Regulation of Enteric Infection and Immunity by Dietary Proanthocyanidins

Proteome evaluation of the biological activity of grape seed extract (GSE) on the intestine of rats

Grape seed extract (GSE) is rich in polyphenols and has garnered attention for its potential health benefits, particularly in the gastrointestinal system. This study explores the principal effects of consuming a low dose of GSE on the intestinal proteome. Using a rat model, we examined the ileum proteomes of rats supplemented with GSE compared with a control group without supplementation. Particularly, this study was conducted using the label-free sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) quantitative proteomics to describe ileum proteome changes derived from GSE flavanols consumption, characterizing its possible mechanisms of action. Our results highlight the substantial impact of GSE on the ileum proteome, suggesting potential mechanisms through which GSE exerts its effects. The observed protein regulation patterns indicate significant alterations in metabolic and immune regulatory pathways, highlighting the importance of considering individual variability and physiological context when evaluating the potential effects of GSE on gastrointestinal function.

The biological functions of proanthocyanidin and its application in pig production

Proanthocyanidins (PACs) are natural polyphenolic compounds widely distributed in various plants, which are mixtures of oligomers and polymers formed by the polymerization of different numbers of catechins and epicatechins. PACs exhibit a range of biological activities, including antioxidant, anti-inflammatory, anti-cancer, anti-atherosclerotic, hypoglycemic, and antihypertensive effects, as well as the ability to regulate intestinal flora and promote fat metabolism. These properties render PACs highly promising for applications in the food, pharmaceutical, and cosmetic industries, garnering substantial interest from researchers globally. Additionally, PACs demonstrate significant nutritional benefits in animal husbandry. Dietary PACs can enhance animal growth, mitigate oxidative stress, decrease feeding expenses, and offer an environmentally friendly, antibiotic-free alternative. Therefore, PACs have great application potential in the field of pig production. This article reviews the basic properties, biological functions, and research status and application in pig production of PACs, aiming to provide theoretical guidance for the development of substitute antibiotic feed additives.

Climate change effects on the human gut microbiome: complex mechanisms and global inequities

Ongoing global climate change is affecting all aspects of life on Earth, including human health. The gut microbiota is an important determinant of health in humans and other organisms, but how climate change affects gut microbiota remains largely unexplored. In this Review, I discuss how the changing climate might affect gut microbiota by altering the quantity and quality of food, as well as environmental microbiomes, such as enteric pathogen pressure and host physiology. Climate change-induced variability in food supply, shifts in elemental and macromolecular composition of plant and animal food, the proliferation of enteric pathogens, and the direct effects of high temperatures on gut physiology might alter gut microbiota in undesirable ways, increasing the health burden of climate change. The importance of different pathways might depend on many geographical, economic, and ecological factors. Microbiomes of populations in low-income countries might be disproportionally affected through greater climate change effects and poor mitigation on diet, pathogen burden, and host physiology.

Combining in vivo and in vitro approaches to investigate the effect of sainfoin on strongyle infection, immunity, and large intestine ecosystem of horses

Sainfoin (Onobrychis viciifolia), a polyphenol-rich plant, has shown promising anti-parasitic properties in ruminants, but results in horses are fewer and inconsistent. The mechanisms of action involved are not fully understood and different factors may influence its anti-parasitic properties. Recently, it has been shown that the effect of sainfoin depends on the horse's diet. Indeed, the inclusion of dehydrated sainfoin pellets in a high-starch diet limited the rate of increase in strongyle egg shedding over a short period of time (21 d). The objective of this study was to evaluate, in vivo, the effect of long-term inclusion of sainfoin in a high-starch diet on strongyle infection and intestinal health in horses and to compare in vitro anti-parasitic activity of 2 different dehydrated sainfoin pellets. Horses known to have a past history of strongyle egg excretion (n = 16) were allocated to 2 groups and fed with a high-starch diet containing either sainfoin (SF) pellets or control pellets (sunflower and hay) (CONT) for 84 d. In vitro tests including egg hatch test (EHT) and larval migration inhibition test (LMIT) were performed with different concentrations of aqueous extracts of the sainfoin pellets. No effect of the inclusion of sainfoin in the high-starch diet was observed on the number of strongyle eggs excreted in the feces (P = 0.671). At the different sampling dates, including sainfoin in a high-starch diet-induced some changes in the relative abundance of bacterial taxa (e.g., Oscillibacter, P < 0.05), but not on bacterial diversity (all P's > 0.05), function (P > 0.05) or activity (P > 0.05). Adding sainfoin to a high-starch diet increased plasma acetate concentration (P = 0.032) but no statistically significant differences were observed on other markers of intestinal integrity (plasma lipopolysaccharides) and health (complete blood count) (all P's > 0.05). Both sainfoin pellets showed anti-parasitic activity in the 2 in vitro tests (all P's < 0.05), and 1 sainfoin had a stronger anti-parasitic effect than the other (EHT, all P's < 0.05; LMIT, P = 0.008). Overall, these results suggest that the anti-parasitic effect of sainfoin may depend on its polyphenolic concentration. Thus, preliminary in vitro testing may help to identify sainfoin best suited for in vivo use.

