Major cereal carbohydrates in relation to intestinal health of monogastric animals: A review

Necrotic enteritis and antibiotic-free production of broiler chickens: Challenges in testing and using alternative products

The global trend towards raising broiler chickens without the use of in-feed antibiotics (IFAs) means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously provided. IFAs supported the productivity performance of chickens and played a key role in maintaining their health. Necrotic enteritis (NE) is an important disease of broilers that affects health, productivity, and welfare, and was previously well controlled by IFAs. However, with the reduction in IFA use, NE is resurgent in some countries. Vaccines and various feed additives, including pre-, pro-, and postbiotics, phytobiotics, fatty acids, and phage therapies have been introduced as alternative methods of NE control. While some of these feed additives have specific activity against the NE pathogen, Clostridium perfringens, most have the more general goal of reinforcing gut health. Extensive reviews of the effects of many of these feed additives on gut health have been published recently. Hence, rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production settings. The review is based on the author's particular experience, reading, thoughts, and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these issues. It is put forward to stimulate thinking and discussion on the issues covered.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

Potential roles of cereal bioactive compounds in the prevention and treatment of type 2 diabetes: A review of the current knowledge

Diabetes is one of the most common non-communicable diseases in both developed and underdeveloped countries with a 9.3% prevalence. Unhealthy diets and sedentary lifestyles are among the most common reasons for type 2 diabetes mellitus (T2DM). Diet plays a crucial role in both the etiology and treatment of T2DM. There are several recommendations regarding the carbohydrate intake of patients with T2DM. One of them is about reducing the total carbohydrate intake and/or changing the type of carbohydrate to reduce the glycaemic index. Cereals are good sources of carbohydrates in the diet with a significant amount of soluble and non-soluble fiber content. Apart from fiber, it has been shown that the bioactive compounds present in cereals such as proteins, phenolic compounds, carotenoids, and tocols have beneficial impacts in the prevention and treatment of T2DM. Moreover, cereal by-products especially the by-products of milling processes, which are bran and germ, have been reported to have anti-diabetic activities mainly because of their fiber and polyphenols content. Considering the potential functions of cereals in patients with T2DM, this review focuses on the roles of cereal bioactive compounds in the prevention and treatment of type 2 diabetes.

Excessive dietary soluble arabinoxylan impairs the intestinal physical and immunological barriers via activating MAPK/NF-κB signaling pathway in rainbow trout (Oncorhynchus mykiss)

Arabinoxylan (AX) has been deemed as an antinutritional factor, but limited information has addressed the effects of dietary AX on intestinal health of fish. The present study investigated the effects of dietary AX on intestinal mucosal physical and immunological barriers of rainbow trout (Oncorhynchus mykiss). Five isoproteic and isolipidic experimental diets (AXE, AX0, AX2.5, AX5 and AX10) were formulated to contain 0.03% arabinoxylanase as well as 0%, 2.5%, 5% and 10% AX, respectively. Each diet was randomly distributed to triplicate groups of 35 juvenile (average weight 3.14 ± 0.02 g) per tank in a rearing system maintained at 17 ± 1 °C for 9 weeks. Dietary AX supplementation regardless of inclusion levels significantly (P < 0.05) depressed the growth performance and feed utilization. The plasma endothelin-1 and d-lactic acid contents as well as diamino oxidase activity were significantly higher in fish fed diet AX10 compared to fish fed diet AX0. Dietary inclusion of 5-10% AX resulted in decreased intestinal villus height, goblet cell number and desmosome density, increased crypt depth, short and irregular microvilli, widened intercellular space; down-regulated the mRNA levels of occludin in hindgut, claudin3 and ZO-1 in foregut and midgut, but up-regulated the mRNA levels of claudin12 and claudin15 in midgut as well as claudin23 in foregut, midgut and hindgut. Furthermore, dietary 5-10% AX supplementation decreased the midgut and hindgut complement 3, complement 4 and sIgT contents as well as the midgut IgM and hindgut IL-10 contents. Conversely, the hindgut TNF-α and IL-6 contents increased with the rising dietary AX level. RT-qPCR demonstrated that the pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-12β, IFN-γ, and TNF-α) and pIgR mRNA levels in midgut and hindgut were up-regulated by dietary AX inclusion of 5-10% AX. Meanwhile, the mRNA levels of p38 MAPK, IκBα, and NF-κB p65 in midgut and hindgut raised gradually with the increasing dietary AX content. The Western blot results showed that the protein expression levels of p38 MAPK and NF-κB generally increased with the rising dietary AX content. Dietary treatment with 0.03% arabinoxylanase did not affect the growth performance and intestinal health of rainbow trout (P > 0.05). In conclusion, excessive dietary AX inclusion (5-10%) increased the intestinal permeability and induced the intestinal inflammatory response via activating MAPK/NF-κB signaling pathway, and ultimately damaged the intestinal barrier function of rainbow trout.

