Patient attitudes towards faecal sampling for gut microbiome studies and clinical care reveal positive engagement and room for improvement

Circulating Exosomal Proteins as New Diagnostic Biomarkers for Colorectal Cancer (EXOSCOL01): A Pilot Case-Controlled Study Focusing on MMP14 Potential

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. The French CRC screening campaign is based on fecal immunochemical tests (FIT), confirmed by colonoscopy, an invasive procedure with a poor participation rate. This study aimed to compare the expression of circulating exosomal proteins (MMP14, β1-Integrin subunit, β3-Integrin subunit, and α1(I) Collagen chain) in patients with CRC or adenomas.

METHODS

A total of 71 patients were recruited, including 24 controls (normal colonoscopy), 11 patients with adenoma, and 36 with CRC. Plasmatic exosomal protein expression was measured by western blot analysis and reported to either protein or exosome content.

RESULTS

The three groups were comparable regarding clinical characteristics. A significant difference was observed for MMP14 relative expression (p = 0.0007), MMP14 expression reported to exosomal protein content (p = 0.0003), and MMP14 expression reported to exosome content (p = 0.0005). These three parameters were significantly higher in patients with adenoma vs. control patients (p = 0.0013, p = 0.0004, and p = 0.0003, respectively). Only MMP14 relative intensity was significantly higher in the CRC group vs. the control group (p = 0.0018).

CONCLUSIONS

Exosomal MMP14 is a promising early diagnostic biomarker for CRC and adenoma. These preliminary results warrant confirmation in larger studies using quantitative measurements such as ELISA or flow cytometry.

Faecal intestinal permeability and intestinal inflammatory markers in older adults with age-related disorders: A systematic review and meta-analysis

This systematic review and meta-analysis appraised previous findings to uncover potential faecal intestinal permeability and intestinal inflammatory markers in older adults. A comprehensive literature search led to the identification of ten eligible studies with findings of potential faecal intestinal permeability (zonulin and alpha-1-antitrypsin) and intestinal inflammatory markers [calprotectin, lactoferrin and neutrophil gelatinase-associated lipocalin (NGAL)]. Most of the cases (n > 2) [Parkinson's disease (PD) and Alzheimer's disease (AD)] exhibited higher faecal alpha-1-antitrypsin, zonulin and calprotectin levels. The present meta-analysis confirmed significantly higher faecal alpha-1-antitrypsin in older persons with PD compared to non-PD [MD = 22.92 mg/dL; 95 % CI = 14.02-31.81, p < 0.00001; I2 = 0 % (p = 0.73)]. There was, however, no significant difference in faecal zonulin between PD and non-PD individuals [MD = 26.88 ng/mL; 95 % CI = -29.26-83.01, p = 0.35; I2 = 94 % (p < 0.0001)]. Meanwhile, faecal calprotectin was higher in older adults with GI symptoms, multiple system atrophy (MSA) or PD than the healthy controls [MD = 9.51 μg/g; 95 % CI = 0.07-18.95, p = 0.05; I2 = 84 % (p < 0.00001)]. Altogether, faecal calprotectin appears to be a potential intestinal inflammatory marker whereas previous findings on faecal alpha-1-antitrypsin as an intestinal permeability marker remain limited and require further validation.

Walk before you run: Feasibility challenges and lessons learned from the PROCLAIM study, a multicenter randomized controlled trial of misoprostol for prevention of recurrent Clostridioides difficile during COVID-19

We analyzed our challenging experience with a randomized controlled trial of misoprostol for prevention of recurrent C. difficile. Despite careful prescreening and thoughtful protocol modifications to facilitate enrollment, we closed the study early after enrolling just 7 participants over 3 years. We share lessons learned, noting the importance of feasibility studies, inclusion of biomarker outcomes, and dissemination of such findings to inform future research design and implementation successes.

Standards for Collection, Preservation, and Transportation of Fecal Samples in TCM Clinical Trials

Background

Unlike chemical drugs with a single or a few kinds of active compounds, traditional Chinese medicines (TCMs)uses herbal formulas composed of numerous kinds of chemical constituents. Therefore, TCM clinical trials require unique and stricter standards for collecting, preserving, and transporting fecal samples than those used for chemical drugs. Unfortunately, there are no special standards for processing fecal samples in TCM clinical trials.

Methods

We invited interdisciplinary experts within TCM clinical trials and gut microbiome research to help formulate this standard. After more than a year's in-depth discussion and amendments, we achieved a standard via expert interviews, literature research, questionnaire surveys, and public opinion solicitation. This standard has been reviewed and approved by the Standards Office of China of the Association of Chinese medicine.

Results

We established a sample information processing method prior to TCM clinical sample collection, which is adapted to the unique features of TCM. The method formulates detailed processing requirements for TCM information in addition to the factors that may disturb the gut microbiome. We also constructed a set of methods for collecting, preserving, and transporting fecal samples that meet the characteristics of TCM. These methods formulate detailed operating specifications on the collection approaches, storage conditions, transportation requirements, and management of fecal samples.

Conclusions

This standard guides the information processing prior to sample collection and the standard operating procedures for the collection, preservation, and transportation of fecal samples in TCM clinical trials, which also can be used as a reference by clinicians and researchers in modern medicines.

Systematic review: non-endoscopic surveillance for colorectal neoplasia in individuals with Lynch syndrome

BACKGROUND

Individuals with Lynch syndrome are at high risk for colorectal cancer (CRC). Regular colonoscopies have proven to decrease CRC incidence and mortality. However, colonoscopy is burdensome and interval CRCs still occur. Hence, an accurate, less-invasive screening method that guides the timing of colonoscopy would be of important value.

AIM

To outline the performance of non-endoscopic screening modalities for Lynch-associated CRC and adenomas.

METHODS

Systematic literature search in MEDLINE and EMBASE to identify studies investigating imaging techniques and biomarkers for detection of CRC and adenomas in Lynch syndrome. The QUADAS-2 tool was used for the quality assessment of included studies.

RESULTS

Seven of 1332 screened articles fulfilled the inclusion criteria. Two studies evaluated either CT colonography or MR colonography; both techniques were unable to detect CRC and (advanced) adenomas <10 mm. The other five studies evaluated plasma methylated-SEPTIN9, faecal immunochemical test (FIT), faecal tumour DNA markers (BAT-26, hMLH1, p53, D9S171, APC, D9S162, IFNA and DCC) and faecal microbiome as screening modalities. Sensitivity for CRC varied from 33% (BAT-26) to 70% (methylated-SEPTIN9) to 91% (hMLH1). High specificity (94-100%) for CRC and/or adenomas was observed for methylated-SEPTIN9, FIT and BAT-26. Desulfovibrio was enriched in the stool of patients having adenomas. However, all these studies were characterised by small populations, high/unclear risk of bias and/or low prevalence of adenomas.

CONCLUSIONS

Imaging techniques are unsuitable for colon surveillance in Lynch syndrome, whereas biomarkers are understudied. Having outlined biomarker research in Lynch-associated and sporadic CRC/adenomas, we believe that these non-invasive markers may hold potential (whether or not combined) for this population. As they could be of great value, (pre-)clinical studies in this field should be prioritised.