Probiotics and β-glucan as Alternatives to Antibiotics in Chicken FeedABSTRACT
The objective of this study was to evaluate the effects of replacing antibiotics with dietary probiotics and β-glucan on broiler performance and intestinal health. A total of 1,080 male Cobb® chicks were allocated to one of five treatments, with six replicates in each group and 36 birds in each plot. The treatments included the basal diet without additives, the basal diet with antibiotics, the basal diet with β-glucan, the basal diet with probiotics, and the basal diet with both β-glucan and probiotics. The β-glucan used was based on algae, while the probiotic was a Bacillus velezensis PB6 strain. The parameters evaluated were performance, intestinal integrity, and intestinal microbiota. From 1 to 42 days of age, the chickens fed the probiotic presented greater live weights (p≤0.05) than those in the control group, while the weights in the β-glucan and β-glucan plus probiotic treatments did not differ (p>0.05) from the antibiotic treatment group. The ileal villus/crypt ratio was greater in the β-glucan + probiotic group (p≤0.05). The intestinal integrity in the probiotic group was improved (p≤0.05). The production of IgA immunoglobulins was lower after the β-glucan and probiotic treatment, while IgY production was lower in the β-glucan, probiotic, and β-glucan + probiotic treatments (p≤0.05), indicating a reduced challenge in the birds that received these additives. The probiotic B. velezensis provided the strongest evidence as an antibiotic alternative, while β-glucan and the combination β-glucan + probiotic showed positive intestinal or microbiota-related effects but did not demonstrate equivalent overall performance.
Keywords:
Additives; performance; intestinal integrity; microbiota
INTRODUCTION
The intestinal microbiota of birds is composed of bacteria, fungi, protozoa, and viruses, and these microorganisms can be either beneficial or potentially pathogenic (Wei et al., 2013). Bacteria are the predominant microorganisms in the intestinal microbiota of birds, and their main beneficial functions are acting as a barrier to protect the intestinal epithelium by reducing the populations of pathogenic bacteria through competitive exclusion, as well as producing short-chain fatty acids and vitamins B and K (Leeson et al., 2005; Guilloteau et al., 2010; Oakley & Kogut, 2016). The poultry gut microbiome also plays a crucial role in feed digestion, enhances animal health by interacting with the host against pathogens, and contributes to production efficiency (Naeem & Bourassa, 2025).
Several factors influence the intestinal microbiota in birds, such as the rearing system (intensive or free-range) (Kuswandi et al., 2025), amino acid supplementation (Brugaletta et al., 2023), genetic and environmental factors (Hen et al., 2026), and dietary probiotics and antibiotics (Silva et al., 2024). Since it is possible to modulate the gut microbiota of broilers, prebiotics and probiotics are being studied as broiler feed additives with the potential to increase the abundance of beneficial bacteria and reduce the colonization of pathogenic microorganisms (Naeem & Bourassa, 2025).
Prebiotics are feed additives that are fermented by microorganisms in the intestinal tract and favor the beneficial bacterial population (MAPA, 2020). β-glucans, one type of prebiotic used in poultry feed, can act in different ways in the gastrointestinal tract, such as producing short-chain fatty acids and being fermented by intestinal bacteria, which reduces the pH in the gastrointestinal tract and consequently reduces the population of problematic microorganisms sensitive to acidic environments (Meimandipour et al., 2011). Short-chain fatty acids, such as butyrate, increase claudin-1 protein abundance in the gut of broilers (Mátis et al., 2022), thus improving intestinal integrity.
On the other hand, probiotics are live microorganisms that benefit chickens when added to feed (MAPA, 2020). Probiotics have several mechanisms of action, such as the competitive exclusion of pathogenic bacteria (Collado et al., 2005) and the production of bacteriocins, which inhibit the growth of pathogenic bacteria by disrupting their cell walls (Anthony et al., 2009). Moreover, probiotics can also stimulate the production of enzymes such as amylase, protease, and lipase to improve nutrient absorption (Wang & Gu, 2010). The combined use of probiotics and prebiotics may contribute to improving broiler performance (Olmez et al., 2025).
The objective of this study was to evaluate the effects of β-glucan and a probiotic (Bacillus velezensis PB6) in the diet, both separately and together, as replacements for growth-promoting antibiotics on broiler performance and intestinal health.
