Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Peficitinib ameliorates 5-fluorouracil-induced intestinal damage by inhibiting aging, inflammatory factors and oxidative stress

5-Fluorouracil (5-FU) is a conventional and effective drug for colorectal cancer patients, and it is an important part of combined chemotherapy and adjuvant chemotherapy. Chemotherapy intestinal mucositis (CIM) is a severe side effect caused by 5-FU that, induces cancer treatment failure and affects patients' quality of life. The mechanism of 5-FU-induced CIM is related to normal cell senescence induced by 5-FU. Peficitinib, a Janus Kinase (JAK) inhibitor, treats inflammatory disorders, including rheumatoid arthritis, psoriasis, and inflammatory bowel disease. However, the therapeutic role and underlying mechanism of peficitinib in CIM remain unclear. The main objective of our research was to investigate the effects of peficitinib on 5-FU-induced senescence and intestinal damage in human umbilical vein endothelial (HUVEC) cells, human intestinal epithelial (HIEC) cells and BABL/C mice. The results showed that 5-FU caused intestinal damage by inducing aging and increasing inflammation and oxidative stress. Peficitinib alleviated aging by reducing senescence-beta-galactosidase (SA-β-gal) activity and the protein levels of aging indicators (p53, p21, p16). Moreover, peficitinib reversed the changes in senescence-associated secretory phenotype (SASP) expression caused by 5-FU. Besides, 5-FU induced release of inflammatory factors and oxidative stress indicators was reversed by peficitinib. Additionally, the combination of peficitinib and 5-FU reinforced the anticancer curative intent of 5-FU in two colorectal cancer cell lines (HCT116 cells and SW620 cells). In conclusion, peficitinib alleviates mucositis by alleviating aging, reducing inflammatory accumulation and oxidative stress and enhancing the antitumor activity of 5-FU.

Rodent models for anticancer toxicity studies: contributions to drug development and future perspectives

Antineoplastic treatment induces a type of gastrointestinal toxicity known as mucositis. Findings in animal models are usually easily reproducible, and standardized treatment regimens are often used, thus supporting translational science. Essential characteristics of mucositis, including intestinal permeability, inflammation, immune and oxidative responses, and tissue repair mechanisms, can be easily investigated in these models. Given the effects of mucositis on the quality of life of patients with cancer, and the importance of experimental models in the development of more effective new therapeutic alternatives, this review discusses progress and current challenges in using experimental models of mucositis in translational pharmacology research. Teaser Experimental models for studying gastrointestinal mucositis have provided a wealth of information improving the understanding of antineoplastic toxicity.

Mining Anti-Inflammation Molecules From Nippostrongylus brasiliensis-Derived Products Through the Metabolomics Approach

Hookworm is one type of soil-transmitted helminth, which could exert an anti-inflammatory effect in human or animal host, which provides a beneficial possibility for the discovery of inflammatory-related disease interventions. The identification of hookworm-derived anti-inflammatory molecules is urgently needed for future translational research. The emergence of metabolomics has become a powerful approach to comprehensively characterize metabolic alterations in recent times. Herein, excretory and secretory products (ESPs) were collected from cultured adult worm, while small intestinal contents were obtained from Nippostrongylus brasiliensis (N. brasiliensis, Nb)-infected mice. Through ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) platform, metabolomics analysis was used to explore the identification of anti-inflammatory molecules. Out of 45 differential metabolites that were discovered from ESPs, 10 of them showed potential anti-inflammatory properties, which could be subclassed into amino acids, furanocoumarins, linear diarylheptanoids, gamma butyrolactones, and alpha-keto acids. In terms of intestinal contents that were derived from N. brasiliensis-infected mice, 14 out of 301 differential metabolites were discovered to demonstrate anti-inflammatory effects, with possible subclassification into amino acids, benzylisoquinolines, quaternary ammonium salts, pyrimidines, pregnane steroids, purines, biphenyls, and glycerophosphocholines. Furthermore, nine of the differential metabolites appeared both in ESPs and infected intestinal contents, wherein four were proven to show anti-inflammation properties, namely, L-glutamine, glutamine (Gln), pyruvate, and alanine-Gln (Ala-Gln). In summary, we have provided a method for the identification and analysis of parasite-derived molecules with potential anti-inflammatory properties in the present study. This array of anti-inflammatory metabolites could provide clues for future evaluation and translational study of these anti-inflammatory molecules.

