Interference of age and supplementation of direct-fed microbial and essential oil in the activity of digestive enzymes and expression of genes related to transport and digestion of carbohydrates and proteins in the small intestine of broilers

Chitosan oligosaccharide improves intestinal function by promoting intestinal development, alleviating intestinal inflammatory response, and enhancing antioxidant capacity in broilers aged d 1 to 14

This study was conducted to investigate the effects of chitosan oligosaccharide (COS) supplementation on intestinal development and functions, inflammatory response, antioxidant capacity and the related signaling pathways in broilers aged d 1 to 14. A total of 240 one-day old male Arbor Acres broilers (40.47 ± 0.30 g) were randomly allotted to 4 groups, and each group consisted of 6 replicate pens with 10 broilers per replicate. Broilers fed a basal diet supplementation with COS at 0 (CON group), 200 (COS200 group), 400 (COS400 group), and 800 mg/kg (COS800 group) for 14 d, respectively. Broilers in the COS supplementation groups had no significant effects on growth performance. Compared to the CON group, dietary COS supplementation increased (P < 0.05) the relative weight of duodenum, jejunal lipase activity, duodenal and ileal villus surface area, and lower (P < 0.05) ileal amylase and alkaline phosphatase activity, and crypt depth. The expression level of duodenal glucose transporter 1 (GLUT1), Na+-glucose cotransporter 1 (SGLT1), peptide transporter 1 (PepT1), occludin, zonula occludens-1 (ZO-1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and interleukin-10 (IL-10), jejunal SGLT1, PepT1, occludin, tumor necrosis factor-α (TNF-α), and ileal SGLT1, PepT1, and fatty acid binding protein 1 (FABP1) was upregulated by COS. However, the expression level of duodenal FABP1 and TNF-α, jejunal GLUT1, ZO-1, TLR4, MyD88, nuclear factor kappa-B p65 (NF-κB p65), and IL-1β, and ileal GLUT1, NF-κB p65, and IL-1β was downregulated by COS. Furthermore, dietary COS supplementation increased duodenal catalase (CAT), glutathione peroxidase (GSH-Px), and total superoxide dismutase (T-SOD) activity, jejunal CAT and T-SOD activity, upregulated the expression level of duodenal nuclear factor-erythroid 2-related factor 2 (Nrf2), CAT, glutathione peroxidase 1 (GPX1), and copper and zinc superoxide dismutase (Cu/Zn SOD), jejunal CAT, and ileal Nrf2, CAT, and GPX1. These results suggested that COS could promote intestinal development and functions in broilers aged d 1 to 14, which might be mediated by alleviating intestinal inflammatory response and enhancing antioxidant capacity.

Effects of three probiotics and their interactions on the growth performance of and nutrient absorption in broilers

The purpose of this study was to investigate the effects of three probiotics and their interactions on growth performance, intestinal digestion and absorption, and nutrient transporters in broilers. A total of 350 one-day-old male Arbor Acres broilers were randomly divided into seven groups: the control group (broilers receiving normal drinking water), groups P1, P2 and P3 (broilers receiving drinking water with 1% Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis , respectively) and groups CP1, CP2 and CP3 (broilers receiving drinking water with a 1% compound probiotic mixture in 2:1:1, 1:2:1, 1:1:2 ratios, respectively). The feeding period was divided into two experimental periods: 1∼21 days and 22∼42 days. Compared to those in the control group, the broiler slaughter indexes and average daily feed intakes in the probiotics groups were not significantly different (P > 0.05), but the villus height in the small intestine increased significantly, and the crypt depth decreased significantly (P < 0.05). In the 1- to 21-day, experimental period, the broiler average daily gains in groups CP2 and CP3 were significantly greater than that in the control group. Amylase, lipase, and trypsin activities in the jejunum in groups CP and P3 increased significantly. GLUT2 mRNA expression in the probiotics group was significantly incresaed compared with that in the control group (P < 0.05). In the 22- to 42-day period, the average daily gain in the CP group was significantly greater than that in the control group. Amylase activity in the CP2 group, and lipase and trypsin activities in the CP, P1 and P3 groups increased significantly. The GLUT2 mRNA expression in the CP group increased significantly (P < 0.05). In summary, three probiotics and their interactions improved the digestibility and absorption of nutrients by increasing the activities of digestive enzymes, improving the morphology of the digestive tract, and upregulating the expression of GLUT2 mRNA in the intestinalcell membrane to improve the production performance in broilers.