MATERIALS AND METHODS
The project was approved by the local Ethics Committee for the Use of Animals in the year 2022 (CEUA; approval no. 021/22). The experiment was conducted in an industrial shed housing 21,000 broilers in Goiânia, Goiás, Brazil (16°35’48.3” S and 49°17’08.8” W).
Experimental Design
The experiment was conducted in an industrial shed with 30 boxes (each 1.8 m × 1.6 m) in the middle of the shed housing 21,000 broilers; the bedding was reused and made of rice husks. A total of 1,080 one-day-old male Cobb500™ (Cobb-Vantress, Inc., Springdale, AR) chicks acquired from a commercial hatchery with an average weight of 46 ± 0.02 g were used in this study.
The birds were allocated in a completely randomized design with five treatment groups totaling 30 plots; there were six replicates in each group, with each experimental unit consisting of 36 birds. The treatments used were as follows: the basal diet without additives (control); the basal diet and supplementation with a growth promoter antibiotic (enramycin); the basal diet and supplementation with 0.01% β-glucan; the basal diet and supplementation with 0.05% probiotic (B. velezensis PB6); and the basal diet and supplementation with 0.01% β-glucan plus 0.05% probiotic (B. velezensis PB6). The birds were given ad libitum access to water and mashed feed, which was formulated according to the levels proposed by the supplier for each of five rearing phases (Table 1).
Experimental Tests: Performance, Integrity, and Intestinal Microbiota
The performance parameters evaluated were live weight, feed intake (FI; FI = feed offered - uneaten feed), feed conversion ratio (FCR; FCR = feed intake/ body weight gain), breeding viability (V; V = 100 - mortality (%)), uniformity (determined by weighing the birds individually; at the end, the average weight of each plot was calculated considering a margin of ±10%), and production factor (PF; PF= [(body weight gain x Viability/FCR) x 100)].
At 21 and 42 days of age, six birds per treatment were euthanized by cervical dislocation and eviscerated for intestinal histomorphometry evaluation. For intestinal histomorphometry analysis, samples of approximately 2 cm were collected from each segment of the small intestine (jejunum and ileum). The collected fragments were fixed in 10% buffered formalin, prepared, and subjected to hematoxylin-eosin (HE) staining using standard protocols, according to Luna (1968). The following histological parameters were evaluated: villus height, crypt depth, villus/crypt ratio, and the presence of intestinal lesions (e.g. edema, congestion, infiltration, degeneration, necrosis, or the presence of parasites). The degree of injury was graded from 0 to 3 as follows: 0, no injury; 1, mild; 2, moderate; and 3, severe (Hussein et al., 2018).
At 42 days of age, blood was collected from the ulnar vein of one bird from each experimental unit to evaluate immunoglobulin (IgA and IgG) levels and intestinal permeability. The relative levels of immunoglobulins were determined by quantifying the level of immunoglobulins in each experimental group for comparison with the total level of immunoglobulins (IgA, IgG or IgY) by Western blotting, using a methodology standardized by the Imunova laboratory. Intestinal integrity was evaluated indirectly by assessing intestinal permeability (Martins et al., 2024). The fluorescent molecule FITC-dextran (3000-4000 kDa) was administered orally, and the amount recovered in the plasma/serum corresponds to the severity of the lesion in the intestinal epithelial monolayer. A volume of 0.5 mL of FITC-dextran was orally administered to six birds in each treatment group. After 2 hours and 30 minutes of fasting, 2 mL of blood was collected from each bird, placed in tubes with a clot activator, and sent to the laboratory for recovery and quantification of the biomarker FITC-dextran.
For intestinal microbiota analysis, four birds from each treatment group were euthanized by cervical dislocation and eviscerated, and the cecal contents were collected in sterile 2 mL tubes. The samples were placed in a Styrofoam box containing nitrogen, and frozen. The dual-index methodology was applied for determination, with DNA extracted using commercial kits. A fragment of approximately 460 base pairs, corresponding to the V3 and V4 hypervariable regions of the rRNA gene, was amplified using universal primers. The amplicons were used to construct a metagenomic library for sequencing. The readings obtained were analyzed for bacterial genus classification using operational taxonomic unit recognition.
