Improvement of intestinal microflora balance and prevention of digestive and respiratory organ diseases in calves by green tea extracts

Olive Mill Waste-Water Extract Enriched in Hydroxytyrosol and Tyrosol Modulates Host-Pathogen Interaction in IPEC-J2 Cells

The dietary supplementation of olive oil by-products, including olive mill waste-water (OMWW) in animal diets, is a novel application that allows for their re-utilization and recycling and could potentially decrease the use of antibiotics, antimicrobial resistance risk in livestock species, and the occurrence of intestinal diseases. Salmonella serovar typhimurium is one of the most widespread intestinal pathogens in the world, causing enterocolitis in pigs. The aim of this study was to investigate the effect of an OMWW extract enriched in polyphenols (hydroxytyrosol and tyrosol) in the immune response of an intestinal porcine epithelial cell line (IPEC-J2) following S. typhimurium infection. Cells were pre-treated with OMWW-extract polyphenols (OMWW-EP, 0.35 and 1.4 µg) for 24 h and then infected with S. typhimurium for 1 h. We evaluated bacterial invasiveness and assayed IPEC-J2 gene expression with RT-qPCR and cytokine release with an ELISA test. The obtained results showed that OMWW-EP (1.4 µg) significantly reduced S. typhimurium invasiveness; 0.35 µg decreased the IPEC-J2 gene expression of IL1B, MYD88, DEFB1 and DEFB4A, while 1.4 µg down-regulated IL1B and DEFB4A and increased TGFB1. The cytokine content was unchanged in infected cells. This is the first study demonstrating the in vitro immunomodulatory and antimicrobial activity of OMWW extracts enriched in polyphenols, suggesting a protective role of OMWW polyphenols on the pig intestine and their potential application as feed supplements in farm animals such as pigs.

Defense against oxidative stress in Caenorhabditis elegans by dark tea

Dark tea, rich in nutricines including tea polyphenols and free amino acids, is a kind of post-fermented tea. The potential application of nutricines against oxidative damage and senescence, which drives animal health maintenance and disease prevention, has attracted considerable interest. In this study, the effect of dark tea and its effects on longevity and defense against oxidative stress was investigated in the Caenorhabditis elegans (C. elegans) model. Under normal conditions, dark tea extended the lifespan without significant impairment of propagation. It also improved the motility, alleviated the fat accumulation and apoptosis. Additionally, orally administered dark tea could significantly decrease the level of reactive oxygen species (ROS) and resulted in a superior lifespan in H2O2-induced oxidative stressed C. elegans. In antioxidant assays in vitro, dark tea was found to be rich in strong hydroxyl, DPPH and ABTS+ free radical scavenging capacity. Interestingly, mRNA sequence analyses further revealed that dark tea may catalyze intracellular relevant oxidative substrates and synthesize antioxidants through synthetic and metabolic pathways. These results suggest that dark tea is worth further exploration as a potential dietary supplement for the maintenance of animal health and the prevention of related diseases.

Role of dietary tea polyphenols on growth performance and gut health benefits in juvenile hybrid sturgeon (Acipenser baerii ♀ × A. schrenckii ♂)

The present study aimed to evaluate the effects of dietary TPs on growth performance, intestinal digestion, microflora and immunity in juvenile hybrid sturgeon. A total of 450 fish (97.20 ± 0.18 g) were randomly divided into a standard diet (TP-0) or four treatments consisting of a standard diet supplemented with four concentrations of TPs (mg/kg): 100 (TP-100), 300 (TP-300), 500 (TP-500), and 1000 (TP-1000) for 56 days. The TP-300 significantly increased weight gain rate (WGR) and specific growth rate (SGR) (p < 0.05), and TP-1000 significantly increased the feed conversion ratio (FCR) (p < 0.05). TP-300 and TP-500 significantly increased intestinal trypsin, amylase, and lipase activities (p < 0.05). Besides, TP-300 significantly enhanced total antioxidant capacity (T-AOC) and the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) content (p < 0.05). Moreover, TP-300 decreased the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin 8 (IL-8), and interleukin 1β(IL-1β) compared with TP-0 and TP-1000 (p < 0.05). In addition, the intestinal microbiota diversity in the TP-300 group was observably higher, the dominant microbiota was Bacteroidota, Cyanobacteria, Proteobacteria and Firmicutes at the phylum level, Enterobacteriaceae, Nostocaceae and Clostridiaceae at the family level. The relative abundances of potential probiotics including Rhodobacteraceae and potential pathogens especially Clostridiaceae were the highest, and lowest, respectively. In conclusion, TP-300 altered the abundance of microbial taxa, resulting in enhancing the intestinal digestion, antioxidant status and non-specific immunity to improve the growth performance in juvenile hybrid sturgeon.

