Novel Combination of Prebiotics Galacto-Oligosaccharides and Inulin-Inhibited Aberrant Crypt Foci Formation and Biomarkers of Colon Cancer in Wistar Rats

Dietary β-Glucan Alleviates Antibiotic-Associated Side Effects by Increasing the Levels of Antioxidant Enzyme Activities and Modifying Intestinal Microbiota in Pacific White Shrimp (Litopenaeus vannamei)

Antibiotics and their secondary metabolites are commonly found in aquatic ecosystems, leading to the passive exposure of many aquatic animals to low doses of antibiotics, which can affect their health. However, there is limited information available on how to mitigate the side effects of antibiotics on normal aquatic animals. This study aimed to investigate the potential of dietary β-glucan to alleviate the side effects induced by antibiotics in Pacific white shrimp (Litopenaeus vannamei) (0.37 ± 0.02 g). A six-week feeding trial was conducted with four dietary treatments including a control, 1 g/kg β-glucan (β-glucan), 50 mg/kg oxytetracycline (OTC), and a combination of 50 mg/kg OTC and 1 g/kg β-glucan (Mix) groups. At the end of the trial, the growth performance, intestinal microbial composition, antioxidant capacity, and immune response of the shrimp were assessed. There were no significant differences in growth performance among the groups, but the condition factor of the shrimp in the Mix group was significantly decreased when compared to the control and β-glucan groups. The activities of hepatopancreas catalase (CAT) and serum phenol oxidase in the OTC group were significantly lower than those in the control group. On the other hand, the activities of hepatopancreas superoxide dismutase and CAT enzymes in the β-glucan group were significantly higher than those in the OTC group. The supplementation of β-glucan in combination with antibiotics significantly increased the CAT activity and bacteriolytic activity compared to the OTC and control groups, respectively. Moreover, an analysis of the intestinal microbiota revealed that the Observed_species estimator in the Mix group was significantly higher than that in the control group. Dietary antibiotics significantly increased the abundance of Actinobacteria at the phylum level, but the Mix group showed no significant difference. The supplementation of β-glucan in combination with antibiotics also significantly increased the relative abundance of Meridianimaribacter compared to the control group. Additionally, the synergistic influence of β-glucan with antibiotics increased the beta diversity of intestinal microbiotas. These findings suggest that the supplementation of β-glucan in combination with antibiotics on Pacific white shrimp can alleviate the low antioxidant capacity and immune response caused by antibiotics while enhancing the intestinal microbial composition. This provides a potential solution to mitigate the negative impacts of antibiotics in aquaculture.

Mechanisms by which the intestinal microbiota affects gastrointestinal tumours and therapeutic effects

The intestinal microbiota is considered to be a forgotten organ in human health and disease. It maintains intestinal homeostasis through various complex mechanisms. A significant body of research has demonstrated notable differences in the gut microbiota of patients with gastrointestinal tumours compared to healthy individuals. Furthermore, the dysregulation of gut microbiota, metabolites produced by gut bacteria, and related signal pathways can partially explain the mechanisms underlying the occurrence and development of gastrointestinal tumours. Therefore, this article summarizes the latest research progress on the gut microbiota and gastrointestinal tumours. Firstly, we provide an overview of the composition and function of the intestinal microbiota and discuss the mechanisms by which the intestinal flora directly or indirectly affects the occurrence and development of gastrointestinal tumours by regulating the immune system, producing bacterial toxins, secreting metabolites. Secondly, we present a detailed analysis of the differences of intestinal microbiota and its pathogenic mechanisms in colorectal cancer, gastric cancer, hepatocellular carcinoma, etc. Lastly, in terms of treatment strategies, we discuss the effects of the intestinal microbiota on the efficacy and toxic side effects of chemotherapy and immunotherapy and address the role of probiotics, prebiotics, FMT and antibiotic in the treatment of gastrointestinal tumours. In summary, this article provides a comprehensive review of the pathogenic mechanisms of and treatment strategies pertaining to the intestinal microbiota in patients with gastrointestinal tumours. And provide a more comprehensive and precise scientific basis for the development of microbiota-based treatments for gastrointestinal tumours and the prevention of such tumours.

