Omega-3 Polyunsaturated Fatty Acids and Their Bioactive Metabolites in Gastrointestinal Malignancies Related to Unresolved Inflammation. A Review

Novel insights into dietary bioactive compounds and major depressive disorders: evidence from animal studies and future perspectives

Clinical depression, including major depressive disorder (MDD), is a chronic mental illness characterized by persistent sadness and indifference. Depression is associated with neuroinflammation, oxidative stress, and neuronal apoptosis in the brain, resulting in microglial overactivation, decreased neuronal and glial proliferation, monoamine depletion, structural abnormalities, and aberrant biochemical activity via the hypothalamic-pituitary-adrenal axis. Recent studies have exhibited the role of dietary bioactive compounds in the mitigation of MDD progression. Here, in this narrative review, we reported the effects of commonly consumed bioactive compounds (curcumin, saffron, garlic, resveratrol, omega-3 fatty acids, ginger, blueberry, tea, and creatine) on MDD and MDD-related neuroinflammation and oxidative stress. The evidence reviewed here is almost exclusively from animal studies and strongly suggest that these commonly consumed bioactive compounds have anti-MDD effects as shown in anti-depression-like behaviors, such as increased immobility, sucrose preference, and social interaction. Based on the literature/studies reviewed, the proposed molecular mechanisms include (i) the reduction of neuroinflammation activation and oxidative stress, (ii) the enhancement of anti-inflammatory and anti-oxidant properties, (iii) the reduction of monoamine oxidase-A production, and (iv) the elevation of brain-derived neurotropic factor and neurogenesis. In the future, dietary bioactive compounds on clinical randomized controlled trials are warranted to confirm the findings of preclinical efficacies using bioactive compounds in individuals with MDD.

The Multifaceted Impact of Bioactive Lipids on Gut Health and Disease

Bioactive lipids have a multifaceted role in health and disease and are recognized to play an important part in gut immunity and disease conditions such as inflammatory bowel disease and colon cancer. Advancements in lipidomics, enabled by mass spectrometry and chromatographic techniques, have enhanced our understanding of lipid diversity and functionality. Bioactive lipids, including short-chain fatty acids, saturated fatty acids, omega-3 fatty acids, and sphingolipids, exhibit diverse effects on inflammation and immune regulation. Short-chain fatty acids like butyrate demonstrate anti-inflammatory properties, enhancing regulatory T cell function, gut barrier integrity, and epigenetic regulation, making them promising therapeutic targets for inflammatory bowel disease and colon cancer. Conversely, saturated fatty acids promote inflammation by disrupting gut homeostasis, triggering oxidative stress, and impairing immune regulation. Omega-3 lipids counteract these effects, reducing inflammation and supporting immune balance. Sphingolipids exhibit complex roles, modulating immune cell trafficking and inflammation. They can exert protective effects or exacerbate colitis depending on their source and context. Additionally, eicosanoids can also prevent pathology through prostaglandin defense against damage to epithelial barriers. This review underscores the importance of dietary lipids in shaping gut health and immunity and also highlights the potential use of lipids as therapeutic strategies for managing inflammatory conditions and cancer.

Associations between eicosapentaenoic acid and docosahexaenoic acid consumption and inflammatory bowel disease in adults: The National Health and Nutrition Examination Survey (NHANES) 2009-2010

BACKGROUND AND OBJECTIVES

Current evidence on the associations of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) consumption with the risk of inflammatory bowel disease (IBD) is inconsistent. This study aimed to investigate the relationship between dietary EPA and DHA consumption with the incidence of IBD in a population of the United States, which potentially provides insights for global nutritional prevention and control strategies for IBD.

METHODS AND STUDY DESIGN

Data were sourced from the National Health and Nutrition Examination Survey for the years 2009-2010. EPA and DHA consumption was measured using twice 24-h dietary recall questionnaires. In the arthritis questionnaire, the incidence of IBD was inquired via a sub-analysis for arthropathy. To assess the relationship between dietary EPA and DHA consumption with the incidence of IBD, binary logistic regression and limited cubic spline models were used.

RESULTS

A total of 4,242 individuals aged 20 years and older participated in this survey. IBD was diagnosed in 52 individuals, representing a prevalence of 1.23%. The 95% confidence interval for crude odds ratios (ORs) of IBD in quartiles 2 and 3 of dietary EPA consumption was 0.14 (0.04-0.55) (p<0.05) and 0.36 (0.18-0.73) (p<0.05) when compared to quartile 1, respectively. The 95% confidence interval for crude ORs of IBD in quartile 4 of dietary DHA consumption was 0.09(0.02-0.35) (p<0.05) when compared to quartile 1.

CONCLUSIONS

For the National Health and Nutrition Examination Survey in 2009-2010, increased dietary EPA and DHA consumption may be related to a decreased risk of IBD in Americans aged 20 and above.

