Interaction Between Host MicroRNAs and the Gut Microbiota in Colorectal Cancer

AbstractBackgroundAlthough variation in gut microbiome composition has been linked with colorectal cancer (CRC), the factors that mediate the interactions between CRC tumors and the microbiome are poorly understood. MicroRNAs (miRNAs) are known to regulate CRC progression and patient survival outcomes. In addition, recent studies suggested that host miRNAs can also regulate bacterial growth and influence the composition of the gut microbiome. Here, we investigated the association between miRNAs expression in human CRC tumor and normal tissues and the microbiome composition associated with these same tissues.MethodWe sequenced the small RNAs from patient-matched tumor and normal tissue samples collected from 44 human CRC patients performed an integrated analysis with microbiome taxonomic composition data from these same samples. We then interrogated the functions of the bacteria correlated with miRNAs that were differentially expressed (DE) between tumor and matched normal tissues, as well as the functions of miRNAs correlated with bacterial taxa that have been previously associated with CRC, including Fusobacterium, Providencia, Bacteroides, Akkermansia, Roseburia, Porphyromonas, and Peptostreptococcus.ResultsWe identified 76 miRNAs as DE between CRC and normal tissue, including known oncogenic miRNAs miR-182, miR-503, and miR-17∼92. These DE miRNAs were correlated with the relative abundance of several bacterial taxa, including Firmicutes, Bacteroidetes, and Proteobacteria. Bacteria correlated with DE miRNAs were enriched with distinct predicted metabolic categories. Additionally, we found that miRNAs correlated with CRC-associated bacteria are predicted to regulate targets that are relevant for host-microbiome interactions, and highlight a possible role for miRNA-driven glycan production in the recruitment of pathogenic microbial taxa.ConclusionsOur work characterized a global relationship between microbial community composition and miRNA expression in human CRC tissues. Our results support a role for miRNAs in mediating a bi-directional host-microbiome interaction in CRC. In addition, we highlight sets of potentially interacting microbes and host miRNAs, suggesting several pathways that can be targeted via future therapies.

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Interaction between Host MicroRNAs and the Gut Microbiota in Colorectal Cancer

mSystems ◽

10.1128/msystems.00205-17 ◽

2018 ◽

Vol 3 (3) ◽

Cited By ~ 35

Author(s):

Ce Yuan ◽

Michael B. Burns ◽

Subbaya Subramanian ◽

Ran Blekhman

Keyword(s):

Gene Expression ◽

Colorectal Cancer ◽

Gut Microbiota ◽

Mirna Expression ◽

Gut Microbiome ◽

Noncoding Rna ◽

Microbial Community Composition ◽

Host Cells ◽

Microbiome Composition ◽

Small Noncoding Rna

ABSTRACT Although variation in gut microbiome composition has been linked with colorectal cancer (CRC), the factors that mediate the interactions between CRC tumors and the microbiome are poorly understood. MicroRNAs (miRNAs) are known to regulate CRC progression and are associated with patient survival outcomes. In addition, recent studies suggested that host miRNAs can also regulate bacterial growth and influence the composition of the gut microbiome. Here, we investigated the association between miRNA expression and microbiome composition in human CRC tumor and normal tissues. We identified 76 miRNAs as differentially expressed (DE) in tissue from CRC tumors and normal tissue, including the known oncogenic miRNAs miR-182, miR-503, and mir-17~92 cluster. These DE miRNAs were correlated with the relative abundances of several bacterial taxa, including Firmicutes , Bacteroidetes , and Proteobacteria . Bacteria correlated with DE miRNAs were enriched with distinct predicted metabolic categories. Additionally, we found that miRNAs that correlated with CRC-associated bacteria are predicted to regulate targets that are relevant for host-microbiome interactions and highlight a possible role for miRNA-driven glycan production in the recruitment of pathogenic microbial taxa. Our work characterized a global relationship between microbial community composition and miRNA expression in human CRC tissues. IMPORTANCE Recent studies have found an association between colorectal cancer (CRC) and the gut microbiota. One potential mechanism by which the microbiota can influence host physiology is through affecting gene expression in host cells. MicroRNAs (miRNAs) are small noncoding RNA molecules that can regulate gene expression and have important roles in cancer development. Here, we investigated the link between the gut microbiota and the expression of miRNA in CRC. We found that dozens of miRNAs are differentially regulated in CRC tumors and adjacent normal colon and that these miRNAs are correlated with the abundance of microbes in the tumor microenvironment. Moreover, we found that microbes that have been previously associated with CRC are correlated with miRNAs that regulate genes related to interactions with microbes. Notably, these miRNAs likely regulate glycan production, which is important for the recruitment of pathogenic microbial taxa to the tumor. This work provides a first systems-level map of the association between microbes and host miRNAs in the context of CRC and provides targets for further experimental validation and potential interventions.