A synbiotic combination of Bifidobacterium longum Bif10 and Bifidobacterium breve Bif11, isomaltooligosaccharides and finger millet arabinoxylan prevents dextran sodium sulphate induced ulcerative colitis in mice

Decreased bifidobacterial abundance, disrupted gut barrier function, dysregulated immune response and ulceration have been reported in the gut microbiota of IBD patients. Non-digestible carbohydrates with bifidogenic effect enrich the gut microbiota with Bifidobacterium spp. and could help in overcoming inflammatory gut conditions. In this study, the protective effect of Bifidobacterium longum Bif10 and Bifidobacterium breve Bif11; isomaltooligosaccharides (IMOS); Finger millet arabinoxylan (FM-AX) and their Synbiotic mix were evaluated against dextran sodium sulphate (DSS) induced UC in male Balb/c mice for 25 days. All the interventions ameliorated symptoms of colitis such as disease activity index (DAI), histological damage to the colon, gut-bacterial dysbiosis and inflammation. However, the synbiotic mix was more potent in amelioration of some of the parameters such as decreased TNF-α and lipocalin levels; increased anti-inflammatory markers (IL-10 and IL-22), and improved short chain fatty acids (SCFAs) levels in the cecum content. Furthermore, mouse colitis histological scoring (MCHI) also suggested the preventive role of synbiotic mix. All the dietary interventions aid in improving the DAI and immune parameters; restoration or regeneration of the altered selected gut bacteria, enhances the SCFA production, strengthens gut barrier, prevents gut inflammation and decreases the colonic MCHI score in DSS fed mice.

Debranching enzymes decomposed corn arabinoxylan into xylooligosaccharides and achieved prebiotic regulation of gut microbiota in broiler chickens

BACKGROUND

Corn arabinoxylan (AX) is a complicated and multibranched antinutritional factor, thereby proving the use of endo-xylanase (EX) to be marginally valid. This study focused on specific types of AX-degrading enzymes (ADEs) to exert the synergy of debranching enzymes and track the prebiotic potential of enzymatic hydrolysates. This study investigated the effects of ADEs on the growth performance, intestinal histomorphology, absorption functions, changes in polysaccharide components, fermentation, and gut microbiota of broiler chickens. Five hundred seventy-six five-day-old Arbor Acres male broiler chickens were randomly allocated into eight treatments with six replicates each. Corn basal diets supplemented with or without enzymes were fed for a 21-day period, specifically including EX, its compatible use with arabinofuranosidase (EXA) or ferulic acid esterase (EXF), and compound groups with the above three enzymes (XAF).

RESULTS

Specific ADEs stimulated the jejunal villus height and goblet cell number and evidently decreased the crypt depth (P < 0.05), while the ratio of ileal villus height to crypt depth was significantly increased in EXF (P < 0.05). Maltase activities of ileal mucosa in XAF groups were extremely enhanced (P < 0.01), and EX boosted the activity of Na⁺-K⁺ ATPase in the small intestine (P < 0.01). The insoluble AX concentrations comparatively lessened, thereby notably raising the sundry xylooligosaccharide (XOS) yield in the ileal chyme (P < 0.05), which was dominant in xylobiose and xylotriose. Improvements in the abundance and diversity of ileal microbial communities within the EXA, EXF, and XAF treatments were observed (P < 0.05). Positive correlations between microbiota and XOS were revealed, with xylobiose and xylotriose being critical for ten beneficial bacteria (P < 0.05). EXF increased the BWG and FCR of broiler chickens in this phase (P < 0.05), which was attributed to the thriving networks modified by Lactobacillus. The intracecal contents of acetic acid, butyric acid, and propionic acid were greatly enhanced in most ADE groups, such as EXF (P < 0.05).

CONCLUSIONS

Debranching enzymes appreciably targeted corn AX to release prebiotic XOS in the posterior ileum and facilitated intracaecal fermentation. It was beneficial for improving gut development, digestion and absorption and modulating the microflora to promote the early performance of broiler chickens.