Roles of Essential Oils, Polyphenols, and Saponins of Medicinal Plants as Natural Additives and Anthelmintics in Ruminant Diets: A Systematic Review

Public awareness on health and safety issues in using antibiotics for livestock production has led many countries to ban the use of all growth-promoting antibiotics (GPA) for livestock feeding. The ban on the utilization of antibiotics in livestock, on the other hand, is an opportunity for researchers and livestock practitioners to develop alternative feed additives that are safe for both livestock and the consumers of animal derived foods. Many feed additives were developed from a number of plants that contain secondary metabolites, such as essential oils, polyphenols, and saponins. These secondary metabolites are extracted from various parts of many types of plants for their uses as feed additives and anthelmintics. Recent investigations on using essential oils, polyphenols, and saponins as dietary additives and anthelmintics demonstrate that they can increase not only the production and health of ruminants but also ensure the safety of the resulting foods. There are many publications on the advantageous impacts of dietary plant bioactive components on ruminants; however, a comprehensive review on individual bioactive constituents of each plant secondary metabolites along with their beneficial effects as feed additives and anthelmintics on ruminants is highly required. This current study reviewed the individual bioactive components of different plant secondary metabolites and their functions as additives and anthelmintics to improve ruminant production and health, with respect to safety, affordability and efficiency, using a systematic review procedure.

The Impact of Plant Phytochemicals on the Gut Microbiota of Humans for a Balanced Life

The gastrointestinal tract of humans is a complex microbial ecosystem known as gut microbiota. The microbiota is involved in several critical physiological processes such as digestion, absorption, and related physiological functions and plays a crucial role in determining the host’s health. The habitual consumption of specific dietary components can impact beyond their nutritional benefits, altering gut microbiota diversity and function and could manipulate health. Phytochemicals are non-nutrient biologically active plant components that can modify the composition of gut microflora through selective stimulation of proliferation or inhibition of certain microbial communities in the intestine. Plants secrete these components, and they accumulate in the cell wall and cell sap compartments (body) for their development and survival. These compounds have low bioavailability and long time-retention in the intestine due to their poor absorption, resulting in beneficial impacts on gut microbiota population. Feeding diets containing phytochemicals to humans and animals may offer a path to improve the gut microbiome resulting in improved performance and/or health and wellbeing. This review discusses the effects of phytochemicals on the modulation of the gut microbiota environment and the resultant benefits to humans; however, the effect of phytochemicals on the gut microbiota of animals is also covered, in brief.

Therapeutic effectiveness of green tea leaf extract on clinical symptoms in children suffering viral gastroenteritis: A randomized clinical trial

The use of tea plant extract has been reported to reduce viral complications, but its role in improving viral gastritis has not been investigated. The aim of this randomized clinical trial was to evaluate the effect of green tea consumption in improving pediatric viral gastroenteritis. This clinical trial study was performed on children aged 12 to 17 years with diarrhea who were not treated within 48 hours of the onset of clinical symptoms during September 2019 to September 2020. The children were randomly assigned to a green tea leaf extract (GTE) tablet. The placebo group was considered as a control. Treatment (prescribing the tablets) was continued until a Bristol Stool Scale of 3 or 4 was obtained. Two groups were compared in terms of clinical symptoms. The complete and partial improvement was revealed in 63.2% and 31.6% respectively in the GTE group while only in 15.8% and 57.9% respectively in control group indicating a significant difference (p <0.001). The increase in the number of tablets led to higher improvement rate in response to GTE prescription. The mean hospital stay in GTE and control groups was also 1.66 ± 0.63 days and 3.36 ± 0.4 days indicated shorter hospitalization in former group (p < 0.001). The use of GTE leads to effectively improve the diarrhea as well as to reduce the hospital stay in children suffering viral gastroenteritis.

Effect of Green Tea on Weight Gain and Semen Quality of Rabbit Males

The goal of the current study was to evaluate the action of the green tea plant (Camellia sinensis, L) on male rabbit reproduction and some non-reproductive indexes. Male rabbits were fed either a standard diet (control group) or a diet enriched with green tea powder (experimental groups; E): 5 g (E1) or 20 g (E2) per 100 kg of the milled complete feed mixture. Weight gain, sperm concentration, total and progressive motility, as well as haematological, and biochemical parameters and changes in testicular tissue histomorphology were evaluated. Feeding with green tea, at both tested concentrations, decreased weight gain per week and the total average weight gain compared to the control group (p < 0.05). Furthermore, green tea decreased sperm concentration, motility and progressive motility in the group fed with a lower dose (5 g) of green tea powder (p < 0.05), whilst a higher dose (20 g) was neutral. Some haematological and biochemical indexes, like medium-size cell count (MID), mean corpuscular haemoglobin concentration (MCHC), platelet percentage (PCT), levels of phosphorus (P) and total proteins (TP) were decreased in one or both experimental groups (p < 0.05), whilst the triglyceride level (TG) was increased in the E2 group (p < 0.05). The thicknesses of the testicular seminiferous tubules and epithelial layer were not affected by any concentration of green tea powder (p > 0.05). These observations suggest that green tea in the diet may have an adverse effect on rabbit growth and sperm quality, but their effect may be potentially dose-dependent.

Potential Application of Tea Polyphenols to the Prevention of COVID-19 Infection: Based on the Gut-Lung Axis

Coronavirus disease 2019 (COVID-19) disrupts the intestinal micro-ecological balance, and patients often develop the intestinal disease. The gut is the largest immune organ in the human body; intestinal microbes can affect the immune function of the lungs through the gut-lung axis. It has been reported that tea polyphenols (TPs) have antiviral and prebiotic activity. In this review, we discussed TPs reduced lung-related diseases through gut-lung axis by inhibiting dysbiosis. In addition, we also highlighted the preventive and therapeutic effects of TPs on COVID-19 complications, further demonstrating the importance of research on TPs for the prevention and treatment of COVID-19 in humans. Based on this understanding, we recommend using TPs to regulate the gut microbiota to prevent or alleviate COVID-19 through the gut-lung axis.

