abundance, T cell level, and SDS score. Multivariate logistic analysis showed that after controlling for the SDS score, abundance of Alistipes and Faecalibacterium, and double negative T cell (DNT) level, DPT was significantly associated with a lower risk of advanced-stage disease (hazard ratio, 0.918; P = .022).

CONCLUSION

Our study suggested associations between clinical stage, SDS, gut microbiota, and T lymphocytes, which provided insights for a potential prediction model for the disease progression of CRC.

Specific fungi associated with response to capsulized fecal microbiota transplantation in patients with active ulcerative colitis

Objective

Fecal microbiota transplantation (FMT) is a novel microbial treatment for patients with ulcerative colitis (UC). In this study, we performed a clinical trial of capsulized FMT in UC patients to determine the association between the gut fungal community and capsulized FMT outcomes.

Design

This study recruited patients with active UC (N = 22) and healthy individuals (donor, N = 9) according to the criteria. The patients received capsulized FMT three times a week. Patient stool samples were collected before (week 0) and after FMT follow-up visits at weeks 1, 4, and 12. Fungal communities were analysed using shotgun metagenomic sequencing.

Results

According to metagenomic analysis, fungal community evenness index was greater in samples collected from patients, and the overall fungal community was clustered among the samples collected from donors. The dominant fungi in fecal samples collected from donors and patients were Ascomycota and Basidiomycota. However, capsulized FMT ameliorated microbial fungal diversity and altered fungal composition, based on metagenomic analysis of fecal samples collected before and during follow-up visits after capsulized FMT. Fungal diversity decreased in samples collected from patients who achieved remission after capsulized FMT, similar to samples collected from donors. Patients achieving remission after capsulized FMT had specific enrichment of Kazachstania naganishii, Pyricularia grisea, Lachancea thermotolerans, and Schizosaccharomyces pombe compared with patients who did not achieve remission. In addition, the relative abundance of P. grisea was higher in remission fecal samples during the follow-up visit. Meanwhile, decreased levels of pathobionts, such as Candida and Debaryomyces hansenii, were associated with remission in patients receiving capsulized FMT.

Conclusion

In the metagenomic analysis of fecal samples from donors and patients with UC receiving capsulized FMT, shifts in gut fungal diversity and composition were associated with capsulized FMT and validated in patients with active UC. We also identified the specific fungi associated with the induction of remission. ClinicalTrails.gov (NCT03426683).

Examining the Role of Microbiota-Centered Interventions in Cancer Therapeutics: Applications for Urothelial Carcinoma

Modern advances in genomic and molecular technologies have sparked substantial research on the human intestinal microbiome over the past decade. A deeper understanding of the microbiome has illuminated that dysbiosis, or a disruption in the microbiome, is associated with inflammatory disease states and carcinogenesis. Novel therapies that target the microbiome and restore healthy flora may have value in dampening the immunopathologic state induced by dysbiosis. A narrative review of the literature on the use of microbiota-centered interventions (MCIs) was conducted. Several randomized clinical trials show that MCIs can augment response to immune checkpoint inhibitor (ICI) therapy in patients with metastatic cancer. Clinical trials have also demonstrated that modulation of the intestinal microbiome can enhance recovery and reduce infectious complications in the surgical management of colorectal adenocarcinoma. Overall, these major discoveries suggest future clinical applications of MCIs for a wide range of immune-mediated conditions. These results may also translate to improved patient outcomes in systemic immunotherapy for urothelial carcinoma as well as in patients recovering from radical cystectomy (RC), which is complicated by high infection rates. Further research is needed to evaluate the optimal bacterial composition of microbiota-centered therapies and the specific cellular changes that lead to improved tumor antigen recognition after microbiota-centered therapies.

Prediction model of poorly differentiated colorectal cancer (CRC) based on gut bacteria

BACKGROUND

The mortality of colorectal cancer is high, the malignant degree of poorly differentiated colorectal cancer is high, and the prognosis is poor.

OBJECTIVE

To screen the characteristic intestinal microbiota of poorly differentiated intestinal cancer.