Effect of Arabinoxylan and Xylo-Oligosaccharide on Growth Performance and Intestinal Barrier Function in Weaned Piglets

The purpose of this study was to explore the effects of xylose with different polymerizations on growth performance, intestinal barrier function, and gut microbial composition in weaned piglets. A total of 144 weaned piglets were assigned to 3 dietary treatments in a completely randomized design according to their body weight and sex. Dietary treatments included a corn-soybean meal basal diet (CON) and 2 additional diets formulated with 1% arabinoxylan (AX) and 1% xylo-oligosaccharide (XOS), respectively. Results showed that dietary supplementation of XOS or AX reduced diarrhea incidence of weaned piglets compared with the CON group (p < 0.05). XOS or AX increased the ileal villus height and intestinal activity of antioxidases in weaned piglets compared with the CON group (p < 0.05). XOS or AX reduced the ileal and colonic IL-6 content and increased the colonic sIgA and IL-10 concentrations in weaned piglets compared with the CON group (p < 0.05). XOS or AX increased the total organic acids concentrations in the ileum and in vitro fermentation (p < 0.05). XOS increased the abundance of Lactobacillus and Bifidobacterium in the ileal digesta (p < 0.05), while AX increased the population of Lactobacillus in the ileal digesta and the abundance of Bifidobacterium in the colonic digesta of weaned piglets (p < 0.05). In conclusion, both XOS and AX reduce diarrhea incidence and improve antioxidant capacity, immune function, and populations of beneficial bacteria, while microbial fermentation of XOS with a lower polymerization and molecular mass can produce more organic acids and an increased abundance of Lactobacillus and Bifidobacterium in the upper gut of weaned pigs compared with AX.

The interaction between dietary fiber and gut microbiota, and its effect on pig intestinal health

Intestinal health is closely associated with overall animal health and performance and, consequently, influences the production efficiency and profit in feed and animal production systems. The gastrointestinal tract (GIT) is the main site of the nutrient digestive process and the largest immune organ in the host, and the gut microbiota colonizing the GIT plays a key role in maintaining intestinal health. Dietary fiber (DF) is a key factor in maintaining normal intestinal function. The biological functioning of DF is mainly achieved by microbial fermentation, which occurs mainly in the distal small and large intestine. Short-chain fatty acids (SCFAs), the main class of microbial fermentation metabolites, are the main energy supply for intestinal cells. SCFAs help to maintain normal intestinal function, induce immunomodulatory effects to prevent inflammation and microbial infection, and are vital for the maintenance of homeostasis. Moreover, because of its distinct characteristics (e.g. solubility), DF is able to alter the composition of the gut microbiota. Therefore, understanding the role that DF plays in modulating gut microbiota, and how it influences intestinal health, is essential. This review gives an overview of DF and its microbial fermentation process, and investigates the effect of DF on the alteration of gut microbiota composition in pigs. The effects of interaction between DF and the gut microbiota, particularly as they relate to SCFA production, on intestinal health are also illustrated.

Efecto del consumo de harina de frutos de la Palma Real (Roystonea regia) en la bioquímica sanguínea de pollos de ceba

El experimento se llevó a cabo con el objetivo de estudiar el efecto del consumo de harina de frutos de la palma real –PR– (Roystonea regia) en la bioquímica sanguínea de pollos de ceba (PC). Se utilizaron 32 animales machos de ocho a 42 días-d- de edad, que se distribuyeron según diseño completamente aleatorizado en cuatro tratamientos (T) y ocho repeticiones: control (maíz-soya) y la inclusión de harina de palmiche (HP) en 5; 10 y 15 %. Se determinaron el peso vivo (PV), indicadores digestivos y de la bioquímica sanguínea relacionados con el metabolismo proteico, de carbohidratos, de lípidos y minerales así como de funcionalidad hepática. El PV fue mayor en las aves que consumieron 15 % de HP respecto al resto de los T. Se observó aumento en las proteínas totales y el ácido úrico en los tratamientos donde se incluyó el fruto de la PR respecto al control (29,86 vs 34,78; 34,78 y 37,34 gramos·litros-1 [g·L-1]; 252,75 vs 310,63; 278,88 y 303,13 micromol·L-1 [µM·L-1]) , respectivamente. Los triglicéridos disminuyeron con la presencia del alimento alternativo (1,49 vs 1,00; 1,06 y 1,06 milimol·L-1 [mmol·L-1]), en tanto el colesterol sólo lo hizo con el 5 % de inclusión. No se observaron diferencias entre T para los indicadores del metabolismo de carbohidratos y minerales. No hubo daño en la funcionalidad hepática con los niveles que se probaron. Se concluye que el consumo de HP por PC hasta 15 % modifica indicadores de la bioquímica sanguínea relacionados con el metabolismo proteico y lipídico y no se muestran signos de daños hepáticos.

