Association of circulating short chain fatty acid levels with colorectal adenomas and colorectal cancer

Identification of Gut Microbiota Profile Associated with Colorectal Cancer in Saudi Population

Colorectal cancer (CRC) is a significant global health concern. Microbial dysbiosis and associated metabolites have been associated with CRC occurrence and progression. This study aims to analyze the gut microbiota composition and the enriched metabolic pathways in patients with late-stage CRC. In this study, a cohort of 25 CRC patients diagnosed at late stage III and IV and 25 healthy participants were enrolled. The fecal bacterial composition was investigated using V3-V4 ribosomal RNA gene sequencing, followed by clustering and linear discriminant analysis (LDA) effect size (LEfSe) analyses. A cluster of ortholog genes' (COG) functional annotations and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were employed to identify enrichment pathways between the two groups. The findings showed that the fecal microbiota between the two groups varied significantly in alpha and beta diversities. CRC patients' fecal samples had significantly enriched populations of Streptococcus salivarius, S. parasanguins, S. anginosus, Lactobacillus mucosae, L. gasseri, Peptostreptococcus, Eubacterium, Aerococcus, Family XIII_AD3001 Group, Erysipelatoclostridium, Escherichia-Shigella, Klebsiella, Enterobacter, Alistipes, Ralstonia, and Pseudomonas (Q < 0.05). The enriched pathways identified in the CRC group were amino acid transport, signaling and metabolism, membrane biogenesis, DNA replication and mismatch repair system, and protease activity (Q < 0.05). These results suggested that the imbalance between intestinal bacteria and the elevated level of the predicated functions and pathways may contribute to the development of advanced CRC tumors. Further research is warranted to elucidate the exact role of the gut microbiome in CRC and its potential implications for use in diagnostic, prevention, and treatment strategies.

Gut Microbial and Associated Metabolite Markers for Colorectal Cancer Diagnosis

Globally, colorectal cancer (CRC) is the second most common cause of mortality worldwide. Considerable evidence indicates that dysbiosis of the gut microbial community and its metabolite secretions play a fundamental role in advanced adenoma (ADA) and CRC development and progression. This study is a systematic review that aims to assess the clinical association between gut microbial markers and/or gut and circulating metabolites with ADA and CRC. Five electronic databases were searched by four independent reviewers. Only controlled trials that compared ADA and/or CRC with healthy control (HC) using either untargeted (16s rRNA gene or whole genome sequencing) or targeted (gene-based real-time PCR) identification methods for gut microbiome profile, or untargeted or targeted metabolite profiling approaches from the gut or serum/plasma, were eligible. Three independent reviewers evaluated the quality of the studies using the Cochrane Handbook for Systematic Reviews of Interventions. Twenty-four studies were eligible. We identified strong evidence of two microbial markers Fusobacterium and Porphyromonas for ADA vs. CRC, and nine microbial markers Lachnospiraceae-Lachnoclostridium, Ruminococcaceae-Ruminococcus, Parvimonas spp., Parvimonas micra, Enterobacteriaceae, Fusobacterium spp., Bacteroides, Peptostreptococcus-Peptostreptococcus stomatis, Clostridia spp.-Clostridium hylemonae, Clostridium symbiosum, and Porphyromonas-Porphyromonas asaccharolytica for CRC vs. HC. The remaining metabolite marker evidence between the various groups, including ADA vs. HC, ADA vs. HC, and CRC vs. HC, was not of sufficient quality to support additional findings. The identified gut microbial markers can be used in a panel for diagnosing ADA and/or CRC. Further research in the metabolite markers area is needed to evaluate the possibility to use in diagnostic or prognostic markers for colorectal cancer.

Evaluation of plasma Short chain fatty acid levels as markers for Inflammatory bowel disease

BACKGROUND

Specific variations of short chain fatty acids in fecal samples have been shown for patients with inflammatory bowel disease. The aim of this study was to assess if Crohn's disease and ulcerative colitis are associated with altered concentrations of short chain fatty acids also in blood plasma.

METHOD

Between 2016-2019, Swedish adults referred to a tertiary center for colonoscopy were asked to participate in a cross-sectional study. Individuals with Crohn's disease or ulcerative colitis as well as individuals with no findings on the colonoscopy (defined as clean colon) were included in the study. Data on colonoscopy findings, blood samples (including haemoglobin, C-reactive protein and short chain fatty acid analysis) as well as a validated lifestyle questionnaire including 277 questions were collected from all participants. Linear regression was used to compare mean concentrations of short chain fatty acids between Crohn's disease, ulcerative colitis and clean colon.

