Dietary supplemental coated essential oils and organic acids mixture improves growth performance and gut health along with reduces Salmonella load of broiler chickens infected with Salmonella Enteritidis

Background Reducing Salmonella infection in broiler chickens by using effective and safe alternatives to antibiotics is vital to provide safer poultry meat and minimize the emergence of drug-resistant Salmonella and the spread of salmonellosis to humans.This study was to first evaluate the protective efficacy of feeding coated essential oils and organic acids mixture(EOA)on broiler chickens infected with Salmonella Enteritidis(S.Enteritidis,SE),and then its action mechanism was further explored.Methods A total of 4801-day-old Arbor Acres male chickens were randomly assigned into five treatments with six replicates,including non-challenged control fed with basal diet(A),SE-challenged control(B),and SE-infected birds fed a basal diet with 300 mg/kg of EOA(BL),500 mg/kg of EOA(BM)and 800 mg/kg of EOA(BH),respectively.All birds on challenged groups were infected with Salmonella Enteritidis on d 13.Results Feeding EOA showed a reversed ability on negative effects caused by SE infection,as evidenced by decreasing the feed conversion rate(FCR)and the ratio of villus height to crypt depth(VH/CD)(P<0.05),obviously decreasing intestinal and internal organs Salmonella load along with increasing cecal butyric acid-producing bacteria abundance(P<0.05).Moreover,supplemental different levels of EOA notably up-regulated claudin-1(CLDN-1),occludin(OCLN),zonula occludens-1(ZO-1),mucin-2(MUC-2),fatty acid binding protein-2(FABP-2),nuclear factor kappa-light-chainenhancer of activated B cells(NF-κB),myeloid differential protein-88(MyD88)and interleukin-6(IL-6)mRNA levels in the ileum of the infected chickens after challenge,whereas down-regulated toll-like receptor-4(TLR-4)mRNA levels(P<0.05).Linear discriminant analysis combined effect size measurements analysis(LEfSe)showed that the relative abundance of g_Butyricicoccus,g_Anaerotruncus and g_unclassified_f_Bacillaceae significantly was enriched in infected birds given EOA.Also,phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt)analysis showed that alpha-linolenic acid metabolism,fatty acid metabolism and biosynthesis of unsaturated fatty acids were significantly enriched in the EOA group.Conclusion Our data suggest that the essential oils and organic acids mixture can be used as an effective strategy to ameliorate and alleviate Salmonella Enteritidis infection in broilers.

Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.

Medium-chain fatty acids and monoglycerides as feed additives for pig production:towards gut health improvement and feed pathogen mitigation

Ongoing challenges in the swine industry,such as reduced access to antibiotics and virus outbreaks(e.g.,porcine epidemic diarrhea virus,African swine fever virus),have prompted calls for innovative feed additives to support pig production.Medium-chain fatty acids(MCFAs)and monoglycerides have emerged as a potential option due to key molecular features and versatile functions,including inhibitory activity against viral and bacterial pathogens.In this review,we summarize recent studies examining the potential of MCFAs and monoglycerides as feed additives to improve pig gut health and to mitigate feed pathogens.The molecular properties and biological functions of MCFAs and monoglycerides are first introduced along with an overview of intervention needs at different stages of pig production.The latest progress in testing MCFAs and monoglycerides as feed additives in pig diets is then presented,and their effects on a wide range of production issues,such as growth performance,pathogenic infections,and gut health,are covered.The utilization of MCFAs and monoglycerides together with other feed additives such as organic acids and probiotics is also described,along with advances in molecular encapsulation and delivery strategies.Finally,we discuss how MCFAs and monoglycerides demonstrate potential for feed pathogen mitigation to curb disease transmission.Looking forward,we envision that MCFAs and monoglycerides may become an important class of feed additives in pig production for gut health improvement and feed pathogen mitigation.