METHODS

Fecal samples were collected from 124 patients with moderately differentiated CRC and 123 patients with poorly differentiated CRC, and the bacterial 16S rRNA V1-V4 region of the fecal samples was sequenced. Alpha diversity analysis was performed on fecal samples to assess the diversity and abundance of flora. The RDP classifier Bayesian algorithm was used to analyze the community structure. Linear discriminant analysis and Student's t test were used to screen the differences in flora. The PICRUSt1 method was used to predict the bacterial function, and six machine learning models, including logistic regression, random forest, neural network, support vector machine, CatBoost and gradient boosting decision tree, were used to construct a prediction model for the poor differentiation of colorectal cancer.

RESULTS

There was no significant difference in fecal flora alpha diversity between moderately and poorly differentiated colorectal cancer (P > 0.05). The bacteria that accounted for a large proportion of patients with poorly differentiated and moderately differentiated colorectal cancer were Blautia, Escherichia-Shigella, Streptococcus, Lactobacillus, and Bacteroides. At the genus level, there were nine bacteria with high abundance in the poorly differentiated group, including Bifidobacterium, norank_f__Oscillospiraceae, Eisenbergiella, etc. There were six bacteria with high abundance in the moderately differentiated group, including Megamonas, Erysipelotrichaceae_UCG-003, Actinomyces, etc. The RF model had the highest prediction accuracy (100.00% correct). The bacteria that had the greatest variable importance in the model were Pseudoramibacter, Megamonas and Bifidobacterium.

CONCLUSION

The degree of pathological differentiation of colorectal cancer was related to gut flora, and poorly differentiated colorectal cancer had some different bacterial flora, and intestinal bacteria can be used as biomarkers for predicting poorly differentiated CRC.

Female reproductive dysfunctions and the gut microbiota

The gut microbiome is considered an endocrine organ that can influence distant organs and associated biological pathways. Recent advances suggest that gut microbial homeostasis is essential for reproductive health and that perturbations in the gut microbiota can lead to reproductive pathologies. This review provides an updated overview of the relationship between the gut microbiome and female reproductive diseases. Specifically, we highlight the most recent findings on the gut microbiome in gynecological pathologies including polycystic ovarian syndrome, endometriosis, and endometrial cancer. Most studies revealed associations between altered gut microbial compositions and these reproductive diseases, though few have suggested cause-effect relationships. Future studies should focus on determining the molecular mechanisms underlying associations between gut microbiota and reproductive diseases. Understanding this bidirectional relationship could lead to the development of novel and effective strategies to prevent, diagnose, and treat female reproductive organ-related diseases.

Antitumor effects of fecal microbiota transplantation: Implications for microbiome modulation in cancer treatment

Fecal microbiome transplantation (FMT) from healthy donors is one of the techniques for restoration of the dysbiotic gut, which is increasingly being used to treat various diseases. Notably, mounting evidence in recent years revealed that FMT has made a breakthrough in the oncology treatment area, especially by improving immunotherapy efficacy to achieve antitumor effects. However, the mechanism of FMT in enhancing antitumor effects of immune checkpoint blockers (ICBs) has not yet been fully elucidated. This review systematically summarizes the role of microbes and their metabolites in the regulation of tumor immunity. We highlight the mechanism of action of FMT in the treatment of refractory tumors as well as in improving the efficacy of immunotherapy. Furthermore, we summarize ongoing clinical trials combining FMT with immunotherapy and further focus on refined protocols for the practice of FMT in cancer treatment, which could guide future directions and priorities of FMT scientific development.