Effect of Bacillus species–fermented products and essential oils on growth performance, gut morphology, cecal short-chain fatty acid levels, and microbiota community in broilers

In this study, the effects of Bacillus species–fermented products (synbiotics [SYNs]) and essential oils (EOs) on the growth performance, gut morphology, cecal short-chain fatty acid (SCFA) levels, and microbiota of broilers were investigated. A total of 180 one-day-old unsexed broiler chicks (Ross 308) were randomly assigned to 5 dietary treatments as follows: basal diet (control group), basal diet plus enramycin (10 mg/kg; A group), basal diet plus SYNs (3 × 10¹¹ CFU spore/kg of feed; SYN group), basal diet plus EOs (100 mg/kg; EO group), and basal diet plus SYNs and EOs (SYN + EO group), with 6 replicate cages per treatment group and 6 birds per cage. The SYN+EO treatment resulted in a higher (P = 0.003) average daily gain at 1 to 14 d of age than did the control and EO treatments. SYNs had a significant effect on the average daily gain at 1 to 14 d (P < 0.001) and 1 to 35 d (P = 0.045) of age. EOs had a significant effect on the villus height of the duodenum (P = 0.015) and jejunum (P = 0.027). Superoxide dismutase (SOD) and mucin 2 (MUC2) mRNA expression in the duodenum, jejunum, and ileum in the SYN + EO group was higher (P < 0.001) than that in any of the other groups. The SYN+EO treatment resulted in higher (P < 0.001) 2-methylbutyric acid and 3-methylbutyric acid levels in the cecal digesta of the broilers than did the control treatment. Cecal species evenness in the SYN + EO group was higher (P < 0.001) than that in the control group. The abundance of the phylum Firmicutes in the cecal digesta of the broilers was higher (P < 0.001) in the SYN+EO group than in the control group. SYNs had a significant effect (P < 0.001) on the abundance of the genus Lactobacillus in the cecal digesta of the broilers. The abundance of the genus Lactobacillus was positively associated with 2-methylbutyric acid and 3-methylbutyric acid levels. The 2-methylbutyric acid and 3-methylbutyric acid levels were positively correlated with the villus height of the duodenum and ileum. These results suggest that simultaneous supplementation with SYNs and EOs can increase the average daily gain, improve gut health–associated gene expression, increase SCFA levels, and modulate the gut microbiota composition of broilers.

The Impact of Probiotic Bacillus subtilis on Injurious Behavior in Laying Hens

Simple Summary

Injurious behavior prevention is a critical issue in the poultry industry due to increasing social stress, leading to negative effects on bird production and survivability, consequently enhancing gut microbiota dysbiosis and neuroinflammation via the microbiota–gut–brain axis. Probiotics have been used as potential therapeutic psychobiotics to treat or improve neuropsychiatric disorders or symptoms by boosting cognitive and behavioral processes and reducing stress reactions in humans and various experimental animals. The current data will first report that probiotic Bacillus subtilis reduces stress-induced injurious behavior in laying hens via regulating microbiota–gut–brain function with the potential to be an alternative to beak trimming during poultry egg production.