Dietary encapsulated essential oils and organic acids mixture improves gut health in broiler chickens challenged with necrotic enteritis

Background:The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE)due to Clostridium perfringens.In the present study,we investigated the effects of dietary supplementation with a blend of encapsulated essential oils and organic acids(BLJ)on growth performance and gut health using a coinfection model of NE in broiler chickens.Methods:Two hundred and eighty-eight one-day-old male Arbor Acres broiler chicks were randomly assigned using a 2×2 factorial design into two groups fed either 0 or 500 mg/kg dietary BLJ and co-challenged(or not challenged for the control)with Eimeria spp./C.perfringens.Results:Infected birds fed the BLJ-supplemented diet exhibited an improved feed conversion ratio throughout the trial(P<0.01),a higher villus height and villus height/crypt depth ratio,and reduced intestinal C.perfringens counts,liver C.perfringens carriage,gut lesion scores and serum fluorescein isothiocyanate dextran(FITC-D)concentrations at 7 d postinfection compared with those of birds without BLJ supplementation(P<0.05).NE-infected birds fed BLJ exhibited significantly upregulated claudin-1 and IGF-2 mRNA levels(P<0.05),increased A20 mRNA expression and significantly downregulated TRAF-6,TNFSF15 and TOLLIP mRNA levels in the jejunum at 7 d post-infection compared with those in birds without BLJ supplementation(P<0.05).Compared with the uninfected and untreated birds,the uninfected birds fed BLJ displayed increased relative abundances of Lactobacillus and Coprococcus but reduced Rikenellaceae levels.Compared with the unsupplemented NE-challenged birds,infected birds fed BLJ showed an increased relative abundance of Unclassified_Lachnospiraceae and a significantly decreased relative abundance of Erysipelotrichaceae.Conclusion:BLJ supplementation improved growth performance and gut health in NE-infected broiler chickens by strengthening the intestinal barrier function,positively modulating the gut microbiota community and differentially regulating intestinal immune responses.Our results also suggested that adding BLJ effectively controlled NE infections after experimental Eimeria and Clostridium perfringens coinfection.

Black soldier fly and gut health in broiler chickens:insights into the relationship between cecal microbiota and intestinal mucin composition

Background:The relationship between diet and intestinal microbiota and mucin composition appears to be fundamental for poultry gut health.The effects of insect meal(whose role as alternative feed ingredient is now well recognized)on gut microbiota and mucin composition have recently been reported in Tenebrio molitor-fed free-range and broiler chickens,but no data are currently available for Hermetia illucens(HI)-fed broilers.The present study evaluated the effects of dietary HI meal inclusion on cecal microbiota and intestinal mucin composition of broiler chickens.Results:A total of 256 male broiler chickens were allotted to 4 dietary treatments(control diet[C]and 5%,10%and 15%HI meal inclusion,with 8 replicate pens/treatment and 8 birds/pen)and slaughtered at 35 d of age(2 animals/pen,16 birds/diet).The cecal microbiota assessment by 16S rRNA amplicon based sequencing showed lower alpha diversity in HI15 chickens(Shannon,P<0.05)and higher beta diversity(Adonis and ANOSIM,P<0.001)in birds fed HI diets than C.Furthermore,HI15 birds displayed significant increase of the relative abundance of Proteobacteria phylum(False Discovery Rate[FDR]<0.05)when compared to HI10.L-Ruminococcus(Ruminococcus from Lachnospiraceae family),Faecalibacterium,Blautia and Clostridium genera were found to be characteristic of HI5 cecal microbiota(FDR<0.05),while broiler chickens fed HI10 and HI15 diets were characterized(FDR<0.05)by Lactobacillus and Ruminococcus(HI10)and Bacteroides,Roseburia and Helicobacter genera(HI15).Periodic-acid Schiff,Alcian Blue pH 2.5 and high iron diamine staining on small and large intestine also demonstrated lower mucin staining intensity in the intestinal villi of HI10 and HI15 birds than C(P<0.05).Conclusions:Dietary HI meal utilization at low inclusion levels(i.e.,5%)positively influenced either the cecal microbiota or the gut mucin dynamics in terms of selection of potentially beneficial bacteria and increase in villi mucins.However,high inclusion levels(in particular the 15%)may have a negative influence in terms of partial reduction of microbial complexity,reduction of potentially beneficial bacteria,selection of bacteria with mucolytic activity and decrease in villi mucins.