Interactions between the gut microbiota-derived functional factors and intestinal epithelial cells - implication in the microbiota-host mutualism

Mutual interactions between the gut microbiota and the host play essential roles in maintaining human health and providing a nutrient-rich environment for the gut microbial community. Intestinal epithelial cells (IECs) provide the frontline responses to the gut microbiota for maintaining intestinal homeostasis. Emerging evidence points to commensal bacterium-derived components as functional factors for the action of commensal bacteria, including protecting intestinal integrity and mitigating susceptibility of intestinal inflammation. Furthermore, IECs have been found to communicate with the gut commensal bacteria to shape the composition and function of the microbial community. This review will discuss the current understanding of the beneficial effects of functional factors secreted by commensal bacteria on IECs, with focus on soluble proteins, metabolites, and surface layer components, and highlight the impact of IECs on the commensal microbial profile. This knowledge provides a proof-of-concept model for understanding of mechanisms underlying the microbiota-host mutualism.

Changes of gut microbiota in colorectal cancer patients with Pentatrichomonas hominis infection

Pentatrichomonas hominis is a parasitic trichomonads protozoa that parasitizes in the colon and cecum of humans and other animals. Our previous studies have demonstrated that infection with P. hominis is associated with the incidence of colon cancer (37.93%). However, the mechanism by which P. hominis infections increase the incidence of colon cancer remains unclear. Previous studies have suggested that certain parasites promote colon cancer by regulating gut microbiota. This study aimed to elucidate whether the association between P. hominis infections and the increased incidence of colon cancer is related to changes in gut microbiota. Therefore, the gut microbiota patients with colon cancer who were infected with P. hominis and uninfected patients with colon cancer were analyzed by 16S rRNA high-throughput sequencing. The results demonstrated that patients with colon cancer who were not infected with P. hominis showed increased gut bacterial diversity, a higher relative abundance of Alcaligenes sp., Leucobacter sp., Paraprevotella sp., Ruminococcaceae UCG-002, and a significant reduction in the abundance of Veillonella sp., compared to individuals without colon cancer. Additionally, the relative abundance of the Ruminococcaceae UCG-002 and the Eubacterium eligens groups was reduced, while the relative abundance of bacteria associated with colon cancer, including Flavonifractor sp., Lachnoclostridium sp., and the Ruminococcus gnavus group, increased significantly in patients with colon cancer who were infected with P. hominis, compared to those of uninfected patients with colon cancer. In conclusion, these results suggested that P. hominis infections may aggravate the development of colon cancer and the findings provide new insights for subsequent in-depth studies on the pathogenesis, diagnosis, and prevention of colon cancer.

Alterations in the gastric microbiota and metabolites in gastric cancer: An update review

Gastric cancer (GC) is one of the leading causes of cancer mortality worldwide. Numerous studies have shown that the gastric microbiota can contribute to the occurrence and development of GC by generating harmful microbial metabolites, suggesting the possibility of discovering biomarkers. Metabolomics has emerged as an advanced promising analytical method for the analysis of microbiota-derived metabolites, which have greatly accelerated our understanding of host-microbiota metabolic interactions in GC. In this review, we briefly compiled recent research progress on the changes of gastric microbiota and its metabolites associated with GC. And we further explored the application of metabolomics and gastric microbiome association analysis in the diagnosis, prevention and treatment of GC.

Efficacy and safety of herbal formulas with the function of gut microbiota regulation for gastric and colorectal cancer: A systematic review and meta-analysis

Background

Currently, gastric cancer (GC) and colorectal cancer (CRC) are the most common causes of cancer-related mortality worldwide. Gut microbiota is closely related to the occurrence of GC and CRC and the efficacy of chemotherapy. This study is aimed at evaluating the efficacy and safety of herbal formulas with the function of gut microbiota regulation (HFGMR) in the treatment of GC and CRC and to assess the quality of the synthesized evidence.

