Publications by authors named "Neelendu Dey"

Article Synopsis
  • - The study investigates how the gut microbiome is related to colorectal cancer (CRC) and health, finding that about 23-40% of gut bacteria are associated with either CRC or overall health.
  • - Researchers utilized advanced sequencing techniques to identify and analyze protein-coding gene clusters, discovering 2,319 co-abundant gene clusters related to CRC, including many previously unknown bacteria linked to the disease.
  • - The findings provide evidence that certain gut bacteria can influence precancerous conditions in the colon and suggest that understanding these microbial connections could lead to new cancer prevention strategies.
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We tested the feasibility and preliminary efficacy of an online diet and physical activity program for women with early-stage breast cancer who had completed surgery, chemotherapy, and radiation therapy (ongoing endocrine therapy allowed). Participants with low fruit and vegetable (F/V) consumption and/or low moderate-to-vigorous physical activity (MVPA) levels were randomized to one of two doses - low (one Zoom group session) or high (12 Zoom group sessions) - of an online lifestyle program with the goal of improving F/V intake and MVPA. All participants received eHealth communications (text messages, study website access), a Fitbit, and a WiFi-enabled scale.

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Article Synopsis
  • Juvenile dermatomyositis (JDM) is a rare childhood autoimmune disease potentially linked to microbial exposure, prompting a study on its association with oral and gut microbiome differences.
  • In this study, researchers analyzed microbiome samples from JDM patients and their unaffected family members to understand the impact of genetics and environment on microbiome diversity.
  • Findings indicated that JDM patients had microbiomes more similar to their unaffected siblings than to other JDM patients, with specific bacterial differences potentially influencing the disease's development or being a result of immune dysfunction.
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Article Synopsis
  • - Research on precancers is crucial because early intervention is more effective for treatment, focusing on at-risk tissues and early lesions.
  • - There is a need for risk stratification to avoid overtreatment, highlighting the importance of genetic and epigenetic aging in assessing risk levels.
  • - Effective intervention and health policy strategies should integrate both macroenvironmental risk factors and the molecular and cellular aspects of lesions and at-risk tissues.
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The multitude of barriers between the mouth and colon may eliminate swallowed oral bacteria. Ascertaining the presence of the same bacteria in the mouth and colon is methodologically challenging partly because 16S rRNA gene sequencing - the most commonly used method to characterize the human microbiota - has low confidence in taxonomic assignments deeper than genus for most bacteria. As different species of the same genus can have low-level variation across the same 16S rRNA gene region, shotgun sequencing is needed to identify a true overlap.

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Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic stem cell transplantation (SCT), and severe intestinal manifestation is the major cause of early mortality. Intestinal microbiota control MHC class II (MHC-II) expression by ileal intestinal epithelial cells (IECs) that promote GVHD. Here, we demonstrated that genetically identical mice of differing vendor origins had markedly different intestinal microbiota and ileal MHC-II expression, resulting in discordant GVHD severity.

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Background: Despite pharmacological treatment, individuals with inflammatory bowel disease (IBD) experience a variety of symptoms, including abdominal pain, fatigue, anxiety, and depression. Few nonmedical self-management interventions are available for people with IBD. A validated comprehensive self-management (CSM) intervention is effective for patients with irritable bowel syndrome who can have symptoms similar to those of individuals with IBD.

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Background: The oral and colonic microbiota are distinct in healthy individuals. However, this distinction is diminished in common diseases such as colon cancer and inflammatory bowel disease, suggesting a potential pathogenic role for oral bacteria when ectopically colonized in the gut. A key mechanism for the segregation of oral and colonic microbiota niches is thought to be microbiota-mediated colonization resistance whereby the commensal gut microbiota outcompete and eliminate the ingested oral bacteria.

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is implicated in colorectal cancer (CRC) as both a proto-oncogene and a tumor suppressor. We asked whether RET signaling regulates tumorigenesis in an -deficient preclinical model of CRC. We observed a sex-biased phenotype: +/- females had significantly greater tumor burden than Ret+/- males, a phenomenon not seen in mice, which had equal distributions by sex.

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Colorectal cancer (CRC) is among the most common cancers globally and a major cause of cancer-related deaths. The American Cancer Society estimates that CRC will kill 1 in 60 Americans, and CRC screening is recommended for all Americans ≥45 years of age. Current CRC screening methods are effective for preventing CRC and have been shown to reduce CRC-related mortality.

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Background: The design of a randomized pilot trial evaluating the feasibility of two doses of a digital health intervention promoting changes in nutrition and physical activity in breast cancer (BC) survivors is described.