Bacteroides utilization for dietary polysaccharides and their beneficial effects on gut health

Polysaccharide was a class of macromolecular substance with various bioactive functions.Gut symbiotic microorganisms could utilize the polysaccharides from various sources,thus have important impact on human health.Bacteroides represented one of the dominant colonizers in the human gut.The utilization of polysaccharide by Bacteroides was important for supporting the function and stability of gut microbiota.After the degradation of polysaccharides by Bacteroides,gut microbes could ferment the monosaccharides and oligosaccharides degraded from polysaccharides into some metabolites,such as short-chain fatty acids(SCFAs),amino acids,etc.Among the metabolites,the SCFAs could have beneficial effects on gut health.This review summarized the niches of Bacteroides among gut microbiota,and also described the gene clusters and membrane proteins involved in the utilization processes of polysaccharide by gut Bacteroides.SCFAs could act as energy substrates for intestinal epithelial cells,inhibit histone deacetylases and activate G protein-coupled receptors.In addition,the future perspectives in investigating new degradation pathways for polysaccharide,and using polysaccharides or their metabolites as therapeutic approaches for diseases mediated by the gut dysbiosis were also provided.

Resistant starch: Implications of dietary inclusion on gut health and growth in pigs:a review

Starch from cereal grains,pulse grains,and tubers is a major energy substrate in swine rations constituting up to 55%of the diet.In pigs,starch digestion is initiated by salivary and then pancreaticα-amylase,and has as final step the digestion of disaccharides by the brush-border enzymes in the small intestine that produce monosaccharides(glucose)for absorption.Resistant starch(RS)is the proportion of starch that escapes the enzymatic digestion and absorption in the small intestine.The undigested starch reaches the distal small intestine and hindgut for microbial fermentation,which produces short-chain fatty acids(SCFA)for absorption.SCFA in turn,influence microbial ecology and gut health of pigs.These fermentative metabolites exert their benefits on gut health through promoting growth and proliferation of enterocytes,maintenance of intestinal integrity and thus immunity,and modulation of the microbial community in part by suppressing the growth of pathogenic bacteria while selectively enhancing beneficial microbes.Thus,RS has the potential to confer prebiotic effects and may contribute to the improvement of intestinal health in pigs during the post-weaning period.Despite these benefits to the well-being of pigs,RS has a contradictory effect due to lower energetic efficiency of fermented vs.digested starch absorption products.The varying amount and type of RS interact differently with the digestion process along the gastrointestinal tract affecting its energy efficiency and host physiological responses including feed intake,energy metabolism,and feed efficiency.Results of research indicate that the use of RS as prebiotic may improve gut health and thereby,reduce the incidence of post-weaning diarrhea(PWD)and associated mortality.This review summarizes our current knowledge on the effects of RS on microbial ecology,gut health and growth performance in pigs.

Gut health benefit and application of postbiotics in animal production

Gut homeostasis is of importance to host health and imbalance of the gut usually leads to disorders or diseases for both human and animal.Postbiotics have been applied in manipulating of gut health,and utilization of postbiotics threads new lights into the host health.Compared with the application of probiotics,the characteristics such as stability and safety of postbiotics make it a potential alternative to probiotics.Studies have reported the beneficial effects of components derived from postbiotics,mainly through the mechanisms including inhibition of pathogens,strengthen gut barrier,and/or regulation of immunity of the host.In this review,we summarized the characteristics of postbiotics,main compounds of postbiotics,potential mechanisms in gut health,and their application in animal production.

Effects of a Food Supplement with a Wild Thyme (Thymus serpyllum L.) Extract on Gut Health and the Microbiome in Humans: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Background: Based on the scientific and traditional knowledge, benefits for gut and digestive health were expected from Wild Thyme (Thymus serpyllum L.) extract (WThE) consumption, but no controlled human studies were performed yet to prove the proposed health benefits. Method: The aim of this human randomized, double-blind parallel arm pilot study was to explore the impact of aqueous Wild Thyme extract, a food supplement, in a healthy but overweight study collective (N = 40). In detail, the impact on digestion, gastrointestinal symptoms, gut microbiome, and quality of life by employing an essential oil-free WThE preparation or a matching placebo was investigated. Results: The study results indicate that WThE has the potential to improve gastrointestinal symptoms and increase stool frequency, thus an improved quality of life was observed. The stool microbiome of study collective was characterized by a high Firmicutes to Bacteroidetes ratio. A decrease in the mean Firmicutes/Bacteroidetes ratio was seen in WThE group. Conclusion: The data support the potential applications of WThE as a food supplement with benefits on gut health.

