Understanding the gut microbiota in cancer cachexia.

PURPOSE OF REVIEW: Cachexia is a complex, multifactorial syndrome primarily characterized by weight loss, muscle wasting, anorexia, and systemic inflammation. It is prevalent in cancer patients and is associated with a poor prognosis, including lower resistance to intervention toxicity, quality of life, and survival, compared to patients without the syndrome. The gut microbiota and its metabolites have been shown to influence host metabolism and immune response. Our article reviews the current evidence suggesting a role of gut microbiota in the development and progression of cachexia, while discussing the potential mechanisms involved. We also describe promising interventions targeting gut microbiota aiming to improve outcomes related to cachexia. RECENT FINDINGS: Dysbiosis, an imbalance in gut microbiota, has been associated with cancer cachexia through pathways involving muscle wasting, inflammation, and gut barrier dysfunction. Interventions targeting gut microbiota, such as probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, have shown promising results in managing this syndrome in animal models. However, evidence in humans is currently limited. SUMMARY: Mechanisms linking gut microbiota and cancer cachexia need to be further explored, and additional human research is necessary to evaluate the appropriate dosages, safety, and long-term outcomes of prebiotic and probiotic use in microbiota management for cancer cachexia.

Roux-en-Y gastric bypass affects the expression of genes related to the intestinal folate metabolism pathway in obese women.

OBJECTIVES: Roux-en-Y gastric bypass (RYGB) promotes sustained weight loss, and the resulting new gastrointestinal anatomy can contribute to nutritional depletions. Folate deficiency is one of the most frequently observed nutritional deficiencies after RYGB. The aim of this study was to assess whether RYGB affects the expression of genes related to the intestinal folate metabolism pathway as an additional molecular mechanism contributing to its postoperative deficiency. METHODS: Biopsies from the duodenum, jejunum, and ileum of 20 obese women were collected before and 3 mo after RYGB. The expression of genes involved in intestinal folate metabolism was assessed by microarray and reverse transcriptase polymerase chain reaction (RT-qPCR). Folate intake (7-d food record) and plasma levels (electrochemiluminescence) also were measured. RESULTS: Compared with the preoperative phase, transcriptomic alterations were observed in all intestinal segments studied after RYBG, mainly marked by decreased expression of genes encoding folate transporters/receptors and increased expression of genes involved in folate biosynthesis (P < 0.05). Reduced folate intake and plasma folate levels were also observed simultaneously (P < 0.05). Plasma folate concentrations correlated inversely with intestinal FOLR2 and SHMT2 genes (P < 0.001). CONCLUSION: The present findings suggested that impaired expression of genes related to intestinal folate metabolism may contribute to the early systemic deficiency after RYGB and highlight a potential transcriptomic reprogramming of the intestine in response to RYGB to compensate for folate depletion induced by this surgical technique.

Intestinal expression of toll-like receptor gene changes early after gastric bypass surgery and association with type 2 diabetes remission.

OBJECTIVES: Abnormal activation of toll-like receptors (TLRs) is observed in obese rodents and is correlated with local dysbiosis and increased gut permeability. These purported changes trigger systemic inflammation associated with obesity-related comorbidities, including type 2 diabetes (T2D). Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for severe obesity and known to induce changes in the gut microbiota and decrease systemic inflammation in humans. This study examined the intestinal expression of TLR-encoding genes in obese women (n = 20) treated with RYGB surgery and the relationship of these genes with T2D remission (T2Dr METHODS: Intestinal biopsies were performed before and 3 months after RYGB surgery. Partial and complete T2Dr after 1 year was assessed using the American Diabetes Association criteria. Affymetrix Human GeneChip 1.0 ST array (microarray) and TaqMan assay (real-time quantitative polymerase chain reaction) were used to analyze intestinal gene expression, and associations with systemic markers of energy homeostasis were examined. RESULTS: Patients experienced significant weight loss (P < 0.001) and altered gut TLR gene expression 3 months after surgery. The main effects were a reduction in jejunal TLR4 expression in patients with complete and partial T2Dr (P < 0.05). There was a postoperative decrease in jejunal TLR7 expression in patients with complete T2Dr that correlated inversely with high-density lipoprotein cholesterol and positively with triglyceride concentrations, but not with weight loss. CONCLUSIONS: RYGB-induced weight loss-independent changes in the expression of intestinal TLR-encoding genes in obese women and complete T2Dr that was correlated with systemic markers of energy homeostasis. The modulation of intestinal TLRs may mediate inflammatory mechanisms linked to T2Dr after RYGB surgery.