Abstract

Intestinal microbiota functions such as an endocrine organ to regulate host physiological homeostasis and behavioral exhibition in stress responses via regulating the gut–brain axis in humans and other mammals. In humans, stress-induced dysbiosis of the gut microbiota leads to intestinal permeability, subsequently affecting the clinical course of neuropsychiatric disorders, increasing the frequency of aggression and related violent behaviors. Probiotics, as direct-fed microorganism, have been used as dietary supplements or functional foods to target gut microbiota (microbiome) for the prevention or therapeutic treatment of mental diseases including social stress-induced psychiatric disorders such as depression, anxiety, impulsivity, and schizophrenia. Similar function of the probiotics may present in laying hens due to the intestinal microbiota having a similar function between avian and mammals. In laying hens, some management practices such as hens reared in conventional cages or at a high stocking density may cause stress, leading to injurious behaviors such as aggressive pecking, severe feather pecking, and cannibalism, which is a critical issue facing the poultry industry due to negative effects on hen health and welfare with devastating economic consequences. We discuss the current development of using probiotic Bacillus subtilis to prevent or reduce injurious behavior in laying hens.

META-ANALYSIS OF PHYTOGENIC ADDITIVES FOR BROILERS

Phytogenic additives have been studied intensively in broiler chickens’ production to substitute growth-promoting antibiotics. However, the comprehensive literature on this topic makes it difficult to understand overall results because there are a noticeable number of studies with conflicting conclusions. While several research studies have shown that phytogenic additives may increment broiler chicken’s performance, others make the opposite evident. This study aimed to organize and understand information through meta-analysis considering a great number of publications and the factors that may interfere in the results of phytogenic additives, evaluating whether phytogenic additives can be used as a performance-enhancing additive for broilers, comparing with the effectiveness of growth-promoting antibiotics. The main factor that interferes in the evaluation of phytogenic additives is the microbiological challenge. Phytogenic additives improved average daily gain (ADG) (P < 0.001) and feed conversion (P < 0.001) regardless of microbiological challenge; however, they were worse compared to antibiotics under higher challenge (P < 0.020). A meta-regression of ADG in function of average daily feed intake confirmed that phytogenic additives increased the feed efficiency of broilers, but with less effectiveness than antibiotics. The blends of phytogenic additives increased the ADG in relation to the isolated use of only one phytogenic additive.

Determination of the Nutritional Value of Diet Containing Bacillus subtilis Hydrolyzed Feather Meal in Adult Dogs

Simple Summary

The production of meat for human consumption produces extra ingredients used in animal nutrition. Feathers, for example, account for about 7% of the chicken’s body weight. When discarded, it presents a potential risk of environmental contamination. Feathers are minimally digested in mammals and are a very rich source of protein. Improved digestibility can be done by thermal processing or by microorganisms. Bacillus subtilis was shown to have great feather-degrading activity In vitro and we produced an amount of microbial hydrolysate to test in dogs. We did some evaluations on the ingredient to measure the effects of the microorganism on feathers. In dogs, a test of total tract digestibility, microbial resistance to the gastrointestinal tract, and fecal characteristics were performed. Bacillus subtilis was less efficient to digest feathers when a higher concentration of feathers was added to the culture. The amino acid profile in feathers has probably changed due to fermentation. Dogs ate the diets quickly, with no refusals. Nutrient and energy total tract digestibility were lower when compared to thermally processed feathers, but Bacillus subtilis was found viable in the feces of dogs that ingested fermented feathers, signaling that Bacillus subtilis is resistant to digestion and may bring some probiotic effect.

Abstract

Feathers are naturally made up of non-digestible proteins. Under thermal processing, total tract digestibility can be partially improved. Furthermore, Bacillus subtilis (Bs) has shown a hydrolytic effect In vitro. Then, a Bs FTC01 was selected to hydrolyze enough feathers to produce a meal, and then test the quality and inclusion in the dog’s diet to measure the apparent total tract digestibility coefficient (ATTDC) in vivo and the microorganism’s ability to survive in the gastrointestinal tract. A basal diet was added with 9.09% hydrolyzed Bs feather meal (HFMBs) or 9.09% thermally hydrolyzed feather meal (HFMT). Nine adult dogs were randomized into two 10-day blocks and fed different diets. Microbial counts were performed on feather meal, diets and feces. The Bs was less effective in digesting the feathers, which reduced the ATTDC of dry matter, crude protein, energy and increased the production of fecal DM, but the fecal score was maintained (p > 0.05). The digestible energy of HFMT and HFMBs was 18,590 J/kg and 9196 J/kg, respectively. Bacillus subtilis showed limitation to digest feather in large scale, but the resistance of Bs to digestion was observed since it grown on feces culture.