Effects of Bacillus coagulans supplementation on the growth performance and gut health of broiler chickens with Clostridium perfringens-induced necrotic enteritis

Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effects of feeding Bacil us coagulans on the growth performance and gut health of broiler chickens with C. perfringens-induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels(0 or 4 × 109 CFU/kg of diet) and two disease chal enge statuses(control or NE chal enged).Results: NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C.perfringens growth and liver invasion, and enhanced anti-C. perfringens specific sI gA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly(P < 0.05) decreased mucin-2(at 14 d post-infection(DPI), tol-like receptor 2(TLR2, at 7 and 14 DPI), TLR4(at 7 and 14 DPI), tumor necrosis factor super family15(TNFSF15, at 7 and 14 DPI), lysozyme(LYZ, at 14 DPI) and fowlicidin-2(at 7 and 14 DPI) mR NA levels, whereas it dramatical y(P = 0.001) increased IFN-γ mR NA levels at 7 DPI. However, chal enged birds fed diets supplemented with B.coagulans showed a significant(P < 0.01) decrease in gut lesion scores, decreased C. perfringens numbers in the cecum and liver, and an increase in fowlicidin-2 mR NA levels in compared with the uninfected birds. In addition, compared with the non-supplemented group, dietary inclusion of B. coagulans improved intestinal barrier structure, further increased specific sI gA levels and alkaline phosphatase(IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mR NA, and inhibited the growth, colonization, and invasion of C. perfringens; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mR NA levels.Conclusion: These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens-induced NE in broiler chickens.

Probiotic cocktails accelerate baicalin metabolism in the ileum to modulate intestinal health in broiler chickens

Background Baicalin and probiotic cocktails are promising feed additives with broad application prospects.While probiotic cocktails are known to enhance intestinal health,the potential synergistic impact of combining baicalin with probiotic cocktails on the gut health of broiler chickens remains largely unexplored.Therefore,this study aims to investigate the influence of the combined administration of baicalin and probiotic cocktails on the composition of ileal and cecal microbiota in broiler chickens to elucidate the underlying mechanisms responsible for the healthpromoting effects.Results A total of 3201-day-old male Arbor Acres broilers were divided into 4 groups,each with 8 replicates of 10 chicks per replicate.Over a period of 42 d,the birds were fed a basal diet or the same diet supplemented with 37.5 g/t baicalin(BC),1,000 g/t probiotic cocktails(PC),or a combination of both BC(37.5 g/t)and PC(1,000 g/t).The results demonstrated that BC+PC exhibited positive synergistic effects,enhancing intestinal morphology,immune function,and barrier function.This was evidenced by increased VH/CD ratio,sIgA levels,and upregulated expression of occludin and claudin-1(P<0.05).16S rRNA analysis indicated that PC potentiated the effects of BC,particularly in the ileum,where BC+PC significantly increased theα-diversity of the ileal microbiota,altered itsβ-diversity,and increased the relative abundance of Flavonifractor(P<0.05),a flavonoid-metabolizing bacterium.Furthermore,Flavonifractor positively correlated with chicken ileum crypt depth(P<0.05).While BC+PC had a limited effect on cecal microbiota structure,the PC group had a very similar microbial composition to BC+PC,suggesting that the effect of PC at the distal end of the gut overshadowed those of BC.Conclusions We demonstrated the synergistic enhancement of gut health regulation in broiler chickens by combining baicalin and probiotic cocktails.Probiotic cocktails enhanced the effects of baicalin and accelerated its metabolism in the ileum,thereby influencing the ileal microbiota structure.This study elucidates the interaction mechanism between probiotic cocktails and plant extract additives within the host microbiota.These findings provide compelling evidence for the future development of feed additive combinations.

Weaning stress and gastrointestinal barrier development:Implications for lifelong gut health in pigs

The gastrointestinal(GI) barrier serves a critical role in survival and overall health of animals and humans. Several layers of barrier defense mechanisms are provided by the epithelial, immune and enteric nervous systems. Together they act in concert to control normal gut functions(e.g., digestion,absorption, secretion, immunity, etc.) whereas at the same time provide a barrier from the hostile conditions in the luminal environment. Breakdown of these critical GI functions is a central pathophysiological mechanism in the most serious GI disorders in pigs. This review will focus on the development and functional properties of the GI barrier in pigs and how common early life production stressors, such as weaning, can alter immediate and long-term barrier function and disease susceptibility.Specific stress-related pathophysiological mechanisms responsible for driving GI barrier dysfunction induced by weaning and the implications to animal health and performance will be discussed.