Reduced intestinal FADS1 gene expression and plasma omega-3 fatty acids following Roux-en-Y gastric bypass.

BACKGROUND & AIMS: Roux-en-Y gastric bypass (RYGB) limits food ingestion and may alter the intestinal expression of genes involved in the endogenous synthesis of polyunsaturated fatty acids (PUFAs). These changes may decrease the systemic availability of bioactive PUFAs after RYGB. To study the impact of RYGB on the dietary ingestion and plasma concentration of PUFAs and on the intestinal expression of genes involved in their endogenous biosynthesis in severely obese women with type 2 diabetes. METHODS: Before, and 3 and 12 months after RYGB, obese women (n = 20) self-reported a seven-day dietary record, answered a food frequency query and provided plasma samples for alpha-linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acid assessment by gas chromatography. Intestinal biopsies (duodenum, jejunum and ileum) were collected through double-balloon endoscopy before and 3 months after RYGB for gene expression analysis by microarray (Human GeneChip 1.0 ST array) and RT-qPCR validation. RESULTS: Compared to the preoperative period, patients had decreased intakes of PUFAs, fish and soybean oil (p < 0.05) and lower plasma concentrations of ALA and EPA (p < 0.001) 3 and 12 months after RYGB. FADS1 gene expression was lower in duodenum (RT-qPCR fold change = -1.620, p < 0.05) and jejunum (RT-qPCR fold change = -1.549, p < 0.05) 3 months following RYGB, compared to before surgery. CONCLUSION: RYGB decreased PUFA ingestion, plasma ALA and EPA levels, and intestinal expression of FADS1 gene. The latter encodes a key enzyme involved in endogenous biosynthesis of PUFAs. These data suggest that supplementation of omega-3 PUFAs may be required for obese patients undergoing RYGB. Clinical Trial Registry number and website: www.clinicaltrials.gov - NCT01251016; Plataforma Brasil - 19339913.0.0000.0068.

Tissue-specific methylation profile in obese patients with type 2 diabetes before and after Roux-en-Y gastric bypass.

Eating habits, lifestyles, and exposure to specific environmental factors can greatly impact the risk of developing type 2 diabetes (T2D), influence the genome epigenetically, and affect the expression of genes, including genes related to glycemic control, at any stage of life. The epigenetic mechanism underlying obesity and T2D pathogenesis remains poorly understood. Conventional strategies for the treatment of obesity and its comorbidities often have poor long-term adherence, and pharmacological interventions are limited. Bariatric surgery is the most effective current option to treat severe obesity, and Roux-en-Y gastric bypass (RYGB) is the most applied technique worldwide. Epigenetic changes differ depending on the approach used to treat obesity and its associated comorbidities (clinical or surgical). Compared to primary clinical care, bariatric surgery leads to much greater loss of body weight and higher remission rates of T2D and metabolic syndrome, with methylation profiles in promoter regions of genes in obese individuals becoming similar to those of normal-weight individuals. Bariatric surgery can influence DNA methylation in parallel with changes in gene expression pattern. Changes in clinical biomarkers that reflect improvements in glucose and lipid metabolism after RYGB often occur before major weight loss and are coordinated by surgery-induced changes in intestinal hormones. Therefore, the intestine methylation profile would assist in understanding the mechanisms involved in improved glycemic control after bariatric surgery. The main objectives in this area for the future are to identify epigenetic marks that could be used as early indicators of metabolic risk, and to develop treatments able to delay or even reverse these epigenetic changes. Studies that provide the "human epigenetic profile" will be of considerable value to identify tissue-specific epigenetic signatures and their role in the development of chronic diseases. Further studies should apply methods based on global analysis of the genome to identify methylated sites associated with disease and epigenetic marks associated with the remodeling response to bariatric surgery. This review describes the main epigenetic alterations associated with obesity and T2D and the potential role of RYGB in remodeling these changes.

The SURMetaGIT study: Design and rationale for a prospective pan-omics examination of the gastrointestinal response to Roux-en-Y gastric bypass surgery.