Recent development in fabrication and evaluation of phenolic-dietary fiber composites for potential treatment of colonic diseases

Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GIT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. In addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.

Effects of compound probiotics on growth performance, rumen fermentation, blood parameters, and health status of neonatal Holstein calves

This study aimed to investigate the effects of compound probiotics (consisting of 10⁸ cfu/g of Lactobacillus plantarum, 10⁸ cfu/g of Pediococcus acidilactici, 10⁸ cfu/g of Pediococcus pentosaceus, 10⁷ cfu/g of and Bacillus subtilis) on growth performance, rumen fermentation, bacteria community, blood parameters, and health status of Holstein calves at the first 3 mo of age. Forty-eight newborn calves were randomly divided into the following 3 groups: control group (milk replacer with no compound probiotics), low compound probiotics group (milk replacer + 0.12 g of compound probiotics per head per day), and high compound probiotics group (HP; milk replacer + 1.2 g of compound probiotics per head per day). Starter pellets of the low compound probiotics and HP groups were coated with 0.05% compound probiotics. Milk replacer was provided from 2 to 63 d of age (6 L at 2-10 d, 8 L at 11-42 d, 6 L at 43-49 d, 4 L at 50-56 d, and 2 L at 57-63 d), and starter pellets were provided ad libitum from 7 to 90 d of age. Body weight and body size (d 1, 30, 60, and 90), blood (d 40 and 80), and rumen fluid (d 90) were analyzed using the one-way ANOVA procedure; fecal score was recorded daily and analyzed as repeated measures using the mixed model procedure. Results showed that diet supplemented with compound probiotics had no effects on the body weight, average daily gain, dry matter intake, and feed efficiency. At 90 d of age, diet supplemented with compound probiotics decreased the withers height. Immunity activities increased in the HP group, supported by the increased concentrations of serum total protein and immunoglobulins at 40 d of age, and by the increased activity of superoxide dismutase at 80 d of age. Diet supplemented with compound probiotics altered rumen fermentation, indicated by the decreased rumen acetic acid and propionic acid, and the increased butyric acid concentrations. Diet supplemented with compound probiotics improved the health status of calves, indicated by the decreased fecal score at 3 wk of age and the decreased medicine treatments. In summary, although diet supplemented with HP decreased the withers height, this level of probiotics is recommended to improve rumen development and health status of newborn Holstein calves.

The Role of Polyphenols in Regulation of Heat Shock Proteins and Gut Microbiota in Weaning Stress

Gut microbiota is the natural residents of the intestinal ecosystem which display multiple functions that provide beneficial effects on host physiology. Disturbances in gut microbiota in weaning stress are regulated by the immune system and oxidative stress-related protein pathways. Weaning stress also alters gut microbiota response, limits digestibility, and influences animal productive performance through the production of inflammatory molecules. Heat shock proteins are the molecular chaperones that perform array functions from physiological to pathological point of view and remodeling cellular stress response. As it is involved in the defense mechanism, polyphenols ensure cellular tolerance against enormous stimuli. Polyphenols are nature-blessed compounds that show their existence in plenty of amounts. Due to their wider availability and popularity, they can exert strong immunomodulatory, antioxidative, and anti-inflammatory activities. Their promising health-promoting effects have been demonstrated in different cellular and animal studies. Dietary interventions with polyphenols may alter the gut microbiome response and attenuate the weaning stress related to inflammation. Further, polyphenols elicit health-favored effects through ameliorating inflammatory processes to improve digestibility and thereby exert a protective effect on animal production. Here, in this article, we will expand the role of dietary polyphenol intervention strategies in weaning stress which perturbs gut microbiota function and also paid emphasis to heat shock proteins in gut health. This review article gives new direction to the feed industry to formulate diet containing polyphenols which would have a significant impact on animal health.

Green tea dietary supplementation in broiler chickens: Effect on the development of chicken intestine

This experiment explored the dietary effects of green tea (Camellia sinensis) in feed supplementation on the development of broiler chicks. Totally, two hundred and seventy-day-old male broiler chicks were assigned to 27 broiler groups each with 10 individuals (initial mean body weight 44.2 ± 1.3 g) in a 4 × 2 factorial arrangement. Each chicken group was supplemented with the feed additives of green tea powder. The trial data were measured and obtained based on the records of carcass traits and intestine characteristics of broiler chicken fed with four different additive levels of green tea (0.25%, 0.50%, 0.75%, and 1.00%). The experiment lasted for two trial periods of 21 days and 42 days for each treatment of the green tea supplement with full records of broiler traits. There were interesting results recorded in the majority of broiler intestinal traits between the two trial periods. There are a few significant differences (p < .05) observed among multiple comparisons of some intestinal traits in broiler chicks such as colon diameter (p = .022) and jejunum width (p = .01). The most significant differences exist in these intestinal traits of chicken right and left cecum among broiler chicks fed with dietary green tea powder (p < .05). The other intestinal characteristics of broiler chicks were recorded from single treatment are insignificantly distinguished compared with the control groups. There are also some near significant differences of chicken intestinal carcass traits and characteristics. These results and experimental data of this study extend the current knowledge on the dietary effects of green tea in chicken raising and feeding with dietary supplementation.