The bridge of the gut–joint axis: Gut microbial metabolites in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint destruction, synovitis, and pannus formation. Gut microbiota dysbiosis may exert direct pathogenic effects on gut homeostasis. It may trigger the host’s innate immune system and activate the “gut–joint axis”, which exacerbates the RA. However, although the importance of the gut microbiota in the development and progression of RA is widely recognized, the mechanisms regulating the interactions between the gut microbiota and the host immune system remain incompletely defined. In this review, we discuss the role of gut microbiota-derived biological mediators, such as short-chain fatty acids, bile acids, and tryptophan metabolites, in maintaining intestinal barrier integrity, immune balance and bone destruction in RA patients as the bridge of the gut–joint axis.

Capsaicin combined with dietary fiber prevents high-fat diet associated aberrant lipid metabolism by improving the structure of intestinal flora

Capsaicin (CAP) and dietary fibers are natural active ingredients that given separately do positively affect obesity and metabolic diseases. However, it was unknown whether their combined administration might further improve blood lipids and gut flora composition. To test this hypothesis we administered capsaicin plus dietary fibers (CAP + DFs) to male rats on a high-fat diet and analyzed any changes in the intestinal microbiota make up, metabolites, and blood indexes. Our results showed that combining CAP with dietary fibers more intensely reduced total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). CAP + DFs also increased gut bacteria variety, and the abundance of several beneficial bacterial strains, including Allobaculum and Akkermansia, while reducing harmful strains such as Desulfovibrio. Additionally, CAP + DFs significantly increased arginine levels and caused short-chain fatty acids accumulation in the contents of the cecal portion of rats' gut. In conclusion, notwithstanding the rats were kept on a high-fat diet, adding CAP + DFs to the chow further improved, as compared with CAP alone, the lipidemia and increased the gut beneficial bacterial strains, while reducing the harmful ones.

Intestinal nutrition: role of vitamins and biofactors and gaps of knowledge

The role of the microbiota in the health of the host is complex and multifactorial. The microbiota both consumes nutrients in competition with the host, but also creates nutrients that can be used by other microbes, but also the host. However, the quantitative impact of the microbiota on nutrient supply and demand is not well understood in poultry. The gastrointestinal tract is one of the largest points of contact with the external environment, and the intestinal microbiome is the largest and most complex of any system. Although the intestinal microbiota has first access to consumed nutrients, including vitamins, and is potentially a major contributor to production of various vitamins, the quantification of these impacts remains very poorly understood in poultry. Based on the human literature, it is clear that vitamin deficiencies can have systemic effects on the regulation of many physiological systems, beyond the immediate, direct nutrient functions of the vitamins. The impact of excessive supplementation of vitamins on the microbiota is not well understood in any species. In the context of poultry nutrition, in which substantial dietary excesses of most vitamins are provided, this represents a knowledge gap. Given the paucity of studies investigating the vitamin requirements of modern, high-producing poultry, the limited understanding of vitamin nutrition (supply and utilization) by the microbiome, and the potential impacts on the microbiome of the move away from dietary growth-promoting antibiotic use, more research in this area is required.

The microbiota also contributes a vast array of other metabolites involved in intramicrobiota communication, symbiosis and competition that can also have an impact on the host. Myo-inositol and butyrate are briefly discussed as examples of biofactors produced by the microbiota as mediators of intestinal health.

Cordyceps militaris Modulates Intestinal Barrier Function and Gut Microbiota in a Pig Model

This study investigated the effects of Cordyceps militaris (CM) on intestinal barrier function and gut microbiota in a pig model. A total of 160 pigs were randomly allocated to either a control group (fed the basal diet) or a CM group (fed the basal diet supplemented with 300 mg/kg CM). CM improved intestinal morphology and increased the numbers of goblet cells and intraepithelial lymphocytes. CM also elevated the expression of zona occluden-1, claudin-1, mucin-2 and secretory immunoglobulin A. Furthermore, the mucosal levels of pro-inflammatory cytokines were downregulated while the levels of anti-inflammatory cytokines were upregulated in the CM group. Mechanistically, CM downregulated the expression of key proteins of the TLR4/MyD88/NF-κB signaling pathway. Moreover, CM altered the colonic microbial composition and increased the concentrations of acetate and butyrate. In conclusion, CM can modulate the intestinal barrier function and gut microbiota, which may provide a new strategy for improving intestinal health.