Integrated computational biophysics approach for drug discovery against Nipah virus

The Nipah virus (NiV) poses a pressing global threat to public health due to its high mortality rate, multiple modes of transmission, and lack of effective treatments. NiV glycoprotein G (NiV-G) emerges as a promising target for the discovery of NiV drugs because of its essential role in viral entry and membrane fusion. Therefore, in this study, we applied an integrated computational and biophysics approach to identify potential inhibitors of NiV-G within a curated dataset of Peruvian phytochemicals. The virtual screening results indicated that these compounds could represent a natural source of potential NiV-G inhibitors with ΔG values ranging from -8 to -11 kcal/mol. Among them, procyanidin B2, B3, B7, and C1 exhibited the highest binding affinities and formed the most molecular interactions with NiV-G. Molecular dynamics simulations revealed the induced-fit mechanism of NiV-G pocket interaction with these procyanidins, primarily driven by its hydrophobic nature. Non-equilibrium free energy calculations were used to determine binding affinities, highlighting Procyanidin B3 and B2 as the ligands with the most substantial interactions. In general, this work underscores the potential of Peruvian phytochemicals, particularly procyanidins B2, B3, B7, and C1, as lead compounds for developing anti-NiV drugs through an integrated computational biophysics approach.

From Structure to Function: How Prebiotic Diversity Shapes Gut Integrity and Immune Balance

The microbiota stability, diversity, and composition are pillars for an efficient and beneficial symbiotic relationship between its host and itself. Microbial dysbiosis, a condition where a homeostatic bacterial community is disturbed by acute or chronic events, is a predisposition for many diseases, including local and systemic inflammation that leads to metabolic syndrome, diabetes, and some types of cancers. Classical dysbiosis occurs in the large intestine. During this period, pathogenic strains can multiply, taking advantage of the compromised environment. This overgrowth triggers an exaggerated inflammatory response from the human immune system due to the weakened integrity of the intestinal barrier. Such inflammation can also directly influence higher polyp formation and/or tumorigenesis. Prebiotics can be instrumental in preventing or correcting dysbiosis. Prebiotics are molecules capable of serving as substrates for fermentation processes by gut microorganisms. This can promote returning the intestinal environment to homeostasis. Effective prebiotics are generally specific oligo- and polysaccharides, such as FOS or inulin. However, the direct effects of prebiotics on intestinal epithelial and immune cells must also be taken into consideration. This interaction happens with diverse prebiotic nondigestible carbohydrates, and they can inhibit or decrease the inflammatory response. The present work aims to elucidate and describe the different types of prebiotics, their influence, and their functionalities for health, primarily focusing on their ability to reduce and control inflammation in the intestinal epithelial barrier, gut, and systemic environments.

Supplementation with a cranberry extract favors the establishment of butyrogenic guilds in the human fermentation SHIME system

Background: Proanthocyanidins (PAC) and oligosaccharides from cranberry exhibit multiple bioactive health properties and persist intact in the colon post-ingestion. They display a complex bidirectional interaction with the microbiome, which varies based on both time and specific regions of the gut; the nature of this interaction remains inadequately understood. Therefore, we aimed to investigate the impact of cranberry extract on gut microbiota ecology and function. Methods: We studied the effect of a cranberry extract on six healthy participants over a two-week supplementation period using the ex vivo artificial fermentation system TWIN-M-SHIME to replicate luminal and mucosal niches of the ascending and transverse colon. Results: Our findings revealed a significant influence of cranberry extract supplementation on the gut microbiota ecology under ex vivo conditions, leading to a considerable change in bacterial metabolism. Specifically, Bifidobacterium adolescentis (B. adolescentis) flourished in the mucus of the ascending colon, accompanied by a reduced adhesion of Proteobacteria. The overall bacterial metabolism shifted from acetate to propionate and, notably, butyrate production following PAC supplementation. Although there were variations in microbiota modulation among the six donors, the butyrogenic effect induced by the supplementation remained consistent across all individuals. This metabolic shift was associated with a rise in the relative abundance of several short-chain fatty acid (SCFA)-producing bacterial genera and the formation of a consortium of key butyrogenic bacteria in the mucus of the transverse colon. Conclusions: These observations suggest that cranberry extract supplementation has the potential to modulate the gut microbiota in a manner that may promote overall gut health.

