Effect of the dietary polyacetylenes falcarinol and falcarindiol on the gut microbiota composition in a rat model of colorectal cancer

Abstract Objectives (3R)-Falcarinol (FaOH) and (3R,8S)-falcarindiol (FaDOH) have previously been shown to reduce the number of neoplastic lesions and the growth rate of polyps in the colon of azoxymethane (AOM) treated rats. Based on previous investigations, it appears that different mechanisms of actions are involved in the antineoplastic effect of FaOH and FaDOH. One mechanism of action may be related to the antibacterial effect of FaOH and FaDOH and thus their effect on the gut microbiota. This study aimed to determine the effect of FaOH and FaDOH on gut microbiota composition of AOM treated rats. Results Azoxymethane treated rats were fed either a standard rat diet or a rat diet supplemented with FaOH and FaDOH. The gut microbiota of AOM-induced rats was determined by 16S rRNA gene-amplicon sequencing. Analysis of fecal cecum samples demonstrated a significant gut microbiota change in rats receiving standard rat diet supplemented with FaOH and FaDOH compared with the control group that only received the rat diet. Comparison of the gut microbiota of rats who developed large neoplasms in the colon with rats without large neoplasms showed that the gut microbiota was significantly different in rats who developed large colon neoplasms compared to rats with no macroscopic colon neoplasms

The Diagnostic Yield of Colonoscopy Stratified by Indications

Introduction. Danish centers reserve longer time for screening colonoscopies and allocate the most experienced endoscopists to these cases. The objective of this study is to determine the diagnostic yield in colonoscopies for different indications to improve planning of colonoscopy activity and allocation of the highly skilled endoscopists. Methods. Nine hundred and ninety-nine randomly collected patients from a prospectively maintained database were grouped in defined referral indication groups. Five groups were compared in respect of the detection rate of adenomas and cancers. Results. Two hundred and eighty-nine of 1098 colonoscopies in 999 patients showed significant neoplastic findings, resulting in 591 adenoma resections. Eighty-five percent were treated with a snare resection, and 15% with endoscopic mucosa resection (EMR). Positive findings in the indication groups were (1) symptoms, 25%; (2) positive screening, 17%; (3) previous resection of adenomas, 45%; (4) previous resection of colorectal cancer, 15%; and (5) surveillance of patients with high-risk family history of cancer, 35%. Conclusion. The majority of adenomas found during colonoscopy can be treated with simple techniques. If individualized time slots are considered, the adenoma follow-up colonoscopies are likely to be the most time-consuming group with more than twice the number of adenomas detected as compared to other indications

Cause of Death, Mortality and Occult Blood in Colorectal Cancer Screening

SIMPLE SUMMARY: Colorectal cancer (CRC) screening participants with significant traces of hemoglobin in their stool have been reported to have higher mortality and different causes of death (other than CRC) compared to those without. We aimed to investigate these differences among screening participants after 33 years of follow-up. We confirmed that participants with detectable fecal hemoglobin were more likely to die in the study period and to die from different causes, such as cardiovascular and endocrine and hematological diseases, compared to those without detectable fecal hemoglobin. This confirms that fecal hemoglobin may have potential as a marker for diseases not directly related to the colon and rectum and may represent a target for future preventive measures. ABSTRACT: Fecal hemoglobin (f-Hb) detected by the guaiac fecal occult blood test (gFOBT) may be associated with mortality and cause of death in colorectal cancer (CRC) screening participants. We investigated this association in a randomly selected population of 20,694 participants followed for 33 years. We followed participants from the start of the Hemoccult-II CRC trial in 1985–1986 until December 2018. Data on mortality, cause of death and covariates were retrieved using Danish national registers. We conducted multivariable Cox regressions with time-varying exposure, reporting results as crude and adjusted hazard ratios (aHRs). We identified 1766 patients with at least one positive gFOBT, 946 of whom died in the study period. Most gFOBT-positive participants (93.23%) died of diseases unrelated to CRC and showed higher non-CRC mortality than gFOBT-negative participants (aHR: 1.20, 95% CI 1.10–1.30). Positive gFOBT participants displayed a modest increase in all-cause (aHR: 1.28, 95% CI: 1.18–1.38), CRC (aHR: 4.07, 95% CI: 3.00–5.56), cardiovascular (aHR: 1.22, 95% CI: 1.07–1.39) and endocrine and hematological mortality (aHR: 1.58, 95% CI: 1.19–2.10). In conclusion, we observed an association between positive gFOBT, cause of death and mortality. The presence of f-Hb in the gFOBT might indicate the presence of systemic diseases

Faecal haemoglobin concentrations are associated with all-cause mortality and cause of death in colorectal cancer screening

BACKGROUND: Colorectal cancer (CRC) screening reduces all-cause and CRC-related mortality. New research demonstrates that the faecal haemoglobin concentration (f-Hb) may indicate the presence of other serious diseases not related to CRC. We investigated the association between f-Hb, measured by a faecal immunochemical test (FIT), and both all-cause mortality and cause of death in a population-wide cohort of screening participants. METHODS: Between 2014 and 2018, 1,262,165 participants submitted a FIT for the Danish CRC screening programme. We followed these participants, using the Danish CRC Screening Database and several other national registers on health and population, until December 31, 2018. We stratified participants by f-Hb and compared them using a Cox proportional hazards regression on all-cause mortality and cause of death reported as adjusted hazard ratios (aHRs). We adjusted for several covariates, including comorbidity, socioeconomic factors, demography and prescription medication. RESULTS: We observed 21,847 deaths in the study period. Our multivariate analyses indicated an association relationship between increasing f-Hb and the risk of dying in the study period. This risk increased steadily from aHR 1.38 (95% CI: 1.32, 1.44) in those with a f-Hb of 7.1–11.9 μg Hb/g faeces to 2.20 (95% CI: 2.10, 2.30) in those with a f-Hb ≥60.0 μg Hb/g faeces, when compared to those with a f-Hb ≤7.0 μg Hb/g faeces. The pattern remained when excluding CRC from the analysis. Similar patterns were observed between incrementally increasing f-Hb and the risk of dying from respiratory disease, cardiovascular disease and cancers other than CRC. Furthermore, we observed an increased risk of dying from CRC with increasing f-Hb. CONCLUSIONS: Our findings support the hypothesis that f-Hb may indicate an elevated risk of having chronic conditions if causes for the bleeding have not been identified. The mechanisms still need to be established, but f-Hb may be a potential biomarker for several non-CRC diseases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-022-02724-3