Role of Physiology, Immunity, Microbiota, and Infectious Diseases in the Gut Health of Poultry

“Gut health” refers to the physical state and physiological function of the gastrointestinal tract and in the livestock system; this topic is often focused on the complex interacting components of the intestinal system that influence animal growth performance and host-microbial homeostasis. Regardless, there is an increasing need to better understand the complexity of the intestinal system and the various factors that influence gut health, since the intestine is the largest immune and neuroendocrine organ that interacts with the most complex microbiome population. As we face the post-antibiotic growth promoters (AGP) era in many countries of the world, livestock need more options to deal with food security, food safety, and antibiotic resilience to maintain agricultural sustainability to feed the increasing human population. Furthermore, developing novel antibiotic alternative strategies needs a comprehensive understanding of how this complex system maintains homeostasis as we face unpredictable changes in external factors like antibiotic-resistant microbes, farming practices, climate changes, and consumers’ preferences for food. In this review, we attempt to assemble and summarize all the relevant information on chicken gut health to provide deeper insights into various aspects of gut health. Due to the broad and complex nature of the concept of “gut health”, we have highlighted the most pertinent factors related to the field performance of broiler chickens.

Utilization of Sake lees as Broiler Feedstuff and its Effects on Growth Performance and Intestinal Immunity

Increasing food loss and waste (FLW) is a global problem, and efforts are being made to use waste food as potential livestock feed material. The amount of self-supplied feed is lower in Japan than in other countries, and the government recommends FLW use for animal feed. Sake (Japanese rice wine) is a traditional alcoholic beverage. During the sake manufacturing process, large amounts of squeezed solids or “lees” (sake lees) are generated. Sake lees are nutritious and functional, but are prone to spoilage. In this study, we investigated whether sake lees should be mixed with animal feed immediately or after drying. To assess the usefulness of sake lees as a poultry feed ingredient and determine the effect of sake lees on intestinal immunity, we performed a feeding trial with three treatments: a raw sake lees (RSL) diet, dried sake lees (DSL) diet, and control diet. Three-week-old broilers were fed these diets (n=8 per group) for two weeks. We then calculated feed efficiency and performed RT-qPCR to assess the effects of diet on intestinal immunity. The growth performance in the RSL diet group was equivalent to that in the control diet group. The DSL diet became difficult for broilers to eat, resulting in decreased growth performance. In the ileum of RSL-diet broilers, the mRNA expression levels of TGF-β1 and avian β-defensin (AvBD)12 were significantly increased compared to those of control diet broilers (p<0.05), and a significant correlation was observed between the two genes (p<0.05). Our results indicated that sake lees should not be dried and should be mixed immediately with feed, and this sake lees when fed to chicken activates the intestinal immunity. However, sake lees have a lower fat content than corn, and it is thus important to combine sake lees with high-energy feed.

Effect of Lactobacillus rhamnosus MN-431 Producing Indole Derivatives on Complementary Feeding-Induced Diarrhea Rat Pups Through the Enhancement of the Intestinal Barrier Function

SCOPE

Many infants suffer from complementary feeding-induced diarrhea (CFID). Studies have shown that intestinal microbes can enhance the intestinal barrier and prevent diarrhea by producing indole derivatives that promote pregnane X receptor (PXR) expression.

METHODS AND RESULTS

In this study, the indole test and determination of the PXR concentration are performed on tryptophan broth cultures of 320-suspected Lactobacillus and Enterococcus strains. Four strains that produce indole derivatives that promote the expression of PXR are screened as potential functional probiotics. Both Lactobacillus rhamnosus MN-431 (L. rhamnosus MN-431) and Lactobacillus oris FN-448 (L. oris FN-448) can colonize the intestine of rat pups, and L. rhamnosus MN-431 can significantly decrease the incidence of diarrhea and intestinal permeability in rat pups. Using real-time qPCR and the analysis of the intestinal morphology using immunohistochemistry, it is observed that the metabolized tryptophan from L. rhamnosus MN-431 can reduce small intestinal mucosal damage by stimulating PXR/NF-κB signaling and activating PXR and aryl hydrocarbon receptor. The intestinal barrier is also enhanced by promoting the expression of tight junction proteins such as Occludin and zonula occludens-1 in baby rats.

CONCLUSION

The results demonstrate that L. rhamnosus MN-431 can metabolize tryptophan to prevent infantile CFID by promoting the expression of PXR.