Methods

A comprehensive search was performed on eight electronic databases, PubMed, EMBASE, CENTRAL, Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang database, Chinese Scientific Journals Database, and two registries, Chinese Clinical Trial Registry and ClinicalTrials.gov, from their initiation to January 2022. Randomized controlled trials (RCTs) studying the therapeutic effects of HFGMR were included. We used Stata 16 for data synthesis and Risk of Bias 2 (RoB 2) for methodological quality evaluation and assessed the quality of the synthesized evidence in the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

Results

Fifty-three RCTs involving 4,478 patients were included. These trials involve seven herbal formulas that could regulate the gut microbiota of Bifidobacterium, Lactobacillus, Escherichia coli, Bacteroides, and Enterococcus faecalis. The meta-analysis results were subgrouped to three different stages in GC and CRC. 1) For the perioperative stage, HFGMR combined with conventional therapy could shorten the time to bowel sound recovery by 1.63 h [mean difference (MD) = -1.63, 95% confidence interval (CI) (-2.62, -0.65)], the time to first flatus by 9.69 h [MD = -9.69, 95% CI (-10.89, -8.48)], and the duration of hospitalization by 2.91 days [MD = -2.91, 95% CI (-4.01, -1.80)] in GC. There were no significant differences in outcomes of gastrointestinal function recovery and adverse events in CRC. 2) For postoperative patients, combined with adjuvant chemotherapy, HFGMR could decrease the incidence of diarrhea, nausea and vomiting, anorexia, and peripheral neurotoxicity in GC; boost Karnofsky performance status (KPS) improvement rate [risk ratio (RR) = 1.96, 95% CI (1.38, 2.79)]; and decrease the incidence of leucopenia and nausea and vomiting in CRC. 3) For advanced stage, HFGMR can significantly improve the objective response rate (ORR) [RR = 1.35, 95% CI (1.19~1.53)], disease control rate (DCR) [RR = 1.14, 95% CI (1.05~1.23)], and KPS improvement rate [RR = 1.56, 95% CI (1.17, 2.09)] and decrease the incidence of leucopenia, neutropenia, anemia, nausea and vomiting, diarrhea, and fatigue in GC. There were no significant differences in ORR [RR = 1.32, 95% CI (0.94~1.86)] and DCR [RR = 1.22, 95% CI (0.99~1.50)], but they can improve the KPS response rate [RR = 1.62, 95% CI (1.13, 2.32)] and decrease the incidence of myelosuppression, nausea and vomiting, diarrhea, and hepatic and renal dysfunction in CRC.

Conclusion

This study indicates that herbal formulas that could regulate the composition and proportion of gut microbiota have a positive effect in three stages (perioperative, postoperative, and advanced) of GC and CRC. They could promote the recovery of postoperative gastrointestinal function, increase tumor response, improve performance status, and reduce the incidence of adverse events. Herbal formulas exerted anti-cancer efficacy through multiple mechanisms and pathways; among them, the regulation of gut microbiota has not been paid enough attention. To further support the conclusion and better understand the role of gut microbiota in the treatment of GC and CRC, more rigorously designed, large-scale, and multicenter RCTs that focus on herbal formulas and gut microbiota are needed in the future.

Exploring Gut Microenvironment in Colorectal Patient with Dual-Omics Platform: A Comparison with Adenomatous Polyp or Occult Blood

The gut mucosa is actively absorptive and functions as the physical barrier to separate the gut ecosystem from host. Gut microbiota-utilized or food-derived metabolites are closely relevant to the homeostasis of the gut epithelial cells. Recent studies widely suggested the carcinogenic impact of gut dysbiosis or altered metabolites on the development of colorectal cancer (CRC). In this study, liquid chromatography coupled-mass spectrometry and long-read sequencing was applied to identify gut metabolites and microbiomes with statistically discriminative abundance in CRC patients (n = 20) as compared to those of a healthy group (n = 60) ofenrolled participants diagnosed with adenomatous polyp (n = 67) or occult blood (n = 40). In total, alteration in the relative abundance of 90 operational taxonomic units (OTUs) and 45 metabolites were identified between recruited CRC patients and healthy participants. Among the candidates, the gradual increases in nine OTUs or eight metabolites were identified in healthy participants, patients diagnosed with occult blood and adenomatous polyp, and CRC patients. The random forest regression model constructed with five OTUs or four metabolites achieved a distinct classification potential to differentially discriminate the presence of CRC (area under the ROC curve (AUC) = 0.998 or 0.975) from the diagnosis of adenomatous polyp (AUC = 0.831 or 0.777), respectively. These results provide the validity of CRC-associated markers, including microbial communities and metabolomic profiles across healthy and related populations toward the early screening or diagnosis of CRC.

