Research Note: Effect of butyric acid glycerol esters on ileal and cecal mucosal and luminal microbiota in chickens challenged with Eimeria maxima

Effects of Eimeria acervulina infection on the luminal and mucosal microbiota of the cecum and ileum in broiler chickens

Coccidiosis, an intestinal disease caused by Eimeria parasites, is responsible for major losses in the poultry industry by impacting chicken health. The gut microbiota is associated with health factors, such as nutrient exchange and immune system modulation, requiring understanding on the effects of Eimeria infection on the gut microbiota. This study aimed to determine the effects of Eimeria acervulina infection on the luminal and mucosal microbiota of the cecum (CeL and CeM) and ileum (IlL and IlM) at multiple time points (days 3, 5, 7, 10, and 14) post-infection. E. acervulina infection decreased evenness in CeL microbiota at day 10, increased richness in CeM microbiota at day 3 before decreasing richness at day 14, and decreased richness in IlL microbiota from day 3 to 10. CeL, CeM, and IlL microbiota differed between infected and control birds based on beta diversity at varying time points. Infection reduced relative abundance of bacterial taxa and some predicted metabolic pathways known for short-chain fatty acid production in CeL, CeM, and IlL microbiota, but further understanding of metabolic function is required. Despite E. acervulina primarily targeting the duodenum, our findings demonstrate the infection can impact bacterial diversity and abundance in the cecal and ileal microbiota.

Butyric acid and prospects for creation of new medicines based on its derivatives: a literature review

The widespread use of antimicrobials causes antibiotic resistance in bacteria. The use of butyric acid and its derivatives is an alternative tactic. This review summarizes the literature on the role of butyric acid in the body and provides further prospects for the clinical use of its derivatives and delivery methods to the animal body. Thus far, there is evidence confirming the vital role of butyric acid in the body and the effectiveness of its derivatives when used as animal medicines and growth stimulants. Butyric acid salts stimulate immunomodulatory activity by reducing microbial colonization of the intestine and suppressing inflammation. Extraintestinal effects occur against the background of hemoglobinopathy, hypercholesterolemia, insulin resistance, and cerebral ischemia. Butyric acid derivatives inhibit histone deacetylase. Aberrant histone deacetylase activity is associated with the development of certain types of cancer in humans. Feed additives containing butyric acid salts or tributyrin are used widely in animal husbandry. They improve the functional status of the intestine and accelerate animal growth and development. On the other hand, high concentrations of butyric acid stimulate the apoptosis of epithelial cells and disrupt the intestinal barrier function. This review highlights the biological activity and the mechanism of action of butyric acid, its salts, and esters, revealing their role in the treatment of various animal and human diseases. This paper also discussed the possibility of using butyric acid and its derivatives as surface modifiers of enterosorbents to obtain new drugs with bifunctional action.

Revealing the role of microalgae-bacteria niche for boosting wastewater treatment and energy reclamation in response to temperature

Conventional biological treatment usually cannot achieve the same high water quality as advanced treatment when conducted under varied temperatures. Here, satisfactory wastewater treatment efficiency was observed in a microalgae-bacteria consortia (MBC) over a wide temperature range because of the predominance of microalgae. Microalgae contributed more toward wastewater treatment at low temperature because of the unsatisfactory performance of the accompanying bacteria, which experienced cold stress (e.g., bacterial abundance below 3000 sequences) and executed defensive strategies (e.g., enrichment of cold-shock proteins). A low abundance of amoA-C and hao indicated that conventional nitrogen removal was replaced through the involvement of microalgae. Diverse heterotrophic bacteria for nitrogen removal were identified at medium and high temperatures, implying this microbial niche treatment contained diverse flexible consortia with temperature variation. Additionally, pathogenic bacteria were eliminated through microalgal photosynthesis. After fitting the neutral community model and calculating the ecological niche, microalgae achieved a maximum niche breadth of 5.21 and the lowest niche overlap of 0.38, while the accompanying bacterial community in the consortia were shaped through deterministic processes. Finally, the maximum energy yield of 87.4 kJ L^-1 and lipid production of 1.9 g L^-1 were achieved at medium temperature. Altogether, this study demonstrates that advanced treatment and energy reclamation can be achieved through microalgae-bacteria niche strategies.