Nutritional combinatorial impact on the gut microbiota and plasma short-chain fatty acids levels in the prevention of mammary cancer in Her2/neu estrogen receptor-negative transgenic mice

Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention.

Gut/Oral Bacteria Variability May Explain the High Efficacy of Green Tea in Rodent Tumor Inhibition and Its Absence in Humans

Consumption of green tea (GT) and GT polyphenols has prevented a range of cancers in rodents but has had mixed results in humans. Human subjects who drank GT for weeks showed changes in oral microbiome. However, GT-induced changes in RNA in oral epithelium were subject-specific, suggesting GT-induced changes of the oral epithelium occurred but differed across individuals. In contrast, studies in rodents consuming GT polyphenols revealed obvious changes in epithelial gene expression. GT polyphenols are poorly absorbed by digestive tract epithelium. Their metabolism by gut/oral microbial enzymes occurs and can alter absorption and function of these molecules and thus their bioactivity. This might explain the overall lack of consistency in oral epithelium RNA expression changes seen in human subjects who consumed GT. Each human has different gut/oral microbiomes, so they may have different levels of polyphenol-metabolizing bacteria. We speculate the similar gut/oral microbiomes in, for example, mice housed together are responsible for the minimal variance observed in tissue GT responses within a study. The consistency of the tissue response to GT within a rodent study eases the selection of a dose level that affects tumor rates. This leads to the theory that determination of optimal GT doses in a human requires knowledge about the gut/oral microbiome in that human.

16S ribosomal RNA sequencing reveals a modulation of intestinal microbiome and immune response by dietary L-theanine supplementation in broiler chickens

Despite the availability of abundant literature on green tea, studies on the use of L-theanine (an amino acid found only in green tea) as a feed additive in poultry especially broiler are limited. So, this study was conducted to explore the effects of L-theanine on the intestinal microbiome and immune response in a broiler. A total of 400-d-old chicks were randomly divided into four treatment groups (A, B, C, and D) using a complete randomized design. Treatments were as follows: A, control (basal diet); B, basal diet + 100 mg L-theanine/kg diet; C, basal diet + 200 mg L-theanine/kg diet; and D, basal diet + 300 mg L-theanine/kg diet. Mucosal samples from ileum and jejunum of broiler chicken were extracted at 21 and 42 d of age. Extraction of genomic DNA was followed by amplification of V3 and V4 hypervariable regions of 16S ribosomal RNA. After Illumina sequencing, results revealed that treatment with L-theanine significantly increased the population of Lactobacillus in ileum and jejunum as compared to a control group, but the higher population was observed in jejunum at both 21 and 42 d of age. The overall diversity of the jejunum microbiome in the treatment group was significantly lower than that of the ileum and control group (P < 0.05). Results of this study revealed that mRNA expression of TLRs (TLR-2 and TLR-4) and cytokines (TNF-α, IFN-γ, and IL-2) was decreased in response to treatment with L-theanine. Moreover, the negative correlation of abundance of Lactobacillus was observed with expression of IL-2 and IFN-γ in the intestine and these effects were highly significant (P < 0.01). In summary, our finding revealed that dietary supplementation of L-theanine exhibited a positive influence on intestinal bacteria by supporting beneficial microbes like Lactobacillus while decreasing harmful microbes like Clostridium.

Green tea can supress rabbit ovarian functions in vitro and in vivo

The aim of present study was to evaluate the action of green tea and its constituents on rabbit ovarian functions and some non-reproductive indexes. In in vitro experiments, rabbit ovarian fragments were cultured with green tea constituents - epigallocatechin-3-gallate (EGCG), green tea polyphenols (GTPP) and resveratrol (RSV) (at 0, 1, 10 or 100 μg/mL medium). The accumulation of an apoptosis marker - caspase 3 and the release of progesterone (P4) and testosterone (T) were measured. In in vivo experiments, does were fed a standard diet or a diet enriched with green tea powder. The weight gain, mortality, ovarian length and weight, conception and kindling rate, number of liveborn, stillborn, and weaned pups, diameter of ovarian follicles and some blood haematological and biochemical parameters were analysed. Culture of ovarian fragments with EGCG increased accumulation of caspase 3, whilst both GTTP and RSV decreased it. EGCG inhibited both P4 and T output, GTPP stimulated P4 and inhibited T, whilst RSV promoted release of both P4 and T. Feeding with green tea increased ovarian length and diameter of ovarian non-ovulated peri-ovulatory haemorrhagic but not of primary and secondary growing follicles. Furthermore, green tea reduced conception and kindling rate, the number of liveborn and weaned pups, increased female mortality but not their weight gain. It reduced platelet distribution width, but it did not affect other haematological and biochemical indexes. These observations suggest that dietary green tea can reduce rabbit doe's viability, ovarian functions and fecundity, perhaps due to changes in ovarian cell apoptosis, steroid hormones release and blockade of the ovulation of large ovarian follicles. The anti-reproductive action of green tea could be due to its constituent - EGCG with pro-apoptotic and anti-steroid hormone properties.