Statistical Analysis
The normality and homoscedasticity of the performance, histomorphometry, intestinal permeability, IgA, and IgY data were assessed using the Shapiro-Wilk and Bartlett tests, followed by analysis of variance, and the means were compared using the Student-Newman-Keuls (SNK) test at the 5% significance level. Nonparametric data were analyzed using the Kruskal-Wallis test at the 5% significance level. Data on Salmonella spp., Enterobacteriaceae, and E. coli counts were evaluated using the Kruskal-Wallis test. Results of the microbiota composition of the cecum were analyzed using descriptive statistics, presenting the population values as a percentage. The R Studio program was used, with a significance level of 5%.
RESULTS
The live weights from 1 to 42 days of age of broilers fed diets supplemented with probiotics did not differ from those supplemented with antibiotics, but the weights of both groups were greater (p<0.001) than the control group (without additives) (Table 2). Broilers fed β-glucan or β-glucan + probiotic showed lower live body weight than those fed the antibiotic and did not differ from the control group. Moreover, the additives had no effect on feed intake, feed conversion ratio, viability, uniformity, or production factor (p>0.05).
Regarding jejunal histomorphometry at 21 days of age, the villus height was greater in the β-glucan and probiotic treatment groups than in the control and antibiotic groups (p=0.006). However, the villus/crypt ratio was greater (p=0.001) in the control and antibiotic treatment groups, and these ratios in the β-glucan and probiotic groups were greater than those in the β-glucan + probiotic group. Additionally, the absorption area was greater (p=0.036) after probiotic treatment than after the β-glucan and β-glucan + probiotic treatments. The β-glucan + probiotic group presented a smaller area of absorption in the jejunum (Table 3).
With respect to the ileum, the villus heights were greater (p<0.001) in the probiotic and β-glucan groups than in the control and β-glucan + probiotic groups and did not differ from the antibiotic group. However, the villus/crypt ratio was greater in the group fed antibiotics than in the control, probiotic, and β-glucan + probiotic groups. Compared with the probiotic and β-glucan + probiotic treatments, β-glucan treatment was equivalent to antibiotic treatment and more effective (p=0.001). The absorption area of the ileum was greater (p=0.0016) in the probiotic group than in the other treatment groups (Table 3).
The jejunal histomorphometry results revealed that, at 42 days of age, the villus height was greater (p=0.0047) in the probiotic group than in the antibiotic, β-glucan, and β-glucan + probiotic groups. However, the villus/crypt ratio was greater (p=0.039) in the antibiotic group than in the other treatment groups, and the lowest ratio was detected in the β-glucan and β-glucan + probiotic groups. Finally, the absorption area was greater (p<0.001) in birds fed probiotics and antibiotics (Table 3).
In the ileum, the villus height was greater (p<0.001) in the control, β-glucan, and β-glucan + probiotic treatment groups than in the antibiotic treatment group. The villus/crypt ratio was greater in birds fed β-glucan and β-glucan + probiotics than in those fed antibiotics, and the worst results were found in the control and probiotic-treated groups. The villus absorption area in the antibiotic-treated group was lower than in the other treatment groups (p<0.001) (Table 3).
The jejunal lesion scores (Table 4) were not different between the treatment groups (p>0.05). However, in the ileum, there was a difference between the treatments in terms of infiltration (p=0.007) in comparison with the control.
Intestinal permeability was lower (p=0.014) in birds fed the probiotic (Table 5), as lower amounts of FITC were detected in blood plasma than those detected in the control and β-glucan + probiotic groups.
The production of IgA and IgY in the blood was greater (p<0.001) in the control group than in the other treatment groups (antibiotic, β-glucan, probiotic, and β-glucan + probiotic) (Table 5).
Quantification of the microbial population and identification of the predominant phyla in the ceca of the chickens fed the different additives revealed the presence of Bacteroidetes (ranging from 62 to 71% of the bacterial population) and Firmicutes (ranging from 22 to 32%) in all treatment groups (Figure 1). Moreover, the phyla Cyanobacteria (0.26%) and Proteobacteria (0.15%) were less abundant, and other phyla or unknown phyla were present in 4 to 7%.
Relative abundance (%) of Phyla present in the ceca of chickens fed different diets (control without additives and diets supplemented with antibiotics, β-glucan, probiotics, and β-glucan + probiotics) at 42 days of age.
The predominant classes of bacteria found in the ceca of chickens fed different diets were Bacteroidia (ranging from 62.54 to 72.04%) and Clostridia (from 17.93 to 29.55%) (Figure 2). To a lesser extent, the classes Bacilli (0.56 to 2.4%), Synergistia (0.05 to 0.3%), f_ (0.52 to 7%) and o_(1.42 to 2.14%) were identified, with 2 to 3% in other classes or unknown.