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Distinct Colon Mucosa Microbiomes associated with Tubular Adenomas and Serrated Polyps

10.1101/2021.07.20.453135 ◽

2021 ◽

Author(s):

Julio Avelar-Barragan ◽

Lauren DeDecker ◽

Zachary Lu ◽

Bretton Coppedge ◽

William Karnes ◽

...

Keyword(s):

Colorectal Cancer ◽

Gut Microbiome ◽

Microbial Community Composition ◽

Tubular Adenoma ◽

Colon Mucosa ◽

Fecal Samples ◽

Serrated Polyps ◽

Microbiome Composition ◽

Serrated Polyp ◽

Mechanisms Of Carcinogenesis

Background: Colorectal cancer is the second most deadly and third most common cancer in the world. Its development is heterogenous, with multiple mechanisms of carcinogenesis. Two distinct mechanisms include the adenoma-carcinoma sequence and the serrated pathway. The gut microbiome has been identified as a key player in the adenoma-carcinoma sequence, but its role in serrated carcinogenesis is unclear. In this study, we characterized the gut microbiome of 140 polyp-free and polyp-bearing individuals using colon mucosa and fecal samples to determine if microbiome composition was associated with each of the two key pathways. Results: We discovered significant differences between colon mucosa and fecal samples, explaining 14% of the variation observed in the microbiome. Multiple mucosal samples were collected from each individual to investigate the gut microbiome for differences between polyp and healthy intestinal tissue, but no such differences were found. Colon mucosa sampling revealed that the microbiomes of individuals with tubular adenomas and serrated polyps were significantly different from each other and polyp-free individuals, explaining 2-10% of the variance in the microbiome. Further analysis revealed differential abundances of Eggerthella lenta, Clostridium scindens, and three microbial genes across tubular adenoma, serrated polyp, and polyp-free cases. Conclusion: By directly sampling the colon mucosa and distinguishing between the different developmental pathways of colorectal cancer, this study helps characterize potential mechanistic targets and diagnostic biomarkers for serrated carcinogenesis. This research also provides insight into multiple microbiome sampling strategies by assessing each methods practicality and effect on microbial community composition.

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Association between colorectal cancer and Fusobacterium nucleatum and Bacteroides fragilis bacteria in Iranian patients: a preliminary study

Infectious Agents and Cancer ◽

10.1186/s13027-021-00381-4 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Aref Shariati ◽

Shabnam Razavi ◽

Ehsanollah Ghaznavi-Rad ◽

Behnaz Jahanbin ◽

Abolfazl Akbari ◽

...

Keyword(s):

Colorectal Cancer ◽

Relative Abundance ◽

Normal Tissue ◽

Bacteroides Fragilis ◽

Fusobacterium Nucleatum ◽

Normal Mucosa ◽

Clinicopathologic Characteristics ◽

Tissue Samples ◽

Adjacent Normal Mucosa ◽

Iranian Patients

Abstract Background and aim Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied. Method To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed. Results In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60% of paired tumor and normal samples, respectively. Furthermore, 15% of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23% of tumors and 13% of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2-ΔCT was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes. Conclusion The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown.

