Publications by authors named "Wendy S Garrett"

Although diet is a substantial determinant of the human gut microbiome, the interplay between specific foods and microbial community structure remains poorly understood. Coffee is a habitually consumed beverage with established metabolic and health benefits. We previously found that coffee is, among >150 items, the food showing the highest correlation with microbiome components.

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Alterations in intestinal permeability and the gut microbiome caused by alcohol abuse are associated with alcoholic liver disease and with worsening of inflammatory bowel diseases (IBD) symptoms. To resolve the direct effects of chronic ethanol consumption on the colon and its microbiome in the absence of acute or chronic alcohol-induced liver disease, we developed a mouse model of chronic binge drinking that uncovers how alcohol may enhance susceptibility to colitis via the microbiota. Employing daily ethanol gavage, we recapitulate key features of binge ethanol consumption.

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Background & Aims: Epidemiologic evidence for dietary influence on colorectal cancer (CRC) risk through the gut microbiome remains limited.

Methods: Leveraging 307 men and 212 women with stool metagenomes and dietary data, we characterized and validated a sex-specific dietary pattern associated with the CRC-related gut microbial signature (CRC Microbial Dietary Score [CMDS]). We evaluated the associations of CMDS with CRC risk according to Fusobacterium nucleatum, pksEscherichia coli, and enterotoxigenic Bacteroides fragilis status in tumor tissue using Cox proportional hazards regression in the Health Professionals Follow-Up Study (1986-2018), Nurses' Health Study (1984-2020), and Nurses' Health Study II (1991-2019).

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Dietary patterns and specific dietary components, in concert with the gut microbiota, can jointly shape susceptibility, resistance and therapeutic response to cancer. Which diet-microbial interactions contribute to or mitigate carcinogenesis and how they work are important questions in this growing field. Here we interpret studies of diet-microbial interactions to assess dietary determinants of intestinal colonization by opportunistic and oncogenic bacteria.

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Preclinical human inflammatory bowel disease (IBD) mechanisms is one of 5 focus areas of the Challenges in IBD Research 2024 document, which also includes environmental triggers, novel technologies, precision medicine, and pragmatic clinical research. Herein, we provide a comprehensive overview of current gaps in inflammatory bowel diseases research that relate to preclinical research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in IBD interception, remission, and restoration. The document is the result of multidisciplinary input from scientists, clinicians, patients, and funders and represents a valuable resource for patient-centric research prioritization.

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Article Synopsis
  • - The study aimed to investigate whether having an appendectomy reduces the long-term risk of colorectal cancer, particularly for tumors associated with the bacterial species Fusobacterium nucleatum, which is linked to colorectal tumor development.
  • - Using data from extensive cohort studies, researchers found that 2811 cases of colorectal cancer were recorded, with appendectomy appearing to lower the incidence of F. nucleatum-positive cancers (hazard ratio of 0.53) but not F. nucleatum-negative cancers (hazard ratio of 0.98).
  • - The findings suggest that while appendectomy may reduce the risk of developing certain types of colorectal cancer (specifically F. nucleatum-positive ones), it does not significantly impact the risk for other types,
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Microbial biochemistry is central to the pathophysiology of inflammatory bowel diseases (IBD). Improved knowledge of microbial metabolites and their immunomodulatory roles is thus necessary for diagnosis and management. Here, we systematically analyzed the chemical, ecological, and epidemiological properties of ~82k metabolic features in 546 Integrative Human Microbiome Project (iHMP/HMP2) metabolomes, using a newly developed methodology for bioactive compound prioritization from microbial communities.

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Studies in preclinical models support that the gut microbiota play a critical role in the development and progression of colorectal cancer (CRC). Specific microbial species and their corresponding virulence factors or associated small molecules can contribute to CRC development and progression either via direct effects on the neoplastic transformation of epithelial cells or through interactions with the host immune system. Induction of DNA damage, activation of Wnt/β-catenin and NF-κB proinflammatory pathways, and alteration of the nutrient's availability and the metabolic activity of cancer cells are the main mechanisms by which the microbiota contribute to CRC.

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Article Synopsis
  • Research suggests that enterotoxigenic Bacteroides fragilis (ETBF) may play a role in colorectal cancer development, particularly in tumors with specific genetic markers like high-level CpG island methylator phenotype (CIMP-high) and BRAF mutations.
  • The study utilized quantitative PCR to measure levels of Bacteroides fragilis and ETBF in colorectal cancer cases, finding that high levels of these bacteria are significantly linked to the presence of CIMP-high and MSI-high tumors.
  • Overall, the results provide evidence that Bacteroides fragilis and ETBF may influence colorectal cancer progression through particular genetic pathways, although they do not appear to affect patient survival rates.
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Introduction: There remains an unmet need for safe and cost-effective adjunctive treatment of advanced colorectal cancer (CRC). The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and has anti-inflammatory as well as antineoplastic properties. A phase 2 randomised trial of preoperative EPA free fatty acid 2 g daily in patients undergoing surgery for CRC liver metastasis showed no difference in the primary endpoint (histological tumour proliferation index) compared with placebo.

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Objectives: The CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) immune checkpoint axis is known to regulate the antitumor immune response. Evidence also supports an immunosuppressive effect of . We hypothesised that tumor CD274 overexpression might be inversely associated with abundance of in colorectal carcinoma.

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Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community.

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Background: The gut microbiome regulates host energy balance and adiposity-related metabolic consequences, but it remains unknown how the gut microbiome modulates body weight response to physical activity (PA).

