Impact of Novel Prebiotic Galacto-Oligosaccharides on Various Biomarkers of Colorectal Cancer in Wister Rats

Obesity-Associated Colorectal Cancer

Colorectal cancer (CRC) affects approximately 2 million people worldwide. Obesity is the major risk factor for CRC. In addition, obesity contributes to a chronic inflammatory stage that enhances tumor progression through the secretion of proinflammatory cytokines. In addition to an increased inflammatory response, obesity-associated cancer presents accrued molecular factors related to cancer characteristics, such as genome instability, sustained cell proliferation, telomere dysfunctions, angiogenesis, and microbial alteration, among others. Despite the evidence accumulated over the last few years, the treatments for obesity-associated CRC do not differ from the CRC treatments in normal-weight individuals. In this review, we summarize the current knowledge on obesity-associated cancer, including its epidemiology, risk factors, molecular factors, and current treatments. Finally, we enumerate possible new therapeutic targets that may improve the conditions of obese CRC patients. Obesity is key for the development of CRC, and treatments resulting in the reversal of obesity should be considered as a strategy for improving antineoplastic CRC therapies.

Development and validation of derivatization-based LC-MS/MS method for quantification of short-chain fatty acids in human, rat, and mouse plasma

Short-chain fatty acids (SCFAs), the end products of gut microbial fermentation of dietary fibers and non-digestible polysaccharides, act as a link between the microbiome, immune system, and inflammatory processes. The importance of accurately quantifying SCFAs in plasma has recently emerged to understand their biological role. In this work, a sensitive and reproducible LC-MS/MS method is reported for SCFAs quantification in three different matrices such as human, rat and mouse plasma via derivatization, using as derivatizing agent O-benzylhydroxylamine (O-BHA), coupled with liquid-liquid extraction. First, the instrumental parameters of the mass spectrometer and then the chromatographic conditions were optimized using previously SCFAs derivatives synthetized and used as standards. After that, the best conditions for derivatization and extraction from plasma were studied and a series of determinations were performed on human, rat, and mouse plasma aliquots to validate the overall method (derivatization, extraction, and LC-MS/MS determination). The method showed good performance in terms of recovery (> 80%), precision (RSD <14%), accuracy (RE < ± 10%) and sensitivity (LOQ of 0.01 µM for acetic, butyric, propionic and isobutyric acid) in all plasma samples. The method thus developed and validated was applied to the quantification of major SCFAs in adult and aged mice, germ-free mice and in germ-free recipient mice subjected to fecal transplant from adult and aged donors. Results highlighted how plasma concentrations of SCFAs are correlated with age further highlighting the importance of developing a method that is reliable for the quantification of SCFAs to study their biological role.

Recent Research and Application Prospect of Functional Oligosaccharides on Intestinal Disease Treatment

The intestinal tract is an essential digestive organ of the human body, and damage to the intestinal barrier will lead to various diseases. Functional oligosaccharides are carbohydrates with a low degree of polymerization and exhibit beneficial effects on human intestinal health. Laboratory experiments and clinical studies indicate that functional oligosaccharides repair the damaged intestinal tract and maintain intestinal homeostasis by regulating intestinal barrier function, immune response, and intestinal microbial composition. Functional oligosaccharides treat intestinal disease such as inflammatory bowel disease (IBD) and colorectal cancer (CRC) and have excellent prospects for therapeutic application. Here, we present an overview of the recent research into the effects of functional oligosaccharides on intestinal health.