Agrimonia procera exerts antimicrobial effects, modulates the expression of defensins and cytokines in colonocytes and increases the immune response in lipopolysaccharide-challenged piglets

Background

Because antibiotic use in livestock is assumed to contribute to the emerging public health crisis of antibiotic resistance, alternatives are required. Phytogenic additives are extensively studied due to their antibiotic properties. Components of Agrimonia species have been reported as candidate antimicrobials that possess antioxidative and anti-inflammatory properties. We studied the impact of Agrimonia procera (AP) on the growth of selected strains of gut bacteria, the effect of AP on the mRNA abundance of genes involved in inflammation and bacterial defense in a colon carcinoma cell line, the effect of AP in piglets challenged with lipopolysaccharides, and the effect of AP on the growth performance of healthy piglets.

Results

The in vitro growth rate of different bacteria strains was negatively affected by AP, especially in Pediococcus pentosaceus and all tested E. coli strains. Stimulation of Caco-2 cells with TNFα resulted in elevated mRNA expression of CXCL1, IL-8 and GPX2. After pretreatment of cells with AP, stimulation of Caco-2 cells with TNFα still resulted in elevated mRNA expression of CXCL1 and IL-8 at all measured points in time. However, mRNA expression in AP-pretreated cells was lower after 6 h and 24 h. In addition, expression of DEFB1 and GPX2 was significantly elevated after TNFα stimulation. In vivo, application of lipopolysaccharides induced significantly increased animal body temperatures. Piglets pretreated with AP prior to lipopolysaccharide application showed a faster and larger increase in body temperature than controls. In addition, piglets pretreated with AP appeared to release more TNFα than controls. In healthy piglets, AP treatment had no impact on growth performance parameters. Fecal dry matter and total plasma antioxidant capacity tended to be higher in piglets treated with AP than in control piglets (P = 0.055 and P = 0.087, respectively).

Conclusions

AP has antimicrobial effects in vitro and stimulated the expression of proinflammatory cytokines in Caco-2 cells. The additive had no effect on growth in healthy piglets but increased the immune response in LPS-treated animals. In addition, AP appeared to have antioxidative effects in vivo. Therefore, AP merits testing as a future alternative to antibiotics in animal husbandry.

Green and Black Tea Phenolics: Bioavailability, Transformation by Colonic Microbiota, and Modulation of Colonic Microbiota

Monomeric green tea catechin (GTC) and oligomeric, oxidized black tea phenolic (BTP) have shown promising health benefits, although GTC has been more extensively studied than BTP. We review the current knowledge on bioavailability, colonic transformation, and gut microbiota modulatory effects of GTC and BTP. As a result of their similar poor bioavailability in the small intestine and potentially similar metabolites upon colonic fermentation, it seems as if GTC and BTP have similar health effects, although it cannot be excluded that they have different gut microbiota modulatory effects and that BTP gives a poorer yield of bioactive phenolic metabolites upon colonic fermentation than GTC.

Effects of green tea on miRNA and microbiome of oral epithelium

Consumption of green tea (GT) extracts or purified catechins has shown the ability to prevent oral and other cancers and inhibit cancer progression in rodent models, but the evidence for this in humans is mixed. Working with humans, we sought to understand the source of variable responses to GT by examining its effects on oral epithelium. Lingual epithelial RNA and lingual and gingival microbiota were measured before and after 4 weeks of exposure in tobacco smokers, whom are at high risk of oral cancer. GT consumption had on average inconsistent effects on miRNA expression in the oral epithelium. Only analysis that examined paired miRNAs, showing changed and coordinated expression with GT exposure, provided evidence for a GT effect on miRNAs, identifying miRNAs co-expressed with two hubs, miR-181a-5p and 301a-3p. An examination of the microbiome on cancer prone lingual mucosa, in contrast, showed clear shifts in the relative abundance of Streptococcus and Staphylococcus, and other genera after GT exposure. These data support the idea that tea consumption can consistently change oral bacteria in humans, which may affect carcinogenesis, but argue that GT effects on oral epithelial miRNA expression in humans vary between individuals.

Effect of supplementing milk replacer with aromatic oregano (Oreganum onites L.) water on performance, immunity and general health profiles of Holstein calves

The purpose of this study was to examine the effects of supplementing milk replacer (MR) with aromatic oregano (Origanum onite L.) water on weaning age, performance during the pre- and post-weaning periods, immune systems, blood parameters and general health of 40 Holstein Friesian calves. The calves fed with oregano water (OW)-supplemented MR were weaned earlier than those in the Control group. There were no statistical differences in the liveweight and body measurements among the groups at the weaning age and post-weaning period. The feed intake of the calves fed with OW was higher than that of calves in the Control group in the pre-weaning period. The OW supplementation significantly increased the faecal firmness of calves (P < 0.05). It also decreased the number of E. coli, Coliforms and Enterobacteriaceae pathogens, but only the amount of Enterobacteriaceae was significantly decreased (P < 0.05). Non-pathogens, such as Lactic acid bacteria, were not affected by OW supplementation. The OW supplementation had no significant effect on hematologic and biochemical blood values. There was significant interaction between age and groups in gamma-glutamyl transpeptidase (P < 0.05). The immunoglobulins (IgA, IgG and IgM) values of calves were steadily higher than those of the calves in the Control group. The general health profiles of the calves improved. It can be concluded that MR containing 1–2% OW fed to calves in the early weaning period is a promising treatment to improve their wellbeing and shorten the weaning period.