Metabolic dysfunction-associated steatotic liver disease and extrahepatic gastrointestinal cancers

Metabolic dysfunction-associated steatotic liver disease (MASLD) poses a significant and ever-increasing health and economic burden worldwide. Substantial epidemiological evidence shows that MASLD is a multisystem disease that is associated not only with liver-related complications but is also associated with an increased risk of developing cardiometabolic comorbidities and extrahepatic cancers (principally gastrointestinal [GI] cancers). GI cancers account for a quarter of the global cancer incidence and a third of cancer-related deaths. In this narrative review, we provide an overview of the literature on (a) the epidemiological data on the risk of non-liver GI cancers in MASLD, (b) the putative mechanisms by which MASLD (and factors linked with MASLD) may increase this risk, and (c) the possible pharmacotherapies beneficially affecting both MASLD and extrahepatic GI cancer risk. There are multiple potential pathophysiological mechanisms by which MASLD may increase extrahepatic GI cancer risk. Although further studies are needed, the current evidence supports a possible extrahepatic carcinogenic role for MASLD, regardless of obesity and diabetes status, thus highlighting the potential role of tailoring cancer screening for individuals with MASLD. Although there are conflicting data in the literature, aspirin, statins and metformin appear to exert some chemo-preventive effects against GI cancer.

Relationship between Markers of Gut Barrier Function and Erythrocyte Membrane PUFAs in Diarrhea-Predominant IBS Patients Undergoing a Low-FODMAP Diet

Many patients with irritable bowel syndrome (IBS) have a compromised intestinal barrier associated with low-grade inflammation. Polyunsaturated fatty acids (PUFAs) are potential mediators of inflammation: omega-6 PUFAs are pro-inflammatory, while omega-3 PUFAs are antioxidant and anti-inflammatory. Zonulin is a potential biomarker for small intestinal permeability (s-IP). This study investigated the relationship between PUFAs and gastrointestinal (GI) barrier integrity in IBS patients with predominant diarrhea (IBS-D). We evaluated GI barrier function indicators in the urine and bloodstream and erythrocyte membrane PUFA composition in 38 IBS-D patients (5 men, 33 women, 44.11 ± 1.64 years), categorized at baseline by fecal zonulin levels into high (≥107 ng/mL, H-FZ) and normal (<107 ng/mL N-FZ) groups. Evaluations were conducted prior to and following a 12-week diet low in FODMAPs (LFD). At baseline, H-FZ patients had s-IP significantly higher than the reference value, lower n-3 PUFAs levels, and higher n-6/n-3 PUFAs and arachidonic acid (AA) to eicosapentaenoic acid (EPA) ratios than N-FZ. After LFD, H-FZ patients showed significant increases in n-3 PUFAs levels; decreases in n-6 PUFAs, n-6/n-3 PUFAs and AA/EPA ratios; and improved s-IP. The n-6/n-3 PUFAs ratio positively correlated with fecal zonulin levels in all subjects. These findings highlight the relationship between PUFAs and the intestinal barrier, suggesting their role in IBS-D pathophysiology and confirming the positive effects of LFD in managing IBS-D.

Associations between diet and nutritional supplements and colorectal cancer: A systematic review

Background and Aim

Colorectal cancer (CRC) is one of the most prevalent cancers around the world. The link between nutrients and the likelihood of developing CRC remains uncertain. The primary objective of the present study was to investigate the potential connection between dietary intake/dietary supplements and the occurrence of CRC through a literature review.

Methods

A comprehensive online search was conducted in PubMed, Scopus, Web of Science, and the Cochrane Library from January 1990 to March 2023 using appropriate keywords. A systematic search was conducted for clinical trials and cohort studies in order to determine the relationship between dietary components/supplements and CRC.

Results

The intake of long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs), consisting of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), has the potential to decrease the likelihood of developing CRC (eight studies found positive effects and four studies found no association). Some other dietary components such as probiotics, prebiotics, and synbiotics may contribute to suppressing CRC development (three studies found positive effects, whereas three studies did not find any association). There is inconclusive evidence that supplementation with certain micronutrients including vitamin D (one trial found positive effects and another trial reported no association), folate, zinc, and selenium may reduce the risk of CRC.

Conclusion

Some dietary supplements such as n-3 LCPUFAs and probiotics have the potential to reduce the risk of developing CRC. Further studies are necessary to validate these results and understand the underlying mechanisms.

Clinical value of serum polyunsaturated fatty acids in patients with gastric polyps

Polyunsaturated fatty acids (PUFAs) are vital nutrients in human physiology and are implicated in various chronic diseases. However, the relationship between PUFAs and gastric polyps remains unclear. This study employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess PUFA levels in the serum of 350 patients, along with analyzing the ω-6 to ω-3 ratio. The results revealed significant differences in the levels of C16:1, C18:1, C18:2, α-C18:3, γ-C18:3, C20:1, C20:4, C20:5, ω-3-C22:5, ω-6-C22:5, and C22:6, as well as ω-6 to ω-3 ratio between the control and gasteic polyp groups. Moreover, setting the threshold for ω-6: ω-3 at 10 revealed a close correlation between polyp occurrence and this ratio. These findings suggest that PUFAs and the ω-6 to ω-3 ratio hold promise as potential early screening markers for gastric polyps. However, further research is imperative to elucidate the underlying mechanisms and therapeutic potential of PUFAs in managing gastric polyps.

