Epigallocatechin Gallate (EGCG) Promotes the Immune Function of Ileum in High Fat Diet Fed Mice by Regulating Gut Microbiome Profiling and Immunoglobulin Production

Effect of compound polysaccharide on immunity, antioxidant capacity, gut microbiota, and serum metabolome in kittens

Introduction

This study was conducted to investigate the effects of compound polysaccharides (CP), composed of Astragalus polysaccharide and Poria cocos polysaccharide, on immunity, antioxidant capacity, gut microbiota, and serum metabolome in kittens.

Methods

A total of 14 4-month-old kittens, with an average body weight of 2.39 kg, were used in a 56-day experiment. They were randomly assigned to the control (CON) group (n = 7) and CP group (n = 7). Blood samples and fresh feces were collected at the end of the experimental period.

Results

The results displayed that supplementation with CP increased the concentrations of serum immunoglobulin A, immunoglobulin G, interleukin 6, and tumor necrosis factor-α (p < 0.05). However, there was no difference in the concentrations of serum amyloid A between the two groups (p > 0.05). Furthermore, the serum biochemical parameters of all the kittens were within the reference range. The relative abundance of beneficial bacteria (norank_f__Butyricicoccaceae and Bacteroides plebeius) was higher in the CP group (p < 0.05), while the opportunistic pathogen (Anaerotruncus) was lower in the CP group (p < 0.05). In addition, serum metabolomic analysis demonstrated that the differential metabolites, including arachidonic acid, dihomo-gamma-linolenic acid, and glycine, and the relevant metabolic pathway, including glyoxylate and dicarboxylate metabolism, glycine, serine, and threonine metabolism, and biosynthesis of unsaturated fatty acids, were implicated in regulating immune function in the kitten after CP treatment.

Conclusion

CP supplementation can enhance immune function in kittens and increase the relative abundance of beneficial gut microbiota, and does not lead to generalized inflammation. Dietary supplementation with CP may generate nutritional benefits in kittens, and this study offers insight into the development of functional pet food for kittens.

Phenotype variability in diet-induced obesity and response to (-)-epigallocatechin gallate supplementation in a Diversity Outbred mouse cohort: A model for exploring gene x diet interactions for dietary bioactives

The flavan-3-ol (-)-epigallocatechin gallate (EGCG) blunts obesity in inbred mice, but human clinical trials have yielded mixed results. Genetic homogeneity in preclinical models may explain translational disconnect between rodents and humans. The Diversity Outbred (DO) mouse model provides genotype and phenotype variability for characterization of gene x environment (i.e., diet) interactions. We conducted a longitudinal phenotyping study in DO mice. Mice (n = 50) were fed a high-fat diet for 8 weeks and then a high-fat diet + 0.3% EGCG for 8 weeks. We hypothesized that obesity and any protective effects of EGCG would exhibit extreme variability in these genetically heterogeneous mice. As anticipated, DO mice exhibited extreme variation in body composition at baseline (4%-13.9% fat), after 8 weeks of high-fat diet (6.5%-38.1% fat), and after 8 weeks of high-fat diet + EGCG (7.6%-42.6% fat), greater than what is observed in inbred mice. All 50 mice gained body fat on the high-fat diet (changes from baseline of +5% ± 640%). Intriguingly, adiposity variability increased when EGCG was added to the diet (changes from the high-fat diet alone of -52% ± 390%), with 11/50 mice losing body fat. We postulate that the explanation for this variability is genetic heterogeneity. Our data confirm the promise for EGCG to manage obesity but suggest that genetic factors may exert significant control over the efficacy of EGCG. Larger studies in DO mice are needed for quantitative trait loci mapping to identify genetic loci governing EGCG x obesity interactions and translate these findings to precision nutrition in humans.