Effect of amount and duration of waste green tea powder on the growth performance, carcass characteristics, blood parameters, and lipid metabolites of growing broilers

This study has evaluated the possible effect of waste powder of green tea (Camellia sinensis) in feed supplementation on the growth performance, carcass characteristics, blood parameters, and lipid metabolites of growing broilers (chicks) in both the amount and duration aspects of dietary additives during the finisher phases. In the experiment, growth performance, carcass characteristics, blood parameters, and lipid metabolites of broiler chicks have been fully recorded and explored. The diet of 271 day-old Ross 308 male broiler chicks has been supplemented with 0, 0.25, 0.50, 0.75, and 1.00% (w/w) green tea powder in addition to normal feeding additives. The experiment lasted for 21 and 42 days, respectively, for each value of the green tea supplement and for separate groups of animals. Broiler feed has been supplemented with different levels of green tea powder to assess the trial effect and potential beneficial dose on selected growth performance, carcass characteristics, and blood parameters of broiler chicks. Although there are almost no differences of broiler parameters and characteristics measured from one point of view of single treatment factor (amount or duration), against the control groups during the three trial periods, the overall effect of amount and duration of feeding green tea powder is positive on growth performance, carcass characteristics, blood parameters, and lipid metabolites of growing broilers, although there are nearly no differences in some broiler parameters and characteristics. However, there are a remarkable interactive effect of amount and duration of different feeding levels of green tea powder and obvious differences observed in all the parameters and characteristics of growing broilers. Especially, usage of feeding green tea powder largely decreased the abdominal fat content and some lipid metabolites, including VLDL cholesterol, LDL cholesterol, triglycerides, and AST of broiler chicks. While additional data are still needed to evaluate and analyze the optimum supplement feed doses, it can be concluded that dietary green tea is a positive feed supplementation to reduce abdominal fat and lipid metabolites and induce antioxidants.

Antimicrobial activity of tea catechin against canine oral bacteria and the functional mechanisms

Epigallocatechin gallate (EGCG) is the major polyphenolic compound of green tea. Polyphenolic compounds were extracted from the leaf of Camellia sinensis (Japanese green tea), and the minimum inhibitory concentration against canine oral bacteria was measured. Subsequently, we investigated the inhibitory effects of polyphenolic compounds and EGCG on the growth of canine oral bacteria. EGCG showed antimicrobial activity against a model bacterium, Streptococcus mutans. Our results indicate that EGCG can inhibit the growth and biofilm formation of S. mutans and that EGCG does not interact with streptococcal lipoteichoic acid (LTA). Furthermore, our findings suggest that EGCG interacts with other component(s) of the bacterial membrane aside from streptococcal LTA to inhibit biofilm formation and damage biofilms.

In vitro extraction and fermentation of polyphenols from grape seeds (Vitis vinifera) by human intestinal microbiota

The effects of several parameters on the extraction yield of total polyphenols from grape seeds by pressurized liquid extraction were investigated.

Short communication: Effects of oral flavonoid supplementation on the metabolic and antioxidative status of newborn dairy calves

Scientific proof for flavonoids as a health tool in calf nutrition is inconsistent. We investigated the effects of the most abundant flavonoid, quercetin, and of a green tea extract (GTE) containing various catechins on the metabolic and antioxidative traits in dairy calves to clarify their potential health-promoting effects. Male newborn German Holstein calves (n=7 per group) received either no flavonoid (control group), 10mg of quercetin equivalents as quercetin aglycone or as rutin/kg of body weight (BW) per day, or 10mg/kg of BW per day of a GTE from d 2 to 26 of life. The supplements were provided with the morning and evening feeding. The calves were fed colostrum and milk replacer, and BW, feed intake, and health status were evaluated daily. Blood samples were collected from a jugular vein on d 1, 5, 12, 19, and 26 before the morning feeding to investigate the metabolic and antioxidative status of the calves. The growth performance and health status remained unchanged, but the GTE-fed calves had fewer loose feces than the controls. The plasma concentrations of quercetin changed over time and were higher in the rutin-fed group than in the control group, whereas the catechins were below the detection limit. The plasma Trolox equivalent antioxidative capacity and ferric reducing ability of plasma were measured as markers for plasma antioxidative capacity. The concentrations of Trolox equivalent antioxidative capacity increased, whereas ferric reducing ability of plasma decreased after the first day of life in all the groups. The oxidative stress markers in the plasma were measured as thiobarbituric acid reactive substances and F2-isoprostanes, but these did not indicate treatment or time effects. The plasma concentrations of total protein, albumin, urea, lactate, glucose, and nonesterified fatty acids and of insulin and cortisol varied over time, but no group differences were caused by the flavonoid supplementation. In summary, orally administered quercetin and catechins at the dosages used in the present study resulted in weak effects on health and no effects on the metabolic and antioxidative status of newborn dairy calves.

The Effects of Oral Quercetin Supplementation on Splanchnic Glucose Metabolism in 1-Week-Old Calves Depend on Diet after Birth

BACKGROUND

Inadequate colostrum supply results in insufficient intake of macronutrients and bioactive factors, thereby impairing gastrointestinal development and the maturation of glucose metabolism in neonatal calves. The flavonoid quercetin has been shown to have health-promoting properties, including effects in diabetic animals. However, quercetin interacts with intestinal glucose absorption and might therefore exert negative effects in neonates.

OBJECTIVE

We evaluated the interaction between neonatal diet and quercetin feeding on splanchnic glucose metabolism in neonatal calves.