Citral alleviates peptidoglycan-induced inflammation and disruption of barrier functions in porcine intestinal epithelial cells

Peptidoglycan (PGN) is a major polymer in bacterial cell walls and may constrain gut functionality and lower intestinal efficiencies in livestock. Citral has been reported to exhibit antibacterial and anti-inflammatory biological activities, improving the gastrointestinal function of swine. However, the protective effect of citral against PGN-elicited cellular responses and possible underlying mechanisms are unknown. In this study, the porcine jejunal epithelial cell line (IPEC-J2) was challenged with PGN from Staphylococcus aureus (S. aureus) or Bacillus subtilis (B. subtilis) to explore PGN-induced inflammatory responses. Our data showed that the inflammatory response stimulated by PGN from harmful bacteria (S. aureus) was more potent than that from commensal bacteria (B. subtilis) in IPEC-J2 cells. Based on the inflammatory model by PGN from S. aureus, it was demonstrated that PGN could significantly induce inflammatory cytokine production and influence nutrient absorption and barrier function in a dose-dependent manner. However, the PGN-mediated immune responses were remarkably suppressed by citral. In addition, citral significantly attenuated the effect of PGN on the intestine nutrient absorption and barrier function. The expression of TLR2 was strongly induced by PGN stimulation, which was suppressed by citral. All data nominated that citral downregulated PGN-induced inflammation via TLR2-mediated activation of the NF-κB signaling pathway in IPEC-J2 cells. Furthermore, the results also indicate that the PGN degradation through the inclusion of enzymes (e.g., muramidase) as well as the inclusion of citral for attenuating inflammation may improve pig gut health and functionality.

Dietary oregano essential oil supplementation improves intestinal functions and alters gut microbiota in late-phase laying hens

BACKGROUND

Dietary essential oil (EO) supplementation can exert favorable effects on gut health in broilers. However, it is unknown whether EO could improve intestinal functions, consequently beneficial for egg performance and quality in late-phase laying hens. This study was aimed to investigate the potential effects of EO on production performance, egg quality, intestinal health and ileal microbiota of hens in the late phase of production. A total of 288 60-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet (control) or basal diets supplemented with oregano EO at 100, 200 and 400 mg/kg (EO100, EO200 and EO400).

RESULTS

Dietary EO supplementation resulted in a quadratic decrease (P < 0.05) in feed conversion ratio with lower (P < 0.05) feed conversion ratio in EO200 group than the control during weeks 9-12 and 1-12 of the trial. Compared to the control, EO addition resulted in higher (P < 0.05) eggshell thickness at the end of week. 4, 8 and 12 and higher (P < 0.05) chymotrypsin activity. There was a quadratic elevation (P < 0.05) in ileal chymotrypsin and lipase activity, along with a linear increase in villus height to crypt depth ratio. Quadratic declines (P < 0.05) in mRNA expression of IL-1β, TNF-α, IFN-γ and TLR-4, concurrent with a linear and quadratic increase (P < 0.05) in ZO-1 expression were identified in the ileum with EO addition. These favorable effects were maximized at medium dosage (200 mg/kg) of EO addition and intestinal microbial composition in the control and EO200 groups were assessed. Dietary EO addition increased (P < 0.05) the abundances of Burkholderiales, Actinobacteria, Bifidobacteriales, Enterococcaceae and Bacillaceae, whereas decreased Shigella abundance in the ileum.

CONCLUSIONS

Dietary EO addition could enhance digestive enzyme activity, improve gut morphology, epithelial barrier functions and modulate mucosal immune status by altering microbial composition, thus favoring feed efficiency and eggshell quality of late-phase laying hens.