Acute blockade of endogenous melatonin by Luzindole, with or without peripheral LPS injection, induces jejunal inflammation and morphological alterations in Swiss mice

This study investigated the acute blockade of endogenous melatonin (MLT) using Luzindole with or without systemic lipopolysaccharide (LPS) challenge and evaluated changes in inflammatory and oxidative stress markers in the mouse jejunum. Luzindole is an MT1/MT2 MLT receptor antagonist. Both receptors occur in the small intestine. Swiss mice were treated with either saline (0.35 mg/kg, ip), Luzindole (0.35 mg/kg, ip), LPS (1.25 mg/kg, ip), or Luzindole+LPS (0.35 and 1.25 mg/kg, ip, respectively). Jejunum samples were evaluated regarding intestinal morphometry, histopathological crypt scoring, and PAS-positive villus goblet cell counting. Inflammatory Iba-1, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nuclear factor (NF)-kB, myeloperoxidase (MPO), and oxidative stress (NP-SHs, catalase, MDA, nitrate/nitrite) markers were assessed. Mice treated with Luzindole, LPS, and Luzindole+LPS showed villus height shortening. Crypt damage was worse in the LPS group. Luzindole, LPS, and Luzindole+LPS reduced the PAS-goblet cell labeling and increased Iba-1-immunolabelled cells compared to the saline group. Immunoblotting for IL-1β, TNF-α, and NF-kB was greater in the Luzindole group. The LPS-challenged group showed higher MPO activity than the saline and Luzindole groups. Catalase was reduced in the Luzindole and Luzindole+LPS groups compared to saline. The Luzindole group showed an increase in NP-SHs, an effect related to compensatory GSH activity. The acute blockade of endogenous MLT with Luzindole induced early changes in inflammatory markers with altered intestinal morphology. The other non-detectable deleterious effects of Luzindole may be balanced by the unopposed direct action of MLT in immune cells bypassing the MT1/MT2 receptors.

Anti-inflammatory effect of L-cysteine (a semi-essential amino acid) on 5-FU-induced oral mucositis in hamsters

Oral mucositis is an inflammation of the oral mucosa mainly resulting from the cytotoxic effect of 5-fluorouracil (5-FU). The literature shows anti-inflammatory action of L-cysteine (L-cys) involving hydrogen sulfide (H₂S). In view of these properties, we investigate the effect of L-cys in oral mucositis induced by 5-FU in hamsters. The animals were divided into the following groups: saline 0.9%, mechanical trauma, 5-FU 60-40 mg/kg, L-cys 10/40 mg and NaHS 27 µg/kg. 5-FU was administered on days 1st to 2nd; 4th day excoriations were made on the mucosa; 5th-6th received L-cys and NaHS. For data analysis, histological analyses, mast cell count, inflammatory and antioxidants markers, and immunohistochemistry (cyclooxygenase-2(COX-2)/inducible nitric oxide synthase (iNOs)/H₂S) were performed. Results showed that L-cys decreased levels of inflammatory markers, mast cells, levels of COX-2, iNOS and increased levels of antioxidants markers and H₂S when compared to the group 5-FU (p < 0.005). It is suggested that L-cys increases the H₂S production with anti-inflammatory action in the 5-FU lesion.