METHODS

Calves (n = 28) were assigned to 4 groups and fed either colostrum or a milk-based formula on days 1 and 2 and supplemented daily with 148 μmol quercetin aglycone/kg body weight [colostrum with quercetin (CQ+)/formula with quercetin (FQ+)] or without this substance [colostrum without quercetin (CQ-)/formula with quercetin (FQ-)] from days 2-8. From day 3 onward, all calves received milk replacer. A xylose absorption test was performed on day 3, and on day 7, blood samples were collected to study glucose first-pass uptake after [(13)C6]-glucose feeding and intravenous [6,6-(2)H2]-glucose bolus injection. Plasma concentrations of metabolites and hormones were measured by taking additional blood samples. A biopsy specimen of the liver was harvested on day 8 to measure the mRNA expression of gluconeogenic enzymes.

RESULTS

Higher postprandial plasma concentrations of glucose, lactate, urea, adrenaline, noradrenaline, insulin, and glucagon on day 7 in colostrum-fed calves indicate that metabolic processes were stimulated. Postabsorptive xylose and glucose plasma concentrations each increased by an additional 26%, and splanchnic glucose turnover decreased by 35% in colostrum-fed calves, suggesting improved glucose absorption and lower splanchnic glucose utilization in colostrum-fed calves. Quercetin supplementation resulted in higher noradrenaline concentrations and enhanced peak absorption and oxidation of [(13)C6]-glucose by 10%. Liver mitochondrial phosphoenolpyruvate carboxykinase mRNA abundance was reduced by 34% in colostrum-deprived calves.

CONCLUSIONS

Feeding colostrum during the first 2 d of life is crucial for maturation of splanchnic glucose metabolism in calves. Supplementing quercetin improves gastrointestinal absorption capacity, particularly in colostrum-deprived calves.

A survey of modulation of gut microbiota by dietary polyphenols

Dietary polyphenols present in a broad range of plant foods have been related to beneficial health effects. This review aims to update the current information about the modulation of the gut microbiota by dietary phenolic compounds, from a perspective based on the experimental approaches used. After referring to general aspects of gut microbiota and dietary polyphenols, studies related to this topic are presented according to their experimental design: batch culture fermentations, gastrointestinal simulators, animal model studies, and human intervention studies. In general, studies evidence that dietary polyphenols may contribute to the maintenance of intestinal health by preserving the gut microbial balance through the stimulation of the growth of beneficial bacteria (i.e., lactobacilli and bifidobacteria) and the inhibition of pathogenic bacteria, exerting prebiotic-like effects. Combination of in vitro and in vivo models could help to understand the underlying mechanisms in the polyphenols-microbiota-host triangle and elucidate the implications of polyphenols on human health. From a technological point of view, supplementation with rich-polyphenolic stuffs (phenolic extracts, phenolic-enriched fractions, etc.) could be an effective option to improve health benefits of functional foods such as the case of dairy fermented foods.

Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH₃-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH₃-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH₃-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

Immune-stimulatory effects of a bacteria-based probiotic on peripheral leukocyte subpopulations and cytokine mRNA expression levels in scouring holstein calves

Subpopulations of peripheral leukocytes and cytokine mRNA expression levels were evaluated in scouring and healthy Holstein calves (age 10 ± 5 days; n=42) treated with a probiotic consisting of Lactobacillus plantarum, Enterococcus faecium and Clostridium butyricum. The calves were assigned to the scouring or healthy group and then subdivided into pathogen-positive treated (n=8), pathogen-positive control (n=8), pathogen-negative treated (n=6), pathogen-negative control (n=6), healthy treated (n=6) and healthy control (n=8) groups. A single dose of the probiotic (3.0 g/100 kg body weight) was given to each calf in the treatment groups for 5 days. Blood samples were collected on the first day of scour occurrence (day 0) and on day 7. In the scouring calves, smaller peripheral leukocyte subpopulations and cytokine mRNA expression levels were noted on day 0. The numbers of CD3⁺ T cells; CD4⁺, CD8⁺ and WC1⁺ γδ T cell subsets; and CD14⁺, CD21⁺ and CD282⁺ (TLR2) cells were significantly increased in the scouring and healthy treated calves on day 7. Furthermore, interleukin-6, tumor necrosis factor-alpha and interferon-gamma mRNA expression was elevated in the peripheral leukocytes of the scouring and healthy treated calves on day 7. The scouring calves given the probiotic recovered on day 7. A significantly smaller number of peripheral leukocytes and lower cytokine mRNA expression level might be induced by scouring in calves. Repeated probiotic administration might stimulate cellular immunity and encourage recovery from scouring in pre-weaning Holstein calves.