Bowel function and inflammation: Is motility the other side of the coin?

Digestion and intestinal absorption allow the body to sustain itself and are the emblematic functions of the bowel. On the flip side, functions also arise from its role as an interface with the environment. Indeed, the gut houses microorganisms, collectively known as the gut microbiota, which interact with the host, and is the site of complex immune activities. Its role in human pathology is complex and scientific evidence is progressively elucidating the functions of the gut, especially regarding the pathogenesis of chronic intestinal diseases and inflammatory conditions affecting various organs and systems. This editorial aims to highlight and relate the factors involved in the pathogenesis of intestinal and systemic inflammation.

Diet modulates strongyle infection and microbiota in the large intestine of horses

The use of anthelminthic drugs has several drawbacks, including the selection of resistant parasite strains. Alternative avenues to mitigate the negative effects of helminth infection involve dietary interventions that might affect resistance and/or tolerance by improving host immunity, modulating the microbiota, or exerting direct anthelmintic effects. The aim of this study was to assess the impact of diet on strongyle infection in horses, specifically through immune-mediated, microbiota-mediated, or direct anthelmintic effects. Horses that were naturally infected with strongyles were fed either a high-fiber or high-starch diet, supplemented with either polyphenol-rich pellets (dehydrated sainfoin) or control pellets (sunflower and hay). When horses were fed a high-starch diet, they excreted more strongyle eggs. Adding sainfoin in the high-starch diet reduced egg excretion. Additionally, sainfoin decreased larval motility whatever the diet. Moreover, the high-starch diet led to a lower fecal bacterial diversity, structural differences in fecal microbiota, lower fecal pH, lower blood acetate, and lower hematocrit compared to the high-fiber diet. Circulating levels of Th1 and Th2 cytokines, lipopolysaccharides, procalcitonin, and white blood cells proportions did not differ between diets. Overall, this study highlights the role of dietary manipulations as an alternative strategy to mitigate the effect of helminth infection and suggests that, in addition to the direct effects, changes in the intestinal ecosystem are the possible underlying mechanism.

Bioactive Compounds from Plant Origin as Natural Antimicrobial Agents for the Treatment of Wound Infections

The rising prevalence of drug-resistant bacteria underscores the need to search for innovative and nature-based solutions. One of the approaches may be the use of plants that constitute a rich source of miscellaneous compounds with a wide range of biological properties. This review explores the antimicrobial activity of seven bioactives and their possible molecular mechanisms of action. Special attention was focused on the antibacterial properties of berberine, catechin, chelerythrine, cinnamaldehyde, ellagic acid, proanthocyanidin, and sanguinarine against Staphylococcus aureus, Enterococcus spp., Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Serratia marcescens and Pseudomonas aeruginosa. The growing interest in novel therapeutic strategies based on new plant-derived formulations was confirmed by the growing number of articles. Natural products are one of the most promising and intensively examined agents to combat the consequences of the overuse and misuse of classical antibiotics.

Oligomeric Proanthocyanidins: An Updated Review of Their Natural Sources, Synthesis, and Potentials

Oligomeric Proanthocyanidins (OPCs), as a class of compounds widely found in plants, are particularly abundant in grapes and blueberries. It is a polymer comprising many different monomers, such as catechins and epicatechins. The monomers are usually linked to each other by two types of links, A-linkages (C-O-C) and B-linkages (C-C), to form the polymers. Numerous studies have shown that compared to high polymeric procyanidins, OPCs exhibit antioxidant properties due to the presence of multiple hydroxyl groups. This review describes the molecular structure and natural source of OPCs, their general synthesis pathway in plants, their antioxidant capacity, and potential applications, especially the anti-inflammatory, anti-aging, cardiovascular disease prevention, and antineoplastic functions. Currently, OPCs have attracted much attention, being non-toxic and natural antioxidants of plant origin that scavenge free radicals from the human body. This review would provide some references for further research on the biological functions of OPCs and their application in various fields.