Causal associations between dietary factors and colorectal cancer risk: a Mendelian randomization study

Background

Previous epidemiological studies have found a link between colorectal cancer (CRC) and human dietary habits. However, the inherent limitations and inevitable confounding factors of the observational studies may lead to the inaccurate and doubtful results. The causality of dietary factors to CRC remains elusive.

Methods

We conducted two-sample Mendelian randomization (MR) analyses utilizing the data sets from the IEU Open GWAS project. The exposure datasets included alcoholic drinks per week, processed meat intake, beef intake, poultry intake, oily fish intake, non-oily fish intake, lamb/mutton intake, pork intake, cheese intake, bread intake, tea intake, coffee intake, cooked vegetable intake, cereal intake, fresh fruit intake, salad/raw vegetable intake, and dried fruit intake. In our MR analyses, the inverse variance weighted (IVW) method was employed as the primary analytical approach. The weighted median, MR-Egger, weighted mode, and simple mode were also applied to quality control. Heterogeneity and pleiotropic analyses were implemented to replenish the accuracy of the results.

Results

MR consequences revealed that alcoholic drinks per week [odds ratio (OR): 1.565, 95% confidence interval (CI): 1.068-2.293, p = 0.022], non-oily fish intake (OR: 0.286; 95% CI: 0.095-0.860; p = 0.026), fresh fruit intake (OR: 0.513; 95% CI: 0.273-0.964; p = 0.038), cereal intake (OR: 0.435; 95% CI: 0.253-0.476; p = 0.003) and dried fruit intake (OR: 0.522; 95% CI: 0.311-0.875; p = 0.014) was causally correlated with the risk of CRC. No other significant relationships were obtained. The sensitivity analyses proposed the absence of heterogeneity or pleiotropy, demonstrating the reliability of the MR results.

Conclusion

This study indicated that alcoholic drinks were associated with an increased risk of CRC, while non-oily fish intake, fresh fruit intake, cereal intake, and dried fruit were associated with a decreased risk of CRC. This study also indicated that other dietary factors included in this research were not associated with CRC. The current study is the first to establish the link between comprehensive diet-related factors and CRC at the genetic level, offering novel clues for interpreting the genetic etiology of CRC and replenishing new perspectives for the clinical practice of gastrointestinal disease prevention.

Molecular Mechanisms Associated with the Inhibitory Role of Long Chain n-3 PUFA in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the world. Multiple evidence suggests that there is an association between excess fat consumption and the risk of CRC. The long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential for human health, and both in vitro and in vivo studies have shown that these fatty acids can prevent CRC development through various molecular mechanisms. These include the modulation of arachidonic acid (AA) derived prostaglandin synthesis, alteration of growth signaling pathways, arrest of the cell cycle, induction of cell apoptosis, suppression of angiogenesis and modulation of inflammatory response. Human clinical studies found that LC n-3 PUFA combined with chemotherapeutic agents can improve the efficacy of treatment and reduce the dosage of chemotherapy and associated side effects. In this review, we discuss comprehensively the anti-cancer effects of LC n-3 PUFA on CRC, with a main focus on the underlying molecular mechanisms.

Maresin1: A multifunctional regulator in inflammatory bone diseases

Inflammation plays a crucial role in the physical response to danger signals, the elimination of toxic stimuli, and the restoration of homeostasis. However, dysregulated inflammatory responses lead to tissue damage, and chronic inflammation can disrupt osteogenic-osteoclastic homeostasis, ultimately leading to bone loss. Maresin1 (MaR1), a member of the specialized pro-resolving mediators (SPMs) family, has been found to possess significant anti-inflammatory, anti-allergic, pro-hemolytic, pro-healing, and pain-relieving properties. MaR1 is synthesized by macrophages (Mφs) and omega-3 fatty acids, and it may have the potential to promote bone homeostasis and treat inflammatory bone diseases. MaR1 has been found to stimulate osteoblast proliferation through leucine-rich repeat G protein-coupled receptor 6 (LGR6). It also activates Mφ phagocytosis and M2-type polarization, which helps to control the immune system. MaR1 can regulate T cells to exert anti-inflammatory effects and inhibit neutrophil infiltration and recruitment. In addition, MaR1 is involved in antioxidant signaling, including nuclear factor erythroid 2-related factor 2 (NRF2). It has also been found to promote the autophagic behavior of periodontal ligament stem cells, stimulate Mφs against pathogenic bacteria, and regulate tissue regeneration and repair. In summary, this review provides new information and a comprehensive overview of the critical roles of MaR1 in inflammatory bone diseases, indicating its potential as a therapeutic approach for managing skeletal metabolism and inflammatory bone diseases.