The Diet as a Modulator of Tumor Microenvironment in Colorectal Cancer Patients

Colorectal cancer (CRC) is one of the most common cancers in Western countries and remains the second most common cause of cancer death worldwide. Many studies show the importance of diet and lifestyle in the incidence of CRC, as well as in CRC prevention. However, this review summarizes those studies that analyze the impact of nutrition on tumor microenvironment modulation and cancer progression. We review the available information about the effects of specific nutrients on cancer cell progression and on the different cells within the tumor microenvironment. Diet and nutritional status in the clinical management of colorectal cancer patients are also analyzed. Finally, future perspectives and challenges are discussed, with a view to improving CRC treatments by employing nutritional approaches. These promise great benefits and will eventually improve CRC patients' survival.

Implication of Obesity and Gut Microbiome Dysbiosis in the Etiology of Colorectal Cancer

The complexity and variety of gut microbiomes within and among individuals have been extensively studied in recent years in connection to human health and diseases. Our growing understanding of the bidirectional communication between metabolic diseases and the gut microbiome has also highlighted the significance of gut microbiome dysbiosis in the genesis and development of obesity-related cancers. Therefore, it is crucial to comprehend the possible role of the gut microbiota in the crosstalk between obesity and colorectal cancer (CRC). Through the induction of gut microbial dysbiosis, gut epithelial barrier impairment, metabolomic dysregulation, chronic inflammation, or dysregulation in energy harvesting, obesity may promote the development of colorectal tumors. It is well known that strategies for cancer prevention and treatment are most effective when combined with a healthy diet, physical activity, and active lifestyle choices. Recent studies also suggest that an improved understanding of the complex linkages between the gut microbiome and various cancers as well as metabolic diseases can potentially improve cancer treatments and overall outcomes. In this context, we herein review and summarize the clinical and experimental evidence supporting the functional role of the gut microbiome in the pathogenesis and progression of CRC concerning obesity and its metabolic correlates, which may pave the way for the development of novel prognostic tools for CRC prevention. Therapeutic approaches for restoring the microbiome homeostasis in conjunction with cancer treatments are also discussed herein.

Inulin: properties and health benefits

Inulin, a soluble dietary fiber, is widely found in more than 36 000 plant species as a reserve polysaccharide. The primary sources of inulin, include Jerusalem artichoke, chicory, onion, garlic, barley, and dahlia, among which Jerusalem artichoke tubers and chicory roots are often used as raw materials for inulin production in the food industry. It is universally acknowledged that inulin as a prebiotic has an outstanding effect on the regulation of intestinal microbiota via stimulating the growth of beneficial bacteria. In addition, inulin also exhibits excellent health benefits in regulating lipid metabolism, weight loss, lowering blood sugar, inhibiting the expression of inflammatory factors, reducing the risk of colon cancer, enhancing mineral absorption, improving constipation, and relieving depression. In this review paper, we attempt to present an exhaustive overview of the function and health benefits of inulin.

Bacillus coagulans BACO-17 Alone or in Combination with Galacto-Oligosaccharide Ameliorates Salmonella-Induced Diarrhea and Intestinal Inflammation

In this study, a diarrhea model was established by exposing rats to appropriate antibiotics and Salmonella. After an in vitro screening of prebiotics, fructo-oligosaccharide and galacto-oligosaccharide (GOS) were selected; their synbiotic potential and ability to ameliorate diarrhea symptoms and intestinal inflammation with Bacillus coagulans BACO-17 were evaluated in vivo. After a 27-day feeding experiment including antibiotic intervention and Salmonella infection, it was found that using B. coagulans BACO-17 alone and in combination with GOS as a synbiotic could render a better recovery by lowering diarrhea indexes by 26.9% and 18.7%, respectively. Compared with the negative control, the administration of this synbiotic mixture resulted in the most significant increase in fecal concentrations of total short-chain fatty acids (about 2-fold higher), with a promising improvement in disrupted gut microbial balance. It was worth noting that the administration of B. coagulans BACO-17 alone or in combination with GOS effectively reduced intestinal inflammation (27–31%) and mucosal necrosis (82%) over the negative control. These results suggested that B. coagulans BACO-17 and GOS could be exploited as a promising synbiotic mixture to relieve intestinal inflammatory diseases and improve gut health.