Autophagy: A Versatile Player in the Progression of Colorectal Cancer and Drug Resistance

Colorectal cancer (CRC) is among the topmost malignancies for both genders. Despite the high incidence rate and advances in diagnostic tools, treatment in many cases is still ineffective. Most cancerous lesions in CRC begin as benign, followed by the development of invasive forms and metastases. The development of CRC has been linked to defects in autophagy, which plays both a pro-and anti-tumor role and is mainly context-dependent. Autophagy suppression could enhance apoptosis via p53 activation, or autophagy also promotes tumor progression by maintaining tumor growth and increasing resistance to chemotherapy. Autophagy promotes the invasion and metastasis of CRC cells via increased epithelial-mesenchymal transition (EMT). Moreover, dysbiosis of gut microbiota upregulated autophagy and metastasis markers. Autophagy responses may also modulate the tumor microenvironment (TME) via regulating the differentiation process of several innate immune cells. Treatments that promote tumor cell death by stimulating or inhibiting autophagy could be beneficial if used as an adjunct treatment, but the precise role of various autophagy-modulating drugs in CRC patients is needed to be explored. In this article, we present an overview of the autophagy process and its role in the pathogenesis and therapeutic resistance of CRC. Also, we focused on the current understanding of the role of the EMT and TME, including its relation to gut microbiota and immune cells, in autophagic manipulation of CRC. We believe that there is a potential link between autophagy, TME, EMT, and drug resistance, suggesting that further studies are needed to explore this aspect.

Research Progress on the Anticancer Activities and Mechanisms of Polysaccharides From Ganoderma

Cancer ranks as a primary reason for death worldwide. Conventional anticancer therapies can cause severe side effects, and thus natural products may be promising drug candidates for cancer therapy. Accumulating evidence has verified the prominent anticancer properties of Ganoderma polysaccharides, suggesting that Ganoderma polysaccharides may be effective chemopreventive agents of natural origin. Based on their abilities to prevent cancer development by regulating the DNA damage response, cancer cell proliferation, apoptosis, host immunity, gut microbiota and therapeutic sensitivity, there has been increasing interest in elucidating the clinical implication of Ganoderma polysaccharides in cancer therapy. In this review, we summarize recent findings pertaining to the roles of bioactive polysaccharides from Ganoderma in cancer pathogenesis, discuss the multifarious mechanisms involved and propose future directions for research. A more sophisticated understanding of the anticancer benefits of Ganoderma polysaccharides will be helpful for improving current treatments and developing novel therapeutic interventions for human malignancies.

Aspirin sensitivity of PIK3CA-mutated Colorectal Cancer: potential mechanisms revisited

PIK3CA mutations are amongst the most prevalent somatic mutations in cancer and are associated with resistance to first-line treatment along with low survival rates in a variety of malignancies. There is evidence that patients carrying PIK3CA mutations may benefit from treatment with acetylsalicylic acid, commonly known as aspirin, particularly in the setting of colorectal cancer. In this regard, it has been clarified that Class IA Phosphatidylinositol 3-kinases (PI3K), whose catalytic subunit p110α is encoded by the PIK3CA gene, are involved in signal transduction that regulates cell cycle, cell growth, and metabolism and, if disturbed, induces carcinogenic effects. Although PI3K is associated with pro-inflammatory cyclooxygenase-2 (COX-2) expression and signaling, and COX-2 is among the best-studied targets of aspirin, the mechanisms behind this clinically relevant phenomenon are still unclear. Indeed, there is further evidence that the protective, anti-carcinogenic effect of aspirin in this setting may be mediated in a COX-independent manner. However, until now the understanding of aspirin's prostaglandin-independent mode of action is poor. This review will provide an overview of the current literature on this topic and aims to analyze possible mechanisms and targets behind the aspirin sensitivity of PIK3CA-mutated cancers.