Assessment of the Impact of Dietary Supplementation with Epigallocatechin Gallate (EGCG) on Antioxidant Status, Immune Response, and Intestinal Microbiota in Post-Weaning Rabbits

This study was conducted to investigate the impact of EGCG on antioxidant stress, immune response, and intestinal microbiota flora in post-weaning rabbits. A total of 144 40 d Ira rabbits (equally divided by sex), were randomly allocated to six treatments. with five groups receiving doses of 200, 400, 600, 800, and 1000 mg/kg of EGCG, while one group served as a control without EGCG. Over 48 days, this study the assessed growth performance, antioxidant capacity, immune system, intestinal morphology, and cecal microbiota in the rabbits. The results showed that EGCG did not affect growth performance; however, significant linear and quadratic correlations were observed between the MDA, T-AOC, and GSH-Px activities in the liver and jejunum (p < 0.05). Quadratic effects were observed for the spleen and thymus indexes and serum IgG levels with increasing EGCG dosages (p < 0.05). Additionally, positive linear and quadratic effects were found on the ileal villus height and the villus height/crypt depth ratio. The relative abundances of Euryarchaeota, Patescibacteria, and Synergistota were significantly enriched in rabbits fed with high dosages (600-1000 mg/kg) of EGCG. Conclusively, the addition of large doses of EGCG (400-800 mg/kg) can effectively suppress oxidative stress and alleviate weaning stress, thereby contributing to the protection of post-weaning rabbits.

A Narrative Review: Immunometabolic Interactions of Host-Gut Microbiota and Botanical Active Ingredients in Gastrointestinal Cancers

The gastrointestinal tract is where the majority of gut microbiota settles; therefore, the composition of the gut microbiota and the changes in metabolites, as well as their modulatory effects on the immune system, have a very important impact on the development of gastrointestinal diseases. The purpose of this article was to review the role of the gut microbiota in the host environment and immunometabolic system and to summarize the beneficial effects of botanical active ingredients on gastrointestinal cancer, so as to provide prospective insights for the prevention and treatment of gastrointestinal diseases. A literature search was performed on the PubMed database with the keywords "gastrointestinal cancer", "gut microbiota", "immunometabolism", "SCFAs", "bile acids", "polyamines", "tryptophan", "bacteriocins", "immune cells", "energy metabolism", "polyphenols", "polysaccharides", "alkaloids", and "triterpenes". The changes in the composition of the gut microbiota influenced gastrointestinal disorders, whereas their metabolites, such as SCFAs, bacteriocins, and botanical metabolites, could impede gastrointestinal cancers and polyamine-, tryptophan-, and bile acid-induced carcinogenic mechanisms. GPRCs, HDACs, FXRs, and AHRs were important receptor signals for the gut microbial metabolites in influencing the development of gastrointestinal cancer. Botanical active ingredients exerted positive effects on gastrointestinal cancer by influencing the composition of gut microbes and modulating immune metabolism. Gastrointestinal cancer could be ameliorated by altering the gut microbial environment, administering botanical active ingredients for treatment, and stimulating or blocking the immune metabolism signaling molecules. Despite extensive and growing research on the microbiota, it appeared to represent more of an indicator of the gut health status associated with adequate fiber intake than an autonomous causative factor in the prevention of gastrointestinal diseases. This study detailed the pathogenesis of gastrointestinal cancers and the botanical active ingredients used for their treatment in the hope of providing inspiration for research into simpler, safer, and more effective treatment pathways or therapeutic agents in the field.

Gubra Amylin-NASH Diet Induced Nonalcoholic Fatty Liver Disease Associated with Histological Damage, Oxidative Stress, Immune Disorders, Gut Microbiota, and Its Metabolic Dysbiosis in Colon

SCOPE

The overall changes of colon under nonalcoholic fatty liver disease (NAFLD) remain to be further elucidated.

METHODS AND RESULTS

This study establishes a mouse model of NAFLD through a long-term Gubra Amylin-nonalcoholic steatohepatitis (NASH) diet (GAN diet). The results show that GAN diet significantly induces weight gain, liver steatosis, colonic oxidative stress, and lipid accumulation in blood, liver, and adipose tissue in mice. GAN feeding reduces the diversity of the gut microbiota, alters the composition and abundance of the gut microbiota, and leads to an increase in microbial metabolites such as long-chain fatty acids (LCFAs) and secondary bile acids (BAs), as well as a decrease in short-chain fatty acids (SCFAs). The RNA-seq and immunofluorescence results reveal that the GAN diet alters the expression of proteins and their coding genes involved in oxidative stress, immune response, and barrier function in colon tissue, such as lipocalin-2 (Lcn2, p < 0.05), heme oxygenase-1 (HO-1/Hmox1, p < 0.05), interferon-gamma (IFN-γ), and claudin-3/7. In addition, correlation analysis indicates a strong correlation between the changes in gut microbiota and lipid biomarkers. Additionally, the expression of immune related genes in colon tissue is related to the LCFAs produced by microbial metabolism.