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Fecal Metaproteomics Reveals Reduced Gut Inflammation and Changed Microbial Metabolism Following Lifestyle-Induced Weight Loss

Biomolecules ◽

10.3390/biom11050726 ◽

2021 ◽

Vol 11 (5) ◽

pp. 726

Author(s):

Ronald Biemann ◽

Enrico Buß ◽

Dirk Benndorf ◽

Theresa Lehmann ◽

Kay Schallert ◽

...

Keyword(s):

Metabolic Syndrome ◽

Weight Loss ◽

Gut Microbiome ◽

Taxonomic Composition ◽

Low Grade ◽

Gut Inflammation ◽

Functional Changes ◽

Microbiome Composition ◽

Before And After ◽

Human Proteins

Gut microbiota-mediated inflammation promotes obesity-associated low-grade inflammation, which represents a hallmark of metabolic syndrome. To investigate if lifestyle-induced weight loss (WL) may modulate the gut microbiome composition and its interaction with the host on a functional level, we analyzed the fecal metaproteome of 33 individuals with metabolic syndrome in a longitudinal study before and after lifestyle-induced WL in a well-defined cohort. The 6-month WL intervention resulted in reduced BMI (−13.7%), improved insulin sensitivity (HOMA-IR, −46.1%), and reduced levels of circulating hsCRP (−39.9%), indicating metabolic syndrome reversal. The metaprotein spectra revealed a decrease of human proteins associated with gut inflammation. Taxonomic analysis revealed only minor changes in the bacterial composition with an increase of the families Desulfovibrionaceae, Leptospiraceae, Syntrophomonadaceae, Thermotogaceae and Verrucomicrobiaceae. Yet we detected an increased abundance of microbial metaprotein spectra that suggest an enhanced hydrolysis of complex carbohydrates. Hence, lifestyle-induced WL was associated with reduced gut inflammation and functional changes of human and microbial enzymes for carbohydrate hydrolysis while the taxonomic composition of the gut microbiome remained almost stable. The metaproteomics workflow has proven to be a suitable method for monitoring inflammatory changes in the fecal metaproteome.

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SNORA71A Promotes Colorectal Cancer Cell Proliferation, Migration, and Invasion

BioMed Research International ◽

10.1155/2020/8284576 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Zhengxiang Zhang ◽

Yunxiang Tao ◽

Qingling Hua ◽

Juan Cai ◽

Xiaobing Ye ◽

...

Keyword(s):

Colorectal Cancer ◽

Cell Proliferation ◽

Sensory Perception ◽

The Cancer Genome Atlas ◽

Migration And Invasion ◽

Integrated Analysis ◽

Small Rna Sequencing ◽

Chemical Stimulus ◽

Normal Tissues

Small nucleolar RNAs (snoRNAs) play a crucial role during colorectal cancer (CRC) development. The study of SNORA71A is few, and its role in CRC is unknown. This study focused on screening abnormal snoRNAs in CRC and exploring the role of key snoRNA in CRC. The expression pattern of snoRNAs in 3 CRC and 3 normal colon tissues was detected via small RNA sequencing. The six candidate snoRNAs were identified by quantitative PCR (qPCR). Subsequently, the expression level of SNORA71A was further verified through the Cancer Genome Atlas (TCGA) data analysis and qPCR. The CCK8 and transwell assays were used to detect the functional role of SNORA71A in CRC cells. The integrated analysis of snoRNA expression profile indicated that a total 107 snoRNAs were significantly differentially expressed (DE) in CRC tissues compared with normal tissues, including 45 upregulated and 62 downregulated snoRNAs. Bioinformatics analysis revealed that the DE snoRNAs were mainly implicated in “detection of chemical stimulus involved in sensory perception of smell” and “sensory perception of smell” in the biological process. The DE snoRNAs were preferentially enriched in “olfactory transduction” and “glycosphingolipid biosynthesis-ganglio series pathway.” The expression of SNORA71A was upregulated in CRC tissues and cells. SNORA71A expression showed statistically significant correlations with TNM stage ( P = 0.0196 ) and lymph node metastasis ( P = 0.0189 ) and can serve as biomarkers for CRC. Importantly, SNORA71A significantly facilitated the CRC cell proliferation, migration, and invasion. Our findings indicate that SNORA71A screened by sequencing acted as an oncogene and promoted proliferation, migration, and invasion ability of CRC cells.

