Cecal Short-chain Fatty Acid Concentrations Research Articles

Bacillus licheniformis and phytase combination in broiler chicken diets: Effects on growth performance, digestibility coefficients, gut microbiome activities, and bone quality

In the present study, B. licheniformis was added to broiler chicken diets alone or in combination with 6-phytase and the effects on growth performance, coefficients of ileal nutrient digestibility, morphometrical measurements of selected internal organs, gut microbial activity, and bone quality were determined. Four hundred 1-day-old female birds (Ross 308) were randomly allotted to 4 dietary treatments (10 replicate pens, 10 birds each). The trial was set up as follows: negative control (NC), basal diet without any feed additive; NC+Pro, basal diet with B. licheniformis (500 g/t of diet); NC+Phy, basal diet with 6-phytase (400 g/t of diet); and NC+Pro+Phy, basal diet in which both experimental factors were added at the same levels as above. The interaction between treatments was noted in each evaluated period regarding BWG and FI. In the entire experiment, an increased body weight gain (P < 0.001) was observed in the NC+Pro+Phy treatment compared to the other groups. The birds that received both feed additives combined were characterized by an increased feed intake (P < 0.001), contrary to NC+Pro and NC+Phy. Moreover, in terms of microenvironment modulations, interactions (P < 0.05) were observed in the jejunal and cecal digesta pH, short-chain fatty acid (SCFA) level, and microbial enzyme activities. However, the impacts of B. licheniformis and phytase on cecal SCFA concentrations and bacterial enzymes were mainly opposite. There were no interactions (P < 0.05) in terms of geometrical, mechanical, and structural selected tibia and femur indices. However, 6-phytase addition improved bone structure, stiffness, and elasticity. In conclusion, the interactions between 6-phytase and B. licheniformis positively affect growth performance via microbial activity changes; however, the supportive bone quality maintenance properties are only connected to 6-phytase supplementation.

Heat-killed Akkermansia muciniphila ameliorates allergic airway inflammation in mice.

Allergic asthma (AA) is a common inflammatory airway disease characterized by increased airway hyper-responsiveness (AHR), inflammation, and remodeling. Akkermansia muciniphila is a strictly anaerobic bacterium residing in the gut and is a promising next-generation probiotic to improve metabolic inflammatory syndrome. A recent study suggested the beneficial effect of live A. muciniphila on allergic airway inflammation (AAI) in mice. However, whether the heat-killed form can improve AAI requires further investigation. Mice sensitized and challenged with house dust mites (HDM) develop AA hallmarks including inflammatory cell infiltration, goblet cell hyperplasia, and subepithelial collagen deposition in the lungs. These phenomena were reversed by oral administration of the heat-killed A. muciniphila strain EB-AMDK19 (AMDK19-HK) isolated from the feces of healthy Koreans. Furthermore, AMDK19-HK diminished the HDM-induced AHR to inhaled methacholine, lung mast cell accumulation, and serum HDM-specific IgE levels. It also led to the overall suppression of IL-4, IL-13, and eotaxin production in bronchoalveolar lavage fluids, and Il4, Il5, Il13, and Ccl17 gene expression in lung tissues. Moreover, AMDK19-HK suppressed Th2-associated cytokine production in the splenocytes of HDM-sensitized mice in vitro. Additionally, a combination of 16S rRNA gene sequencing and short-chain fatty acid (SCFA) analysis in cecal samples revealed that AMDK19-HK modulated the relative abundance of circulating SCFA-associated gut genera, including a positive correlation with Lachnospiraceae_ NK4A136_group and a negative correlation with Lachnoclostridium and significantly increased cecal SCFA concentrations. Finally, AMDK19-HK improved intestinal mucosal barrier function. These results suggest that the oral administration of AMDK19-HK ameliorates HDM-induced AAI in mice by suppressing Th2-mediated immune responses and could have a protective effect against AA development.

Abstract 2794: Consumption of dietary fiber correlates with a significant increase in a-diversity in the intestinal Microbiome of allo-HCT recipients and with lower GVHD-lethality in pre-clinical models