Biotechnological Addition of β-Glucans from Cereals, Mushrooms and Yeasts in Foods and Animal Feed

Varied cereal plants including, mushrooms, yeast, bacteria and algae are important sources of β-glucans, and many extraction procedures have been used in order to recover these valuable naturally occurring polysaccharides. The rheological and molecular properties of β-glucans can be utilized to be incorporated into various foods and to offer properties extremely beneficial to human health. Their functional effects are mainly determined by their molecular and structural characteristics. Consumption of foods fortified and enriched with β-glucans can contribute to the treatment of certain chronic diseases. Reduced cholesterol, cardiovascular and diabetic risk and moderate glycemic response of foods have been recorded with the consumption of these biologically active compounds. In addition, β-glucans are characterized by anti-cancer, antioxidant, anti-inflammatory and antiviral activities. As β-glucans interact with the foods in which they are incorporated, this review aims to discuss recent applications with quality and nutritional results of β-glucans incorporation with foods such as beverages, dairy, bakery, meat and pasta products, as well as their addition in animal feeds and their uses in other fields such as medicine.

Variations on gut health and energy metabolism in pigs and humans by intake of different dietary fibers

Many studies have reported that dietary fibers play a crucial role in promoting intestinal health of the host, since it strengthens functions of epithelial barrier and meanwhile maintains intestinal homeostasis of the host by modulating gut microbiota and short-chain fatty acid (SCFA) production. Pig is a good animal model to study effects of dietary fiber on gut health and microbial community. This review has summarized the relevant knowledge available based on roles of various dietary fibers in gut health and energy metabolism of pigs and humans. Evidences summarized in our review indicated that modulating intestinal microbial composition and SCFA production by consuming specific dietary fibers properly could be conducive to health improvement and disease prevention of the host. However, types of dietary fiber from edible foods exert divergent impacts on gut health, energy metabolism, microbial composition, and SCFA production. Therefore, more attention should be focused on different responses of various dietary fibers intake on host metabolism and health.

Environmental fluoride exposure disrupts the intestinal structure and gut microbial composition in ducks

Fluorine (F) and its compounds produced from industrial production and coal combustion can cause air, water and soil contamination, which can accumulate in animals, plants and humans via food chain threatening public health. Fluoride exposure affects liver, kidney, gastrointestinal and reproductive system in humans and animals. Literature regarding fluoride influence on intestinal structure and microbiota composition in ducks is scarce. This study was designed to investigate these effects by using simple and electron microscopy and 16S rRNA sequencing techniques. Results indicated an impaired structure with reduced relative distribution of goblet cells in the fluoride exposed group. Moreover, the gut microbiota showed a significant decrease in alpha diversity. Proteobacteria, Firmicutes and Bacteroidetes were the most abundant phyla in both control and fluoride-exposed groups. Specifically, fluoride exposure resulted in a significant decrease in the relative abundance of 9 bacterial phyla and 15 bacterial genera. Among them, 4 phyla (Latescibacteria, Dependentiae, Zixibacteria and Fibrobacteres) and 4 genera (Thauera, Hydrogenophaga, Reyranella and Arenimonas) weren't even detectable in the gut microbiota of the ducks. In summary, higher fluoride exposure can significantly damage the intestinal structure and gut microbial composition in ducks.

L-Theanine affects intestinal mucosal immunity by regulating short-chain fatty acid metabolism under dietary fiber feeding

To investigate the effects of l-Theanine (LTA) on intestinal mucosal immunity and the regulation of short-chain fatty acid (SCFA) metabolism under dietary fiber feeding, a 28-day feeding experiment was performed in Sprague-Dawley rats. The results show that LTA increased the proportion of Prevotella, Lachnospira, and Ruminococcus while increasing the total SCFA, acetic acid, propionic acid, and butyric acid contents in the feces. LTA also increased IgA, IgE, and IgG levels in the ileum, and increased villi height and crypt depth. Moreover, LTA upregulated the mRNA and protein expression of acetyl-CoA carboxylase 1, sterol element-binding protein 1c, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase in the liver, while downregulating the expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon. Our study suggests that LTA can affect intestinal mucosal immunity by regulating SCFA metabolism under dietary fiber feeding.

Influence of Short-Term Consumption of Hericium erinaceus on Serum Biochemical Markers and the Changes of the Gut Microbiota: A Pilot Study

Hericium erinaceus (H. erinaceus) is widely studied as a medicinal and edible fungus. Recent studies have shown that H. erinaceus has protective effects for diseases, such as inflammatory bowel disease and cancer, which are related to gut microbiota. To investigate the benefits of H. erinaceus intake on gut microbiota and blood indices in adulthood, we recruited 13 healthy adults to consume H. erinaceus powder as a dietary supplement. Blood changes due to H. erinaceus consumption were determined by routine hematological examination and characterized by serum biochemical markers. Microbiota composition was profiled by 16S ribosomal RNA gene sequencing. Results showed that daily H. erinaceus supplementation increased the alpha diversity within the gut microbiota community, upregulated the relative abundance of some short-chain fatty acid (SCFA) producing bacteria (Kineothrix alysoides, Gemmiger formicilis, Fusicatenibacter saccharivorans, Eubacterium rectale, Faecalibacterium prausnitzii), and downregulated some pathobionts (Streptococcus thermophilus, Bacteroides caccae, Romboutsia timonensis). Changes within the gut microbiota were correlated with blood chemical indices including alkaline phosphatase (ALP), low-density lipoprotein (LDL), uric acid (UA), and creatinine (CREA). Thus, we found that the gut microbiota alterations may be part of physiological adaptations to a seven-day H. erinaceus supplementation, potentially influencing beneficial health effects.