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DNA methylation signatures predicting liver metastasis of colorectal cancer: A proof-of-concept pilot study.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e16080 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e16080-e16080

Author(s):

Jianming Ying ◽

Weihua Li ◽

Kaihua Liu ◽

Cong Xiao ◽

Shuyu Wu ◽

...

Keyword(s):

Colorectal Cancer ◽

Liver Metastasis ◽

Early Detection ◽

Predictive Model ◽

Primary Tumor ◽

Metastatic Tumor ◽

Training Data ◽

Training Dataset ◽

Tissue Samples ◽

Normal Tissues

e16080 Background: Liver metastasis (LIM) is the leading cause of death in colorectal cancer (CRC) patients. Early detection of LIM may improve outcome in CRC patients. The aim of this study was to evaluate the feasibility of predicting LIM of CRC using methylation profiles. Methods: We performed Roche targeted (~5.5 million methylation sites) bisulfite sequencing of matched primary, metastatic and their adjacent normal tissue samples from 5 CRC patients with LIM, 5 patients with lung metastasis (LUM) and 8 patients without metastasis in the training cohort (n = 48 samples). Differential methylation regions (DMR) of LUM were identified and a predictive model was developed. The model was further validated in primary tumor sample from nine patients (6 with LIM). Results: By comparing primary tumor vs adjacent normal tissues and metastatic tumor vs adjacent normal tissues in CRC patients with LIM, we identified 28954 common DMRs which indicating the methylation characteristic of CRC with LIM. Similarly, 16187 DMRs were identified in patients with LUM. 9179 DMRs are shared in both LIM and LUM comparisons which should be the common characteristic of CRC tumor tissue regardless of the location of metastasis. 7008 DMRs are LUM specific and 19775 DMRs are LIM specific. In order to predict LIM in primary, early changes in LIM specific DMRs should be identified. Hence, we further selected 4134 DMRs by chossing significantly differentically methylated regions between LIM primary tissues and LUM primary tissues. To increase the ability of distinguishing LIM from other normal tissues and non-matastasis CRC tumors, 1215 DMRs were finally selected which also showed increasing or decreasing trend of methylation level through the progression of CRC. The final 1215 biomarkers were used to construct a random forest model using methlylation profile of 5 CRC patients with LIM as positive training data and 5 CRC patients with LUM as well as 8 patients without metastasis as negative training data. Through the feature recursive elimination method, one methylation site (chr8.72468901-72469000) was identified with ROC of 0.9 in the training dataset. The predictive model was validated in an independent dataset which is composed of 6 patients with LIM and 3 patients without metastasis, and achieved an AUC of 0.87. Conclusions: Our findings demonstrate the utility of methylation biomarkers for the molecular characterization of metastatic precursors, with implications for prediction and early detection of liver metastasis in CRC.

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Microbiomes and Resistomes in Biopsy Tissue and Intestinal Lavage Fluid of Colorectal Cancer

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.736994 ◽

2021 ◽

Vol 9 ◽

Author(s):

Yumeng Yuan ◽

Yihuan Chen ◽

Fen Yao ◽

Mi Zeng ◽

Qingdong Xie ◽

...