Plasma and rectal mucosal oxylipin levels during aspirin and eicosapentaenoic acid treatment in the seAFOod polyp prevention trial

BACKGROUND

Aspirin and eicosapentaenoic acid (EPA) have colorectal polyp prevention activity, alone and in combination. This study measured levels of plasma and rectal mucosal oxylipins in participants of the seAFOod 2 × 2 factorial, randomised, placebo-controlled trial, who received aspirin 300 mg daily and EPA 2000 mg free fatty acid, alone and in combination, for 12 months.

METHODS

Resolvin (Rv) E1, 15-epi-lipoxin (LX) A₄ and respective precursors 18-HEPE and 15-HETE (with chiral separation) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry in plasma taken at baseline, 6 months and 12 months, as well as rectal mucosa obtained at trial exit colonoscopy at 12 months, in 401 trial participants.

RESULTS

Despite detection of S- and R- enantiomers of 18-HEPE and 15-HETE in ng/ml concentrations, RvE1 or 15‑epi-LXA₄ were not detected above a limit of detection of 20 pg/ml in plasma or rectal mucosa, even in individuals randomised to both aspirin and EPA. We have confirmed in a large clinical trial cohort that prolonged (12 months) treatment with EPA is associated with increased plasma 18-HEPE concentrations (median [inter-quartile range] total 18-HEPE 0.51 [0.21-1.95] ng/ml at baseline versus 0.95 [0.46-4.06] ng/ml at 6 months [P<0.0001] in those randomised to EPA alone), which correlate strongly with respective rectal mucosal 18-HEPE levels (r = 0.82; P<0.001), but which do not predict polyp prevention efficacy by EPA or aspirin.

CONCLUSION

Analysis of seAFOod trial plasma and rectal mucosal samples has not provided evidence of synthesis of the EPA-derived specialised pro-resolving mediator RvE1 or aspirin-trigged lipoxin 15‑epi-LXA₄. We cannot rule out degradation of individual oxylipins during sample collection and storage but readily measurable precursor oxylipins argues against widespread degradation.

Role of Dairy Foods, Fish, White Meat, and Eggs in the Prevention of Colorectal Cancer: A Systematic Review of Observational Studies in 2018-2022

There is limited evidence to support the relationship between the consumption of animal-source foods other than red meat and processed meat and colorectal cancer (CRC) risk. We aimed to examine the recent available evidence from observational studies about the association between these food groups’ intake and CRC risk. For this systematic review, we searched the PubMed database for the last five years. A total of fourteen cohort studies and seven case−control studies comprising a total of >60,000 cases were included. The studies showed a consistent significant decrease in CRC risk, overall and by subsites, associated with a high consumption of total dairy products. Less strong effects associated with the consumption of any subtype of dairy product were observed. Fish consumption, overall and by subtypes (oily or non-oily and fresh or canned), showed a mild inverse association with CRC risk. The association between white meat and egg intake and CRC risk was low and based on a small number of studies; thus, these findings should be interpreted with caution. In conclusion, a high consumption of total dairy products was associated with a lower CRC risk. However, evidence for fish, white meat, and eggs and the CRC risk were not as strong.

Synbiotic Compositions of Bacillus megaterium and Polyunsaturated Fatty Acid Salt Enable Self-Sufficient Production of Specialized Pro-Resolving Mediators

Specialized pro-resolving mediators (SPM) have emerged as crucial lipid mediators that confer the inflammation-resolving effects of omega-3 polyunsaturated fatty acids (n-3 PUFA). Importantly, SPM biosynthesis is dysfunctional in various conditions, which may explain the inconclusive efficacy data from n-3 PUFA interventions. To overcome the limitations of conventional n-3 PUFA supplementation strategies, we devised a composition enabling the self-sufficient production of SPM in vivo. Bacillus megaterium strains were fed highly bioavailable n-3 PUFA, followed by metabololipidomics analysis and bioinformatic assessment of the microbial genomes. All 48 tested Bacillus megaterium strains fed with the n-3 PUFA formulation produced a broad range of SPM and precursors thereof in a strain-specific manner, which may be explained by the CYP102A1 gene polymorphisms that we detected. A pilot study was performed to test if a synbiotic Bacillus megaterium/n-3 PUFA formulation increases SPM levels in vivo. Supplementation with a synbiotic capsule product led to significantly increased plasma levels of hydroxy-eicosapentaenoic acids (5-HEPE, 15-HEPE, 18-HEPE) and hydroxy-docosahexaenoic acids (4-HDHA, 7-HDHA) as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in healthy humans. To the best of our knowledge, we report here for the first time the development and in vivo application of a self-sufficient SPM-producing formulation. Further investigations are warranted to confirm and expand these findings, which may create a new class of n-3 PUFA interventions targeting inflammation resolution.