Microencapsulated carvacrol and cinnamaldehyde replace growth-promoting antibiotics: Effect on performance and meat quality in broiler chickens

The aim was to evaluate the use of mixture of microencapsulated carvacrol and cinnamaldehyde as a replacement for growth-promoting antibiotics in broiler diets on performance, intestinal quality, organ development, carcass yields and cuts, and meat quality. In the trial were used 600 male chicks, allocated in a completely randomized design, with five treatments and eight replicates of 15 birds, reared up to 41 days of age. The treatments were: Negative Control (NC), Positive Control (PC) 30 mg/kg of virginiamycin, NC+100 mg/kg of essential oils, NC+200 mg/kg of essential oils and NC+400 mg/kg of essential oils. Essential oils were composed by a micro-encapsulated blend, with of 60% cinnamaldehyde, 30% carvacrol and 10% carrier. Birds received essential oils achieved performance equivalent to those birds received PC diets, having better development than NC broilers. No differences were found on relative organ weight, intestinal mucosa and meat quality parameters, however, higher villus:cript ratio was found in PC, NC+200 and NC+400 groups. Meat crude protein and yellowness were influenced by inclusion of carvacrol and cinnamaldehyde. It was concluded microencapsulated carvacrol and cinnamaldehyde can replace growth-promoting antibiotic in broiler diets, ensuring performance, intestinal integrity and broiler meat quality.

Effects of nutraceutical intervention on serum proteins in aged rats

Aging is associated with many pathophysiological changes that could lead to the onset of degenerative disease. Some of the physiological changes that occur with aging include increased inflammation and decreased stem cell proliferation, leading to decreased capacity for tissue regeneration and loss of function. In previous studies, we and others have found nutraceutical intervention to ameliorate some of the deleterious effects associated with aging. In particular, we have previously shown that NT-020, a supplement composed of a proprietary blend of blueberries, green tea, vitamin D3, and carnosine, is able to rescue age-related cognitive deficits, impaired neurogenesis, and inflammation in rats. We have also previously demonstrated that stem cells cultured with old serum showed decreased proliferation; however, when stem cells were cultured in serum from old rats given a diet supplemented with NT-020, proliferation did not differ from that of cells cultured with serum from young rats. While it is clear that NT-020 is exerting a therapeutic, anti-aging effect, the mechanisms of action were yet to be fully elucidated.To that end, in the present study, we conducted a bioinformatics experiment to examine the rat proteome of serum from young and old control rats and young and old rats given a diet supplemented with NT-020. Serum from old rats showed an increase in some inflammatory and pro-aging factors while serum from old rats given a diet supplemented with NT-020 showed an increase in some anti-aging factors, most notably proteins associated with the complement system and autophagy. A number of immune functions that increase with age were shown to be downregulated with NT-020 treatment.

Effects of phytogenic inclusion level on broiler carcass yield, meat antioxidant capacity, availability of dietary energy, and expression of intestinal genes relevant for nutrient absorptive and cell growth–protein synthesis metabolic functions