Keyword(s):

Colorectal Cancer ◽

Gut Microbiome ◽

Laboratory Data ◽

Antibiotic Resistance Genes ◽

Lavage Fluid ◽

Tissue Samples ◽

Shotgun Metagenomics ◽

Paired Samples ◽

Biopsy Tissue ◽

Cluster 2

Aim: The gut microbiome plays a crucial role in colorectal cancer (CRC) tumorigenesis, but compositions of microorganisms have been inconsistent in previous studies due to the different types of specimens. We investigated the microbiomes and resistomes of CRC patients with colonic biopsy tissue and intestinal lavage fluid (IVF).Methods: Paired samples (biopsy tissue and IVF) were collected from 20 patients with CRC, and their gut microbiomes and resistomes were measured by shotgun metagenomics. Clinical and laboratory data were recorded. Bioinformatics (KneadData, Kraken2, and FMAP) and statistical analysis were done using the R (v4.0.2) software.Results: Bacterial diversity in IVF was higher than in tissue samples, and bacterial operational taxonomic units (OTUs) were 2,757 in IVF vs. 197 in tissue. β-diversity showed distinct clusters in paired samples. The predominant bacteria in IVF were phylum Proteobacteria, while the predominant bacteria of tissue were phylum Actinobacteria. Twenty-seven representative bacteria were selected to form six bacterial clusters, which showed only Firmicutes Cluster 1, and the Bacteroidetes Cluster 1 were significantly more abundant in the IVF group than those in the tissue group (p < 0.05). The Firmicutes Cluster 2, Bacteroidetes Cluster 2, Pathogen Cluster, and Prevotella Cluster were not significantly different between IVF and tissue (p > 0.05). Correlation analysis revealed that some bacteria could have effects on metabolic and inflammatory parameters of CRC patients. A total of 1,295 antibiotic resistance genes (ARGs) were detected in the gut microbiomes, which conferred multidrug resistance, as well as resistance to tetracycline, aminoglycoside, and more. Co-occurrence patterns revealed by the network showed mainly ARG-carrying bacteria to be similar between IVF and tissue, but leading bacteria located in the hub differed between IVF and tissue.Conclusion: Heterogeneity of microbiota is particularly evident when studied with IVF and tissue samples, but bacterial clusters that have close relationships with CRC carcinogenesis are not significantly different, using IVF as an alternative to tissue for gut microbiome, and resistome assessment may be a feasible method.

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Interplay between the human gut microbiome and host metabolism

10.1101/561787 ◽

2019 ◽

Cited By ~ 1

Author(s):

Alessia Visconti ◽

Caroline I. Le Roy ◽

Fabio Rosa ◽

Niccolo Rossi ◽

Tiphaine C. Martin ◽

...

Keyword(s):

Gut Microbiome ◽

Metabolic Pathways ◽

Taxonomic Composition ◽

Metagenomic Sequencing ◽

Human Gut ◽

Metabolic Potential ◽

Microbial Ecosystem ◽

Microbiome Composition ◽

Shotgun Metagenomic Sequencing ◽

Key Species

AbstractThe human gut is inhabited by a complex and metabolically active microbial ecosystem regulating host health. While many studies have focused on the effect of individual microbial taxa, the metabolic potential of the entire gut microbial ecosystem has been largely under-explored. We characterised the gut microbiome of 1,004 twins via whole shotgun metagenomic sequencing (average 39M reads per sample). We observed greater similarity, across unrelated individuals, for functional metabolic pathways (82%) than for taxonomic composition (43%). We conducted a microbiota-wide association study linking both taxonomic information and microbial metabolic pathways with 673 blood and 713 faecal metabolites (Metabolon, Inc.). Metabolic pathways associated with 34% of blood and 95% of faecal metabolites, with over 18,000 significant associations, while species-level results identified less than 3,000 associations, suggesting that coordinated action of multiple taxa is required to affect the metabolome. Finally, we estimated that the microbiome mediated a crosstalk between 71% of faecal and 15% of blood metabolites, highlighting six key species (unclassified Subdoligranulum spp., Faecalibacterium prausnitzii, Roseburia inulinivorans, Methanobrevibacter smithii, Eubacterium rectale, and Akkermansia muciniphila). Because of the large inter-person variability in microbiome composition, our results underline the importance of studying gut microbial metabolic pathways rather than focusing purely on taxonomy to find therapeutic and diagnostic targets.

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Multi-omics characterization of left-right colorectal cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.3542 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 3542-3542

Author(s):

John Marshall ◽

Takayuki Yoshino ◽

Sun Young Rha ◽

David N. Church ◽

Anelisa Kruschewsky Coutinho ◽

...