Dietary soluble non-starch polysaccharide level and xylanase supplementation influence performance, egg quality and nutrient utilization in laying hens fed wheat-based diets

The aim of this study was to evaluate the effects of dietary soluble non-starch polysaccharide (sNSP) content and xylanase supplementation on production performance, egg quality parameters, and nutrient digestibility in Hy-line Brown layers from 25 to 32 wk of age. A total of 144 Hy-line Brown laying hens (25 wk of age) were randomly allocated to 1 of 4 wheat-based dietary treatments in a 2 × 2 factorial experimental design, with 36 replicates of individual hens per treatment. The diets were formulated to contain either a high or low sNSP level (at 13.3 or 10.8 g/kg) and were supplemented with either 0 or 12,000 BXU/kg exogenous xylanase. Birds were fed these treatment diets for an 8-wk period, and hen production performance, including daily egg production, average egg weight, daily egg mass, feed conversion ratio and proportion of dirty and abnormal eggs were measured at bird age 25 to 28 wk and 29 to 32 wk. An interaction between sNSP content of the diet and xylanase supplementation was observed on daily egg production from 25 to 28 wk of age (P = 0.018); birds fed the high sNSP diet without xylanase had lower egg production than those fed any other treatment. An interaction between the 2 dietary factors was also observed on hen weight gain at 29 to 32 wk of age (P = 0.014), with birds fed the low sNSP diet with 12,000 BXU/kg xylanase presenting greater weight gain compared to those fed the high sNSP diet with 12,000 BXU/kg xylanase. Feed intake at 29 to 32 wk of age was reduced by xylanase supplementation (P = 0.047). Xylanase supplementation also increased yolk colour score at both 28 and 32 wk of age, and decreased yolk weight at 32 wk of age (P = 0.014, 0.037 and 0.013, respectively). Birds fed the low sNSP diet presented lower protein digestibility (P = 0.024) than those fed the high sNSP diet. Additionally, birds fed high sNSP presented higher shell reflectivity at both 28 and 32 wk of age (P = 0.05 and 0.036, respectively). The influence of duration of feeding the treatment diets on egg quality was also determined. It was observed that egg weight, yolk weight and yolk colour score consistently increased over time, regardless of experimental treatment effects. In contrast, Haugh Unit and albumen height significantly decreased throughout the study period in all treatments, although this was less pronounced in hens fed the treatment with high sNSP and no supplemental xylanase. A reduction in shell breaking strength over time was observed only in hens fed the treatments without xylanase addition, and shell thickness was improved over time only in birds fed the low sNSP diet with xylanase. The impacts of the dietary treatments were largely inconsistent in this study, so a solid conclusion cannot be drawn. However, these findings do indicate that dietary NSP level influences layer production performance, and thus should be considered when formulating laying hen diets. It also proved that further research is warranted into how to optimize the benefits of xylanase application in laying hens.

Growth and gut performance of young pigs in response to different dietary cellulose concentration and rearing condition

Objective

This experiment was conducted to investigate the effect of insoluble cellulose supplementation to diets on the growth performance, intestinal morphology, the incidence of diarrhea, nutrients digestibility, and inflammatory responses in altering environmental conditions of animals housing.

Methods

A total of 108 male pigs (Duroc×[Yorkshire×Landrace]) were randomly allocated to one of three dietary treatments (cellulose 0%, 1%, 2%) and two environmental conditions (good sanitary condition vs. poor sanitary condition) to give 6 replicate pens per treatment with three pigs per each pen at 14 days post-weaning.