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

A blend of functional amino acids and grape polyphenols improves the pig capacity to cope with an inflammatory challenge caused by poor hygiene of housing conditions

BACKGROUND

Dietary supplementation with a blend of functional amino acids (AA) and grape extract polyphenols contributes to preserve intestinal health and growth performance of piglets during the post-weaning period. In the present experiment, we assessed if a supplementation with a mix of AA and grape extract polyphenols during the post-weaning period would persist to improve the pig capacity to cope with a subsequent challenge caused by poor hygiene of housing conditions. Eighty pigs weaned at 28 days of age were fed a standard diet supplemented (AAP) or not (CNT) with 0.2% of a blend of AA (glutamine, arginine, cystine, valine, isoleucine, and leucine) and grape extract polyphenols during the post-weaning period (from week 0 to 6). At week 6, pigs were transferred to a growing unit where 50% of pigs previously fed AAP and CNT diets were housed in good and the other 50% in poor hygiene conditions for 3 weeks (from week 7 to 9; challenge period). All pigs were fed a standard growing diet that was not supplemented with AAP. We measured pig growth performance, plasma indicators of inflammation, digestive integrity, and oxidative status, and scored fecal consistency. Differences were considered significant at P ≤ 0.05.

RESULTS

One week post-weaning, pigs fed AAP had lower plasma concentrations of haptoglobin than CNT pigs (P = 0.03). Six weeks post-weaning, plasma concentrations of diamine oxidase (DAO) were lower (P = 0.03) whereas those of vitamin E and A were greater (P ≤ 0.05) in pigs fed AAP compared to CNT pigs. The prevalence of diarrhea was higher in CNT pigs compared to AAP pigs (P < 0.01). During the challenge period, only pigs previously fed CNT diet had lower growth rate in poor than good conditions (P ≤ 0.05). They had also greater plasma concentrations of haptoglobin and oxidative stress index (OSI) and lower plasma concentrations of vitamin E in poor than good hygiene conditions (P ≤ 0.05).

CONCLUSIONS

Pigs fed AAP diet during post-weaning had less diarrhea and plasma concentrations of a digestive integrity marker, as well as greater plasma concentrations of antioxidant indicators during the post-weaning period. The beneficial effects of AAP supplementation persisted after the post-weaning period as evidenced by the absence of effects of the hygiene challenge on growth and health indicators in pigs previously fed APP. This clearly indicated a greater ability of pigs fed AAP to cope with the poor hygiene conditions.

Tackling the Future Pandemics: Broad-Spectrum Antiviral Agents (BSAAs) Based on A-Type Proanthocyanidins

A-type proanthocyanidins (PAC-As) are plant-derived natural polyphenols that occur as oligomers or polymers of flavan-3-ol monomers, such as (+)-catechin and (-)-epicatechin, connected through an unusual double A linkage. PAC-As are present in leaves, seeds, flowers, bark, and fruits of many plants, and are thought to exert protective natural roles against microbial pathogens, insects, and herbivores. Consequently, when tested in isolation, PAC-As have shown several biological effects, through antioxidant, antibacterial, immunomodulatory, and antiviral activities. PAC-As have been observed in fact to inhibit replication of many different human viruses, and both enveloped and non-enveloped DNA and RNA viruses proved sensible to their inhibitory effect. Mechanistic studies revealed that PAC-As cause reduction of infectivity of viral particles they come in contact with, as a result of their propensity to interact with virion surface capsid proteins or envelope glycoproteins essential for viral attachment and entry. As viral infections and new virus outbreaks are a major public health concern, development of effective Broad-Spectrum Antiviral Agents (BSAAs) that can be rapidly deployable even against future emerging viruses is an urgent priority. This review summarizes the antiviral activities and mechanism of action of PAC-As, and their potential to be deployed as BSAAs against present and future viral infections.