CONCLUSION

GAN-induced NAFLD is related to microbiota and its metabolic imbalance, oxidative stress, immune disorders, and impaired barrier function in colon.

Lactobacillus acidophilus CICC 6075 attenuates high-fat diet-induced obesity by improving gut microbiota composition and histidine biosynthesis

This study aimed to investigate the potential anti-obesity efficacy of Lactobacillus acidophilus CICC 6075. The study analyzed fecal metagenomic data from 120 obese and 100 non-obese individuals. C57BL/6 mice on normal diet or high-fat diet (HFD) were treated with L. acidophilus CICC 6075 by daily oral gavage for 12 weeks, followed by evaluations of the obesity phenotype. Metagenomic analysis revealed depletion of L. acidophilus in obese individuals. Administration of L. acidophilus CICC 6075 attenuated excessive weight gain and fat accumulation and maintained the intestinal barrier in HFD-induced obese mice. Sequencing results showed that HFD hindered α- and β-diversity while reducing the relative abundance of Lactobacillus and norank_f_Muribaculaceae and significantly increasing the relative abundance of Ileibacterium. L. acidophilus CICC 6075 reversed these results and reduced the Firmicutes/Bacteroidetes ratio. Supplementation of L. acidophilus CICC 6075 enhanced histidine biosynthesis, inhibited the NF-κB pathway, and significantly reduced the expression levels of inflammatory factors in adipose tissue. These results indicate that L. acidophilus CICC 6075 alleviates HFD-induced obesity in mice by inhibiting the activation of the NF-κB pathway and enhancing gut microbiota functionality. This suggests that L. acidophilus CICC 6075 may be a good candidate probiotic for preventing obesity.

2'-Fucosyllactose Promotes Colonization of Akkermansia muciniphila and Prevents Colitis In Vitro and in Mice

Akkermansia muciniphila is a potential candidate for ulcerative colitis prevention. Considering that it utilizes 2'-fucosyllactose (2'FL) for growth, 2'FL can be used to enrich the abundance of A. muciniphila in feces. However, whether the crosswalk between 2'FL and A. muciniphila can promote the intestinal colonization of A. muciniphila remains unclear. In this study, we explored the effect and the underlying mechanism of 2'FL on the colonization of A. muciniphila in vitro and in vivo as well as its alleviating effect on colitis. Our results revealed that 2'FL can serve as a carbon source of A. muciniphila to support the growth and increase cell-surface hydrophobicity and the expression of the genes coding fibronectin-binding autotransporter adhesin to promote the adhesion to Caco2/HT29 methotrexate (MTX) cells but not of galactooligosaccharides (GOS) and glucose. Moreover, 2'FL could increase the host mucin formation to promote the adhesion of A. muciniphila to Caco2/HT29 MTX cells but not of GOS and glucose. Furthermore, 2'FL could significantly increase the colonization of A. muciniphila in the gut to alleviate colitis in mice. Overall, the interplay between A. muciniphila and 2'FL is expected to provide an advantageous ecological niche for A. muciniphila so as to confer further health benefits against colitis.