Isomaltooligosaccharides inhibit early colorectal carcinogenesis in a 1,2-dimethylhydrazine-induced rat model

Colon cancer (CC) is a multistage disease and one of the most common cancers worldwide. Establishing an effective treatment strategies of early colon cancer is of great significance for preventing its development and reducing mortality. The occurrence of colon cancer is closely related to changes in the intestinal flora structure. Therefore, remodelling the intestinal flora structure through prebiotics is a powerful approach for preventing and treating the occurrence and development of colon cancer. Isomaltooligosaccharides (IMOs) are often found in fermented foods and can directly reach the gut for use by microorganisms. In this study, a rat model of early colon cancer (DMH) was established by subcutaneous injection of 1,2-dimethylhydrazine, and the model rats were fed IMOs as a dietary intervention (DI). The untargeted faecal metabolomics, gut metabolome and intestinal function of the model rats were investigated. The results showed that DMH, DI and IMOs alone (IMOs) groups exhibited gut microbial community changes. In the DI group, there was an increased abundance of probiotics (Lactobacillus) and decreased abundance of CC marker bacteria (Fusobacterium). The key variations in the faecal metabolites of the DI group included decreased levels of glucose, bile acids (including deoxycholic acid and chenodeoxycholic acid) and amino acids (including L-glutamic acid and L-alanine). In addition, dietary intake of IMOs attenuated the intestinal inflammatory response, improved the intestinal microecological environment, and slowed the development of DMH-induced early CC in rats. This work provides a theoretical basis and technical support for the clinical prevention or treatment of CC with prebiotics.

Evaluation of Prebiotic Properties of Galactooligosaccharides Produced by Transgalactosylation Using Partially Purified β-Galactosidase from Enterobacter aerogenes KCTC2190

Transgalactosylation reaction is the penultimate step in the production of galactooligosaccharides (GOSs) which has prominent applications in the treatment of disorders. In the present study, partially purified β-galactosidase from Enterobacter aerogenes KCTC2190 was used for the synthesis of prebiotic GOSs. GOSs were produced using lactose as substrate. Structural elucidation of collected fractions of GOSs by liquid chromatography electrospray ionization mass spectrometry exhibited the appearance of major peaks of produced GOSs at m/z 241.20, 481.39, 365.11, 527.17, and 701.51 respectively. GOSs facilitated the growth of potential probiotic strains (Lactobacillus delbrueckii ssp. helveticus, Bifidobacterium bifidum, and Lactiplantibacillus plantarum) and liberated propionate and butyrate as principal short-chain fatty acids which established its prebiotic potency. Synbiotic combinations exhibited good antioxidant activities. Synbiotic combinations also exhibited antimicrobial activities against pathogenic microorganisms namely Staphylococcus aureus and Escherichia coli. Synbiotic combinations of GOSs and the respective probiotic microorganisms were able to decrease viable human bone cancer cells (MG-63).

Purification of Aspergillus tamarii mycelial fructosyltransferase (m-FTase), optimized FOS production, and evaluation of its anticancer potential

In the present study, generation of prebiotic fructooligosaccharides (FOS) using Aspergillus tamarii FTase was optimized by applying response surface methodology. Optimal FOS (251 g L^-1 ) was generated at 28.4°C, pH 7.0 and 50% (w/v) sucrose leading to 1.97-fold yield enhancement. The m-FTase was purified using ultrafiltration followed by HiTrap Q HP anion exchange chromatography resulting in 2.15-fold purified FTase with 12.76 U mg^-1 specific activity. Purified FTase (75 kDa) had K_m and V_max values of 1049.717 mM and 2.094 µmol min^-1  mg^-1 , respectively. FOS incorporation led to upregulation of caspase 3, caspase 9, and Bax genes suggesting mitochondrial apoptosis activation in cancer cells. The study describes characteristics of purified FTase from A. tamarii, production optimization of FOS and unravels the role of FOS in anticancer activity against HT-29 cells. PRACTICAL APPLICATION: This study provides detailed insights of kinetic and thermodynamic characteristics of purified FTase, a prebiotic FOS-generating enzyme. Moreover, the role of the apoptotic genes involved in anticancer activity, and the prebiotic potential of FOS is also investigated. These findings are important in the context of FOS applications, and the optimized production strategies make it useful for industrial application.

In Vivo Healthy Benefits of Galacto-Oligosaccharides from Lupinus albus (LA-GOS) in Butyrate Production through Intestinal Microbiota