A meta-analysis of the effect of Eimeria spp. and/or Clostridium perfringens infection on the microbiota of broiler chickens

Coccidiosis in chickens is caused by Eimeria spp. The infection provides a growth advantage to Clostridium perfringens (CP), frequently leading to necrotic enteritis. One approach to alleviate the negative impacts of the diseases is to improve the bacterial composition in chickens, and many experiments investigating chicken enteric health in recent years include the characterization of the bacterial microbiota. This meta-analysis synthesized the data of studies investigating the intestinal microbiota after infection with coccidia and/or CP to provide a basis for future research. Inclusion criteria were that experiments contained a group infected with one or both pathogens and an uninfected control group, the use of 16SrRNA Illumina sequencing and the availability of raw data. A total of 17 studies could be included. Meta-analyses of 3 different data sets were performed: 1 on data of 9 experiments on chickens infected with coccidia only; the second on data of 4 studies on chickens infected with CP only; the third on raw data of 8 experiments with chickens infected with coccidia and CP. The meta-analysis of relative abundance and alpha diversity of the data sets was performed in R using the SIAMCAT and metafor packages. The number of families of interest identified by the analyses of experiments with infection with coccidia only, CP only and the combined infection were 23, 2, and 29, respectively. There was an overlap of 13 families identified by analyses of experiments with infection with coccidia only and of experiments with the combined infections. Machine learning was not able to find a model to predict changes of the microbiota in either 1 of the 3 analyses. Meta-analyses of functional profiles showed a more uniform reaction to the infections with the relative abundance of many pathways significantly altered. Alpha diversity was not affected by infection with either pathogen or the combination. In conclusion, the heterogeneity of these microbiota studies makes recognizing common trends difficult, although it seems that coccidia infection affects the microbiota more than an infection with CP. Future studies should focus on the bacterial functions that are changed due to these infections using metagenome techniques.

Effects of Eimeria acervulina infection on the luminal and mucosal microbiota of the duodenum and jejunum in broiler chickens

The intestinal disease coccidiosis, caused by Eimeria parasites, impacts nutrient absorption in broiler chickens, leading to weight gain depression and major losses in the poultry industry. To develop alternatives to antibiotics for treating infected chickens, the gut microbiota has been researched because of its association with health factors such as nutrient exchange, immune system modulation, digestive system physiology, and pathogen exclusion. The aim of this study was to determine the effect of Eimeria acervulina infection on the luminal and mucosal microbiota of both the duodenum (DuoL and DuoM) and jejunum (JejL and JejM) at multiple time points (days 3, 5, 7, 10, and 14) post-infection. 16S rRNA amplicon sequencing was utilized to characterize the microbiota and analyze differences in alpha and beta diversity between infected (IF) and control (C) birds at each time point. Alpha diversity differed between IF and C birds in DuoM and JejM microbiota. Combined with beta diversity results, DuoM microbiota appeared to be affected by infection in the longer-term, while JejM microbiota were affected in the shorter-term. Relative abundances of bacterial taxa known for short-chain fatty acid (SCFA) production, such as Lachnospiraceae, Subdoligranulum, and Peptostreptococcaceae, tended to be lower in IF birds for all four microbiota. Moreover, predicted functional abundances showed MetaCyc pathways related to SCFA production, especially butyrate, may be influenced by these differences in bacterial relative abundance. Our findings expand understanding of how Eimeria infection affects luminal and mucosal microbiota in the duodenum and jejunum, and further research on metagenomic function may provide insights on the degree of influence duodenal and jejunal bacteria have on chicken health.

Delayed access to feed early post-hatch affects the development and maturation of gastrointestinal tract microbiota in broiler chickens

Background

The first two weeks of post-hatch (PH) growth in broilers (meat-type birds) are critical for gut development and microbiota colonization. In the current broiler production system, chicks may not receive feed and water for 24 to 72 h due to variations in hatching time and hatchery management. Post-hatch feed delay affects body weight, feed efficiency, mortality, and gut development. The goal of this study was to investigate changes in the microbiome in broiler chickens early PH and the effect of delayed access to feed on the microbiota.

Results

Chicks either received feed and water immediately after hatch or access to feed was delayed for 48 h to mimic commercial hatchery settings (treatment, TRT). Both groups were sampled (n = 6) at -48, 0, 4 h, and 1 (24 h), 2 (48 h), 3 (72 h), 4 (96 h), 6 (144 h), 8 (192 h), 10 (240 h), 12 (288 h) and 14 (336 h) days PH. Ileal (IL) and cecal (CE) epithelial scrapings (mucosal bacteria, M) and digesta (luminal bacteria, L) were collected for microbiota analysis. Microbiota was determined by sequencing the V3-V4 region of bacterial 16S rRNA and analyzed using QIIME2. The microbiota of early ileal and cecal samples were characterized by high abundance of unclassified bacteria. Among four bacterial populations (IL-L, IL-M, CE-L, CE-M), IL-M was the least affected by delayed access to feed early PH. Both alpha and beta diversities were affected by delayed access to feed PH in IL-L, CE-M and CE-L. However, the development effect was more pronounced. In all four bacterial populations, significant changes due to developmental effect (time relative to hatch) was observed in taxonomic composition, with transient changes of bacterial taxa during the first two weeks PH. Delayed access to feed has limited influence on bacterial composition with only a few genera and species affected in all four bacterial populations. Predicted function based on 16S rRNA was also affected by delayed access to feed PH with most changes in metabolic pathway richness observed in IL-L, CE-L and CE-M.