Rhodiola rosea Reduces Intercellular Signaling in Campylobacter jejuni

Campylobacter jejuni is a major foodborne pathogen and the leading cause of bacterial gastroenteritis, i.e., campylobacteriosis. Besides searching for novel antimicrobials, identification of new targets for their action is becoming increasingly important. Rhodiola rosea has long been used in traditional medicine. Ethanolic extracts from the roots and rhizomes of the plant contain a wide range of bioactive compounds with various pharmacological activities. In this study, cultivated plant materials have been used, i.e., "Mattmark" and "Rosavine". Through optimized protocols, we obtained fractions of the initial ethanolic extracts rich in most important bioactive compounds from R. rosea, including salidroside, rosavins, proanthocyanidins (PACs), and flavonoids. The antimicrobial activity in relation to the chemical composition of the extracts and their fractions was studied with an emphasis on C. jejuni AI-2-mediated intercellular signaling. At concentration 15.625 mg/L, bioluminescence reduction rates varied from 27% to 72%, and the membrane remained intact. Fractions rich in PACs had the strongest antimicrobial effect against C. jejuni, with the lowest minimal inhibitory concentrations (MICs) (M F3 40%: 62.5 mg/L; R F3 40%: 250 mg/L) and the highest intercellular signaling reduction rates (M F3 40%: 72%; R F3 40%: 65%). On the other hand, fractions without PACs were less effective (MICs: M F5 PVP: 250 mg/L; R F5 PVP: 1000 mg/L and bioluminescence reduction rates: M F5 PVP: 27%; R F5 PVP: 43%). Additionally, fractions rich in flavonoids had strong antimicrobial activity (MICs: M F4 70%: 125 mg/L; R F4 70%: 250 mg/L and bioluminescence reduction rates: M F4 70%: 68%; R F4 70%: 50%). We conclude that PACs and flavonoids are crucial compound groups responsible for the antimicrobial activity of R. rosea roots and rhizomes in C. jejuni.

Proanthocyanidins at the gastrointestinal tract: mechanisms involved in their capacity to mitigate obesity-associated metabolic disorders

The prevalence of overweight and obesity is continually increasing worldwide. Obesity is a major public health concern given the multiple associated comorbidities. Finding dietary approaches to prevent/mitigate these conditions is of critical relevance. Proanthocyanidins (PACs), oligomers or polymers of flavan-3-ols that are extensively distributed in nature, represent a major part of total dietary polyphenols. Although current evidence supports the capacity of PACs to mitigate obesity-associated comorbidities, the underlying mechanisms remain speculative due to the complexity of PACs' structure. Given their limited bioavailability, the major site of the biological actions of intact PACs is the gastrointestinal (GI) tract. This review discusses the actions of PACs at the GI tract which could underlie their anti-obesity effects. These mechanisms include: i) inhibition of digestive enzymes at the GI lumen, including pancreatic lipase, α-amylase, α-glucosidase; ii) modification of gut microbiota composition; iii) modulation of inflammation- and oxidative stress-triggered signaling pathways, e.g. NF-κB and MAPKs; iv) protection of the GI barrier integrity. Further understanding of the mechanisms and biological activities of PACs at the GI tract can contribute to develop nutritional and pharmacological strategies oriented to mitigate the serious comorbidities of obesity.

Milk Fat Globule Membrane Attenuates Acute Colitis and Secondary Liver Injury by Improving the Mucus Barrier and Regulating the Gut Microbiota

Objective

Inflammatory bowel disease (IBD) often occurs along with extraintestinal manifestations, including hepatic injury. Milk fat globule membrane (MFGM) is an active substance with a potential anti-inflammation activity. However, its alleviated effect and mechanisms in IBD as well as the IBD-induced secondary liver injury are still unclear.

Methods

C57BL/6J mice were administered with a 21-day oral gavage of MFGM, followed by 7 days of drinking water with 4% dextran sulfate sodium (DSS). Disease activity index (DAI), histological features, and cytokines of the colon and liver were evaluated. Then, RNA-seq of the colon and liver was conducted. The gut microbiota was assessed by analyzing 16S rRNA gene sequences, and finally the integrity and the function of the mucus barrier were evaluated by Alcian blue staining, real-time quantitative PCR, and ELISA.