Animal digestive systems host microorganism ecosystems, including integrated bacteria, viruses, fungi, and others, that produce a variety of compounds from different substrates with healthy properties. Among these substrates, α-galacto-oligosaccharides (GOS) are considered prebiotics that promote the grow of gut microbiota with a metabolic output of Short Chain Fatty Acids (SCFAs). In this regard, we evaluated Lupinus albus GOS (LA-GOS) as a natural prebiotic using different animal models. Therefore, the aim of this work was to evaluate the effect of LA-GOS on the gut microbiota, SCFA production, and intestinal health in healthy and induced dysbiosis conditions (an ulcerative colitis (UC) model). Twenty C57BL/6 mice were randomly allocated in four groups (n = 5/group): untreated and treated non-induced animals, and two groups induced with 2% dextran sulfate sodium to UC with and without LA-GOS administration (2.5 g/kg bw). We found that the UC treated group showed a higher goblet cell number, lower disease activity index, and reduced histopathological damage in comparison to the UC untreated group. In addition, the abundance of positive bacteria to butyryl-CoA transferase in gut microbiota was significantly increased by LA-GOS treatment, in healthy conditions. We measured the SCFA production with significant differences in the butyrate concentration between treated and untreated healthy groups. Finally, the pH level in cecum feces was reduced after LA-GOS treatment. Overall, we point out the in vivo health benefits of LA-GOS administration on the preservation of the intestinal ecosystem and the promotion of SCFA production.

Radiotherapy and the gut microbiome: facts and fiction

An ever-growing body of evidence has linked the gut microbiome with both the effectiveness and the toxicity of cancer therapies. Radiotherapy is an effective way to treat tumors, although large variations exist among patients in tumor radio-responsiveness and in the incidence and severity of radiotherapy-induced side effects. Relatively little is known about whether and how the microbiome regulates the response to radiotherapy. Gut microbiota may be an important player in modulating “hot” versus “cold” tumor microenvironment, ultimately affecting treatment efficacy. The interaction of the gut microbiome and radiotherapy is a bidirectional function, in that radiotherapy can disrupt the microbiome and those disruptions can influence the effectiveness of the anticancer treatments. Limited data have shown that interactions between the radiation and the microbiome can have positive effects on oncotherapy. On the other hand, exposure to ionizing radiation leads to changes in the gut microbiome that contribute to radiation enteropathy. The gut microbiome can influence radiation-induced gastrointestinal mucositis through two mechanisms including translocation and dysbiosis. We propose that the gut microbiome can be modified to maximize the response to treatment and minimize adverse effects through the use of personalized probiotics, prebiotics, or fecal microbial transplantation. 16S rRNA sequencing is the most commonly used approach to investigate distribution and diversity of gut microbiome between individuals though it only identifies bacteria level other than strain level. The functional gut microbiome can be studied using methods involving metagenomics, metatranscriptomics, metaproteomics, as well as metabolomics. Multiple ‘-omic’ approaches can be applied simultaneously to the same sample to obtain integrated results. That said, challenges and remaining unknowns in the future that persist at this time include the mechanisms by which the gut microbiome affects radiosensitivity, interactions between the gut microbiome and combination treatments, the role of the gut microbiome with regard to predictive and prognostic biomarkers, the need for multi “-omic” approach for in-depth exploration of functional changes and their effects on host-microbiome interactions, and interactions between gut microbiome, microbial metabolites and immune microenvironment.

Gut mycobiome: A promising target for colorectal cancer

The human gut is mainly habited by a staggering amount and abundance of bacteria as well as fungi. Gut dysbiosis is believed as a pivotal factor in colorectal cancer (CRC) development. Lately increasing evidence from animal or clinical studies suggested that fungal disturbance also contributed to CRC development. This review summarized the current status of fungal dysbiosis in CRC and highlighted the potential tumorigenic mechanisms of fungi. Then the fungal markers and some therapeutic strategies for CRC were discussed. It would provide a better understanding of the correlation of mycobiota and CRC, and modulating fungal community would be a promising target against CRC.

Combination of inulin and β-cyclodextrin properties for colon delivery of hydrophobic drugs

Colon drug delivery is aimed at the administration of selected drugs to act locally or even systematically. Corticosteroid drugs are often used exerting even pronounced side effects due to systemic absorption. Here a new drug delivery system (DDS) based on the chemical conjugation of β-cyclodextrin to inulin to form the INUCD bioconjugate is described. It was designed with the aim to provide this DDS with colon degradable portions (inulin) which degradation products have direct beneficial effects on the well-being of the colon and with a carrier that can solubilize hydrophobic drugs (β-cyclodextrin). This system was specifically designed to promote a local/topical activity with a significant reduction of the drug systemic absorption. The INUCD bioconjugate was obtained by a simple chemistry binding β-cyclodextrin to an inulin succinate previously synthesized. The bioconjugate was then characterized in terms of physicochemical properties by ATR-FTIR, ¹H NMR, DSC and TGA, DLS and SEM. Furthermore phase-solubility test by using curcumin as a model drug were performed as well as biologic evaluations for cytocompatibility and drug transport across in vitro simulated physiological barriers. Moreover enzymatic degradation studies by inulinase were performed. From the gained results a predictable local drug release of the payload could be attained so allowing a local delivery of e.g. corticosteroids thus avoiding a systemic absorption especially in prolonged therapies.