Beneficial Effects of Polysaccharides on the Epithelial Barrier Function in Intestinal Mucositis

Intestinal mucositis is a clinically relevant side effect of anticancer therapies. It is experienced by 60–100% of patients undergoing treatment with high doses of chemotherapy, radiation therapy, and bone marrow transplantation. Intestinal mucositis can manifest as pain, weight loss, inflammation, diarrhea, rectal bleeding, and infection; affecting normal nutritional intake and intestinal function. It often impacts adherence to anticancer therapy as it frequently limits patient’s ability to tolerate treatment, causing schedule delays, interruptions, or premature discontinuation. In some cases, local and systemic secondary infections are observed, increasing the costs toward medical care and hospitalization. Several strategies for managing mucositis are available which do not always halt this condition. In this context, new therapeutic strategies are under investigation to prevent or treat intestinal mucositis. Polysaccharides from natural resources have recently become promising molecules against intestinal damage due to their ability to promote mucosal healing and their anti-inflammatory actions. These effects are associated with the protection of intestinal mucosa and regulation of microbiota and immune system. This review aims to discuss the recent advances of polysaccharides from natural resources as potential therapies for intestinal mucositis. The source, species, doses, treatment schedules, and mechanisms of action of polysaccharides will be discussed in detail.

Antarctic Strain of Rhodotorula mucilaginosa UFMGCB 18,377 Attenuates Mucositis Induced by 5-Fluorouracil in Mice

Mucositis is one of the most strenuous side effects caused by chemotherapy drugs, such as 5-fluorouracil (5-FU), during the treatment of several types of cancers. The disease is so prevalent and aggressive that many patients cannot resist such symptoms. However, despite its frequency and clinical significance, there is no effective treatment to prevent or treat mucositis. Thus, the use of probiotics as an adjuvant for the treatment has gained prominence. In the present study, we evaluated the effectiveness of oral administration of the Antarctic strain of Rhodotorula mucilaginosa UFMGCB 18,377 as an alternative to minimize side effects of 5-FU-induced mucositis in mice. Body weight, food consumption, stool consistency, and presence of blood in the feces were assessed daily in mice orally treated or not with the yeast and submitted or not to experimental mucositis. Blood, bones, and intestinal tissues and fluid were used to determine intestinal permeability and immunological, microbiological, and histopathological parameters. Treatment with R. mucilaginosa UFMGCB 18,377 was able to decrease clinical signs of the disease, such as reduction of food intake and body weight loss, and also decreased the number of intestinal enterobacteria and intestinal length shortening. Additionally, treatment was able to decrease the levels of MPO and EPO activities and inflammatory infiltrates, as well as the histopathological lesions characteristic of mucositis in the jejunum and ileum. Results of the present study showed that the oral administration of R. mucilaginosa UFMGCB 18,377 protected mice against mucositis induced by 5-FU.

Potential applications of alginate oligosaccharides for biomedicine - A mini review

Extensive research on marine algae, especially on their health-promoting properties, has been conducted. Various ingredients with potential biomedical applications have been discovered and extracted from marine algae. Alginate oligosaccharides are low molecular weight alginate polysaccharides present in cell walls of brown algae. They exhibit various health benefits such as anti-inflammatory, anti-microbial, anti-oxidant, anti-tumor and immunomodulation. Their low-toxicity, non-immunogenicity, and biodegradability make them an excellent material in biomedicine. Alginate oligosaccharides can be chemically or biochemically modified to enhance their biological activity and potential in pharmaceutical applications. This paper provides a brief overview on alginate oligosaccharides characteristics, modification patterns and highlights their vital health promoting properties.

Dietary Bioactive Peptide Alanyl-Glutamine Attenuates Dextran Sodium Sulfate-Induced Colitis by Modulating Gut Microbiota