Context Phytogenic applications in animal nutrition currently attract worldwide scientific attention for their potential to contribute positively to sustainable and high-quality animal production. However, further understanding and substantiation of dietary phytogenic functions is required. Aims The inclusion level of a phytogenic premix (PP) comprising functional flavouring substances from ginger, lemon balm, oregano and thyme was studied for its effects on broiler growth performance, carcass traits, nutrient digestibility, liver and meat total antioxidant capacity (TAC), and lipid oxidation. The expression of genes for nutrient transporter proteins (SGLT1, GLUT2, PEPT1, BOAT and LAT1), for FABP2 involved in cellular fatty acid uptake and metabolism, and for the mTORC1 complex relevant for protein synthesis were profiled along the intestine. Methods One-day-old Cobb broiler chickens (n = 500) were assigned to four treatments with five replicates of 25 chickens each. Starter (1–10 days), grower (11–22 days) and finisher (23–42 days) basal diets were supplemented with four levels of PP inclusion as treatments: 0, 750, 1000 and 2000 mg/kg diet, termed control, PP750, PP1000 and PP2000. Feed and water were available ad libitum. Data were analysed by ANOVA, taking the treatment as fixed effect. Statistically significant (P ≤ 0.05) effects were further analysed and means were compared using Tukey’s HSD test. Polynomial contrasts tested the linear and quadratic effect of PP inclusion levels. Key results Growth performance responses were not improved significantly (P &gt; 0.05) by PP inclusion level. However, carcass (P = 0.030) and breast meat yield (P = 0.023) were higher in PP1000 than in the control. In addition, PP1000 had higher (P = 0.049) apparent metabolisable energy than PP2000 and the control. Increasing PP inclusion level increased breast (P = 0.005), thigh (P = 0.002) and liver (P = 0.040) TAC. Breast and thigh meat TAC reached a plateau at PP1000, whereas liver TAC continued to increase linearly. Lipid oxidation in breast meat and liver was delayed linearly (P ≤ 0.05) with increasing PP inclusion level. Expression of genes SGLT1, GLUT2, PEPT1, BOAT and FABP2 were not affected by PP inclusion. However, PP inclusion affected the expression of LAT1 (P &lt; 0.001) in jejunum and of mTORC1 in duodenum (P = 0.010) and ceca (P = 0.025). In particular, expression increased with increasing PP inclusion level in a linear and quadratic pattern depending on the intestinal segment. Conclusions Overall, PP inclusion at 1000 mg/kg diet improved carcass and breast yield, dietary available energy, and overall meat and liver TAC. Preliminary evidence was highlighted for effects of PP in promoting expression of genes relevant for muscle protein synthesis. Implications This study has contributed new information on effects of a phytogenic premix on broiler meat yield and antioxidant capacity, digestibility, absorption and metabolic functions, further supporting phytogenic benefits for broiler production.

Modulation of the growth performance, meat composition, oxidative status, and immunity of broilers by dietary fulvic acids

This study investigated the effects of dietary fulvic acid (FA) supplementation on the growth performance, body composition, oxidative status, and immunity of broilers. A total of 720 broilers were randomly divided into 4 groups, namely a control group and 3 treatment groups that received diets supplemented with 3 different levels of FAs (0.2, 0.6, and 1 g kg-1). The diets supplemented with 0.6 or 1 g kg-1 FAs increased the body weight gain. This treatment also increased the activities of digestive enzymes (amylase, lipase, and protease), the meat protein content, the total polyunsaturated fatty acid content, the superoxide dismutase activity, the glutathione peroxidise activity, and the serum levels of IgG, IgM, and IgA but decreased the meat fat content and the malondialdehyde level compared with those in the control. However, high FA dose (> 0.6 g kg-1) did not further increase the efficiency compared with moderate dose (0.6 g kg-1). Results indicate that FAs might be a promising dietary supplement for broilers.

Intestinal microbiota of broilers submitted to feeding restriction and its relationship to hepatic metabolism and fat mass: Fast-growing strain

The present study was conducted to verify how feed restriction affects gut microbiota and gene hepatic expression in broiler chickens and how these variables are related to body weight gain. For the experiment, 21-d-old Cobb500^TM birds were distributed in a completely randomized experimental design with three treatments: T1. Control (ad libitum-3.176 Mcal/kg ME-metabolizable energy-and 19% CP-crude protein); T2. Energetic restriction (2.224 Mcal/kg ME and 19% CP) from 22 to 42 days with consumption equivalent to control; T3. Quantitative restriction (70% restriction, i.e., restricted broilers ingested only 30% of the quantity consumed by the control group-3.176 Mcal/kg ME and 19% CP) for 7 days, followed by refeeding ad libitum from 28 to 42 days. Ileum and caecum microbiota collections were made at 21, 28 and 42 days of age. Hepatic tissue was collected at 28 and 42 days old for relative gene expression analyses. At 43-d-old, body composition was quantified by DXA (Dual-energy X-ray Absorptiometry). Both feed restriction programmes decreased Lactobacillus and increased Enterococcus and Enterobacteriaceae counts. No differences were found in the refeeding period. Energetic restriction induced the expression of CPT1-A (Carnitine palmitoyltransferase 1A) gene, and decreased body fat mass. Quantitative feed restriction increased lipogenic and decreased lipolytic gene expression. In the refeeding period, CPT1-A gene expression was induced, without changing the broilers body composition. Positive associations were found between BWG (Body Weight Gain) and Lactobacillus and Clostridium cluster IV groups, and negatively associations with Enterobacteriaceae and Enterococcus bacterial groups. In conclusion, differences found in microbiota were similar between the two feed restriction programmes, however, hepatic gene expression differences were only found in quantitative restriction. Higher counts of Lactobacillus and Clostridium cluster IV groups in ileum are likely to be related to better broiler performance and low expression of lipogenic genes.