Effects of the prebiotic inulin-type fructans on post-antibiotic reconstitution of the gut microbiome

AIMS

Interventions using prebiotic inulin-type fructans (ITFs) are widely prescribed to modulate the gut microbiota composition and activity to promote health. However, the impacts of ITFs on post-antibiotic reconstitution of the gut microbiome remain incompletely understood. The aim of the present study was to investigate the effects of ITFs supplementation on intestinal inflammation, the composition of the intestinal microbiota and the colonic transcriptome after antibiotic treatment.

METHODS AND RESULTS

Male BALB/c mice were subjected to an antibiotic cocktail (ABx) treatment for 7 days, and their microbiomes were then reconstituted either spontaneously or with ITFs supplementation (5%) for 14 days. Our data showed that ITFs supplementation delayed the recovery of antibiotic-induced colitis compared with the spontaneous recovery. Neither ITFs supplementation nor spontaneous recovery could restore the microbial community composition at the genus level back to its initial composition. ITFs supplementation increased the relative abundance of some beneficial bacteria and butyrate levels, but resulted in selective blooms of some opportunistic pathogens and elevated the pathways associated with diseases linked to gut microbiota function. Both ITFs supplementation and spontaneous recovery could restore the colonic transcriptome nearly to the initial profile to a certain extent; however, ITFs supplementation delayed the restoration of the immunoglobulin genes compared to spontaneous recovery.

CONCLUSION

These data showed that post-antibiotic ITFs consumption did not always lead to beneficial effects but might lead to potential adverse effects in the context of dysbiosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings highlighted that caution is required when supplementing ITFs to restore intestinal homeostasis in the context of dysbiosis resulting from broad-spectrum antibiotics.

Traditional Processed Meat Products Re-designed Towards Inulin-rich Functional Foods Reduce Polyps in Two Colorectal Cancer Animal Models

Inulin-rich foods exert a prebiotic effect, as this polysaccharide is able to enhance beneficial colon microbiota populations, giving rise to the in situ production of short-chain fatty acids (SCFAs) such as propionic and butyric acids. These SCFAs are potent preventive agents against colorectal cancer due to their histone deacetylases inhibitory properties, which induce apoptosis in tumor colonocytes. As colorectal cancer is the fourth most common neoplasia in Europe with 28.2 new cases per 100,000 inhabitants, a cost-effective preventive strategy has been tested in this work by redesigning common porcine meat products (chorizo sausages and cooked ham) consumed by a substantial proportion of the population towards potential colorectal cancer preventive functional foods. In order to test the preventive effect of these inulin-rich meat products against colorectal cancer, an animal model (Rattus norvegicus F344) was used, involving two doses of azoxymethane (10 mg/kg) and two treatments with dextran sodium sulfate (DSS) during a 20-week assay period. Control feed, control sausages, functional sausages (15.7% inulin), control cooked ham and functional cooked ham (10% inulin) were used to feed the corresponding animal cohorts. Then, the animals were sacrificed and their digestive tract tissues were analyzed. The results showed a statistically significant 49% reduction in the number of colon polyps in the functional meat products cohorts with respect to the control meat products animals, as well as an increase in the cecum weight (an indicator of a diet rich in prebiotic fiber), a 51.8% increase in colon propionate production, a 39.1% increase in colon butyrate concentrations, and a reduction in the number of hyperplastic Peyer's patches. Metagenomics studies also demonstrated colon microbiota differences, revealing a significant increase in Bacteroidetes populations in the functional meat products (mainly due to an increase in Bacteroidaceae and Prevotellaceae families, which include prominent propionate producers), together with a reduction in Firmicutes (especially due to lower Lachnospiraceae populations). However, functional meat products showed a remarkable increase in the anti-inflammatory and fiber-fermentative Blautia genus, which belongs to this Lachnospiraceae family. The functional meat products cohorts also presented a reduction in important pro-inflammatory bacterial populations, such as those of the genus Desulfovibrio and Bilophila. These results were corroborated in a genetic animal model of CRC (F344/NSlc-Apc1588/kyo) that produced similar results. Therefore, processed meat products can be redesigned towards functional prebiotic foods of interest as a cost-effective dietary strategy for preventing colorectal cancer in human populations.