Implications of butyrate and its derivatives for gut health and animal production

Butyrate is produced by microbial fermentation in the large intestine of humans and animals.It serves as not only a primary nutrient that provides energy to colonocytes, but also a cellular mediator regulating multiple functions of gut cells and beyond, including gene expression, cell differentiation, gut tissue development, immune modulation, oxidative stress reduction, and diarrhea control.Although there are a large number of studies in human medicine using butyrate to treat intestinal disease, the importance of butyrate in maintaining gut health has also attracted significant research attention to its application for animal production, particularly as an alternative to in-feed antibiotics.Due to the difficulties of using butyrate in practice(i.e., offensive odor and absorption in the upper gut), different forms of butyrate,such as sodium butyrate and butyrate glycerides, have been developed and examined for their effects on gut health and growth performance across different species.Butyrate and its derivatives generally demonstrate positive effects on animal production, including enhancement of gut development, control of enteric pathogens, reduction of inflammation, improvement of growth performance(including carcass composition), and modulation of gut microbiota.These benefits are more evident in young animals, and variations in the results have been reported.The present article has critically reviewed recent findings in animal research on butyrate and its derivatives in regard to their effects and mechanisms behind and discussed the implications of these findings for improving animal gut health and production.In addition, significant findings of medical research in humans that are relevant to animal production have been cited.

Using probiotics to improve swine gut health and nutrient utilization

To maintain a healthy gut is definitely key for a pig to digest and absorb dietary nutrients efficiently. A balanced microbiota(i.e., a healthy micro-ecosystem) is an indispensable constituent of a healthy gut.Probiotics, the live microorganisms which, when administered in adequate amounts, confer good health benefits onto the host, are a category of feed additives that can be used to replenish the gut microbial population while recuperating the host immune system. Besides their antitoxin and diarrhea reduction effects, dietary supplementation of probiotics can improve gut health, nutrient digestibilities and,therefore, benefit nutrient utilization and growth performance of pigs. Current knowledge in the literature pertinent to the beneficial effects of utilizing various probiotics for swine production has been comprehensively reviewed, and the safety and the risk issues related to probiotic usage have also been discussed in this paper. Considering that the foremost cost in a swine operation is feed cost, feed efficiency holds a very special, if not the paramount, significance in commercial swine production. Globally,the swine industry along with other animal industries is moving towards restricting and eventually a total ban on the usage of antibiotic growth promoters. Therefore, selection of an ideal alternative to the in-feed antibiotics to compensate for the lost benefits due to the ban on the antibiotic usage is urgently needed to support the industry for profitable and sustainable swine production. As is understood, a decision on this selection is not easy to make. Thus, this review paper aims to provide some much needed up-to-date knowledge and comprehensive references for swine nutritionists and producers to refer to before making prudent decisions and for scientists and researchers to develop better commercial products.

Studying the effect of formic acid and potassium diformate on performance,immunity and gut health of broiler chickens

Our trial was conducted to study the effects of formic acid(FA) and potassium di-formate(KDF) in broiler ration on performance, carcass traits, blood biochemical, intestinal microbial load, histological picture of intestine and immune parameters of broilers. In this study 360 one-day-old broiler chicks were divided to 3 groups with 3 replicates of 40 chicks each. The trial continued for 35 days. The control group was fed only basal diet(G1). Group 2(G2) were fed basal diet supplemented with FA(5 g/kg diet), and group 3(G3) received basal diet supplemented with KDF(5 g/kg diet). The results showed that both FA and KDF significantly increased body weight gain(BWG), dressing percentage of broilers and significantly decreased feed conversion ratio(FCR)(P < 0.05). The highest percent of breast and thigh was observed in G3. The improvement in villus height was observed in G2 and G3 compared with the control one, and the highest was in G3. The results evidence that the using of FA or KDF in broiler feeds have significant effects on performance, immune parameters, and gut health without having any significant effects on blood biochemical. However, KDF is more effective than FA as little amount of FA reaches the small intestine due to metabolism and absorption, whereas KDF permits a proportion of FA to pass through the fore-gut intact and enter the small intestinal tract. In addition, FA has a strong odor and corrosiveness to gastrointestinal tract which limits its use.