Relative abundance (%) of Classes present in the ceca of chickens fed different diets (control without additives and diets supplemented with antibiotics, β-glucan, probiotics, and β-glucan + probiotics) at 42 days of age. f_ and o_ represents “family” and “order” nonspecific..
The relative abundances of different bacterial orders revealed that Bacteroidales prevailed in all treatment groups (62%) (Figure 3). The orders found in smaller proportions were Clostridia_UCG-014 (4 to 9%), Clostridia_vadinBB60_group (4 to 8.54%), f_ (1 to 3%), Lachnospirales (2 to 4%), Oscillospirales (4 to 7%), RF39 (0.9 to 1.84%), and other or unknown orders (4 to 8%).
Relative abundance (%) of Orders present in the ceca of chickens fed different diets (control without additives and diets supplemented with antibiotics, β-glucan, probiotics and β-glucan + probiotics) at 42 days of age. f_ represents “family” nonspecific.
With respect to the bacterial families present in the ceca, Rikenellaceae was the most abundant in all treatments, with a population above 47% (Figure 4). Other families included Barnesiellaceae (3 to 15%), Clostridia_vadinBB60 (4 to 9%), Clostridia_UCG-014 (4 to 9%), Bacteroidaceae (2 to 5%), and others or unknown (17 to 23%).
Relative abundance (%) of Families present in the ceca of chickens fed different diets (control without additives and diets supplemented with antibiotics, β-glucan, probiotics, and β-glucan + probiotics) at 42 days of age.
The most abundant bacterial genus present in the ceca in all treatment groups was Alistipes (46.03%) (Figure 5). The following genera were observed to a lesser extent: Barnesiella (2 to 15%), Clostridia_vadinBB60 (4 to 9%), Clostridia_UCG-014 (4 to 9%), Bacteroides (2 to 8%), f_ (0.5 to 3%), and others and unknown (15 to 23%).
Relative abundance (%) of Genera present in the ceca of chickens fed different diets (control without additives and diets supplemented with antibiotics, β-glucan, probiotics, and β-glucan + probiotics) at 42 days of age. f_ represents a nonspecific “family”.
DISCUSSION
Broilers fed the probiotic (B. velezensis) showed greater live weights than those in the control group, which was similar to the results observed in the antibiotic treatment. According to Ramlucken et al. (2020), the probiotic B. velezensis can reduce the population of pathogenic bacteria by producing bacteriocins capable of inhibiting cell wall synthesis by pathogens or by competing for nutrients; after the probiotic has been established in the digestive system, these bacteria can absorb nutrients more quickly.
The use of β-glucan and the combination of probiotics plus β-glucan did not result in better performance in the period from 1 to 42 days of age compared with the control group. It is important to consider the variability associated with commercial production environments. According to Hernandez-Patlan et al. (2019), the use of probiotics in environments with high microbial contents can positively affect the performance of broilers. Tian et al. (2016) used β-glucan in the feed of broilers challenged with Eimeria and C. perfringens and reported better live weights and feed conversion ratios.
The ileal villus/crypt ratio improved with the addition of β-glucan + probiotics to the diet at 42 days of age. After the cecum, the ileum is the segment with the highest abundance of microbes in the digestive system (Stanley et al., 2014). The fermentation of β-glucan by microorganisms present in the ileum results in the production of short-chain fatty acids, such as acetic, propionic, and butyric acids. Fatty acids reduce the intestinal pH (Meimandipour et al., 2011), and low pH inhibits the proliferation of pathogenic bacteria sensitive to acidic environments, such as Clostridium spp., Salmonella, and E. coli (Khan & Naz, 2013). Short-chain fatty acids may also be used as a source of energy for proliferating enterocytes because, according to Rufino et al. (2017), butyric acid is readily absorbed by these cells and can be used as a source of energy for epithelial cell proliferation.
In the ileum, there were differences among groups in terms of infiltration. According to Lammers et al. (2003), probiotics and prebiotics reduce the colonization and proliferation of pathogenic microorganisms that can cause inflammation in the intestinal mucosa and, consequently, reduce the inflammatory reactions of intestinal cells, leading to a reduction in nutrient and energy expenditure in birds during inflammatory processes and antibody production.