Inulin as a multifaceted (active) substance and its chemical functionalization: From plant extraction to applications in pharmacy, cosmetics and food

This review is aimed at critically discussing a collection of research papers on Inulin (INU) in different scientific fields. The first part of this work gives an overview on the main characteristics of native INU, including production, applications in food or cosmetics industries, its benefits on human health as well as its main nutraceutical properties. A particular focus is dedicated to the extraction techniques and to the specific effects of INU on intestinal microbiota. Other than in food industry, the number of INU applications increases dramatically in the pharmaceutical field especially due to its simple chemical functionalization. Thus, aim of this review is also to give practical examples of chemical functionalization performed on INU also by including critical comments based on the direct experience of the Authors. With this aim, a full paragraph is dedicated to practical chemical experiences useful to reduce the efforts when establishing new experimental conditions. Moreover, the pharmaceutical technology is also taken in special consideration by underlining the aspects leading at the preparation of formulations based on INU. At the end of the review, a critical paragraph is intended to feed the scientists' curiosity on this versatile polysaccharide.

Prebiotics from acorn and sago prevent high-fat-diet-induced insulin resistance via microbiome-gut-brain axis modulation

Role of gut microbiome in obesity and type 2 diabetes (T2D) became apparent from several independent studies indicating that gut microbiome modulators like prebiotics may improve microbiome perturbations (dysbiosis) to ameliorate metabolic derangements. We herein isolate water soluble, nondigestible polysaccharides from five plant-based foods (acorn, quinoa, sunflower, pumpkin seeds and sago) and assess their impact on human fecal microbiome and amelioration of high-fat-diet (HFD)-induced obesity/T2D in mice. During polysaccharide isolation, purification, biochemical and digestion resistance characterization, and fermentation pattern by human fecal microbiome, we select acorn- and sago-derived prebiotics (on the basis of relatively higher purity and yield and lower protein contamination) and examine their effects in comparison to inulin. Prebiotics treatments in human fecal microbiome culture system not only preserve microbial diversity but also appear to foster beneficial bacteria and short-chain fatty acids (SCFAs). Feeding of acorn- and sago-derived prebiotics ameliorates HFD-induced glucose intolerance and insulin resistance in mice, with effects comparatively superior to those seen in inulin-fed mice. Feeding of both of novel prebiotics as well as inulin increases SCFAs levels in the mouse gut. Interestingly, gut hyperpermeability and mucosal inflammatory markers were significantly reduced upon prebiotics feeding in HFD-fed mice. Hypothalamic energy signaling in terms of increased expression of pro-opiomelanocortin was also modulated by prebiotics administration. Results demonstrate that these (and/or such) novel prebiotics can ameliorate HFD-induced defects in glucose metabolism via positive modulation of gut-microbiome-brain axis and hence could be useful in preventing/treating diet-induced obesity/T2D.

Modulation of JNK-1/ β-catenin signaling byLactobacillus casei, inulin and their combination in 1,2-dimethylhydrazine-induced colon cancer in mice

Colon cancer is a complex disease that involves numerous genetic alterations that change the normal colonic mucosa into invasive adenocarcinoma. In the current study, the protective effects of inulin (prebiotic), Lactobacillus casei (L. casei, probiotic) and their combination (synbiotic) on 1,2-dimethylhydrazine (DMH)-induced colon cancer in male Swiss mice were evaluated. Animals were divided into: Control group, DMH-treated group, DMH plus inulin, DMH plus L. casei and DMH plus inulin plus L. casei-treated groups. Fecal microbiome analysis, biochemical measurements, histopathological examination of the colon tissues, immunostaining and Western blotting analysis of β-catenin, GSK3β and JNK-1 were performed. The prebiotic-, probiotic- and synbiotic-treated groups showed decreased levels of carcinoembryonic antigen and a lower number of aberrant crypt foci compared to the DMH-treated group with the synbiotic group exhibiting a superior effect. Furthermore, all treatments showed a body weight-reducing effect. Administration of inulin, L. casei or their combination increased the expression level of phospho-JNK-1 while they decreased the expression level of β-catenin and phospho-GSK3β. Remarkably, L. casei treatment resulted in enrichment of certain beneficial bacterial genera i.e. Akkermansia and Turicibacter. Therefore, administration of L. casei and inulin as a synbiotic combination protects against colon cancer in mice.