Divergent Metabolic Effects of Metformin Merge to Enhance Eicosapentaenoic Acid Metabolism and Inhibit Ovarian Cancer In Vivo

Metformin is being actively repurposed for the treatment of gynecologic malignancies including ovarian cancer. We investigated if metformin induces analogous metabolic changes across ovarian cancer cells. Functional metabolic analysis showed metformin caused an immediate and sustained decrease in oxygen consumption while increasing glycolysis across A2780, C200, and SKOV3ip cell lines. Untargeted metabolomics showed metformin to have differential effects on glycolysis and TCA cycle metabolites, while consistent increased fatty acid oxidation intermediates were observed across the three cell lines. Metabolite set enrichment analysis showed alpha-linolenic/linoleic acid metabolism as being most upregulated. Downstream mediators of the alpha-linolenic/linoleic acid metabolism, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were abundant in all three cell lines. EPA was more effective in inhibiting SKOV3 and CaOV3 xenografts, which correlated with inhibition of inflammatory markers and indicated a role for EPA-derived specialized pro-resolving mediators such as Resolvin E1. Thus, modulation of the metabolism of omega-3 fatty acids and their anti-inflammatory signaling molecules appears to be one of the common mechanisms of metformin's antitumor activity. The distinct metabolic signature of the tumors may indicate metformin response and aid the preclinical and clinical interpretation of metformin therapy in ovarian and other cancers.

Fish Consumption and Colorectal Cancer Risk: Meta-Analysis of Prospective Epidemiological Studies and Review of Evidence from Animal Studies

Background: Epidemiological studies on the association between fish consumption and colorectal cancer (CRC) risk have yielded inconsistent results, despite evidence from preclinical studies that long-chain ω-3 polyunsaturated fatty acids inhibit colorectal carcinogenesis. We conducted a meta-analysis of prospective epidemiological studies investigating the association between fish consumption and CRC risk among humans and reviewed studies examining the link between fish components and colorectal carcinogenesis in animal models. Methods: We included studies published until November 2020. We calculated the summary risk ratio (SRR) and 95% confidence intervals (CI) through random effects meta-analysis models in order to summarize evidence from studies among humans. Results: Twenty-five prospective epidemiological studies encompassing 25,777 CRC cases were included. Individuals in the highest (vs. lowest) category of fish consumption had a significantly reduced risk of CRC (SRR 0.94, 95%CI 0.89-0.99). In dose-response meta-analysis, a 50-g increment in the daily consumption of fish was associated with a statistically significant 4% reduction in CRC risk (SRR 0.96, 95%CI 0.92-0.99). Preclinical studies (n = 25) identified multiple mechanisms of action of fish and fish components on colorectal carcinogenesis. Conclusions: Dietary recommendations for cancer prevention should take into account the evidence from epidemiological and preclinical studies that increasing fish consumption may be effective in preventing CRC.

One-anastomosis gastric bypass modulates the serum levels of pro- and anti-inflammatory oxylipins, which may contribute to the resolution of inflammation

BACKGROUND/OBJECTIVES

Oxylipins are polyunsaturated fatty acid derivatives involved in the regulation of various processes, including chronic inflammation, insulin resistance and hepatic steatosis. They can be synthesized in various tissues, including adipose tissue. There is some evidence that obesity is associated with the deregulation of serum oxylipin levels. The aim of this study was to evaluate the effect of bariatric surgery (one-anastomosis gastric bypass) on the serum levels of selected oxylipins and their fatty acid precursors and to verify the hypothesis that their changes after surgery can contribute to the resolution of inflammation. Moreover, we compared the oxylipin levels (prostaglandin E2, 13-HODE, maresin 1 and resolvin E1), fatty acids and the expression of enzymes that synthesize oxylipins in adipose tissue of lean controls and subjects with severe obesity.

SUBJECTS/METHODS

The study included 50 patients with severe obesity that underwent bariatric surgery and 41 subjects in lean, control group. Fatty acid content was analyzed by GC-MS, oxylipin concentrations were measured with immunoenzymatic assay kits and real-time PCR analysis was used to assess mRNA levels in adipose tissue.

RESULTS

Our results show increased expression of some enzymes that synthesize oxylipins in adipose tissue and alterations in the levels of oxylipins in both adipose tissue and serum of subjects with obesity. After bariatric surgery, the levels of anti-inflammatory oxylipins increased, whereas pro-inflammatory oxylipins decreased.

CONCLUSIONS

In patients with obesity, the metabolism of oxylipins is deregulated in adipose tissue, and their concentrations in serum are altered. Bariatric surgery modulates the serum levels of pro- and anti-inflammatory oxylipins, which may contribute to the resolution of inflammation.