Husbandry practices and gut health outcomes in weaned piglets:A review

The immediate post-weaning period is one of the most stressful phases in a pig's life, and during this period, piglets are usually exposed to environmental, social and psychological stressors which have direct or indirect effects on gut health and overall growth performance. In this review, the impact of husbandry practices on gut health outcomes and performance of piglets is discussed. Husbandry practices in the swine barn generally include nutrition and management practices, maintenance of hygienic standards and disease prevention protocols, and animal welfare considerations. Poor husbandry practices could result in reduced feed intake, stress and disease conditions, and consequently affect gut health and performance in weaned piglets. Reduced feed intake is a major risk factor for impaired gut structure and function and therefore a key goal is to maximize feed intake in newly weaned piglets. In weaned piglets, crowding stress could reduce pig performance, favor the proliferation of pathogenic bacteria resulting in diarrhea, stimulate immune responses and interfere with beneficial microbial activities in the gut. Sanitation conditions in the swine barn plays an important role for optimal piglet performance, because unclean conditions reduced growth performance, shifted nutrient requirements to support the immune system and negatively affected the gut morphology in weaned piglets. Appropriate biosecurity measures need to be designed to prevent disease entry and spread within a swine operation,which in turn helps to keep all pigs and piglets healthy. Collectively, husbandry practices relating to feeding and nutrition, animal welfare, biosecurity and disease prevention are important determinants of gut health and piglet performance. Thus, it is suggested that adopting high husbandry practices is a critical piece in strategies aimed at raising pigs without the use of in-feed antibiotics.

Application of resistant starch in swine and poultry diets with particular reference to gut health and function

The immediate post-weaning period poses a major challenge on the survival of piglets. Similarly, newly hatched chicks face life threatening challenges due to enteric infections. In the past several years, in-feed antibiotics have been used to reduce these production problems and improve growth. However, in-feed antibiotics have been banned in many jurisdictions and therefore the most effective alternatives to infeed antibiotics must be developed. To date, several studies have been conducted to develop alternatives to antibiotics. One of the potential candidates as alternatives to in-feed antibiotics is resistant starch(RS). Resistance starch is a type of starch that resists enzymatic digestion in the upper parts of the gastrointestinal tract and therefore passes to hindgut where it can be fermented by resident microorganisms. Microbial fermentation of RS in the hindgut results in the production of short chain fatty acids(SCFA). Production of SCFA in turn results in growth and proliferation of colonic and cecal cells, increased expression of genes involved in gut development, and creation of an acidic environment. The acidic environment suppresses the growth of pathogenic microorganisms while selectively promoting the growth of beneficial microbes. Thus, RS has the potential to improve gut health and function by modifying and stabilising gut microbial community and by improving the immunological status of the host. In this review, we discussed the roles of RS in modifying and stabilising gut microbiota, gut health and function, carcass quality, and energy metabolism and growth performance in pigs and poultry.

Prevotella-rich enterotype may benefit gut health in finishing pigs fed diet with a high amylose-to-amylopectin ratio

To investigate the influence of baseline enterotypes and dietary starch type on the concentration of short-chain fatty acids(SCFA),numbers of butyrate producing bacteria and the expression of genes related to intestinal barrier and inflammatory response in the colon of finishing pigs,a 60-d in vivo trial was conducted.A 2-wk pre-trial with 102 crossbred(Duroc×[Landrace×Yorkshire])finishing barrows(90 d old)was conducted to screen enterotypes.Then,a total of 32 pigs(87.40±2.76 kg)with high(HPBR,>14)and low(LPBR,<2)Prevotella-to-Bacteroides ratios(PBR)in equal measure were selected and randomly divided into 4 groups with 8 replicates per group and 1 pig per replicate.The trial was designed following a 2(PBR)×2(amylose-to-amylopectin ratio,AMR)factorial arrangement.Pigs with different PBR were fed diets based on corn-soybean meal with high AMR(HAMR,1.24)or low AMR(LAMR,0.23),respectively.Results showed that neither PBR nor AMR influenced the growth performance of pigs.HPBR pigs fed HAMR diet had a higher number of colonic Clostridium cluster XIVa and higher gene expression of butyrate kinase compared to the LPBR pigs(P<0.05).The HPBR pigs fed HAMR diets also had increased colonic concentrations of total SCFA and propionate compared to the LPBR pigs(P<0.05).Comparing with other pigs,HPBR pigs fed HAMR diets showed a lower(P<0.05)expression of histone deacetylases(HDAC)gene and higher(P<0.05)expression of G protein-coupled receptor 43 gene(GPR 43)in the colonic mucosa.The interaction(P<0.05)of HPBR and HAMR was also found to decrease the gene expression of interleukin(IL)-6,IL-12,IL-1βand tumor necrosis factor-α(TNF-α)in colonic mucosa.These findings show that HAMR diet increased the abundance and activity of butyrate-producing bacteria and the concentration and absorption of SCFA,which may be associated with the decreased gene expression of inflammatory cytokines in the colonic mucosa of pigs with Prevotella-rich enterotype.All these alterations are likely to have a positive effect on the intestinal health of finishing pigs.