The lactobacillus casei and inulin modulate the expression of JNK-1, GSK3β and β-catenin proteins and enrich the beneficial bacteria to protect from colon cancer in mice.

Impact of the Microbiome on the Immune System

Higher organisms are all born with general immunity as well as with, increasingly, more specific immune systems. All immune mechanisms function with the intent of aiding the body in defense against infection. Internal and external factors alike have varying effects on the immune system, and the immune response is tailored specifically to each one. Accompanying the components of the human innate and adaptive immune systems are the other intermingling systems of the human body. Increasing understanding of the body's immune interactions with other systems has opened new avenues of study, including that of the microbiome. The microbiome has become a highly active area of research over the last 10 to 20 years since the NIH began funding the Human Microbiome Project (HMP), which was established in 2007. Several publications have focused on the characterization, functions, and complex interplay of the microbiome as it relates to the rest of the body. A dysfunction between the microbiome and the host has been linked to various diseases including cancers, metabolic deficiencies, autoimmune disorders, and infectious diseases. Further understanding of the microbiome and its interaction with the host in relation to diseases is needed in order to understand the implications of microbiome dysfunction and the possible use of microbiota in the prevention of disease. In this review, we have summarized information on the immune system, the microbiome, the microbiome's interplay with other systems, and the association of the immune system and the microbiome in diseases such as diabetes and colorectal cancer.

Chemoprevention of Colorectal Cancer by Dietary Compounds

Colorectal cancer is one of the leading causes of death, and the third most diagnosed type of cancer, worldwide. It is most common amongst men and women over 50 years old. Risk factors include smoking, alcohol, diet, physical inactivity, genetics, alterations in gut microbiota, and associated pathologies (diabetes, obesity, chronic inflammatory bowel diseases). This review will discuss, in detail, the chemopreventive properties of some dietary compounds (phenolic compounds, carotenoids, iridoids, nitrogen compounds, organosulfur compounds, phytosterols, essential oil compounds, polyunsaturated fatty acids and dietary fiber) against colorectal cancer. We present recent data, focusing on in vitro, laboratory animals and clinical trials with the previously mentioned compounds. The chemopreventive properties of the dietary compounds involve multiple molecular and biochemical mechanisms of action, such as inhibition of cell growth, inhibition of tumor initiation, inhibition of adhesion, migration and angiogenesis, apoptosis, interaction with gut microbiota, regulation of cellular signal transduction pathways and xenobiotic metabolizing enzymes, etc. Moreover, this review will also focus on the natural dietary compounds' bioavailability, their synergistic protective effect, as well as the association with conventional therapy. Dietary natural compounds play a major role in colorectal chemoprevention and continuous research in this field is needed.

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.

Intestinal microbiota: a novel perspective in colorectal cancer biotherapeutics

It is believed that genetic factors, immune system dysfunction, chronic inflammation, and intestinal microbiota (IM) dysbiosis contribute to the pathogenesis of colorectal cancer (CRC). The beneficial role played by the direct regulation of IM in inflammatory bowel disease treatment is identified by the decreased growth of harmful bacteria and the increased production of anti-inflammatory factors. Interestingly, gut microbiota has been proven to inhibit tumor formation and progression in inflammation/carcinogen-induced CRC mouse models. Recently, evidence has indicated that IM is involved in the negative regulation of tumor immune response in tumor microenvironment, which then abolishes or accelerates anticancer immunotherapy in several tumor animals. In clinical trials, a benefit of IM-based CRC therapies in improving the intestinal immunity balance, epithelial barrier function, and quality of life has been reported. Meanwhile, specific microbiota signature can modulate host's sensitivity to chemo-/radiotherapy and the prognosis of CRC patients. In this review, we aim to 1) summarize the potential methods of IM-based therapeutics according to the recent results; 2) explore its roles and underlying mechanisms in combination with other therapies, especially in biotherapeutics; 3) discuss its safety, deficiency, and future perspectives.