Objective To describe the protocol of the SURgically induced Metabolic effects on the Human GastroIntestinal Tract (SURMetaGIT) study, a clinical pan-omics study exploring the gastrointestinal tract as a central organ driving remission of type 2 diabetes mellitus (T2DM) after Roux-en-Y gastric bypass (RYGB). The main points considered in the study's design and challenges faced in its application are detailed. Methods This observational, longitudinal, prospective study involved collection of gastrointestinal biopsy specimens, faeces, urine, and blood from 25 obese women with T2DM who were candidates for RYGB (20 patients for omics assessment and 5 for omics validation). These collections were performed preoperatively and 3 and 24 months postoperatively. Gastrointestinal transcriptomics; faecal metagenomics and metabolomics; plasma proteomics, lipidomics, and metabolomics; and biochemical, nutritional, and metabolic data were assessed to identify their short- and long-term correlations with T2DM remission. Results Data were collected from 20 patients before and 3 months after RYGB. These patients have nearly completed the 2-year follow-up assessments. The five additional patients are currently being selected for omics data validation. Conclusion The multi-integrated pan-omics approach of the SURMetaGIT study enables integrated analysis of data that will contribute to the understanding of molecular mechanisms involved in T2DM remission after RYGB.

Parenteral fish oil as a pharmacological agent to modulate post-operative immune response: a randomized, double-blind, and controlled clinical trial in patients with gastrointestinal cancer.

BACKGROUND: Fish oil-based lipid emulsions (FOLEs) have shown post-operative immunological and clinical benefits in parenteral nutrition. AIM: To assess post-operative immune response after short-term pre-operative parenteral infusion of isolated FOLE in gastrointestinal cancer patients. METHODS: The patients (n = 63) received pre-operative peripheral infusion (0.2 g fat/kg body weight/d) of FOLE (Omegaven(®)) or control lipid emulsion (MCT/LCT; Lipovenos MCT(®)) for 3 days. Post-operative concentrations of inflammatory mediators, leukocyte functions, surface molecules, infections, and length of intensive care unit (ICU) and hospital stay were measured. RESULTS: FOLE patients had a significant increase of IL-10 levels on day 3, decrease of IL-6 and IL-10 levels on day 6, lower decrease in leukocyte oxidative burst, maintenance of monocyte percentage expressing HLA-DR and CD32, and increase of CD32 neutrophil expression compared to MCT/LCT patients. No changes were observed in the frequency of post-operative infections or length of ICU and hospital stay. CONCLUSIONS: Short-term pre-operative infusion of FO alone improves the post-operative immune response of gastrointestinal cancer patients without significantly changing post-operative infections or length of ICU and hospital stay. ID:NCT01218841.

Human leukocyte death after a preoperative infusion of medium/long-chain triglyceride and fish oil parenteral emulsions: a randomized study in gastrointestinal cancer patients.

BACKGROUND: Parenteral lipid emulsions (LEs) can influence leukocyte functions. The authors investigated the effect of 2 LEs on leukocyte death in surgical patients with gastrointestinal cancer. MATERIAL AND METHODS: Twenty-five patients from a randomized, double-blind clinical trial (ID: NCT01218841) were randomly included to evaluate leukocyte death after 3 days of preoperative infusion (0.2 g fat/kg/d) of an LE composed equally of medium/long-chain triglycerides and soybean oil (MCTs/LCTs) or pure fish oil (FO). Blood samples were collected before (t0) and after LE infusion (t1) and on the third postoperative day (t2). RESULTS: After LE infusion (t1 vs t0), MCTs/LCTs did not influence cell death; FO slightly increased the proportion of necrotic lymphocytes (5%). At the postoperative period (t2 vs t0), MCTs/LCTs tripled the proportion of apoptotic lymphocytes; FO maintained the slightly increased proportion of necrotic lymphocytes (7%) and reduced the percentage of apoptotic lymphocytes by 74%. In the postoperative period, MCT/LCT emulsion increased the proportion of apoptotic neutrophils, and FO emulsion did not change any parameter of apoptosis in the neutrophil population. There were no differences in lymphocyte or neutrophil death when MCT/LCT and FO treatments were compared during either preoperative or postoperative periods. MCT/LCTs altered the expression of 12 of 108 genes related to cell death, with both pro- and antiapoptotic effects; FO modulated the expression of 7 genes, demonstrating an antiapoptotic effect. CONCLUSION: In patients with gastrointestinal cancer, preoperative MCT/LCT infusion was associated with postoperative lymphocyte and neutrophil apoptosis. FO has a protective effect on postoperative lymphocyte apoptosis.