Thymol Improves Barrier Function and Attenuates Inflammatory Responses in Porcine Intestinal Epithelial Cells during Lipopolysaccharide (LPS)-Induced Inflammation

It is well-known that essential oil thymol exhibits antibacterial activity. The protective effects of thymol on pig intestine during inflammation is yet to be investigated. In this study, an in vitro lipopolysaccharide (LPS)-induced inflammation model using IPEC-J2 cells was established. Cells were pretreated with thymol for 1 h and then exposed to LPS for various assays. Interleukin 8 (IL-8) secretion, the mRNA abundance of cytokines, reactive oxygen species (ROS), nutrient transporters, and tight junction proteins was measured. The results showed that LPS stimulation increased IL-8 secretion, ROS production, and tumor necrosis factor alpha (TNF-α) mRNA abundance ( P < 0.05), but the mRNA abundance of sodium-dependent glucose transporter 1 (SGLT1), excitatory amino acid transporter 1 (EAAC1), and H⁺/peptide cotransporter 1 (PepT1) were decreased ( P < 0.05). Thymol blocked ROS production ( P < 0.05) and tended to decrease the production of LPS-induced IL-8 secretion ( P = 0.0766). The mRNA abundance of IL-8 and TNF-α was reduced by thymol pretreatment ( P < 0.05), but thymol did not improve the gene expression of nutrient transporters ( P > 0.05). The transepithelial electrical resistance (TEER) was reduced and cell permeability increased by LPS treatment ( P < 0.05), but these effects were attenuated by thymol ( P < 0.05). Moreover, thymol increased zonula occludens-1 (ZO-1) and actin staining in the cells. However, the mRNA abundance of ZO-1 and occludin-3 was not affected by either LPS or thymol treatments. These results indicated that thymol enhances barrier function and reduce ROS production and pro-inflammatory cytokine gene expression in the epithelial cells during inflammation. The regulation of barrier function by thymol and LPS may be at post-transcriptional or post-translational levels.

Probiotics and plant-derived compounds as eco-friendly agents to inhibit microbial toxins in poultry feed: a comprehensive review

Some of pathogenic bacteria and fungi have the ability to produce fetal toxins which may be the direct causes of cytotoxicity or cellular dysfunction in the colonization site. Biological and non-biological environmental factors, challenge and microbes influence the effect of toxins on these pathogens. Modern research mentions that many natural materials can reduce the production of toxins in pathogenic microbes. However, researches that explain the mechanical theories of their effects are meager. This review aimed to discuss the ameliorative potential role of plant-derived compounds and probiotics to reduce the toxin production of food-borne microbes either in poultry bodies or poultry feedstuff. Moreover, studies that highlight their own toxicological mechanisms have been discussed. Adding natural additives to feed has a clear positive effect on the enzymatic and microbiological appearance of the small intestine without any adverse effect on the liver. Studies in this respect were proposed to clarify the effects of these natural additives for feed. In conclusion, it could be suggested that the incorporation of probiotics, herbal extracts, and herbs in the poultry diets has some beneficial effects on productive performance, without a positive impact on economic efficiency. In addition, the use of these natural additives in feed has a useful impact on the microbiological appearance of the small intestine and do not have any adverse impacts on intestinal absorption or liver activity as evidenced by histological examination.