Inflammatory bowel disease (IBD) is a chronic intestinal disorder threatening human health. Di-peptide alanyl-glutamine (Ala-Gln) has various beneficial effects on gut health. However, its role and functional mechanism in treating IBD are still not clear. Therefore, the protective effects of Ala-Gln and glutamine (Gln) on dextran sulfate sodium- (DSS-) induced colitic mice were investigated in this study. The results showed that oral supplementation of Ala-Gln or Gln significantly attenuated the colitis symptoms in mice, including body weight loss, colon length, disease activity index, histological scores, and tissue apoptosis. The concentrations of interleukin- (IL-) 1β, IL-6, tumor necrosis factor-α, and myeloperoxidase were significantly decreased, while the concentrations of immunoglobulins (IgA, IgG, and IgM) and superoxide dismutase were significantly increased by Ala-Gln or Gln supplementation. The expression of occludin and peptide transporter 1 (PepT1) was significantly increased by Ala-Gln or Gln. Interestingly, Ala-Gln had better beneficial effects than Gln in alleviating colitis. In addition, 16S rDNA sequencing showed that the DSS-induced shifts of the microbiome (community diversity, evenness, richness, and composition) in the mouse colon were restored by Gln and Ala-Gln, including Lactobacillus, Bacteroides_acidifaciens, Bacteroidales, Firmicutes, Clostridia, Helicobacter, and Bacteroides. Correspondingly, the functions of the microflora metabolism pathways were also rescued by Ala-Gln, including fatty acid metabolism, membrane transporters, infectious diseases, and immune system. In conclusion, the results revealed that Ala-Gln can prevent colitis through PepT1, enhancing the intestinal barrier and modulating gut microbiota and microflora metabolites.

5-Fluorouracil disrupts ovarian preantral follicles in young C57BL6J mice

PURPOSE

5-Fluorouracil (5-FU), an anti-cancer drug, has been used for hepatoblastoma (HB) chemotherapy in children, who may have impaired  ovarian follicle pool reserve with lasting effects to reproduction. Therefore, this study aimed to investigate 5-FU effects on survival, growth, and morphology of ovarian preantral follicles from C57BL6J young mice.

METHODS

Experiments were carried-out both in vivo and in vitro. Mice were treated with 5-FU injection (450 mg/kg i.p) or saline and sacrificed 3 days after to obtain ovaries for histology and molecular biology. Ovaries for in vitro studies were obtained from unchallenged mice and cultured under basic culture medium (BCM) or BCM plus 5-FU (9.2, 46.1, 92.2 mM). Preantral follicles were classified according to developmental stages, and as normal or degenerated. To assess cell viability, caspase-3 immunostaining was performed. Transcriptional levels for apoptosis (Bax, Bcl2, p53, Bax/Bcl2) and Wnt pathway genes (Wnt2 and Wnt4) were also analyzed. Ultrastructural analyses were carried-out on non-cultured ovaries. In addition, β-catenin immunofluorescence was assessed in mouse ovaries.

RESULTS

The percentage of all-types normal follicles was significantly lower after 5-FU challenge. A total loss of secondary normal follicles was found in the 5-FU group. The highest 5-FU concentrations reduced the percentage of cultured normal primordial follicles. Large vacuoles were seen in granulosa cells and ooplasm of preantral follicles by electron microscopy. A significantly higher gene expression for Bax and Bax/Bcl2 ratio was seen after 5-FU treatment. A marked reduction in β-catenin immunolabeling was seen in 5-FU-challenged preantral follicles. In the in vitro experiments, apoptotic and Wnt gene transcriptions were significantly altered.

CONCLUSION

Altogether, our findings suggest that 5-FU can deleteriously affect the ovarian follicle reserve by reducing preantral follicles survival.

Microbiota from alginate oligosaccharide-dosed mice successfully mitigated small intestinal mucositis

BACKGROUND

The increasing incidence of cancer and intestinal mucositis induced by chemotherapeutics are causing worldwide concern. Many approaches such as fecal microbiota transplantation (FMT) have been used to minimize mucositis. However, it is still unknown whether FMT from a donor with beneficial gut microbiota results in more effective intestinal function in the recipient. Recently, we found that alginate oligosaccharides (AOS) benefit murine gut microbiota through increasing "beneficial" microbes to rescue busulfan induced mucositis.

RESULTS

In the current investigation, FMT from AOS-dosed mice improved small intestine function over FMT from control mice through the recovery of gene expression and an increase in the levels of cell junction proteins. FMT from AOS-dosed mice showed superior benefits over FMT from control mice on recipient gut microbiotas through an increase in "beneficial" microbes such as Leuconostocaceae and recovery in blood metabolome. Furthermore, the correlation of gut microbiota and blood metabolites suggested that the "beneficial" microbe Lactobacillales helped with the recovery of blood metabolites, while the "harmful" microbe Mycoplasmatales did not.