Therapeutic potential of dietary nutrients and medicinal foods against metabolic disorders: Targeting Akkermansia muciniphila

As one of the most attractive next‐generation probiotics, mucin‐degrading Akkermansia muciniphila has emerged as an essential and integral factor in maintaining human health and affecting pathological outcomes. Its abundance is inversely associated with various metabolic diseases (e.g., obesity and type 2 diabetes), cardiovascular diseases, and intestinal inflammation. Supplementing A. muciniphila to restore the gut microbiota ecosystem is a promising approach for treating metabolic disorders. However, the direct utilization of this probiotic is limited by technological and regulatory hurdles, such as the in vitro bulk culture of A. muciniphila and the need for expensive animal‐derived materials. Therefore, enrichment of A. muciniphila using nutraceutical supplements is a feasible strategy. Dietary supplements, especially medicinal herbs, offer a vast and valuable resource as potential prebiotics for promoting the growth of A. muciniphila in the gut, ensuring reliable safety and efficacy. In this study, we first systemically reviewed the dietary substances and medicinal foods known to promote A. muciniphila from over 100 literature sources, aiming to establish a candidate basis for future exploration of prebiotics targeting A. muciniphila. Furthermore, we summarized and discussed the major regulatory factors and mechanisms responsible for the beneficial effect of A. muciniphila on metabolic disorders, hoping to open up exciting directions for in‐depth research on the pharmacological mechanism of A. muciniphila and pave the way for its clinical therapeutics.

Effect of tea polyphenols supplement on growth performance, antioxidation, and gut microbiota in squabs

Early life nutritional supplementation can significantly improve pigeon health. Both the nutritional crops of parental pigeons and the intestinal development of squabs play key roles in the growth rate of squabs. Tea polyphenols (TPs), as natural plant extracts, exhibit potential biological activities. However, the impact of TPs on the intestinal function of squabs is not known. This study evaluated the effects of TPs on growth performance, immunity, antioxidation, and intestinal function in squabs. A total of 432 young pigeons (1 day old) were divided into four groups: a control group (fed a basic diet) and three treatment groups (low, medium, and high dose groups; 100, 200, and 400 mg/kg TPs, respectively). On the 28th day, samples of serum, mucosal tissue, and digests from the ileum of squabs were collected for analysis. The results revealed that TP supplementation significantly reduced the feed-to-meat ratio and improved the feed utilization rate and serum biochemical indices in squabs. Additionally, it enhanced the intestinal barrier function of birds by promoting intestinal development and integrity of tight junctions and regulating digestive enzyme activities and intestinal flora. Mechanistically, TPs activated the Nrf2-ARE signaling pathway, which may be associated with improved antioxidant and immune responses, correlating with an increased abundance of Candida arthritis and Corynebacterium in the ileum.

The effect of epigallocatechin gallate on laying performance, egg quality, immune status, antioxidant capacity, and hepatic metabolome of laying ducks reared in high temperature condition

Epigallocatechin gallate (EGCG) is a main component in green tea extract, which possesses multiple bioactivities. The present research studied the effects of EGCG on the laying performance, egg quality, immune status, antioxidant capacity, and hepatic metabolome of Linwu laying ducks reared under high temperature. A total of 180 42-w-old healthy Linwu laying ducks were allocated into control or EGCG-treated groups. Each treatment had 6 replicates with 15 ducks in each replicate. Diets for the two groups were basal diets supplemented with 0 or 300 mg/kg EGCG, respectively. All ducks were raised in the high temperature condition (35 ± 2 °C for 6 h from 10:00 to 16:00, and 28 ± 2 °C for the other 18 h from 16:00 to 10:00 the next day) for 21 days. Results showed that EGCG increased the egg production rate (p = 0.014) and enhanced the immunocompetence by improving serum levels of immunoglobulin A (p = 0.008) and immunoglobulin G (p = 0.006). EGCG also fortified the antioxidant capacity by activating superoxide dismutase (p = 0.012), catalase (p = 0.009), and glutathione peroxidase (p = 0.021), and increasing the level of heat-shock protein 70 (p = 0.003) in laying ducks' liver. At the same time, hepatic metabolomics result suggested that EGCG increased the concentration of several key metabolites, such as spermidine (p = 0.031), tetramethylenediamine (p = 0.009), hyoscyamine (p = 0.026), β-nicotinamide adenine dinucleotide phosphate (p = 0.038), and pantothenic acid (p = 0.010), which were involved in the metabolic pathways of glutathione metabolism, arginine and proline metabolism, β-alanine metabolism, and tropane, piperidine, and pyridine alkaloid biosynthesis. In conclusion, 300 mg/kg dietary EGCG showed protection effects on the laying ducks reared in high temperature by improving the immune and antioxidant capacities, which contributed to the increase of laying performance of ducks. The potential mechanism could be that EGCG modulate the synthesis of key metabolites and associated metabolic pathways.