Impacts of energy feeds and supplemental protease on growth performance, nutrient digestibility, and gut health of pigs from 18 to 45 kg body weight

A total of 144 pigs with 18.4 ± 2.3 kg initial body weight(BW) at 6 wk of age were used in a 40-d trial to evaluate effects of protease(300,000 U/kg feed, BioResource International Inc., Durham, NC, USA) on growth performance, apparent ileal digestibility(AID) of nutrients, and gut health of pigs fed diets with sorghum. Pigs were randomly allotted to 4 treatments(12 pens per treatment, 3 pigs per pen) in a 2 x 2 factorial arrangement(corn or sorghum basal diets, and 0 or 0.05% protease as 2 factors) with sex and initial BW as blocks. Experimental period had phase 1(d 1 to 21) and phase 2(d 22 to 40). About 65%(phase 1) and 72%(phase 2) of cereal grains were used in corn or sorghum based diets. Both grains were ground to 400 μm. Body weight and feed intake were recorded weekly. On d 35, serum was collected to quantify tumor necrosis factor-a(TNF-a) and malondialdehyde(MDA). Titanium dioxide(0.3%) was added as an indigestible marker for an additional 4 d feeding. On d 40, 32 pigs(8 pigs per treatment)were euthanized to collect digesta from jejunum and ileum(for viscosity and AID), tissues(for morphology) and mucosa samples(for TNF-α and MDA) from duodenum, jejunum, and ileum. Replacing corn with sorghum in the diet increased(P < 0.05) overall average daily gain(from 756 to 787 g/day) and average daily feed intake(from 1,374 to 1,473 g/day), reduced(P < 0.05) overall gain:feed ratio(from0.553 to 0.537), and did not affect AID. Pigs fed diets with sorghum had lower(P < 0.05) MDA content in serum(from 14.61 to 6.48 μmol/L) and jejunum(from 1.42 to 0.91 μmol/g protein), and reduced(P < 0.05) villus height(from 492 to 396 μm) and crypt depth(from 310 to 257 μm) in jejunum. Dietary protease improved(P < 0.05) AID of crude protein(from 81.8% to 86.0%), decreased MDA level(from 1.20 to 0.98 μmol/g protein) in duodenum, and increased(P < 0.05) the ratio of villus height to crypt depth(from 1.08 to 1.21) in duodenum. Overall, use of sorghum fully replacing corn in diets could benefit pigs with enhanced growth and feed intake potentially by reducing oxidative stress, whereas feed efficiency was compromised. Supplementation of protease improved protein digestion and maintained gut health,irrespective of sorghum or corn based diets.

The Gut Brain Connection

The gut-brain connection is a bidirectional communication system that links the gut microbiome to the central nervous system (CNS). The gut-brain axis communicates through a variety of mechanisms, including the release of hormones, neurotransmitters, and cytokines. These signaling molecules can travel from the gut to the brain and vice versa, influencing various physiological and cognitive functions. Emerging therapeutic strategies targeting the gut-brain connection include probiotics, prebiotics, and faecal microbiota transplantation (FMT). Probiotics are live microorganisms that are similar to the beneficial bacteria that are naturally found in the gut. Prebiotics are non-digestible fibers that feed the beneficial bacteria in the gut. FMT is a procedure in which faecal matter from a healthy donor is transplanted into the gut of a person with a diseased microbiome. Probiotics, prebiotics, and FMT have been shown to be effective in treating a variety of gastrointestinal disorders, and there is growing evidence that they may also be effective in treating neurological and psychiatric disorders. This review explores the emerging field of the gut-brain connection, focusing on the communication pathways between the gut microbiome and the central nervous system. We summarize the potential roles of gut dysbiosis in various neurological and psychiatric disorders. Additionally, we discuss potential therapeutic strategies, research limitations, and future directions in this exciting area of research. More research is needed to fully understand the mechanisms underlying the gut-brain connection and to develop safe and effective therapies that target this pathway. However, the findings to date are promising, and there is the potential to revolutionize the way we diagnose and treat a variety of neurological and psychiatric disorders.