Conclusions

These results show transient changes in chicken microbiota biodiversity during the first two weeks PH and indicate that delayed access to feed affects microbiota development. Proper microbiota development could be an important factor in disease prevention and antibiotic use in broiler chickens. Moreover, significant differences in response to delayed access to feed PH between luminal and mucosal bacterial populations strongly suggests the need for separate analysis of these two populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02619-6.

Microbiota and Transcriptomic Effects of an Essential Oil Blend and Its Delivery Route Compared to an Antibiotic Growth Promoter in Broiler Chickens

This study evaluated the effect of the delivery of a commercial essential oil blend containing the phytonutrients star anise, cinnamon, rosemary, and thyme oil (via different routes) on broiler chickens’ ileal and ceca microbiota and liver transcriptome compared to an antibiotic growth promoter. Eggs were incubated and allocated into three groups: non-injected, in ovo saline, and in ovo essential oil. On day 18 of incubation, 0.2 mL of essential oil in saline (dilution ratio of 2:1) or saline alone was injected into the amnion. At hatch, chicks were assigned to post-hatch treatment combinations: (A) a negative control (corn-wheat-soybean diet), (B) in-feed antibiotics, (C) in-water essential oil (250 mL/1000 L of drinking water), (D) in ovo saline, (E) in ovo essential oil, and (F) in ovo essential oil plus in-water essential oil in eight replicate cages (six birds/cage) and raised for 28 days. On days 21 and 28, one and two birds per cage were slaughtered, respectively, to collect gut content and liver tissues for further analysis. Alpha and beta diversity differed significantly between ileal and ceca samples but not between treatment groups. In-feed antibiotic treatment significantly increased the proportion of specific bacteria in the family Lachnospiraceae while reducing the proportion of bacteria in the genus Christensenellaceae in the ceca, compared to other treatments. Sex-controlled differential expression of genes related to cell signaling and tight junctions were recorded. This study provides data that could guide the use of these feed additives and a foundation for further research.

Altered gene expression of selected matrix metalloproteinase system proteins in the broiler chicken gastrointestinal tract during post-hatch development and coccidia infection*

Matrix metalloproteinases (MMPs) are a family of proteases, that can process extracellular matrix (ECM) components and non-ECM molecules. MMPs can also function intracellularly in proteolytic and nonproteolytic functions. The participation of MMPs in the remodeling of the chicken gastrointestinal tract is largely unknown. The aim of the present study was to examine 1) the early neonatal developmental changes and effect of delayed access to feed immediately post-hatch (PH) and 2) the effect of Eimeria infection on mRNA expression of selected MMPs, their tissue inhibitors (TIMPs), and a disintegrin and metalloproteinase (ADAM) metallopeptidase with thrombospondin type 1 motif 8 (ADAMTS8) in the gastrointestinal tract of chicken. Protein localization of MMPs and TIMPs was also carried out in the normal ileal wall at −48, 24, and 336 h relative to hatch using immunofluorescence. In experiment 1, newly hatched Ross 708 chicks received feed and water immediately PH or were subjected to 48 h delayed access to feed. Chickens were sampled at −48, 0, 4, 24, 48, 72, 96, 144, 192, 240, 288, and 336 h PH. Ileum was collected for investigation of gene expression or fixed in paraformaldehyde for immunofluorescence. In experiments 2 and 3, Ross 708 male broilers were infected, at 21 d of age with Eimeria maxima or E. acervulina or sham-infected with water. Intestinal tissues were collected at 7 and 10 d postinfection for gene expression analysis. In general, mRNA expression patterns of all examined genes showed downregulation during the first 2 wk PH and were not affected by delay in feed access. These development-dependent changes in expression and tissue-dependent localization in the ileum of selected MMPs and TIMPs indicate that these molecules participate in the remodeling of chicken intestinal tissues during PH development. Increased expression of MMP-7 and MMP-9 transcripts in the intestine of Eimeria infected birds suggests an important role for these enzymes in the process of tissue remodeling and destruction in pathological conditions. The findings of this study are important for understanding the relationship between the expression of the MMP system and intestinal development, as well its role in gastrointestinal infection and subsequent recovery.