The role of gut microbiota in the effects of maternal obesity during pregnancy on offspring metabolism

Obesity is considered a global epidemic. Specifically, obesity during pregnancy programs an increased risk of the offspring developing metabolic disorders in addition to the adverse effects on the mother per se Large numbers of human and animal studies have demonstrated that the gut microbiota plays a pivotal role in obesity and metabolic diseases. Similarly, maternal obesity during pregnancy is associated with alterations in the composition and diversity of the intestine microbial community. Recently, the microbiota in the placenta, amniotic fluid, and meconium in healthy gestations has been investigated, and the results supported the "in utero colonization hypothesis" and challenged the traditional "sterile womb" that has been acknowledged worldwide for more than a century. Thus, the offspring microbiota, which is crucial for the immune and metabolic function and further health in the offspring, might be established prior to birth. As a detrimental intrauterine environment, maternal obesity influences the microbial colonization and increases the risk of metabolic diseases in offspring. This review discusses the role of the microbiota in the impact of maternal obesity during pregnancy on offspring metabolism and further analyzes related probiotic or prebiotic interventions to prevent and treat obesity and metabolic diseases.

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

Colorectal cancer (CRC) is one of the leading causes of cancer deaths around the globe. Bioactive food ingredients such as prebiotics have protective potential in colon cancer. Data on galacto-oligosaccharides (GalOS) against CRC are very limited and GalOS used in this study have β-1,6 and β-1,3 as major glycosidic linkages and, to our best knowledge, were never used before against any cancer treatment. This study aims to investigate the protective role of novel GalOS against various biomarkers of CRC including aberrant crypt foci (ACF), bacterial enzymes and short chain fatty acids (SCFA) in a rodent model induced with 1,2-dimethylhydrazine dihydrochloride (DMH). Inulin group was taken as positive control in present study to compare novel GalOS protective effects. GalOS doses of 76-151 mg and inulin doses of 114 mg were given to different groups treated with DMH. Results showed that ACF formation was significantly (p ≤ 0.05) less in high dose GalOS group (27.3%). GalOS also had protective effects against DMH-induced body weight loss and showed higher level of cecal and fecal SCFA (acetate, propionate and butyrate). High doses of GalOS also resulted in significant (p ≤ 0.05) reduction of bacterial enzymatic activities. Increased populations of beneficial bacteria (bifidobacteria and lactobacilli) and decreased concentrations of harmful bacteria were observed in all prebiotics treatment groups. It can be concluded that novel GalOS exhibit robust protective activity against ACF formation in vivo.

Microbiota, Inflammation and Colorectal Cancer

Colorectal cancer, the fourth leading cause of cancer-related death worldwide, is a multifactorial disease involving genetic, environmental and lifestyle risk factors. In addition, increased evidence has established a role for the intestinal microbiota in the development of colorectal cancer. Indeed, changes in the intestinal microbiota composition in colorectal cancer patients compared to control subjects have been reported. Several bacterial species have been shown to exhibit the pro-inflammatory and pro-carcinogenic properties, which could consequently have an impact on colorectal carcinogenesis. This review will summarize the current knowledge about the potential links between the intestinal microbiota and colorectal cancer, with a focus on the pro-carcinogenic properties of bacterial microbiota such as induction of inflammation, the biosynthesis of genotoxins that interfere with cell cycle regulation and the production of toxic metabolites. Finally, we will describe the potential therapeutic strategies based on intestinal microbiota manipulation for colorectal cancer treatment.

Analysis of the Anti-Cancer Effects of Cincau Extract (Premna oblongifolia Merr) and Other Types of Non-Digestible Fibre Using Faecal Fermentation Supernatants and Caco-2 Cells as a Model of the Human Colon

Green cincau (Premna oblongifolia Merr) is an Indonesian food plant with a high dietary fibre content. Research has shown that dietary fibre mixtures may be more beneficial for colorectal cancer prevention than a single dietary fibre type. The aim of this study was to investigate the effects of green cincau extract on short chain fatty acid (SCFA) production in anaerobic batch cultures inoculated with human faecal slurries and to compare these to results obtained using different dietary fibre types (pectin, inulin, and cellulose), singly and in combination. Furthermore, fermentation supernatants (FSs) were evaluated in Caco-2 cells for their effect on cell viability, differentiation, and apoptosis. Cincau increased total SCFA concentration by increasing acetate and propionate, but not butyrate concentration. FSs from all dietary fibre sources, including cincau, reduced Caco-2 cell viability. However, the effects of all FSs on cell viability, cell differentiation, and apoptosis were not simply explainable by their butyrate content. In conclusion, products of fermentation of cincau extracts induced cell death, but further work is required to understand the mechanism of action. This study demonstrates for the first time that this Indonesian traditional source of dietary fibre may be protective against colorectal cancer.

Gum odina: an emerging gut modulating approach in colorectal cancer prevention

This study is focused on Gum Odina (GO), a reported prebiotic in our earlier work, and its impact on colorectal cancer (CRC).