Keyword(s):

Colorectal Cancer ◽

Colon Cancer ◽

Cancer Biology ◽

Normal Tissue ◽

Molecular Mechanisms ◽

Clinical Information ◽

Molecular Testing ◽

Primary Tumors ◽

Ischemia Time ◽

Normal Tissues

3542 Background: Right (R) vs left (L) sided colorectal cancers are clinically distinguishable based on prognosis and response to certain therapies, but as of yet, limited data have emerged to explain these differences. The science of molecular testing has evolved rapidly. Enabled by improved technologies and computing power, it is now feasible to obtain to systematic multi-omic datasets covering DNA, RNA, proteins, phospho-proteins and metabolomics on large numbers of patients. Multi-omic analysis can further define disease specific subgroups but pre-analytic quality of the tissues (ischemia time) and comparison to normal tissue controls is paramount to optimize results. Methods: Following informed consent, 450 colorectal cancer primary tumors and paired normal tissues were collected following an SOP to minimize ischemia time, and were analyzed using comprehensive genomics, transcriptomics, proteomics, phosphoproteomics, morphology and annual clinical information. Right (C18.0,2,3) and left (C18.6,7) CRC tumors, normal tissue were compared using machine learning tools to unravel the molecular mechanisms that underpin these clinically distinguishable phenotypes as well as correlating with known genomic metrics such MSI and KRAS mutation status. Results: Through leveraging the tumor and paired normal patient samples, systematic differences between left and right tumor samples were observed including specific molecular events associated with these anatomical differences. The detailed results will be presented at the meeting. Conclusions: Progress in precision medicine requires the inclusion of multi-omics which in turn requires changes to our current SOPs of tissue collection. The ability to define molecular distinctions such as between R and L colon cancer will permit the rapid discovery of clinically useful prognostic and predictive markers, dramatically adding to our fundamental understanding to colon cancer biology. Future work will focus on the discovery of novel targets and signatures, creating innovative tools that depict multi-omic results for clinicians.

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The Western Dietary Pattern Combined with Vancomycin-Mediated Changes to the Gut Microbiome Exacerbates Colitis Severity and Colon Tumorigenesis

Nutrients ◽

10.3390/nu13030881 ◽

2021 ◽

Vol 13 (3) ◽

pp. 881

Author(s):

Niklas D. Aardema ◽

Daphne M. Rodriguez ◽

Arnaud J. Van Wettere ◽

Abby D. Benninghoff ◽

Korry J. Hintze

Keyword(s):

Colorectal Cancer ◽

Gut Microbiome ◽

Tumor Development ◽

Alpha Diversity ◽

Basal Diet ◽

Plain Water ◽

Microbiome Composition ◽

Colon Tumorigenesis ◽

Induced Changes ◽

The Impact

Previous work by our group using a mouse model of inflammation-associated colorectal cancer (CAC) showed that the total Western diet (TWD) promoted colon tumor development. Others have also shown that vancomycin-mediated changes to the gut microbiome increased colorectal cancer (CRC). Therefore, the objective of this study was to determine the impact of vancomycin on colon tumorigenesis in the context of a standard mouse diet or the TWD. A 2 × 2 factorial design was used, in which C57Bl/6J mice were fed either the standard AIN93G diet or TWD and with vancomycin in the drinking water or not. While both the TWD and vancomycin treatments independently increased parameters associated with gut inflammation and tumorigenesis compared to AIN93G and plain water controls, mice fed the TWD and treated with vancomycin had significantly increased tumor multiplicity and burden relative to all other treatments. Vancomycin treatment significantly decreased alpha diversity and changed the abundance of several taxa at the phylum, family, and genus levels. Conversely, basal diet had relatively minor effects on the gut microbiome composition. These results support our previous research that the TWD promotes colon tumorigenesis and suggest that vancomycin-induced changes to the gut microbiome are associated with higher tumor rates.

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