RESULTS

The cohort consisted of 132 individuals with Crohn's disease, 119 with ulcerative colitis and 205 with clean colon. In the crude model, succinic acid was significantly lower (p < 0.05) among patients with Crohn's disease (mean 3.00 µM SE 0.10) and ulcerative colitis (mean 3.13 µM SE 0.10) in comparison to clean colon (mean 3.41 µM SE 0.08), however when adjusting for sex, age and diet the results did not remain statistically significant. No differences in plasma concentration of the other measured short chain fatty acids were detected.

CONCLUSION

Crohn's disease and ulcerative colitis are not associated with altered short chain fatty acid concentrations in plasma. Further research is needed to confirm or refute our findings.

Determination of short-chain fatty acids as putative biomarkers of cancer diseases by modern analytical strategies and tools: a review

Short-chain fatty acids (SCFAs) are the main metabolites produced by bacterial fermentation of non-digestible carbohydrates in the gastrointestinal tract. They can be seen as the major flow of carbon from the diet, through the microbiome to the host. SCFAs have been reported as important molecules responsible for the regulation of intestinal homeostasis. Moreover, these molecules have a significant impact on the immune system and are able to affect inflammation, cardiovascular diseases, diabetes type II, or oncological diseases. For this purpose, SCFAs could be used as putative biomarkers of various diseases, including cancer. A potential diagnostic value may be offered by analyzing SCFAs with the use of advanced analytical approaches such as gas chromatography (GC), liquid chromatography (LC), or capillary electrophoresis (CE) coupled with mass spectrometry (MS). The presented review summarizes the importance of analyzing SCFAs from clinical and analytical perspective. Current advances in the analysis of SCFAs focused on sample pretreatment, separation strategy, and detection methods are highlighted. Additionally, it also shows potential areas for the development of future diagnostic tools in oncology and other varieties of diseases based on targeted metabolite profiling.

The Modulatory Effects of Fatty Acids on Cancer Progression

Cancer is the second leading cause of death worldwide and the global cancer burden rises rapidly. The risk factors for cancer development can often be attributed to lifestyle factors, of which an unhealthy diet is a major contributor. Dietary fat is an important macronutrient and therefore a crucial part of a well-balanced and healthy diet, but it is still unclear which specific fatty acids contribute to a healthy and well-balanced diet in the context of cancer risk and prognosis. In this review, we describe epidemiological evidence on the associations between the intake of different classes of fatty acids and the risk of developing cancer, and we provide preclinical evidence on how specific fatty acids can act on tumor cells, thereby modulating tumor progression and metastasis. Moreover, the pro- and anti-inflammatory effects of each of the different groups of fatty acids will be discussed specifically in the context of inflammation-induced cancer progression and we will highlight challenges as well as opportunities for successful application of fatty acid tailored nutritional interventions in the clinic.

Systematic Review: Contribution of the Gut Microbiome to the Volatile Metabolic Fingerprint of Colorectal Neoplasia

Colorectal cancer (CRC) has been associated with changes in volatile metabolic profiles in several human biological matrices. This enables its non-invasive detection, but the origin of these volatile organic compounds (VOCs) and their relation to the gut microbiome are not yet fully understood. This systematic review provides an overview of the current understanding of this topic. A systematic search using PubMed, Embase, Medline, Cochrane Library, and the Web of Science according to PRISMA guidelines resulted in seventy-one included studies. In addition, a systematic search was conducted that identified five systematic reviews from which CRC-associated gut microbiota data were extracted. The included studies analyzed VOCs in feces, urine, breath, blood, tissue, and saliva. Eight studies performed microbiota analysis in addition to VOC analysis. The most frequently reported dysregulations over all matrices included short-chain fatty acids, amino acids, proteolytic fermentation products, and products related to the tricarboxylic acid cycle and Warburg metabolism. Many of these dysregulations could be related to the shifts in CRC-associated microbiota, and thus the gut microbiota presumably contributes to the metabolic fingerprint of VOC in CRC. Future research involving VOCs analysis should include simultaneous gut microbiota analysis.

Short-chain fatty acid concentrations in the incidence and risk-stratification of colorectal cancer: a systematic review and meta-analysis

BACKGROUND

The beneficial role of gut microbiota and bacterial metabolites, including short-chain fatty acids (SCFAs), is well recognized, although the available literature around their role in colorectal cancer (CRC) has been inconsistent.