The B. velezensis probiotic group displayed lower intestinal permeability than the control group, denoting a stronger intestinal barrier. The intestinal mucosal epithelium is composed of columnar epithelial cells joined by intercellular junctions, which are proteins that act as an epithelial barrier in the intestine, preventing the invasion of pathogens between enterocytes and their entry into the bloodstream (Khan et al., 2020). Gadde et al. (2017) reported an increase in the expression levels of the intercellular junction proteins JAM2, Occludin, and ZO1 in the small intestine of broilers fed the probiotic B. subtilis. Bacillus-type probiotics may act in different ways to improve intestinal integrity, such as increasing the number of goblet cells in the mucosa of the intestinal epithelium.
It was observed that the production of IgA and IgY antibodies was reduced in birds fed additives compared with those in the control group. The levels of immunoglobulins can be high in the presence of antigens such as those originating from harmful bacteria (Santin et al., 2017). IgA is produced mainly by plasma cells residing in the lamina propria of the intestine; therefore, IgA protects the body against pathogens (Suzuki & Nakajima, 2014). After antigens are recognized by B lymphocytes, antibodies that bind to the antigen are released, leading to elimination of the antigen via phagocytosis or the complement system (Santin et al.,2017). The reduction in the abundance of pathogenic bacteria may have reduced the sanitary challenge in broilers fed the probiotic, which was confirmed by the lower production of IgA and IgY antibodies, thus increasing intestinal health.
Regarding the intestinal microbiota analysis, the predominant phyla present in the cecum were Bacteroidetes and Firmicutes, which together accounted for more than 92% of the population. Bacteria in the phylum Bacteroidetes are gram-negative. This group of bacteria has fermentative characteristics and can favorably modulate the immune system. Compared with the control group, the groups of birds fed diets containing β-glucan and probiotics presented greater amounts of Bacteroides (with differences of 9.26% and 7.44%, respectively). These results are encouraging because the Bacteroides group includes microorganisms that produce butyric acid, which is absorbed by enterocytes and used as a source of energy for their maintenance and development (Rufino et al., 2017). The phylum Firmicutes consists of gram-positive bacteria and includes genera that have beneficial immunomodulatory activity, and those that are related to inflammation and have pathogenic potential, such as Clostridia (Vos et al., 2009). The treatments with additives promoted a reduction in the percentage of the Clostridia_UCG_014 family, which has pathogenic characteristics and belongs to the phylum Firmicutes. The Clostridia_UCG_014 family includes bacteria with proinflammatory effects that may cause necrotic enteritis (Zhong et al., 2023).
The predominant family in the ceca in all treatment groups was Rikenellaceae, which belongs to the phylum Bacteroidetes. However, with the use of additives in feed ( β-glucan, probiotics, and antibiotics), there was an increase in the proportion of Rikenellaceae. According to Favazzo et al. (2020), the predominance of the family Rikenellaceae is associated with low intestinal inflammation.
The most abundant genus in the ceca was Alistipes, which belongs to the family Rikenellaceae. Compared with the control group, broilers fed β-glucan, probiotics, or antibiotics presented an average of 7% more Alistipes. Alistipes spp. are associated with the production of short-chain fatty acids. According to Polansky et al. (2016), Alistipes spp. express enzymes involved in the biosynthesis of propionate and acetate. The production of fatty acids reduces the intestinal pH, and acidic environments reduce the growth of bacteria sensitive to low pH, such as Clostridium (Meimandipour et al., 2011; Khan & Naz, 2013).
With respect to the genera present in the ceca of broilers fed the β-glucan + probiotic combination, there was an abundance of the genus Barnesiella (15.49%) compared with the control group (7.51%) and the antibiotic group (4.60%). Barnesiella can eliminate pathogenic microorganisms such as Enterococcus faecium (Ubeda et al., 2013).
An increase in the abundance of pathogenic bacteria causes an imbalance in the intestinal microbiota known as dysbiosis, and these bacteria compete with the birds themselves for nutrients, while also producing toxins that cause inflammation in the intestinal mucosa (Rood et al., 2018). Probiotics assist in balancing the intestinal microbiota, decreasing the number of pathogenic microorganisms through competitive exclusion or by producing bacteriocins (Ramlucken et al., 2020). Prebiotics can also directly modulate the microbiota. Bacteria adhere to the intestinal epithelium through their fimbriae, which bind to certain sugars present on the surface of the epithelium; however, some prebiotics have alternative binding sites and can bind to pathogens (Spring et al., 2000). These pathogenic bacteria linked to the prebiotic are eliminated in excreta, preserving the intestinal mucosa.