Chemoprevention in Barrett's esophagus and esophageal adenocarcinoma

There has been a dramatic increase in the incidence of Barrett's esophagus and esophageal adenocarcinoma over the past several decades with a continued rise expected in the future. Several strategies have been developed for screening and surveillance of patients with Barrett's esophagus and endoscopic treatment of Barrett's associated dysplasia and early esophageal cancer; however, they have not made a substantial impact on the incidence of cancer. Herein, chemoprevention becomes an attractive idea for reducing the incidence of cancer in Barrett's patients. Several agents appear promising in preclinical and observational studies but very few have been evaluated in randomized controlled trials. Strongest evidence to date is available for proton-pump inhibitors and Aspirin that have been evaluated in a large randomized controlled trial. Other agents such as statins, metformin, ursodeoxycholic acid, and dietary supplements have insufficient evidence for chemoprevention in Barrett's patients.

Orally Administered DHA-Enriched Phospholipids and DHA-Enriched Triglyceride Relieve Oxidative Stress, Improve Intestinal Barrier, Modulate Inflammatory Cytokine and Gut Microbiota, and Meliorate Inflammatory Responses in the Brain in Dextran Sodium Sulfate Induced Colitis in Mice

SCOPE

Studies based on DHA/EPA supplementation in animal models of inflammatory bowel disease (IBD) reveal controversial results. It is speculated that different forms of DHA may explain the controversial results. Therefore, the effects of DHA-enriched phospholipids (DHA-PL) and DHA-enriched triglyceride (DHA-TG) on IBD are compared.

METHODS AND RESULTS

Male C57BL6/J mice are given DHA-PL and DHA-TG for 14 consecutive days, and receive ad libitum a 3.0% dextran sodium sulfate solution on the eighth day to establish IBD model. The results show that both DHA-PL and DHA-TG can reverse the colitis pathological process by decreasing the disease activity indexes (DAI), raising the colon length, suppressing the intestinal permeability, suppressing the oxidative stress, down-regulating pro-inflammatory factors, up-regulating anti-inflammatory factor in colon tissues. DHA-PL and DHA-TG also regulate the composition of gut microbiota via decreasing of the abundance Bacteroidetes and Firmicutes, and DHA-TG increases the abundance of Odoribacter. Importantly, DHA-PL and DHA-TG obviously attenuate the activation of microglia.

CONCLUSIONS

DHA-PL shows outstanding advantages in regulating oxidative stress, inflammatory responses, and intestinal barrier permeability. The current research indicates that the existence of DHA affects the improvement, DHA in phospholipid form could be a more effective choice for nutritional intervention to prevent and treat colitis.

Metabolome and microbiome alterations in tongue coating of gastric precancerous lesion patients

Objective: This paper seeks to provide mechanistic insight into the pathological transition through the analysis of metabolites and microorganisms in the tongue coating of gastric precancerous lesions (GPL) patients.Methods: GC-TOF-MS and UHPLC-QE-MS metabolomics, combined with 16S rRNA microbiome techniques, were performed to explore the changes in metabolites and microorganisms in the tongue coating of GPL patients.Results: When compared with 15 controls, 133 metabolites were found to be differentially expressed in 60 GPL cases, of which could be divided into ten categories. Among them, most of the differentially expressed metabolites identified were lipids or lipid-like molecules. These metabolites were implicated in 6 metabolic pathways including glycine, serine and threonine metabolism, arginine and proline metabolism, sphingolipid metabolism, valine, leucine and isoleucine degradation, arachidonic acid metabolism, and tyrosine metabolism. The relative abundances of Alloprevotella, Solobacterium, Rothia, Eikenella, and Aggregatibacter in the GPL group increased significantly relative to the controls and were associated with lipids and lipid-like molecules, organic nitrogen compounds, organic oxygen compounds, phenylpropanoids and polyketides, and organoheterocyclic compounds, respectively.Conclusions: Compared with healthy people, the changes of tongue coating metabolites in GPL patients were mainly characterized by alterations in lipid metabolism and were associated with localized changes in the microbiome.

Metabolite Characteristics in Tongue Coating from Damp Phlegm Pattern in Patients with Gastric Precancerous Lesion

Objective

In this study, we analyzed the metabolite profile of the tongue coating of patients having gastric precancerous lesion (GPL) with damp phlegm pattern and proposed a mechanism of pathological transition.

Methods

The changes in tongue-coating metabolites in patients with GPL damp phlegm pattern were analyzed using GC-TOF-MS and UHPLC-QE-MS metabolomics methods.

Results

When compared with 20 patients who did not exhibit a nondamp phlegm pattern, 12 metabolites were highly expressed and 10 metabolites were under expressed in 40 cases of damp phlegm pattern, of which involved 9 metabolic pathways. Compared with 15 healthy people, 134 metabolites were upregulated and 3 metabolites were downregulated in 40 cases exhibiting a damp phlegm pattern, of which involved 17 metabolic pathways. The patients with damp phlegm pattern were compared with nondamp phlegm pattern patients and healthy people, the main differential metabolites were primarily lipids and lipid-like molecules, and the main differential metabolic pathways were related to glycerophospholipid metabolism. In the glycerophospholipid metabolism, the metabolites with changes were phosphatidylethanolamine and lysoPC(18 : 1 (9z)). Among them, phosphatidylethanolamine exists in the synthesis stage of glycerophospholipid metabolism.