High-Carbohydrate Diet Consumption Poses a More Severe Liver Cholesterol Deposition than a High-Fat and High-Calorie Diet in Mice

In the past few decades, many researchers believed that a high-fat and high-calorie diet is the most critical factor leading to metabolic diseases. However, increasing evidence shows a high-carbohydrate and low-fat diet may also be a significant risk factor. It needs a comprehensive evaluation to prove which viewpoint is more persuasive. We systematically compared the effects of high-fat and high-calorie diets and high-carbohydrate and low-fat ones on glycolipid metabolism in mice to evaluate and compare the effects of different dietary patterns on metabolic changes in mice. Sixty 8-week-old male C57BL/6 mice were divided into four groups after acclimatization and 15% (F-15), 25% (F-25), 35% (F-35), and 45% (F-45) of their dietary energy was derived from fat for 24 weeks. The body weight, body-fat percentage, fasting blood glucose, lipid content in the serum, and triglyceride content in the livers of mice showed a significantly positive correlation with dietary oil supplementation. Interestingly, the total cholesterol content in the livers of mice in the F-15 group was significantly higher than that in other groups (p < 0.05). Compared with the F-45 group, the mRNA expression of sterol synthesis and absorption-related genes (e.g., Asgr1, mTorc1, Ucp20, Srebp2, Hmgcr, and Ldlr), liver fibrosis-related genes (e.g., Col4a1 and Adamts1) and inflammation-related genes (e.g., Il-1β and Il-6) were significantly higher in the F-15 group. Compared with the F-45 group, the relative abundance of unclassified_f_Lachnospiraceae and Akkermansia was decreased in the F-15 group. While unclassified_f_Lachnospiraceae and Akkermansia are potentially beneficial bacteria, they have the ability to produce short-chain fatty acids and modulate cholesterol metabolism. In addition, the relative abundance of unclassified_f_Lachnospiraceae and Akkermansia was significantly positively correlated with fatty acid transporters expression and negatively correlated with that of cholesteryl acyltransferase 1 and cholesterol synthesis-related genes. In conclusion, our study delineated how a high-fat and high-calorie diet (fat supplied higher than or equal to 35%) induced obesity and hepatic lipid deposition in mice. Although the high-carbohydrate and low-fat diet did not cause weight gain in mice, it induced cholesterol deposition in the liver. The mechanism is mainly through the induction of endogenous synthesis of cholesterol in mice liver through the ASGR1-mTORC1-USP20-HMGCR signaling pathway. The appropriate oil and carbon water ratio (dietary energy supply from fat of 25%) showed the best gluco-lipid metabolic homeostasis in mice.

Gut microbiota and fecal short chain fatty acids differ with adiposity and country of origin: the METS-microbiome study

The relationship between microbiota, short chain fatty acids (SCFAs), and obesity remains enigmatic. We employ amplicon sequencing and targeted metabolomics in a large (n = 1904) African origin cohort from Ghana, South Africa, Jamaica, Seychelles, and the US. Microbiota diversity and fecal SCFAs are greatest in Ghanaians, and lowest in Americans, representing each end of the urbanization spectrum. Obesity is significantly associated with a reduction in SCFA concentration, microbial diversity, and SCFA synthesizing bacteria, with country of origin being the strongest explanatory factor. Diabetes, glucose state, hypertension, obesity, and sex can be accurately predicted from the global microbiota, but when analyzed at the level of country, predictive accuracy is only universally maintained for sex. Diabetes, glucose, and hypertension are only predictive in certain low-income countries. Our findings suggest that adiposity-related microbiota differences differ between low-to-middle-income compared to high-income countries. Further investigation is needed to determine the factors driving this association.