METHODS

We performed a systematic review and meta-analysis to examine the associations of fecal SCFA concentrations to the incidence and risk of CRC. Data extraction through Medline, Embase, and Web of Science was carried out from database conception to June 29, 2022. Predefined inclusion/exclusion criteria led to the selection of 17 case-control and six cross-sectional studies for quality assessment and analyses. Studies were categorized for CRC risk or incidence, and RevMan 5.4 was used to perform the meta-analyses. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model. Studies lacking quantitation were included in qualitative analyses.

RESULTS

Combined analysis of acetic, propionic, and butyric acid revealed significantly lower concentrations of these SCFAs in individuals with a high-risk of CRC (SMD = 2.02, 95% CI 0.31 to 3.74, P = 0.02). Additionally, CRC incidence was higher in individuals with lower levels of SCFAs (SMD = 0.45, 95% CI 0.19 to 0.72, P = 0.0009), compared to healthy individuals. Qualitative analyses identified 70.4% of studies reporting significantly lower concentrations of fecal acetic, propionic, butyric acid, or total SCFAs in those at higher risk of CRC, while 66.7% reported significantly lower concentrations of fecal acetic and butyric acid in CRC patients compared to healthy controls.

CONCLUSIONS

Overall, lower fecal concentrations of the three major SCFAs are associated with higher risk of CRC and incidence of CRC.

Therapeutic approaches to colorectal cancer via strategies based on modulation of gut microbiota

Colorectal cancer (CRC) ranks third in terms of global incidence and second in terms of death toll among malignant tumors. Gut microbiota are involved in the formation, development, and responses to different treatments of CRC. Under normal physiological conditions, intestinal microorganisms protect the intestinal mucosa, resist pathogen invasion, and regulate the proliferation of intestinal mucosal cells via a barrier effect and inhibition of DNA damage. The composition of gut microbiota and the influences of diet, drugs, and gender on the composition of the intestinal flora are important factors in the early detection of CRC and prediction of the results of CRC treatment. Regulation of gut microbiota is one of the most promising new strategies for CRC treatment, and it is essential to clarify the effect of gut microbiota on CRC and its possible mechanisms to facilitate the prevention and treatment of CRC. This review discusses the role of gut microbiota in the pathogenesis of CRC, the potential of gut microbiota as biomarkers for CRC, and therapeutic approaches to CRC based on the regulation of gut microbiota. It might provide new ideas for the use of gut microbiota in the prevention and treatment of CRC in the near future and thus reduce the incidence of CRC.

Application Value of Nutrition Support Team in Chemotherapy Period of Colon Cancer Based on Internet Multidisciplinary Treatment Mode

Objective

To explore the application value of the nutrition support team in chemotherapy period of colon cancer based on the internet multidisciplinary treatment mode.

Methods

For the method of retrospective study, 90 patients with colon cancer admitted to our hospital from August 2018 to August 2020 were selected as the study subjects. They were equally divided into the experimental group (n = 45) and the control group (n = 45) according to the order of initials and the method of parity group. The control group was given conventional nutrition support, and the experimental group was given the nutrition support under the internet multidisciplinary treatment mode. The serum tumor marker levels (CEA and CA19-9), immune function indexes, nutrition indicators, and the incidence of adverse reactions were compared between the two groups before and after intervention.

Results

The serum tumor marker levels in the experimental group after intervention were significantly lower than those in the control group (P < 0.001). The immune function indexes in the experimental group after intervention were significantly better than those in the control group (P < 0.001). The nutrition indicators in the experimental group after intervention were significantly better than those in the control group (P < 0.001). The incidence of gastrointestinal adverse reactions above grade 2 in the experimental group was significantly lower than that in the control group (P < 0.05). There were 20 patients with myelosuppression, 2 patients with neurotoxicity, and 1 patient with hand and foot syndrome in the experimental group, while 22 patients with myelosuppression, 4 patients with neurotoxicity, and 2 patients with hand and foot syndrome in the control group, with no significant difference in the incidence of adverse reactions between the two groups (P > 0.05).

Conclusion

The nutrition support team under the internet multidisciplinary treatment mode can improve the immune function of chemotherapy patients with colon cancer and enhance their nutritional level, thereby reducing the incidence of adverse reactions and improving the chemotherapy effects.