Anti-inflammatory and Antioxidant Effect of Lycoperoside H against the 1,2-Dimethyl Hydrazine (DMH) Induced Colorectal Cancer in Rats

In many developed countries, colorectal cancer is a leading cause of morbidity and mortality and its etiology is familiar to be a grouping of nutritional and environmental factors, less physical activity and hereditary factors. Lycoperoside H (LH) is a steroidal alkaloid saponin commonly found in the tomato and exhibited the various pharmacological effects. The aim of the current study was to scrutinized the anticancer effect of LH against 1,2‑Dimethyl Hydrazine (DMH) induced colorectal cancer (CRC) in rats. Subcutaneous injection of DMH (20 mg/kg) was used for induction the CRC and rats were received the oral administration of LH (10, 20 and 40 mg/kg) for 16 weeks. At the end of the investigation, the tumor incidence, weight, and body weight were calculated. Antioxidant enzymes (phase I and II), inflammatory cytokines, lipids and inflammatory markers were all examined. DMH induced rats exhibited the increased tumor incidence, reduced body weight and LH treatment significantly (p < 0.001) suppressed the tumor incidence, and enhanced the body weight. LH treatment significantly (p < 0.001) boosted the level of SOD, GPx, GSH, CAT and suppressed the MDA level. LH treatment suppressed the level cytochrome b5 (Cyto b5), cytochrome P450 (Cyto P450) and boosted the level of glutathione S‑transferase (GST), uridine diphosphoglucuronyltransferase (UDP‑GT) in the liver and colon tissue. LH also decreased the level of cytokines includes interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α); inflammatory mediators like Inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin (PGE2) and nuclear factor kappa B (NF-κB) in the hepatic and colon tissue. We can conclude that LH revealed the anticancer effect against the DMH induced CRC via suppression of inflammation and oxidative stress.

Metastasis and cachexia: alongside in clinics, but not so in animal models

Cancer cachexia is a paraneoplastic syndrome characterized by lean mass wasting (with or without fat mass decrease), culminating in involuntary weight loss, which is the key clinical observation nowadays. There is a notable lack of studies involving animal models to mimic the clinical reality, which are mostly patients with cachexia and metastatic disease. This mismatch between the clinical reality and animal models could at least partly contribute to the poor translation observed in the field. In this paper, we retrieved and compared animal models used for cachexia research from 2017 and 10 years earlier (2007) and observed that very little has changed. Especially, clinically relevant models where cachexia is studied in an orthotopic or metastatic context were and still are very scarce. Finally, we described and supported the biological rationale behind why, despite technical challenges, these two phenomena-metastasis and cachexia-should be modelled in parallel, highlighting the overlapping pathways between them. To sum up, this review aims to contribute to rethinking and possibly switching the models currently used for cachexia research, to hopefully obtain better and more translational outcomes.

Antitumour effect of glucooligosaccharides obtained via hydrolysis of α-(1 → 3)-glucan from Fomitopsis betulina

Novel α-(1 → 3)-glucooligosaccharides (α-(1 → 3)-GOS) were prepared by acid hydrolysis of α-(1→ 3)-glucan isolated from Fomitopsis betulina fruiting bodies and characterized. Their anti-cancer potential was evaluated in in vitro assays in a colon cancer cell model. The tested α-(1 → 3)-GOS showed antiproliferative (MTT assay) and pro-apoptotic (Annexin V-FITC and PI technique) features against colon cancer but not against normal epithelial colon cells. Additionally, we did not observe cytotoxic activity (neutral red and lactate dehydrogenase assays) of α-(1 → 3)-GOS against several types of normal cell lines. In the present study, we demonstrated the anticancer potential of α-(1 → 3)-GOS in a colon carcinoma model. The anti-tumour effect of α-(1 → 3)-GOS is related with induction of apoptosis. Based on these results, we conclude that α-(1 → 3)-GOS may be considered as a dietary or therapeutic agent with an ability to inhibit the growth of cancer cells.