Plant-Derived Nutraceuticals Involved in Body Weight Control by Modulating Gene Expression

Obesity is the most prevalent health problem in the Western world, with pathological body weight gain associated with numerous co-morbidities that can be the main cause of death. There are several factors that can contribute to the development of obesity, such as diet, sedentary lifestyle, and genetic make-up. Genetic predispositions play an important role in obesity, but genetic variations alone cannot fully explain the explosion of obesity, which is why studies have turned to epigenetics. The latest scientific evidence suggests that both genetics and environmental factors contribute to the rise in obesity. Certain variables, such as diet and exercise, have the ability to alter gene expression without affecting the DNA sequence, a phenomenon known as epigenetics. Epigenetic changes are reversible, and reversibility makes these changes attractive targets for therapeutic interventions. While anti-obesity drugs have been proposed to this end in recent decades, their numerous side effects make them not very attractive. On the other hand, the use of nutraceuticals for weight loss is increasing, and studies have shown that some of these products, such as resveratrol, curcumin, epigallocatechin-3-gallate, ginger, capsaicin, and caffeine, can alter gene expression, restoring the normal epigenetic profile and aiding weight loss.

Interplay between Phytochemicals and the Colonic Microbiota

Phytochemicals are natural compounds found in food ingredients with a variety of health-promoting properties. Phytochemicals improve host health through their direct systematic absorption into the circulation and modulation of the gut microbiota. The gut microbiota increases the bioactivity of phytochemicals and is a symbiotic partner whose composition and/or diversity is altered by phytochemicals and affects host health. In this review, the interactions of phytochemicals with the gut microbiota and their impact on human diseases are reviewed. We describe the role of intestinal microbial metabolites, including short-chain fatty acids, amino acid derivatives, and vitamins, from a therapeutic perspective. Next, phytochemical metabolites produced by the gut microbiota and the therapeutic effect of some selected metabolites are reviewed. Many phytochemicals are degraded by enzymes unique to the gut microbiota and act as signaling molecules in antioxidant, anti-inflammatory, anticancer, and metabolic pathways. Phytochemicals can ameliorate diseases by altering the composition and/or diversity of the gut microbiota, and they increase the abundance of some gut microbiota that produce beneficial substances. We also discuss the importance of investigating the interactions between phytochemicals and gut microbiota in controlled human studies.

Gut microbiota and fecal short chain fatty acids differ with adiposity and country of origin: The METS-Microbiome Study

The relationship between gut microbiota, short chain fatty acid (SCFA) metabolism, and obesity is still not well understood. Here we investigated these associations in a large (n=1904) African origin cohort from Ghana, South Africa, Jamaica, Seychelles, and the US. Fecal microbiota diversity and SCFA concentration were greatest in Ghanaians, and lowest in the US population, representing the lowest and highest end of the epidemiologic transition spectrum, respectively. Obesity was significantly associated with a reduction in SCFA concentration, microbial diversity and SCFA synthesizing bacteria. Country of origin could be accurately predicted from the fecal microbiota (AUC=0.97), while the predictive accuracy for obesity was inversely correlated to the epidemiological transition, being greatest in Ghana (AUC = 0.57). The findings suggest that the microbiota differences between obesity and non-obesity may be larger in low-to-middle-income countries compared to high-income countries. Further investigation is needed to determine the factors driving this association.
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Resveratrol, Epigallocatechin Gallate and Curcumin for Cancer Therapy: Challenges from Their Pro-Apoptotic Properties

Plant-derived bioactive compounds are gaining wide attention for their multiple health-promoting activities and in particular for their anti-cancer properties. Several studies have highlighted how they can prevent cancer initiation and progression, improve the effectiveness of chemotherapy, and, in some cases, limit some of the side effects of chemotherapy agents. In this paper, we provide an update of the literature on the anti-cancer effects of three extensively studied plant-derived compounds, namely resveratrol, epigallocatechin gallate, and curcumin, with a special focus on the anti-cancer molecular mechanisms inducing apoptosis in the major types of cancers globally.

N-acetylcysteine alleviates high fat diet-induced hepatic steatosis and liver injury via regulating intestinal microecology in mice

N-acetylcysteine (NAC), a well-accepted antioxidant, has been shown to protect against high fat diet (HFD)-induced obesity-associated non-alcoholic fatty liver disease (NAFLD) in mice. However, the underlying mechanism(s) of the beneficial...