Conclusions

Abnormal expression of lipids and lipid-like molecules, as the major metabolic change, was involved in the formation of GPL patients with damp phlegm pattern.

Body surface area-based omega-3 fatty acids supplementation strongly correlates to blood concentrations in children

Omega-3 fatty acids have been suggested as a complement in cancer treatment, but doses are not established. We performed a dose-finding study in 33 children in remission from cancer. Participants were allocated to a body surface area (BSA) adjusted dose (mg/m²) of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (40:60), ranging 233-3448 mg/m² daily for 90 days. Fatty acid concentration in plasma phospholipids and red blood cells were determined by GC. Supplementation was well tolerated and correlated strongly with blood ω3-fatty acid concentrations and EPA showed the highest increase. Using the ω3-index disregards docosapentaenoic acid (DPA), which increased 30-43% in our study motivating an EDD-index (∑EPA,DPA,DHA). The ratio between arachidonic acid and EPA or DHA showed negative exponential trends. Dose per BSA enabled an individualized omega-3 supplementation decreasing the variation referred to interindividual differences. Based on our results, we suggest a dose of 1500 mg/m² BSA for further studies.

New Perspectives in the Study of Intestinal Inflammation: Focus on the Resolution of Inflammation

Inflammation is an essential physiological process that is directed to the protection of the organism against invading pathogens or tissue trauma. Most of the existing knowledge related to inflammation is focused on the factors and mechanisms that drive the induction phase of this process. However, since the recognition that the resolution of the inflammation is an active and tightly regulated process, increasing evidence has shown the relevance of this process for the development of chronic inflammatory diseases, such as inflammatory bowel disease. For that reason, with this review, we aimed to summarize the most recent and interesting information related to the resolution process in the context of intestinal inflammation. We discussed the advances in the understanding of the pro-resolution at intestine level, as well as the new mediators with pro-resolutive actions that could be interesting from a therapeutic point of view.

Cancer metabolism and intervention therapy

Metabolic reprogramming with heterogeneity is a hallmark of cancer and is at the basis of malignant behaviors. It supports the proliferation and metastasis of tumor cells according to the low nutrition and hypoxic microenvironment. Tumor cells frantically grab energy sources (such as glucose, fatty acids, and glutamine) from different pathways to produce a variety of biomass to meet their material needs via enhanced synthetic pathways, including aerobic glycolysis, glutaminolysis, fatty acid synthesis (FAS), and pentose phosphate pathway (PPP). To survive from stress conditions (e.g., metastasis, irradiation, or chemotherapy), tumor cells have to reprogram their metabolism from biomass production towards the generation of abundant adenosine triphosphate (ATP) and antioxidants. In addition, cancer cells remodel the microenvironment through metabolites, promoting an immunosuppressive microenvironment. Herein, we discuss how the metabolism is reprogrammed in cancer cells and how the tumor microenvironment is educated via the metabolic products. We also highlight potential metabolic targets for cancer therapies.

Anemonia sulcata and Its Symbiont Symbiodinium as a Source of Anti-Tumor and Anti-Oxoxidant Compounds for Colon Cancer Therapy: A Preliminary in Vitro Study

Simple Summary

Colorectal cancer is one of the most frequent types of cancer in the population. Recently, invertebrate marine animals have been investigated for the presence of natural products which can damage tumor cells, prevent their spread to other tissues or avoid cancer develop. We analyzed the anemone Anemonia sulcata with and without the presence of its microalgal symbiont (Symbiodinium) as a source of bioactive molecules for the colorectal cancer therapy and prevention. Colon cancer tumor cells were exposed to Anemone extracts observing a remarkable cell death and a great antioxidant capacity. These preliminary results support that Anemonia sulcata could be a source of bioactive compounds against colorectal cancer and that the absence of its symbiont may enhance these properties. Further studies will be necessary to define the bioactive compounds of Anemonia sulcata and their mechanisms of action.

Abstract

Recently, invertebrate marine species have been investigated for the presence of natural products with antitumor activity. We analyzed the invertebrate Anemonia sulcata with (W) and without (W/O) the presence of its microalgal symbiont Symbiodinium as a source of bioactive compounds that may be applied in the therapy and/or prevention of colorectal cancer (CRC). Animals were mechanically homogenized and subjected to ethanolic extraction. The proximate composition and fatty acid profile were determined. In addition, an in vitro digestion was performed to study the potentially dialyzable fraction. The antioxidant and antitumor activity of the samples and the digestion products were analyzed in CRC cells in vitro. Our results show a high concentration of polyunsaturated fatty acid in the anemone and a great antioxidant capacity, which demonstrated the ability to prevent cell death and a high antitumor activity of the crude homogenates against CRC cells and multicellular tumor spheroids, especially W/O symbiont. These preliminary results support that Anemonia sulcata could be a source of bioactive compounds with antioxidant and antitumor potential against CRC and that the absence of its symbiont may enhance these properties. Further studies will be necessary to define the bioactive compounds of Anemonia sulcata and their mechanisms of action.