The role of diet and intestinal microbiota in the development of metabolic syndrome

Metabolic syndrome (MetS) is a cluster of metabolic factors that increase the risk of cardiovascular disease and type 2 diabetes mellitus (T2DM), which is in itself a major cardiovascular disease risk factor. The aim of this review is to summarize the data related to the influence of the gut microbiota on the development of obesity and the MetS, highlighting the role of diet in controlling the MetS by modifying the gut microbiota. The main alterations in the gut microbiota of individuals with MetS consist of an increased Firmicutes/Bacteriodetes ratio and a reduced capacity to degrade carbohydrates to short-chain fatty acids, which in turn is related with the metabolic dysfunction of the host organism rather than with obesity itself. In addition to a low-fat, high-carbohydrate diet, with its high fiber intake, a diet with 30% fat content but with a high content in fruit and vegetables, such as the Mediterranean diet, is beneficial and partially restores the dysbiosis found in individuals with MetS. Overall, the shaping of the gut microbiota through the administration of prebiotics or probiotics increases the short-chain fatty acid production and is therefore a valid alternative in MetS treatment.

A Comparative Review on Microbiota Manipulation: Lessons From Fish, Plants, Livestock, and Human Research

During recent years the impact of microbial communities on the health of their host (being plants, fish, and terrestrial animals including humans) has received increasing attention. The microbiota provides the host with nutrients, induces host immune development and metabolism, and protects the host against invading pathogens (1-6). Through millions of years of co-evolution bacteria and hosts have developed intimate relationships. Microbial colonization shapes the host immune system that in turn can shape the microbial composition (7-9). However, with the large scale use of antibiotics in agriculture and human medicine over the last decades an increase of diseases associated with so-called dysbiosis has emerged. Dysbiosis refers to either a disturbed microbial composition (outgrowth of possible pathogenic species) or a disturbed interaction between bacteria and the host (10). Instead of using more antibiotics to treat dysbiosis there is a need to develop alternative strategies to combat disturbed microbial control. To this end, we can learn from nature itself. For example, the plant root (or "rhizosphere") microbiome of sugar beet contains several bacterial species that suppress the fungal root pathogen Rhizoctonia solani, an economically important fungal pathogen of this crop (11). Likewise, commensal bacteria present on healthy human skin produce antimicrobial molecules that selectively kill skin pathogen Staphylococcus aureus. Interestingly, patients with atopic dermatitis (inflammation of the skin) lacked antimicrobial peptide secreting commensal skin bacteria (12). In this review, we will give an overview of microbial manipulation in fish, plants, and terrestrial animals including humans to uncover conserved mechanisms and learn how we might restore microbial balance increasing the resilience of the host species.

Galactooligosaccharide supplementation provides protection against Citrobacter rodentium-induced colitis without limiting pathogen burden

Many enteric pathogens, including Salmonella and enteropathogenic and enterohemorrhagic Escherichia coli, express adhesins that recognize and bind to carbohydrate moieties expressed on epithelial cells. An attractive strategy for inhibiting bacterial adherence employs molecules that mimic these epithelial binding sites. Prebiotic oligosaccharides are non-digestible, fermentable fibres capable of modulating the gut microbiota. Moreover, they may act as molecular decoys that competitively inhibit adherence of pathogens to host cells. In particular, galactooligosaccharides (GOS) and other prebiotic fibres have been shown to inhibit pathogen adherence to epithelial cells in vitro. In the present study, we determined the ability of prophylactic GOS administration to reduce enteric pathogen adherence both in vitro and in vivo as well as protect against intestinal inflammation. GOS supplementation significantly reduced the adherence of the epithelial-adherent murine bacterial pathogen Citrobacter rodentium in a dose-dependent manner to the surface of epithelial cells in vitro. A 1- to 2-log reduction in bacterial adherence was observed at the lowest and highest doses tested, respectively. However, mouse studies revealed that treatment with GOS neither reduced the adherence of C. rodentium to the distal colon nor decreased its dissemination to systemic organs. Despite the absence of adherence inhibition, colonic disease scores for GOS-treated, C. rodentium-infected mice were significantly lower than those of untreated C. rodentium-infected animals (P=0.028). Together, these data suggest that GOS has a direct protective effect in ameliorating disease severity following C. rodentium infection through an anti-adherence-independent mechanism.