In summary, the probiotic B. velezensis may improve intestinal integrity and modulate the intestinal microbiota, resulting in a reduction in the population of pathogenic microorganisms, such as the Clostridia_UCG_014, resulting in greater live body weight. The algae-based β-glucan prebiotic can also be used in chicken feed as an alternative to antibiotics since broiler performance was similar after supplementation with β-glucan and antibiotics in the period from 1 to 35 days. β-Glucan favorably modulated the intestinal microbiota of the chickens, increasing the abundance of beneficial genera such as Alistipes, and reducing the abundance of harmful genera such as Clostridia_UCG_014. This positive modulation of the microbiota shows that chickens fed β-glucan exhibit greater resistance to sanitary challenges, which leads to the production of less IgA and IgY, and demonstrates better intestinal health. The combination of a probiotic B. velezensis and β-glucan as additives in chicken feed may be an alternative to antibiotics, since this combination did not affect broiler performance and increased the absorption area of the ileum.
CONCLUSION
The probiotic B. velezensis provided the strongest results as an antibiotic alternative, while β-glucan and the combination β-glucan + probiotic showed positive intestinal or microbiota-related effects, but did not demonstrate equivalent overall performance.
ACKNOWLEDGEMENTS
The authors would like to thank FAPEG - Fundação de Amparo à Pesquisa do Estado de Goiás for the research funding and scholarship, and São Salvador Alimentos and Kemin.
REFERENCES
-
Anthony T, Rajesh T, Kayalvizhi N, et al. Influence of medium components and fermentation conditions on the production of bacteriocin(s) by Bacillus licheniformis AnBa9. Bioresource Technology 2009;100(2):872-7. https://doi.org/10.1016/j.biortech.2008.07.027
» https://doi.org/10.1016/j.biortech.2008.07.027 -
Brugaletta G, Zampiga M, Laghi L, et al. Feeding broiler chickens with arginine above recommended levels: effects on growth performance, metabolism, and intestinal microbiota. Journal of Animal Science and Biotechnology 2023;14(1):33. https://doi.org/10.1186/s40104-023-00839-y
» https://doi.org/10.1186/s40104-023-00839-y -
Collado MC, Gueimonde M, Hernández M, et al. Adhesion of selected Bifidobacterium strains to human intestinal mucus and the role of adhesion in enteropathogen exclusion. Journal of Food Protection 2005;68(12):2672-8. https://doi.org/10.4315/0362-028X-68.12.2672
» https://doi.org/10.4315/0362-028X-68.12.2672 -
Favazzo LJ, Hendesi H, Villani DA, et al. The gut microbiome-joint connection: implications in osteoarthritis. Current Opinion in Rheumatology. 2020;32(1):92-101. https://doi.org/10.1097/BOR.0000000000000681
» https://doi.org/10.1097/BOR.0000000000000681 -
Gadde U, Oh ST, Lee YS, et al. The effects of direct-fed microbial supplementation, as an alternative to antibiotics, on growth performance, intestinal immune status, and epithelial barrier gene expression in broiler chickens. Probiotics and Antimicrobial Proteins 2017;9:397-405. https://doi.org/10.1007/s12602-017-9275-9
» https://doi.org/10.1007/s12602-017-9275-9 -
Guilloteau P, Martin L, Eeckhaut V, et al. From the gut to the peripheral tissues: the multiple effects of butyrate. Nutrition Research Reviews 2010;23(2):366-84. https://doi.org/10.1017/S0954422410000247
» https://doi.org/10.1017/S0954422410000247 -
Hernandez-Patlan D, Solis-Cruz B, Pontin KP, et al. Impact of a Bacillus direct-fed microbial on growth performance, intestinal barrier integrity, necrotic enteritis lesions, and ileal microbiota in broiler chickens using a laboratory challenge model. Frontiers in Veterinary Science 2019;6:108. https://doi.org/10.3389/fvets.2019.00108
» https://doi.org/10.3389/fvets.2019.00108 -
Hussein EA, Hair-Bejo M, Adamu L, et al. Scoring system for lesions induced by different strains of Newcastle disease virus in chicken. Veterinary Medicine International 2018;2018:9296520. https://doi.org/10.1155/2018/9296520
» https://doi.org/10.1155/2018/9296520 -
Khan RU, Naz S. The applications of probiotics in poultry production. World's Poultry Science Journal 2013;69(3):621-32. https://doi.org/10.1017/S0043933913000627
» https://doi.org/10.1017/S0043933913000627 -
Khan S, Moore RJ, Stanley D, et al. The gut microbiota of laying hens and its manipulation with prebiotics and probiotics to enhance gut health and food safety. Applied and Environmental Microbiology 2020;86(13):e00600-20. https://doi.org/10.1128/AEM.00600-20