CONCLUSION

The data confirm our hypothesis that FMT from a donor with superior microbes leads to a more profound recovery of small intestinal function. We propose that gut microbiota from naturally produced AOS-treated donor may be used to prevent small intestinal mucositis induced by chemotherapeutics or other factors in recipients. Video Abstract.

Protective effect of Andrographolide on 5-Fu induced intestinal mucositis by regulating p38 MAPK signaling pathway

AIMS

Intestinal mucositis is the most common side effect of 5-fluorouracil (5-Fu) treatment in cancer patients. Previous research suggested that andrographolide (Andro) attenuated the intestinal injury in colitis or diarrhea in mice. The present study was aimed at investigating the protective effect of Andro against 5-Fu induced intestinal mucositis and the underlying mechanism.

MAIN METHODS

BALB/C mice were injected 5-Fu at a dose of 100 mg/kg for 5 days to induce intestinal mucositis. Andro at different doses (25, 50, 100 mg/kg/day) was administered. Weight loss, diarrhea score, cellular apoptosis and proliferation were evaluated. Apoptosis related proteins were detected by Western blotting. Then, NCM460 cells were used to explore the possible mechanism in vitro. The effect of Andro on the anti-tumor efficacy of 5-Fu was investigated in H22 tumor-bearing mice.

KEY FINDINGS

Andro significantly ameliorated the 5-Fu induced weight loss and diarrhea. The apoptosis of intestinal cells was also attenuated by Andro treatment both in vivo and in vitro. Besides, Andro markedly down-regulated the 5-Fu-induced protein expression of caspase8/3, Bax and the phosphorylation of p38. Moreover, 5-Fu significantly reduced the viability of NCM460 cells, which was restored by the Andro pretreatment. Furthermore, asiatic acid, an agonist of p38 MAPK, reversed the anti-apoptotic effect of Andro in NCM460 cells. Andro did not weaken the anti-H22 tumor effect of 5-Fu in vivo.

SIGNIFICANCE

We have demonstrated that p38 MAPK inhibition mediates anti-apoptotic effects of Andro against 5-Fu induced intestinal mucositis, suggesting that Andro may benefit the patients undergoing 5-Fu based chemotherapy.

Single-cell RNA sequencing analysis reveals alginate oligosaccharides preventing chemotherapy-induced mucositis

Worldwide the incidence of cancer has been continuing increasing. Mucositis of the gastrointestinal tract is a common side effect in patients under chemotherapy. Anticancer drug busulfan, used for treating chronic myeloid leukemia especially in pediatric patients, causes mucositis of the gastrointestinal tract. Alginate oligosaccharides (AOS) are natural products with attractive pharmaceutical potentials. We aimed to investigate, at the single-cell level, AOS preventing small intestine mucositis induced by busulfan. We found that busulfan disturbed the endoplasmic reticulum and mitochondria of cells in the small intestine, damaged cell membranes especially cell junctions, and disrupted microvilli; all of which were rescued by AOS. Single-cell RNA sequencing analysis and functional enrichment analysis showed that AOS could recover small intestinal function. Deep analysis found that AOS improved the expression of transcriptional factors which explained AOS regulating gene expression to improve small intestine function. Further investigation in IPEC-J2 cells found that AOS acts its function through mannose receptor signaling pathway. Moreover, the improved blood metabolome confirmed small intestinal function was recovered by AOS. As a natural product with many advantages, AOS could be developed to assist in the recovery of intestinal functions in patients undergoing anticancer chemotherapy or other treatments.

