Background: Anastomotic leakage (AL) still remains a common complication after colorectal anastomosis that leads to increased morbidity and mortality. The gut microbiota has been hypothesized as one of the risk factors associated with anastomotic leakage. The aim of the present study was to summarize all existing clinical and experimental studies that evaluate the impact of intestinal microbiota on anastomotic leakage after colorectal resection. Methods: The present scoping review was designed according to PRISMA recommendations and a systematic search in Medline, Scopus, EMBASE, Clinicaltrials.gov, Google Scholar, and CENTRAL was conducted until September 2024. Results: Overall, 7 clinical and 5 experimental studies were included. A diminished α-diversity of the gut microbiota in patients suffering from AL was demonstrated. Specific microbe genera, such as Lachnospiraceae, Bacteroidaceae, Bifidobacterium, Acinetobacter, Fusobacterium, Dielma, Elusimicronium, Prevotella, and Faecalibacterium, seem to be associated with AL. However, specific genera, like Prevotella, Streptococcus, Eubacterium, Enterobacteriaceae, Klebsiella, Actinobacteria, Gordonibacter, Phocaeicola, and Ruminococcus2, seem to be protective against AL. Experimental studies highlighted that the Western diet seems to affect microbiota diversity and increases the AL rate, whereas anastomotic healing seems to be impaired by high metalloproteinase production and increased collagenase activity. Conclusions: The intestinal microbiota seems to play an important role in anastomotic leakage after colorectal resection. Specific interventions targeting the microbiota’s composition and the pathophysiological mechanisms by which it impairs anastomotic healing could diminish the risk for anastomotic leakage and improve clinical outcomes. However, future studies should be based on prospective design and eliminate heterogeneity.

The concept of agnostic biomarkers—molecular modifications that guide therapy irrespective of tumor origin—has gained increasing relevance in oncology, including colorectal cancer (CRC). This review aims to critically evaluate the role of such biomarkers in CRC, highlighting their clinical significance as therapeutic targets and indicators of prognosis. Through a PubMed search using the terms “agnostic treatment AND colorectal cancer,” eight key studies were identified and qualitatively analyzed. We focus on several biomarkers commonly regarded as agnostic across tumor types, including BRAF V600E mutation, receptor tyrosine kinase (RTK) and PI3K fusions, the CpG island methylator phenotype (CIMP), high tumor mutational burden (TMB), and microsatellite instability (MSI). These markers are inspected for their prevalence in CRC, underlying pathophysiological mechanisms of cancer promotion, and predictive or prognostic implications. Moreover, we integrate findings from broader oncologic studies to contextualize the evolving role of agnostic biomarkers beyond organ-specific paradigms. Emerging evidence suggests that leveraging these molecular signatures may inform the use of targeted and immunotherapeutic agents as first-line options in select CRC populations. Collectively, agnostic biomarkers represent an auspicious avenue for personalizing CRC treatment, particularly in advanced-stage disease where traditional treatment options remain limited.

Early-onset colorectal cancer (EO-CRC) refers to CRC diagnosed before the age of 50. Its incidence has risen in recent years, turning researchers’ attention to its oncologic behavior and potentially modifiable risk factors. In this review, PubMed/MEDLINE database was searched for all original research articles concerning EO-CRC. The inclusion criteria were CRC patients under 50, without a known predisposing factor for malignancy or an inherited CRC syndrome, presenting oncological characteristics and outcomes. All studies were assessed for bias, based on the ROBINS-E 2022 tool, and were synthesized in a qualitative analysis. Twenty-nine articles, reporting on 64,376 EO-CRC patients, were included in the qualitative synthesis. Results were classified into 3 categories: a) demographics; b) histopathologic characteristics; and c) treatment outcomes. Of these publications, 21 studies agreed that rectum (45%) and left-sided (47.1%) cancers are most common in younger patients, and 5 indicated that the highest prevalence of CRC concerns the 40-49 years age group. Seventeen of 29 studies reported a higher stage (III and IV) on diagnosis, with lymphovascular and perineural invasion. Our review has some limitations: as it was based on a single database, not all studies provided information on the variables; and patients were not categorized in all studies in the same age groups, although all were under 50 years. As EO-CRC is on the rise, the need for closer monitoring and possibly earlier screening becomes apparent. Further research should focus on finding novel screening biomarkers and modifiable risk factors that would decrease mortality and improve patient outcomes.

Background/Aim: Anastomotic leak (AL) remains one of the most troublesome complications in general surgery. The current review aimed to assess the level of C-reactive protein (CRP) in drainage fluid after entero-enteric, colonic, or colorectal anastomosis as a predictive biomarker for AL. Materials and Methods: Four medical databases (PUBMED-MEDLINE, Google Scholar, UpToDate, and Cochrane Library) were searched in January 2023 for prospective or retrospective studies on the role of acute-phase proteins in drainage fluid as a predictive biomarker of AL. Two independent researchers gathered and processed the data using MedCalc. The data were pooled and Student’s t-test was used to compare the data between the AL and non-AL groups. Results: Overall, four studies were included in the current review, containing 753 patients in total, for whom various types of enteric and colonic anastomoses were constructed. Overall 79 (10.49%) of patients demonstrated AL and the mean CRP level (±standard deviation) on postoperative day 3 was 167.7±77.13 mg/l. On the contrary, the non-AL group (674/753) had a statistically significantly lower mean CRP level at 83.76±20.32 mg/l. CRP values were not related to mortality. It was not possible to propose a CRP cut-off indicating an increased risk for AL as the data were insufficient. Conclusion: The CRP level in drainage fluid might be a valuable biomarker for predicting the possibility of AL in general surgery. However, further and larger-scale studies are needed to establish a CRP cut-off value and this variable would possibly be different for patients with different pathologies.

The human gut microbiome represents a complex and dynamic ecosystem that is central to maintaining health and preventing disease. Defining a “normal” gut microbiome remains challenging, given the significant variability arising from host physiology, lifestyle, genetics, geography and environmental exposures. This review synthesizes current evidence regarding the composition and functions of the gut microbiota in healthy individuals from diverse populations. At the taxonomic level, healthy gut microbial communities are typically dominated by the phyla Firmicutes and Bacteroidetes, with additional contributions from Actinobacteria and Proteobacteria. However, substantial inter-individual and regional differences are observed, such as a higher prevalence of Prevotella in populations consuming fiber-rich Eastern diets, and greater Bacteroides abundance in Western cohorts. Anatomical location and health status also influence alpha-diversity, underscoring the need to interpret diversity metrics within context. Furthermore, the gut microbiome performs essential functional roles across multiple organ systems, including fermentation of dietary fibers into short-chain fatty acids, regulation of immune responses, modulation of the gut-brain axis, maintenance of intestinal barrier integrity, and support of cardiovascular and hepatic functions. These findings support the conceptualization of the microbiome as a multifunctional organ system that integrates host and environmental signals. In summary, a healthy gut microbiome is best understood as a dynamic equilibrium, characterized by functional resilience and adaptability, rather than a fixed microbial profile. Interpreting this variability is crucial for developing targeted interventions to prevent disease.