» https://doi.org/10.1128/AEM.00600-20 -
Kuswandi W, Budiman C, Khaerunnisa I, et al. Rearing system and immune status influence the small intestinal microbiota of IPB-D3 chickens: a full-length 16S rRNA metagenomic approach. Veterinary World 2025;18(8):2206-21. https://doi.org/10.14202/vetworld.2025.2206-2221
» https://doi.org/10.14202/vetworld.2025.2206-2221 -
Lammers KM, Brigidi P, Vitali B, et al. Immunomodulatory effects of probiotic bacteria DNA: IL-1 and IL-10 response in human peripheral blood mononuclear cells. FEMS Immunology & Medical Microbiology 2003;38(2):165-72. https://doi.org/10.1016/S0928-8244(03)00144-5
» https://doi.org/10.1016/S0928-8244(03)00144-5 -
Leeson S, Namkung H, Antongiovanni M, et al. Effect of butyric acid on the performance and carcass yield of broiler chickens. Poultry Science 2005;84(9):1418-22. https://doi.org/10.1093/ps/84.9.1418
» https://doi.org/10.1093/ps/84.9.1418 -
Lu J, Idris U, Harmon B, et al. Diversity and succession of the intestinal bacterial community of the maturing broiler chicken. Applied and Environmental Microbiology 2003;69(11):6816-24. https://doi.org/10.1128/AEM.69.11.6816-6824.2003
» https://doi.org/10.1128/AEM.69.11.6816-6824.2003 - Luna LG. Manual of the histologic staining methods of the Armed Forces Institute of Pathology. 3rd ed. New York: McGraw Hill; 1968.
-
MAPA - Ministério da Agricultura, Pecuária e Abastecimento. Aditivos zootécnicos e tecnológicos: adsorventes de micotoxinas e inoculantes de silagem. Brasília: Ministério da Agricultura, Pecuária e Abastecimento; 2020. Available from: https://www.agricultura.gov.br
» https://www.agricultura.gov.br -
Martins APF, Mello HHCM, Mascarenhas AG, et al. Effect of the use of prebiotics, alone and in combination with antibiotics, in broiler diets. Revista Brasileira de Zootecnia 2024;53:e20230083. https://doi.org/10.37496/rbz5320230083
» https://doi.org/10.37496/rbz5320230083 -
Mátis G, Mackei M, Boomsma B, et al. Dietary protected butyrate supplementation of broilers modulates intestinal tight junction proteins and stimulates endogenous production of short chain fatty acids in the caecum. Animals 2022;12(15):1940. https://doi.org/10.3390/ani12151940
» https://doi.org/10.3390/ani12151940 -
Meimandipour A, Soleimani AF, Houshmand M, et al. Effects of rough handling on short chain fatty acid production and gastrointestinal pH in broilers and modulatory role of Lactobacilli. African Journal of Biotechnology 2011;10(74):17030-7. https://doi.org/10.5897/AJB10.1592
» https://doi.org/10.5897/AJB10.1592 -
Naeem M, Bourassa D. Probiotics in poultry: unlocking productivity through microbiome modulation and gut health. Microorganisms 2025;13(2):257. https://doi.org/10.3390/microorganisms13020257
» https://doi.org/10.3390/microorganisms13020257 -
Oakley BB, Kogut MH. Spatial and temporal changes in the broiler chicken cecal and fecal microbiomes and correlations of bacterial taxa with cytokine gene expression. Frontiers in Veterinary Science 2016;3:11. https://doi.org/10.3389/fvets.2016.00011
» https://doi.org/10.3389/fvets.2016.00011 -
Olmez M, Sahin T, Karadagoglu Ö, et al. Effects of dietary prebiotic, probiotic, and synbiotic supplementation on growth performance, carcass traits, digestive enzymes and some biochemical parameters in broiler chickens. Journal of the Hellenic Veterinary Medical Society 2025;76(1):8705-14. https://doi.org/10.12681/jhvms.37162
» https://doi.org/10.12681/jhvms.37162 -
Polansky O, Sekelova Z, Faldynova M, et al. Important metabolic pathways and biological processes expressed by chicken cecal microbiota. Applied and Environmental Microbiology 2016;82(5):1569-76. https://doi.org/10.1128/AEM.03473-15
» https://doi.org/10.1128/AEM.03473-15 -
Ramlucken U, Lalloo R, Roets Y, et al. Advantages of Bacillus-based probiotics in poultry production. Livestock Science 2020;241:104215. https://doi.org/10.1016/j.livsci.2020.104215
» https://doi.org/10.1016/j.livsci.2020.104215 -
Rood JI, Adams V, Lacey J, et al. Expansion of the Clostridium perfringens toxin-based typing scheme. Anaerobe 2018;53:5-10. https://doi.org/10.1016/j.anaerobe.2018.04.011
» https://doi.org/10.1016/j.anaerobe.2018.04.011 - Rufino JPF, Cruz FGG, Oliveira Filho PA, et al. Fibra alimentar em dietas para aves: uma revisão. Revista Científica de Avicultura e Suinocultura 2017;3(2).