Krill Oil Perturbs Proliferation and Migration of Mouse Colon Cancer Cells in vitro by Impeding Extracellular Signal-Regulated Protein Kinase Signaling Pathway

The prevalence of colorectal cancer (CRC) continues to increase. Treatment of CRC remains a significant clinical challenge, and effective therapies for advanced CRC are desperately needed. Increasing attention and ongoing research efforts have focused on krill oil that may provide health benefits to the human body. Here we report that krill oil exerts in vitro anticancer activity through a direct inhibition on proliferation, colony formation, migration, and invasion of mouse colon cancer cells. Krill oil inhibited the proliferation and colony formation of CT-26 colon cancer cells by causing G0/G1 cell cycle arrest and apoptosis. Cell cycle arrest was attributable to reduction of cyclin D1 levels in krill oil-treated cells. Further studies revealed that krill oil induced mitochondrial-dependent apoptosis of CT-26 cells, including loss of mitochondrial membrane potential, increased cytosolic calcium levels, activation of caspase-3, and downregulation of anti-apoptotic proteins MCL-1 and BCL-XL. Krill oil suppressed migration of CT-26 cells by disrupting the microfilaments and microtubules. Extracellular signal-regulated protein kinase (ERK) plays crucial roles in regulating proliferation and migration of cancer cells. We found that krill oil attenuated the activation of ERK signaling pathway to exert the effects on cell cycle, apoptosis, and migration of colon cancer cells. We speculate that polyunsaturated fatty acids of krill oil may dampen ERK activation by decreasing the phospholipid saturation of cell membrane. Although findings from in vitro studies may not necessarily translate in vivo, our study provides insights into the possibility that krill oil or its components could have therapeutic potential in colon cancer.

Chemoprevention of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is a major cause of cancer-related death, particularly in Western populations, and is rapidly rising in Asian populations at this time. Virtually all EACs develop from the precursor lesion Barrett's esophagus (BE), which is the most significant risk factor for EAC. However, the rates of progression from BE to EAC are low and patients with BE are asymptomatic. Thus, any strategy for EAC prevention must carry a low risk of harm in order to be clinically useful. Since current EAC-screening and BE-surveillance methods carry some procedural risk and are burdensome, there is an opportunity for chemoprevention, i.e. medications or dietary factors that may prevent BE from progressing to EAC. A variety of candidate chemoprevention therapies have been assessed to date. Proton-pump inhibitors (PPIs) are the best studied and have modest EAC-chemoprevention efficacy in BE patients, with a recent randomized trial showing that high-dose PPI may be more effective than low-dose PPI. Aspirin and other non-steroidal anti-inflammatory drugs have moderate quality observational and randomized-trial evidence for preventing progression of BE to EAC, but their risks for harm have precluded their routine clinical use. Other therapies (statins, metformin, female sex hormones) generally do not have strong evidence to support their use in EAC chemoprevention. Although progress has been made in this field, there is still a need for more effective and safe chemoprevention therapies for EAC.

The Role of Pro-Resolving Lipid Mediators in Colorectal Cancer-Associated Inflammation: Implications for Therapeutic Strategies

Inflammation is a recognized hallmark of cancer that contributes to the development and progression of colorectal cancer (CRC). Anti-inflammatory drugs currently used for the treatment of CRC show many adverse side effects that prompted researchers to propose the polyunsaturated fatty acids-derived specialized pro-resolving mediators (SPMs) as promoters of resolution of cancer-associated inflammation. SPMs were found to inhibit the CRC-associated pro-inflammatory milieu via specific G-coupled protein receptors, although clinical data are still lacking. This review aims to summarize the state-of-the-art in this field, ultimately providing insights for the development of innovative anti-CRC therapies that promote the endogenous lipid-mediated resolution of CRC-associated inflammation.

Efficacy of mesenchymal stem cells in the treatment of gastrointestinal malignancies

Mesenchymal stem cells (MSCs), which are a kind of stem cell, possess an immune privileged nature, tumour homing features, and multi-lineage differentiation ability. MSCs have been studied in many fields, such as tissue engineering, nervous system diseases, and cancer treatment. In recent years, an increasing number of researchers have focused on the effects of MSCs on various kinds of tumours. However, the concrete anticancer efficacy of MSCs is still controversial. Gastrointestinal (GI) malignancies are the major causes of cancer-related death worldwide. The interactions of MSCs and GI cancer cells in specific conditions have attracted increasing attention. In this review, we introduce the characteristics of MSCs and analyse the effects of MSCs on GI malignancies, including gastric cancer, hepatoma, pancreatic cancer, and colorectal cancer. In addition, we also provide our perspectives on why MSCs may play different roles in GI malignancies and further research directions to increase the treatment efficacy of MSCs on GI malignancies.