Effervescent Glutamine Formulation Improves the Beneficial Effects of Antiretroviral Therapies on Immune Function in HIV/AIDS Carrier Patients

The impact of oral supplementation with an effervescent glutamine formulation on the beneficial effects of antiretroviral therapies was evaluated in people living with HIV/AIDS. For this purpose, 12 HIV/AIDS carrier patients with CD4⁺ T cell counts <500, and who had received the same antiretroviral therapy for at least 1 year before starting this investigation were selected. The patients were required to dissolve the effervescent glutamine formulation (supplied in sachets) in water immediately before oral ingestion (12.4 g), once a day, after lunch or after dinner during 30 days. CD4⁺ T cell counts, complete blood cell counts, serum cytokines, and amino acids levels were quantified; biochemical and toxicological measurements were performed. The numbers of CD4⁺ T cells were increased (P < .05), and the serum C-reactive protein levels decreased (P < .01) after the administration of effervescent glutamine formulation. Serum levels of interferon-gamma inducible protein-10, RANTES, and macrophage inflammatory protein-1β were decreased after the treatment with effervescent glutamine formulation. No changes were observed in the serum levels of amino acids, hematological, toxicological, and biochemical parameters. In conclusion, the treatment during 30 days with effervescent glutamine formulation was well tolerated, promoted reduction of inflammation, and improved the beneficial effects of antiretroviral therapies in HIV/AIDS carrier patients.

Assessment of dose-response relationship of 5-fluorouracil to murine intestinal injury

5-Fluorouracil (5-FU) is the most frequently prescribed anti-tumor drug, but has been reported to result in intestinal injury. Although some progress has been made in understanding the intestinal toxicity of 5-FU, confusion remains about animal models of 5-FU-induced intestinal injury, especially the dosage of 5-FU. This study aims to assess the dose-response relationship between the severity of intestinal injury and different doses of 5-FU, and to determine a proper dosing for the murine model. We found that mice in the 5-FU groups gradually lost body weight over time. Increasing doses of 5-FU resulted in more severe diarrhea, with a concomitant increase in mortality. Histopathological damage was more severe in mice that received higher doses of 5-FU. In addition, plasma diamine oxidase (DAO) activity decreased in experimental mice with intestinal injury in a dose-dependent way. TUNEL and western blot analysis showed cell apoptosis in the ileum and colon related to 5-FU dosage. However, administration of 200 and 400 mg/kg 5-FU caused extremely high mortality, severe diarrhea and histopathological damage, but 25 mg/kg 5-FU did not result in significant intestinal injury. The severity of intestinal injury induced by 5-FU appeared to be dose-dependent and we concluded that the proper dosage of 5-FU to induce a murine model with intestinal mucositis ranged from 50 mg/kg to 100 mg/kg.

Protective effect of the riboflavin-overproducing strain Lactobacillus plantarum CRL2130 on intestinal mucositis in mice

OBJECTIVES

Intestinal mucositis (IM) is a local inflammatory response that causes alterations of the intestinal structure that in turn affect nutrient absorption and a side effect that is commonly associated with cancer treatments. Lactobacillus plantarum CRL2130 is a riboflavin-overproducing strain that has previously been shown to provide antiinflammatory properties. The objective of this study was to evaluate the effects of this riboflavin-producing strain in a chemically induced murine mucositis model.

METHODS

Mucositis was induced by daily injections of 5-fluororacil (5-FU) after which mice were either given L. plantarum CRL2130, CRL725 (strain from which CRL2130 was derived that does not overproduce riboflavin), or commercial riboflavin twice daily during 6 d of chemotherapy agent injections. The effect of the strains and riboflavin was also evaluated in vitro using Caco-2 intestinal cancer cell cultures to determine if they interfere with 5-FU's anticancer activity.

RESULTS

The administration of L. plantarum CRL2130 significantly attenuated the pathologic changes induced by 5-FU in mice such as body weight loss, diarrhea, shortening of villus height, increases in proinflammatory cytokine concentrations, and elevated production of interleukin 10. In vitro assays using Caco-2 cells showed that the effectiveness of 5-FU was not affected by L. plantarum CRL2130 and that this strain exerted an inhibitory mechanism against oxidative stress.

CONCLUSIONS

These results indicate that the riboflavin-overproducing strain L. plantarum CRL2130 could be useful to prevent mucositis during cancer treatments and would not affect the primary treatment.