Effects of Xylanase in Corn- or Wheat-Based Diets on Cecal Microbiota of Broilers

Xylanase has been demonstrated to improve growth performance of broilers fed wheat- or corn-based diets due to its ability to degrade arabinoxylans (AX). However, content and structure of AX in corn and wheat are different, comparing effects of xylanase on cecal microbiota of broilers fed corn- or wheat-based diets could further elaborate the mechanism of the specificity of xylanase for different cereal grains. Thus, a total of 192 one-day-old broilers were randomly allotted into four dietary treatments, including wheat-soybean basal diet, wheat-soybean basal diet with 4,000U/kg xylanase, corn-soybean basal diet, and corn-soybean basal diet with 4,000U/kg xylanase to evaluate interactive effects of xylanase in corn- or wheat-based diets on broilers cecal microbiota during a 6-week production period. The results indicated that bacterial community clustering was mainly due to cereal grains rather than xylanase supplementation. Compared with broilers fed wheat-based diets, corn-based diets increased alpha-diversity and separated from wheat-based diets (p<0.05). Xylanase modulated the abundance of specific bacteria without changing overall microbial structure. In broilers fed wheat-based diets, xylanase increased the abundance of Lactobacillus, Bifidobacterium, and some butyrate-producing bacteria, and decreased the abundance of non-starch polysaccharides-degrading (NSP) bacteria, such as Ruminococcaceae and Bacteroidetes (p<0.05). In broilers fed corn-based diets, xylanase decreased the abundance of harmful bacteria (such as genus Faecalitalea and Escherichia-Shigella) and promoted the abundance of beneficial bacteria (such as Anaerofustis and Lachnospiraceae_UCG_010) in the cecum (p<0.05). Overall, xylanase supplementation to wheat- or corn-based diets improved broilers performance and cecal microbiota composition. Xylanase supplementation to wheat-based diets increased the abundance of butyrate-producing bacteria and decreased the abundance of NSP-degrading bacteria. Moreover, positive effects of xylanase on cecal microbiota of broilers fed corn-based diets were mostly related to the inhibition of potentially pathogenic bacteria, and xylanase supplementation to corn-based diets slightly affected the abundance of butyrate-producing bacteria and NSP-degrading bacterium, the difference might be related to lower content of AX in corn compared to wheat.

Choice of 16S ribosomal RNA primers affects the microbiome analysis in chicken ceca

We evaluated the effect of applying different sets of 16S rRNA primers on bacterial composition, diversity, and predicted function in chicken ceca. Cecal contents from Ross 708 birds at 1, 3, and 5 weeks of age were collected for DNA isolation. Eight different primer pairs targeting different variable regions of the 16S rRNA gene were employed. DNA sequences were analyzed using open-source platform QIIME2 and the Greengenes database. PICRUSt2 was used to determine the predicted function of bacterial communities. Changes in bacterial relative abundance due to 16S primers were determined by GLMs. The average PCR amplicon size ranged from 315 bp (V3) to 769 bp (V4–V6). Alpha- and beta-diversity, taxonomic composition, and predicted functions were significantly affected by the primer choice. Beta diversity analysis based on Unweighted UniFrac distance matrix showed separation of microbiota with four different clusters of bacterial communities. Based on the alpha- and beta-diversity and taxonomic composition, variable regions V1–V3(1) and (2), and V3–V4 and V3–V5 were in most consensus. Our data strongly suggest that selection of particular sets of the 16S rRNA primers can impact microbiota analysis and interpretation of results in chicken as was shown previously for humans and other animal species.

The effects of tributyrin supplementation on weight gain and intestinal gene expression in broiler chickens during Eimeria maxima-induced coccidiosis

Butyrate is a feed additive that has been shown to have antibacterial properties and improve gut health in broilers. Here, we examined the performance and gene expression changes in the ileum of tributyrin–supplemented broilers infected with coccidia. Ninety-six, Ross 708 broilers were fed either a control corn–soybean–based diet (−BE) or a diet supplemented with 0.25% (w/w) tributyrin (+BE). Birds were further divided into groups that were inoculated with Eimeria maxima oocysts (EM) or sham-inoculated (C) on day 21 posthatch. At 7 d postinfection (7 d PI), the peak of pathology in E. maxima infection, tributyrin-supplemented birds had significantly improved feed conversion ratios (FCR, P < 0.05) and body weight gain (BWG, P < 0.05) compared with -BE-infected birds, despite both groups having similar feed intake (FI, P > 0.05). However, at 10 d post-infection (10 d PI) no significant effects of feed type or infection were observed. Gene expression in the ileum was examined for insights into possible effects of infection and tributyrin supplementation on genes encoding proteins related to immunity, digestion, and gut barrier integrity. Among immune-related genes examined, IL-1B and LEAP2 were only significantly affected at 7 d PI. Transcription of genes related to digestion (APN, MCT1, FABP2, and MUC2) were primarily influenced by infection at 7 d PI and tributyrin supplementation (FABP2 and MUC2) at 10 d PI. With exception of ZO1, tight junction genes were affected by either infection or feed type at 7 d PI. At 10 d PI, only CLDN1 was not affected by either infection or feed type. Overall tributyrin shows promise as a supplement to improve performance during coccidiosis in broiler chickens; however, its effect on gene expression and mode of action requires further research.