- Santin E, Moraes ML, Sanches AWD. Imunologia aplicada. In: Macari M, Maiorka A, editors. Fisiologia das aves comerciais. Jaboticabal: Funep; 2017. p.468-89.
-
Silva JMS, Almeida AMDS, Borsanelli AC, et al. Intestinal microbiome profiles in broiler chickens raised with different probiotic strains. Microorganisms 2024;12(8):1639. https://doi.org/10.3390/microorganisms12081639
» https://doi.org/10.3390/microorganisms12081639 -
Spring P, Wenk C, Dawson KA, et al. The effects of dietary mannanoligosaccharides on cecal parameters and the concentrations of enteric bacteria in the ceca of Salmonella-challenged broiler chicks. Poultry Science 2000;79(2):205-11. https://doi.org/10.1093/ps/79.2.205
» https://doi.org/10.1093/ps/79.2.205 -
Stanley D, Hughes RJ, Moore RJ. Microbiota of the chicken gastrointestinal tract: influence on health, productivity and disease. Applied Microbiology and Biotechnology 2014;98:4301-10. https://doi.org/10.1007/s00253-014-5646-2
» https://doi.org/10.1007/s00253-014-5646-2 -
Suzuki K, Nakajima A. New aspects of IgA synthesis in the gut. International Immunology 2014;26(9):489-94. https://doi.org/10.1093/intimm/dxu059
» https://doi.org/10.1093/intimm/dxu059 -
Tian X, Shao Y, Wang Z, et al. Effects of dietary yeast ß-glucans supplementation on growth performance, gut morphology, intestinal Clostridium perfringens population and immune response of broiler chickens challenged with necrotic enteritis. Animal Feed Science and Technology 2016;215:144-55. https://doi.org/10.1016/j.anifeedsci.2016.03.009
» https://doi.org/10.1016/j.anifeedsci.2016.03.009 -
Ubeda C, Bucci V, Caballero S, et al. Intestinal microbiota containing Barnesiella species cures vancomycin-resistant Enterococcus faecium colonization. Infection and Immunity 2013;81(3):965-973. https://doi.org/10.1128/IAI.01197-12
» https://doi.org/10.1128/IAI.01197-12 - Vos P, Garrity GM, Jones D, et al. The firmicutes. New York: Springer; 2009.
-
Wang Y, Gu Q. Effect of probiotic on growth performance and digestive enzyme activity of Arbor Acres broilers. Research in Veterinary Science 2010;89(2):163-7. https://doi.org/10.1016/j.rvsc.2010.03.009
» https://doi.org/10.1016/j.rvsc.2010.03.009 -
Wei S, Morrison M, Yu Z. Bacterial census of poultry intestinal microbiome. Poultry Science. 2013;92(3):671-683. https://doi.org/10.3382/ps.2012-02822
» https://doi.org/10.3382/ps.2012-02822 -
Zhong X, Zhao Y, Huang L, et al. Remodeling of the gut microbiome by Lactobacillus johnsonii alleviates the development of acute myocardial infarction. Frontiers in Microbiology 2023;14:1140498. https://doi.org/10.3389/fmicb.2023.1140498
» https://doi.org/10.3389/fmicb.2023.1140498