Volatile Oil from Amomi Fructus Attenuates 5-Fluorouracil-Induced Intestinal Mucositis

Amomi Fructus has been used to treat digestive diseases in the context of traditional Chinese medicine, so we evaluated the effects of a volatile oil from Amomum villosum (VOA) on intestinal mucositis induced by 5-fluorouracil (5-FU). We measured the effect of VOA and its main active constituent, bornyl acetate (BA), on body weight, food intake, diarrhea, inflammatory cytokines, the mucosal barrier, and gut microbiota. VOA and BA significantly increased the rats' body weight, relieved diarrhea, and reversed histopathological changes in the gut and inflammation. VOA significantly inhibited apoptosis and alleviated the endoenteritis by downregulating p38 MAPK and caspase-3 expression. VOA and BA strengthened the intestinal mucosal barrier by increasing zonula occludin-1 and occludin expression. VOA and BA reduced the amount of pathogenic bacteria and increased the abundance of probiotics. Thus, VOA prevented the development and progression of intestinal mucositis after chemotherapy.

Alteration of Gut Microbiota and Inflammatory Cytokine/Chemokine Profiles in 5-Fluorouracil Induced Intestinal Mucositis

Disturbed homeostasis of gut microbiota has been suggested to be closely associated with 5-fluorouracil (5-Fu) induced mucositis. However, current knowledge of the overall profiles of 5-Fu-disturbed gut microbiota is limited, and so far there is no direct convincing evidence proving the causality between 5-Fu-disturbed microbiota and colonic mucositis. In mice, in agreement with previous reports, 5-Fu resulted in severe colonic mucositis indicated by weight loss, diarrhea, bloody stool, shortened colon, and infiltration of inflammatory cells. It significantly changed the profiles of inflammatory cytokines/chemokines in serum and colon. Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and VE-Cadherin were increased. While tight junction protein occludin was reduced, however, zonula occludens-1 (ZO-1) and junctional adhesion molecule-A (JAM-A) were increased in colonic tissues of 5-Fu treated mice. Meanwhile, inflammation related signaling pathways including NF-κB and mitogen activated protein kinase (MAPKs) in the colon were activated. Further study disclosed that 5-Fu diminished bacterial community richness and diversity, leading to the relative lower abundance of Firmicutes and decreased Firmicutes/Bacteroidetes (F/B) ratio in feces and cecum contents. 5-Fu also reduced the proportion of Proteobacteria, Tenericutes, Cyanobacteria, and Candidate division TM7, but increased that of Verrucomicrobia and Actinobacteria in feces and/or cecum contents. The fecal transplant from healthy mice prevented body weight loss and colon shortening of 5-Fu treated mice. In addition, the fecal transplant from 5-Fu treated mice reduced body weight and colon length of vancomycin-pretreated mice. Taken together, our study demonstrated that gut microbiota was actively involved in the pathological process of 5-Fu induced intestinal mucositis, suggesting potential attenuation of 5-Fu induced intestinal mucositis by manipulating gut microbiota homeostasis.

Can specific nutrients stimulate bowel wound healing?

PURPOSE OF REVIEW

The purpose of review is to provide an overview on specific nutrients which play an important role in bowel wound healing, and to judge the efficacy of supplementation to derive recommendations for clinical practice.

RECENT FINDINGS

Glutamine, arginine, butyrate, ω-3 fatty acids, nucleotides, and several micronutrients are involved in bowel wound healing. However, with regard to clinical trials, the efficacy of supplementation of specific nutrients on bowel wound healing in patients with inflammatory bowel diseases has not been clarified yet. In patients undergoing colon surgery, sufficient evidence exists that the perioperative supply of an enteral immunomodulating formula enriched with arginine, nucleotides, and ω-3 fatty acids may improve intestinal wound healing, considering the lower risk of wound infections, wound dehiscence, and intra-abdominal abscess.

SUMMARY

Even if a range of nutrients are involved in bowel wound healing, only perioperative supply of an enteral immunomodulating formula to cancer patients undergoing colon surgery, can be recommended. Further randomized controlled trials are needed to elucidate the efficacy of individual nutrients on intestinal wound healing.