Results

Prophylactic MFGM treatment was effective against colitis to include effects in body weight loss, DAI score, colonic length, intestinal pathology, and histological score. Additionally, prophylactic MFGM decreased the levels of interleukin (IL)-1β, IL-6, and myeloperoxidase in colonic tissue, while it increased the IL-10 level. Moreover, the gene expressions of MUC2, MUC4, Reg3b, and Reg3g associated with the production of the molecular mediator of immune response, membrane invagination, and response to protozoan were strikingly upregulated when administered with MFGM. On the other hand, the beneficial effects of MFGM were related to the enriched abundance of genera such as Faccalibacumum and Roseburia in feces samples. Consistently, the administration of MFGM was also found to alleviate DSS-induced hepatic injury. Furthermore, the glutathione transferase activity pathway was enriched in the liver of MFGM-treated mice after DSS administration. Mechanistically, prophylactic MFGM enhanced the mucosal barrier by increasing the gene levels of Reg3b and Reg3g. Meanwhile, the alleviation of MFGM on liver injury was dependent on the reduced hepatic oxidative stress.

Conclusions

MFGM attenuated colitis and hepatic injury by maintaining the mucosal barrier and bacterial community while inhibiting oxidative stress, which might be an effective therapy of hepatic injury secondary to IBD.

Inclusion of Sainfoin in the Diet Might Alter Strongyle Infection in Naturally Infected Horses

It is increasingly difficult to control equine strongyles with synthetic drugs, as resistance is commonly observed. Here, we investigated the possible anthelmintic effect of sainfoin (Onobrychis viciifolia), a polyphenol-rich legume, in naturally infected horses. On Day 0 (D0), 17 horses were allocated to three different homogenous groups in terms of fecal egg count (FEC): the control group (CONT) received a diet composed on a DM basis of 83% hay and 17% wheat bran, while in the sainfoin 1 (SF1) and sainfoin 2 (SF2) groups, half or all wheat bran, respectively, was replaced by dehydrated sainfoin pellets. The infection dynamics were monitored by weekly FEC, from D0 to D84. On D28, all horses were treated with fenbendazole. Larval motility was assessed from coprocultures at D0, D28, D56 and D84. Horses in Group SF2 had lower FEC from D7 to D28. After fenbendazole treatment, no effect of the diet was measured on FEC. Both before and after anthelmintic treatment, larvae from horses consuming sainfoin were less motile than larvae from the CONT group. These results suggest that sainfoin has an in vivo anthelmintic activity in naturally infected horses, although this effect appears to be context-dependent.

Dietary proanthocyanidins promote localized antioxidant responses in porcine pulmonary and gastrointestinal tissues during Ascaris suum-induced type 2 inflammation

Proanthocyanidins (PAC) are dietary polyphenols with putative anti-inflammatory and immunomodulatory effects. However, whether dietary PAC can regulate type-2 immune function and inflammation at mucosal surfaces remains unclear. Here, we investigated if diets supplemented with purified PAC modulated pulmonary and intestinal mucosal immune responses during infection with the helminth parasite Ascaris suum in pigs. A. suum infection induced a type-2 biased immune response in lung and intestinal tissues, characterized by pulmonary granulocytosis, increased Th2/Th1 T cell ratios in tracheal-bronchial lymph nodes, intestinal eosinophilia, and modulation of genes involved in mucosal barrier function and immunity. Whilst PAC had only minor effects on pulmonary immune responses, RNA-sequencing of intestinal tissues revealed that dietary PAC significantly enhanced transcriptional responses related to immune function and antioxidant responses in the gut of both naïve and A. suum-infected animals. A. suum infection and dietary PAC induced distinct changes in gut microbiota composition, primarily in the jejunum and colon, respectively. Notably, PAC consumption substantially increased the abundance of Limosilactobacillus reuteri. In vitro experiments with porcine macrophages and intestinal epithelial cells supported a role for both PAC polymers and PAC-derived microbial metabolites in regulating oxidative stress responses in host tissues. Thus, dietary PAC may have distinct beneficial effects on intestinal health during infection with mucosal pathogens, while having a limited activity to modulate naturally-induced type-2 pulmonary inflammation. Our results shed further light on the mechanisms underlying the health-promoting properties of PAC-rich foods, and may aid in the design of novel dietary supplements to regulate mucosal inflammatory responses in the gastrointestinal tract.