Efeito da infusão pré-operatória de emulsão lipídica parenteral de óleo de peixe sobre a resposta imunológica pós-operatória e a evolução clínica imediata de pacientes com câncer gastrintestinal / Effect of the preoperative infusion of fish oil parenteral lipid emulsion on postoperative immune response and immediate clinical outcome of patients with gastrointestinal cancer

INTRODUÇÃO: Emulsão lipídica parenteral composta por óleo de peixe, rica em ácidos graxos ômega-3, é infundida associada a emulsões lipídicas convencionais, como parte da terapia nutricional parenteral. Em pacientes cirúrgicos, a infusão perioperatória de emulsão lipídica de óleo de peixe se associa à preservação de funções imunológicas e modulação favorável de mediadores inflamatórios pós-operatórios, com redução na frequência de complicações infecciosas e no tempo de internação em unidade de terapia intensiva e hospitalar. Os benefícios descritos encorajam a infusão parenteral isolada de emulsão lipídica de óleo de peixe, como fármaconutriente adjuvante no tratamento de pacientes cirúrgicos, independente da indicação de terapia nutricional parenteral. OBJETIVO: O presente estudo avaliou o efeito da infusão parenteral pré-operatória, por curto prazo, de emulsão lipídica de óleo de peixe isolada sobre a resposta imunológica pósoperatória e a evolução clínica imediata de pacientes com câncer gastrintestinal. MÉTODOS: Estudo prospectivo, aleatório, duplo-cego e controlado em 63 pacientes cirúrgicos eletivos com câncer gastrintestinal. Os doentes receberam infusão por veia periférica (0,2g gordura/kg de peso corpóreo/dia) de emulsão lipídica parenteral de óleo de peixe (Omegaven® 10% - Fresenius-Kabi) ou emulsão lipídica parenteral controle (Lipovenos MCT® 10% - Fresenius-Kabi) durante os 3 últimos dias pré-operatórios. Amostras de sangue foram coletadas antes e após a infusão parenteral das emulsões lipídicas e nos 3º e 6º (apenas para citocinas) dias pósoperatórios. Analisou-se a concentração plasmática de IL-6 e IL-10 e a migração, fagocitose, explosão oxidativa e expressão de moléculas HLA-DR e CD32 leucocitárias. A frequência de complicações infecciosas e tempo de internação na unidade de terapia intensiva e hospitalar também foram avaliados no período pós-operatório imediato...

BACKGROUND: Parenteral lipid emulsion composed by fish oil, rich in omega-3 fatty acids, is infused in addition to other standard lipid emulsions, as part of parenteral nutrition therapy. In surgical patients, the perioperative infusion of fish oil lipid emulsion is associated with immune functions preservation and favorably modulation of postoperative inflammatory mediators, with decreased infectious complications and length of intensive care unit and hospital stay. These reported benefits encourage the use of fish oil lipid emulsion alone, as a pharmacological adjuvant agent for the treatment of surgical patients, independent of parenteral nutritional therapy indication. AIM: This clinical trial assessed the effect of short-term preoperative infusion of fish oil lipid emulsion alone on postoperative immune response and immediate clinical outcomes of patients with gastroenterological cancer. METHOD: In a prospective, randomized, controlled and double-blind design, elective surgical patients with gastrointestinal cancer (n= 63) received, for the last 3 pre-operative days, peripheral infusion (0.2g fat/kg of body weight./d) of fish oil lipid emulsion (Omegaven® 10% - Fresenius-Kabi) or control lipid emulsion (Lipovenos MCT® 10% - Fresenius-Kabi). Peripheral blood samples were collected before and after lipid emulsion infusion at the 3rd and 6th (only for cytokines) postoperative days to analyze plasma concentration of IL-6 and IL-10, as well as leukocyte migration, phagocytosis, oxidative burst and expression of HLADR and CD32 molecules. Postoperative infections, length of intensive care unit and hospital stay were also measured. RESULTS: At postoperative period, patients treated with fish oil lipid emulsion had increase of IL-10 (day 3, p < 0.0001), decrease of IL-6 (day 3, p = 0.029) and IL-10 (day 6, p<0.0001), lower decrease of leukocyte oxidative burst...