Methods: Eligible women were adults with history of early-stage breast cancer and > 60 days post-treatment, consumed <5 servings/day of fruits/vegetables and/or engaged in <150 min/week of aerobic moderate-to-vigorous physical activity, and had internet access. Participants were randomized to 6 months of either a "low" (1 session) or "high" (12 sessions) dose digital health intervention.

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Here, we describe the isolation and genomic annotation of two novel siphovirus species of bacteriophages that infect Bacteroides uniformis: Bacteroides phage EMB1 and Bacteroides phage EMB2. EMB1 has a 34,204-bp genome with 48 coding sequences, and EMB2 has a 34,008-bp genome with 47 coding sequences.

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Gastrointestinal motility is regulated by a variety of environmental factors including gut microbes and metabolites. The ability to interrogate mouse models of gut motility has enabled elucidation of these relationships. Here we describe integration of the red carmine dye and fluorescence isothiocyanate-dextran marker-based assays for characterizing gut transit with spatial resolution, along with an optional intracolonic infusion protocol for studying the effects of metabolites on colonic transit.

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Gut motility is regulated by the microbiome via mechanisms that include bile acid metabolism. To localize the effects of microbiome-generated bile acids, we colonized gnotobiotic mice with different synthetic gut bacterial communities that were metabolically phenotyped using a functional screen. Using two different marker-based assays of gut transit, we inferred that bile acids exert effects on colonic transit.

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COVID-19 (coronavirus disease 2019) patients exhibiting gastrointestinal symptoms are reported to have worse prognosis. Ace2 (angiotensin-converting enzyme 2), the gene encoding the host protein to which SARS-CoV-2 spike proteins bind, is expressed in the gut and therefore may be a target for preventing or reducing severity of COVID-19. Here we test the hypothesis that Ace2 expression in the gastrointestinal and respiratory tracts is modulated by the microbiome.

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Growing evidence indicates a role for the gut microbiota in modulating anti-tumor treatment efficacy in human cancer. Here we study mucosa-associated invariant T (MAIT) cells to look for evidence of bacterial antigen recognition in human colon, lung, and kidney carcinomas. Using mass cytometry and single-cell mRNA sequencing, we identify a tumor-infiltrating MAIT cell subset expressing CD4 and Foxp3 and observe high expression of CD39 on MAIT cells from colorectal cancer (CRC) only, which we show to be expressed specifically after TCR stimulation.

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The American Gastroenterological Association's Center for Gastrointestinal Innovation and Technology convened a consensus conference in December 2018, entitled, "Colorectal Cancer Screening and Surveillance: Role of Emerging Technology and Innovation to Improve Outcomes." The goal of the conference, which attracted more than 60 experts in screening and related disciplines, including the authors, was to envision a future in which colorectal cancer (CRC) screening and surveillance are optimized, and to identify barriers to achieving that future. This White Paper originates from that meeting and delineates the priorities and steps needed to improve CRC outcomes, with the goal of minimizing CRC morbidity and mortality.

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Introduction: Gastrointestinal (GI) dysfunction precedes the motor symptoms of Parkinson's disease (PD) by several years. PD patients have abnormal aggregation of intestinal α-synuclein, the accumulation of which may be promoted by inflammation. The relationship between intestinal α-synuclein aggregates and central nervous system neuropathology is unknown.

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To model how interactions among enteropathogens and gut microbial community members contribute to undernutrition, we colonized gnotobiotic mice fed representative Bangladeshi diets with sequenced bacterial strains cultured from the fecal microbiota of two 24-month-old Bangladeshi children: one healthy and the other underweight. The undernourished donor's bacterial collection contained an enterotoxigenic Bacteroides fragilis strain (ETBF), whereas the healthy donor's bacterial collection contained two nontoxigenic strains of B. fragilis (NTBF).

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Background And Aims: Vedolizumab inhibits leucocyte vascular adhesion and migration into the gastrointestinal tract through α4β7 integrin blockade. This agent became available in mid-2014 for the treatment of moderate to severe Crohn's disease (CD) and UC (UC). The aim of this study was to assess the patterns of use, effectiveness and safety of vedolizumab in an inflammatory bowel disease (IBD) clinical practice.

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To understand how different diets, the consumers' gut microbiota, and the enteric nervous system (ENS) interact to regulate gut motility, we developed a gnotobiotic mouse model that mimics short-term dietary changes that happen when humans are traveling to places with different culinary traditions. Studying animals transplanted with the microbiota from humans representing diverse culinary traditions and fed a sequence of diets representing those of all donors, we found that correlations between bacterial species abundances and transit times are diet dependent. However, the levels of unconjugated bile acids-generated by bacterial bile salt hydrolases (BSH)-correlated with faster transit, including during consumption of a Bangladeshi diet.

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