Anthelmintic resistance in ruminants: challenges and solutions

Anthelmintic resistance (AR) is a growing concern for effective parasite control in farmed ruminants globally. Combatting AR will require intensified and integrated research efforts in the development of innovative diagnostic tests to detect helminth infections and AR, sustainable anthelmintic treatment strategies and the development of complementary control approaches such as vaccination and plant-based control. It will also require a better understanding of socio-economic drivers of anthelmintic treatment decisions, in order to support a behavioural shift and develop targeted communication strategies that promote the uptake of evidence-based sustainable solutions. Here, we review the state-of-the-art in these different fields of research activity related to AR in helminths of livestock ruminants in Europe and beyond. We conclude that in the advent of new challenges and solutions emerging from continuing spread of AR and intensified research efforts, respectively, there is a strong need for transnational multi-actor initiatives. These should involve all key stakeholders to develop indicators of infection and sustainable control, set targets and promote good practices to achieve them.

Dietary proanthocyanidins on gastrointestinal health and the interactions with gut microbiota

Many epidemiological and experimental studies have consistently reported the beneficial effects of dietary proanthocyanidins (PAC) on improving gastrointestinal physiological functions. This review aims to present a comprehensive perspective by focusing on structural properties, interactions and gastrointestinal protection of PAC. In brief, the main findings of this review are summarized as follows: (1) Structural features are critical factors in determining the bioavailability and subsequent pharmacology of PAC; (2) PAC and/or their bacterial metabolites can play a direct role in the gastrointestinal tract through their antioxidant, antibacterial, anti-inflammatory, and anti-proliferative properties; (3) PAC can reduce the digestion, absorption, and bioavailability of carbohydrates, proteins, and lipids by interacting with them or their according enzymes and transporters in the gastrointestinal tract; (4). PAC showed a prebiotic-like effect by interacting with the microflora in the intestinal tract, and the enhancement of PAC on a variety of probiotics, such as Bifidobacterium spp. and Lactobacillus spp. could be associated with potential benefits to human health. In conclusion, the potential effects of PAC in prevention and alleviation of gastrointestinal diseases are remarkable but clinical evidence is urgently needed.

A mix of functional amino acids and grape polyphenols promotes the growth of piglets, modulates the gut microbiota in vivo and regulates epithelial homeostasis in intestinal organoids

Weaning is a challenging period for gut health in piglets. Previous studies showed that dietary supplementations with either amino acids or polyphenols promote piglet growth and intestinal functions, when administered separately. Thus, we hypothesized that a combination of amino acids and polyphenols could facilitate the weaning transition. Piglets received during the first two weeks after weaning a diet supplemented or not with a mix of a low dose (0.1%) of functional amino acids (L-arginine, L-leucine, L-valine, L-isoleucine, L-cystine) and 100 ppm of a polyphenol-rich extract from grape seeds and skins. The mix of amino acids and polyphenols improved growth and feed efficiency. These beneficial effects were associated with a lower microbiota diversity and a bloom of Lactobacillaceae in the jejunum content while the abundance of Proteobacteria was reduced in the caecum content. The mix of amino acids and polyphenols also increased the production by the caecum microbiota of short-chain fatty acids (butyrate, propionate) and of metabolites derived from amino acids (branched-chain fatty acids, valerate, putrescine) and from polyphenols (3-phenylpropionate). Experiments in piglet jejunum organoids revealed that the mix of amino acids and polyphenols upregulated the gene expression of epithelial differentiation markers while it reduced the gene expression of proliferation and innate immunity markers. In conclusion, the supplementation of a mix of amino acids and polyphenols is a promising nutritional strategy to manage gut health in piglets through the modulation of the gut microbiota and of the epithelial barrier.

Structure-function analysis of purified proanthocyanidins reveals a role for polymer size in suppressing inflammatory responses

Proanthocyanidins (PAC) are dietary compounds that have been extensively studied for beneficial health effects due to their anti-inflammatory properties. However, the structure-function relationships of PAC and their mode-of-action remain obscure. Here, we isolated a wide range of diverse PAC polymer mixtures of high purity from plant material. Polymer size was a key factor in determining the ability of PAC to regulate inflammatory cytokine responses in murine macrophages. PAC polymers with a medium (9.1) mean degree of polymerization (mDP) induced substantial transcriptomic changes, whereas PAC with either low (2.6) or high (12.3) mDP were significantly less active. Short-term oral treatment of mice with PAC modulated gene pathways connected to nutrient metabolism and inflammation in ileal tissue in a polymerization-dependent manner. Mechanistically, the bioactive PAC polymers modulated autophagic flux and inhibited lipopolysaccharide-induced autophagy in macrophages. Collectively, our results highlight the importance of defined structural features in the health-promoting effects of PAC-rich foods.