Use of pigs as a potential model for research into dietary modulation of the human gut microbiota

The human intestinal microbial ecosystem plays an important role in maintaining health. A multitude of diseases including diarrhoea, gastrointestinal inflammatory disorders, such as necrotising enterocolitis (NEC) of neonates, and obesity are linked to microbial composition and metabolic activity. Therefore, research on possible dietary strategies influencing microbial composition and activity, both preventive and curative, is being accomplished. Interest has focused on pre- and probiotics that stimulate the intestinal production of beneficial bacterial metabolites such as butyrate, and beneficially affect microbial composition. The suitability of an animal model to study dietary linked diseases is of much concern. The physiological similarity between humans and pigs in terms of digestive and associated metabolic processes places the pig in a superior position over other non-primate models. Furthermore, the pig is a human-sized omnivorous animal with comparable nutritional requirements, and shows similarities to the human intestinal microbial ecosystem. Also, the pig has been used as a model to assess microbiota–health interactions, since pigs exhibit similar syndromes to humans, such as NEC and partly weanling diarrhoea. In contrast, when using rodent models to study diet–microbiota–health interactions, differences between rodents and humans have to be considered. For example, studies with mice and human subjects assessing possible relationships between the composition and metabolic activity of the gut microbiota and the development of obesity have shown inconsistencies in results between studies. The present review displays the similarities and differences in intestinal microbial ecology between humans and pigs, scrutinising the pig as a potential animal model, with regard to possible health effects.

Impact of polyphenols and polyphenol-rich dietary sources on gut microbiota composition

Gut microbiota plays a key role in host physiology and metabolism. Indeed, the relevance of a well-balanced gut microbiota composition to an individual's health status is essential for the person's well-being. Currently, investigations are focused on analyzing the effects of pre- and probiotics as new therapeutic tools to counteract the disruption of intestinal bacterial balance occurring in several diseases. Polyphenols exert a wide range of beneficial health effects. However, although specific attention has been paid in recent years to the function of this "biological entity" in the metabolism of polyphenols, less is known about the modulatory capacity of these bioactive compounds on gut microbiota composition. This review provides an overview of the latest investigations carried out with pure polyphenols, extracts rich in polyphenols, and polyphenol-rich dietary sources (such as cocoa, tea, wine, soy products, and fruits) and critically discusses the consequences to gut microbiota composition which are produced.

Chemical composition, plant secondary metabolites, and minerals of green and black teas and the effect of different tea-to-water ratios during their extraction on the composition of their spent leaves as potential additives for ruminants

This study characterized the chemical composition of green and black teas as well as their spent tea leaves (STL) following boiling in water with different tea-to-water ratios. The green and black tea leaves had statistically similar (g/kg dry matter (DM), unless stated otherwise) DM (937 vs 942 g/kg sample), crude protein (240 vs 242), and ash (61.8 vs 61.4), but green tea had significantly higher (g/kg DM) total phenols (231 vs 151), total tannins (204 vs 133), condensed tannins (176 vs 101), and total saponins (276 vs 86.1) and lower neutral detergent fiber (254 vs 323) and acid detergent fiber (211 vs 309) than the black tea leaves. There was no significant difference between the green and black tea leaves for most mineral components except Mn, which was significantly higher in green tea leaves, and Na and Cu, which were significantly higher in black tea leaves. A higher tea-to-water ratio during extraction significantly reduced the loss of soluble compounds into water and hence yielded more nutrient-rich STL. On the basis of these analyses it appears that the green and black tea leaves alongside their STL have the potential for use as sources of protein, fiber, secondary metabolites, and minerals in ruminant diets. The presence of high levels of plant secondary metabolites in either tea leaves or their STL suggests that they may have potential for use as natural additives in ruminant diets.

Effects of green tea consumption on human fecal microbiota with special reference to Bifidobacterium species

Green tea is one of the most popular beverages in the world. Its beneficial health effects and components have been extensively reviewed. However, little is known about the influence of green tea consumption on the human intestinal microbiota (HIM), which plays a crucial role in human health. Ten volunteers who did not usually consume green tea, drank it for 10 days and then stopped drinking it for 7 days. Their fecal samples were collected at three time points: before beginning the 10-day green-tea regime, at the conclusion of that 10 days, and 7 days after stopping the regime. Their fecal samples were analyzed by terminal restriction fragment length polymorphism with specific primer-restriction enzyme systems for HIM and by using a real-time PCR method for the Bifidobacterium species. Although the HIM of each subject was relatively stable, the proportion of Bifidobacterium species played an important role in the classification of their fecal microbiota. Although there were inter-individual differences in the Bifidobacterium species, an overall tendency for the proportion of bifidobacteria to increase because of green tea consumption was noted. However, little change was observed in the composition of Bifidobacterium species in each sample. This suggests that the change in proportion was induced, not by an inter-species transition, but by an intra-species increase and/or decrease. In conclusion, green tea consumption might act as a prebiotic and improve the colon environment by increasing the proportion of the Bifidobacterium species.

Updated knowledge about polyphenols: functions, bioavailability, metabolism, and health

Polyphenols are important constituents of food products of plant origin. Fruits, vegetables, and beverages are the main sources of phenolic compounds in the human diet. These compounds are directly related to sensory characteristics of foods such as flavor, astringency and color. Polyphenols are extensively metabolized both in tissues and by the colonic microbiota. Normally, the circulating polyphenols are glucuronidated and/or sulphated and no free aglycones are found in plasma. The presence of phenolic compounds in the diet is beneficial to health due to their antioxidant, anti-inflammatory, and vasodilating properties. The health effects of polyphenols depend on the amount consumed and their bioavailability. Moreover, polyphenols are able to kill or inhibit the growth of microorganisms such as bacteria, fungi, or protozoans. Some dietary polyphenols may have significant effects on the colonic flora providing a type of prebiotic effect. The anti-nutrient properties of polyphenols are also discussed in this paper. The antioxidant, anti-inflammatory, vasodilating, and prebiotic properties of polyphenols make them potential functional foods.