Methods: Nested in the Health Professionals Follow-up Study, a subcohort of 307 healthy men (mean[SD] age, 70[4] years) provided stool and blood samples in 2012-2013. Data from cohort long-term follow-ups and from the accelerometer, doubly labeled water, and plasma biomarker measurements during the time of stool collection were used to assess long-term and short-term associations of PA with adiposity.

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Article Synopsis
  • Inclusion of advocates in research is now mandated by many international funding agencies, emphasizing their crucial role.
  • Advocates are involved across all research areas, including basic cancer research and clinical trials, enhancing collaboration despite the challenges faced.
  • The text aims to define patient advocacy, detail advocate engagement, and provide insights into training programs that facilitate partnership between advocates and researchers.
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Drug platforms that enable the directed delivery of therapeutics to sites of diseases to maximize efficacy and limit off-target effects are needed. Here, we report the development of PROTEcT, a suite of commensal Escherichia coli engineered to secrete proteins directly into their surroundings. These bacteria consist of three modular components: a modified bacterial protein secretion system, the associated regulatable transcriptional activator, and a secreted therapeutic payload.

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Article Synopsis
  • Scientists are debating whether a fetus and its surroundings are home to stable groups of tiny living things called microbes during a healthy pregnancy.
  • Recent studies suggest that when they find these microbes, it could be because of mistakes during the testing process, not that the fetus actually has them.
  • Understanding these findings is important for learning how our immune system develops and shows that studying tiny living things in places with very few of them can be really tricky, so we need to use different science methods to get it right.
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The intestinal epithelium plays critical roles in sensing and integrating dietary and microbial signals. How microbiota and intestinal epithelial cell (IEC) interactions regulate host physiology in the proximal small intestine, particularly the duodenum, is unclear. Using single-cell RNA sequencing of duodenal IECs under germ-free (GF) and different conventional microbiota compositions, we show that specific microbiota members alter epithelial homeostasis by increasing epithelial turnover rate, crypt proliferation, and major histocompatibility complex class II (MHCII) expression.

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Background & Aims: Evidence supports a carcinogenic role of Escherichia coli carrying the pks island that encodes enzymes for colibactin biosynthesis. We hypothesized that the association of the Western-style diet (rich in red and processed meat) with colorectal cancer incidence might be stronger for tumors containing higher amounts of pksE coli.

Methods: Western diet score was calculated using food frequency questionnaire data obtained every 4 years during follow-up of 134,775 participants in 2 United States-wide prospective cohort studies.

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Article Synopsis
  • Disruption of microbial communities and their bioactive compounds is linked to inflammatory bowel diseases (IBD), with many microbial proteins remaining uncharacterized despite their potential bioactivity.
  • Researchers identified over 340,000 protein families possibly involved in gut inflammation related to IBD, with a significant portion previously uncharacterized, using a combination of metagenomic techniques.
  • The new methodology, called MetaWIBELE, helped validate findings and revealed that specific microbial proteins could influence host immune responses, offering insights into potential therapeutic targets for chronic diseases like IBD.
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The importance of the microbiota in the development of colorectal cancer (CRC) is increasingly evident, but identifying specific microbial features that influence CRC initiation and progression remains a central task for investigators. Studies determining the microbial mechanisms that directly contribute to CRC development or progression are revealing bacterial factors such as toxins that contribute to colorectal carcinogenesis. However, even when investigators have identified bacteria that express toxins, questions remain about the host determinants of a toxin's cancer-potentiating effects.

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Gut bacteria modulate the response to immune checkpoint blockade (ICB) treatment in cancer, but the effect of diet and supplements on this interaction is not well studied. We assessed fecal microbiota profiles, dietary habits, and commercially available probiotic supplement use in melanoma patients and performed parallel preclinical studies. Higher dietary fiber was associated with significantly improved progression-free survival in 128 patients on ICB, with the most pronounced benefit observed in patients with sufficient dietary fiber intake and no probiotic use.

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The colorectal cancer (CRC)-associated microbiota creates a pro-tumorigenic intestinal milieu and shapes immune responses within the tumor microenvironment. However, how oncomicrobes - like , found in the oral cavity and associated with CRC tissues affect these distinct aspects of tumorigenesis is difficult to parse. Herein, we found that neonatal inoculation of mice with strain Fn7-1 circumvents technical barriers preventing its intestinal colonization, drives colonic expression prior to tumor formation, and potentiates intestinal tumorigenesis.

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There is an increasing appreciation for the role of metabolism in cell signaling and cell decision making. Precise metabolic control is essential in development, as evident by the disorders caused by mutations in metabolic enzymes. The metabolic profile of cells is often cell-type specific, changing as cells differentiate or during tumorigenesis.

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Introduction: We recently described the sulfur microbial diet, a pattern of intake associated with increased gut sulfur-metabolizing bacteria and incidence of distal colorectal cancer (CRC). We assessed whether this risk differed by CRC molecular subtypes or presence of intratumoral microbes involved in CRC pathogenesis (Fusobacterium nucleatum and Bifidobacterium spp.).

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Background & Aims: Diet may contribute to the increasing incidence of colorectal cancer (CRC) before age 50 (early-onset CRC). Microbial metabolism of dietary sulfur produces hydrogen sulfide (HS), a gastrointestinal carcinogen that cannot be easily measured at scale. As a result, evidence supporting its role in early neoplasia is lacking.

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