Results

Pigs were in good sanitary condition had higher average daily gain (p<0.01) and improved feed efficiency (p<0.05) from day 1 to 14 after weaning compared to their counterparts. The interactions were found between environmental conditions and dietary treatments (day 7: crypt depth [p<0.01], villous height to crypt depth [p<0.001]; day 14: crypt depth [p<0.001], villous to crypt ratio [p<0.01]) in ileum morphology. Crypt depth was decreased (p<0.05), and villous to crypt ratio was increased (p<0.05) only in poor sanitary conditions. Pigs exposed to the good sanitary condition had higher (p<0.05) apparent ileal digestibility (day 7, gross energy; day 14, dry matter), apparent total tract digestibility (day 14, dry matter and crude protein) compared to pigs housed in the poor sanitary condition. Meanwhile, pigs fed a diet supplemented with 2% cellulose had decreased (p<0.05) apparent ileal digestibility (day 7, dry matter; day 14, crude protein), apparent total tract digestibility (day 7, dry matter; day 14, crude protein, gross energy) compared to pigs fed a diet supplemented with 0% or 1% cellulose.

Conclusion

Our results indicated that a diet supplemented with 1% cellulose increased villous to crypt ratio, however feeding a diet containing cellulose (1% or 2%) impaired nutrient digestibility for 14 day after weaning in both good sanitary and poor sanitary conditions.

Debranching enzymes in corn/soybean meal-based poultry feeds: a review

This review discusses the complex nature of the primary nonstarch polysaccharide (NSP) in corn with respect to the merit of debranching enzymes. Celluloses, hemicelluloses, and pectins comprise the 3 major categories of NSP that make up nearly 90% of plant cell walls. Across cereals, the hemicellulose arabinoxylan exists as the primary NSP, followed by cellulose, glucans, and others. Differences in arabinoxylan structure among cereals and cereal fractions are facilitated by cereal type, degree and pattern of substitution along the xylan backbone, phenol content, and cross-linkages. In particular, arabinoxylan (also called glucuronoarabinoxylan) in corn is heavily fortified with substituents, being more populated than in wheat and other cereal grains. Feed-grade xylanases - almost solely of the glycoside hydrolase (GH) 10 and GH 11 families - require at least 2 or 3 contiguous xylose units to be free of attachments to effectively attack the xylan chain. This canopy of attachments, along with a high phenol content and the insoluble nature of corn glucuronoarabinoxylan, confers a significant resistance to xylanase attack. Both in vitro and in vivo studies demonstrate that debranching enzymes appreciably increase xylanase access and fiber degradability by removing these attachments and breaking phenolic linkages. The enzymatic degradation of the highly branched arabinoxylan can facilitate disassembly of other fibers by increasing exposure to pertinent carbohydrases. For cereals, the arabinofuranosidases, α-glucuronidases, and esterases are some of the more germane debranching enzymes. Enzyme composites beyond the simple core mixes of xylanases, cellulases, and glucanases can exploit synergistic benefits generated by this class of enzymes. A broad scope of enzymatic activity in customized mixes can more effectively target the resilient NSP construct of cereal grains in commercial poultry diets, particularly those in corn-based feeds.

Effects of cereal fibers on short-chain fatty acids in healthy subjects and patients: a meta-analysis of randomized clinical trials

Short-chain fatty acids (SCFAs) are involved in the regulation of a wide array of diseases. However, the effect of cereal dietary fibers on SCFA production remains unclear. We reviewed relevant clinical studies between 1950 and 2021 and aimed to evaluate the effect of cereal fiber consumption on SCFA production in healthy subjects and patients. PubMed, Web of Science, and the Cochrane Library databases were used for systematically searching published relevant trials with adults and a minimum intervention duration of 2 weeks. The effect size was estimated using standardized mean difference (SMD) and 95% confidence interval (CI). Of the 555 identified studies, 14 intervention groups involving 205 participants aged between 20 and 69 years are eligible. The results of meta-analysis revealed that cereal fiber supplementation significantly increased acetate [SMD: 0.86, 95% CI (0.46, 1.25), p < 0.0001], propionate [SMD: 0.48, 95% CI: (0.15, 0.81), p = 0.004], butyrate [SMD: 0.61, 95% CI: (0.20, 1.01), p = 0.003], and total SCFA [SMD, 0.96, 95% CI: (0.54, 1.39), p < 0.00001] concentrations. Subgroup analysis suggested that a long intervention duration (>4 weeks) significantly promoted acetate and propionate production, whereas a short intervention duration (≤4 weeks) significantly facilitated butyrate production. Cereal fiber supplementation had a more significant impact on overweight and obese subjects with body mass index (BMI) >29 kg m-2 than on individuals with BMI ≤29 kg m-2. Furthermore, we found that cereal fibers and wheat/rye arabinoxylan oligosaccharides, rather than wheat bran fibers, barley fibers, and barley β-glucan, could significantly elevate the SCFA concentration. Overall, our meta-analysis demonstrated that cereal fiber supplementation is helpful in increasing the SCFA concentration, which provided strong proof for the beneficial role of cereal fibers.