Abstract Background: Graft-versus-host disease (GVHD) is associated with a decrease in intestinal microbiota and beneficial short-chain fatty acids (SCFAs). Dietary fiber can modulate the intestinal microbiome and SCFA production which effect intestinal epithelium health and immunity. Therefore, we hypothesized that a high-fiber diet in recipients of an allogeneic hematopoietic cell transplantation (allo-HCT) could result in an increase of beneficial commensals, concentrations of SCFAs, and decreased risk of GVHD. Methods: We evaluated dietary data and fecal samples of allo-HCT patients receiving unmodified grafts (n=95) at MSKCC (day -10 to day +30 relative to allo-HCT) and correlated microbial α-diversity (16s rRNA, n=568 samples) with fiber intake and acute GVHD in No-GVHD (n=30), Non-LGI-GVHD (GVHD except lower gastrointestinal tract, n=41), and LGI-GVHD patients (lower gastrointestinal tract GVHD, n=24).We tested concentrations of cellulose fiber (0%, 6%, 12% and 40%) in a GVHD mouse model (C57BL/6J into BALB/c) to assess survival, microbial composition (shotgun sequencing n=180; n=30 per group), cecal SCFAs concentrations (GC-MS n=24, n=8 per group), and lastly, T cell subsets (Th1/Th17/Tregs) and colonic epithelial MHC-II expression (flow cytometry n=54, n=18 per group). Results: In allo-HCT patients, fiber intake correlated positively with microbial α-diversity (R=0.3, p=0.04), especially in the LGI-GVHD group (p=0.007). Additionally, patients with high fiber intake had higher microbial α-diversity compared to the low fiber cohort (p&amp;lt;0.0001).GVHD mice receiving a fiber-rich diet (12%), compared to 0% and 6%, had a higher microbial α-diversity (p=0.01); reduced GVHD lethality (p=0.02); and a decrease in the Enterococcus sp. (p=0.004) and Akkermansia sp. (p=0.01) abundance; taxa which are associated with worse overall survival and increased risk of lethal GVHD. In contrast, compared to 12%, the 40% fiber diet resulted in worse survival (p=0.002), lower α-diversity (p=0.05) and a higher abundance of Bifidobacterium sp. (p&amp;lt;0.0001).Cecal butyrate in GVHD mice was higher in response to the 12% vs. the 0% (p=0.01) and 6% (p=0.05) fiber diets. Mice treated with12% fiber displayed higher number of Tregs (CD4+CD25+FOXP3+), than those with 0% (p=0.001) and 6% (p=0.02); and a lower expression of MHC-II in epithelial cells (EpCAM+CD45-) vs. 0% fiber (p=0.02). Conclusions: We demonstrated that a higher fiber intake in allo-HCT patients is associated with an increase in α-diversity; especially in LGI-GVHD patients. In a pre-clinical GVHD-model, optimal fiber consumption (12% cellulose) leads to an increase in α-diversity, a decrease in pathogen relative abundance, increased T-regulatory cells, and a decrease in GVHD lethality. These results suggest that dietary fiber could be utilized to prevent GVHD. Citation Format: Jenny Paredes, Anqi Dai, Ruben J. Faustino Ramos, Peter Adintori, Teng Fei, Chi Nguyen, Harold Elias, Kristen Victor, Romina Ghale, Charlotte Pohl, Ana Gradissimo, Justin Cross, Oriana Miltiadous, Jonathan Peled, Marina Burgos da Silva, Marcel RM van den Brink. Consumption of dietary fiber correlates with a significant increase in a-diversity in the intestinal Microbiome of allo-HCT recipients and with lower GVHD-lethality in pre-clinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2794.

Characterizing the Effect of Campylobacter jejuni Challenge on Growth Performance, Cecal Microbiota, and Cecal Short-Chain Fatty Acid Concentrations in Broilers.

This study aimed to understand the effect of C. jejuni challenge on the cecal microbiota and short-chain fatty acid (SCFA) concentration to form a better understanding of the host-pathogen interaction. Sixty broilers were randomly allocated into two treatments: control and challenge. Each treatment was replicated in six pens with five birds per pen. On day 21, birds in the challenge group were orally gavaged with 1 × 108C. jejuni/mL, while the control group was mock challenged with PBS. The C. jejuni challenge had no effect on body weight, feed intake, and feed conversion ratio compared to the control group. On day 28, the C. jejuni challenge decreased the observed features and Shannon index compared to the control group. On the species level, the C. jejuni challenge decreased (p = 0.02) the relative abundance of Sellimonas intestinalis on day 28 and increased (p = 0.04) the relative abundance of Faecalibacterium sp002160895 on day 35 compared to the control group. The C. jejuni challenge did not change the microbial function and the cecal concentrations of SCFA on days 28 and 35 compared to the control group. In conclusion, C. jejuni might alter the gut microbiota's composition and diversity without significantly compromising broilers' growth.

Effects of LED Light Colors on the Growth Performance, Intestinal Morphology, Cecal Short-Chain Fatty Acid Concentrations and Microbiota in Broilers

This study aimed to explore the effects of light-emitting diode (LED) light colors on growth, intestinal morphology, and cecal microbiota in broilers. A total of 360 healthy male Arbor Acres (AA) broilers with similar weights were selected and divided into four groups with six replicates in each group and 15 broilers in each replicate: LED white light (W), LED green light (G), LED blue light (B), and LED blue–green composite light (BG). The experimental period was 42 d, the light cycle of each treatment group was 23L:1D (23 h of light, one hour of darkness) from 1 to 3 d, and the light cycle from 4 to 42 d was 16L:8D; light intensity was 20 Lux. The results showed that the average daily feed intake and final weight of broilers receiving the B group were the highest in 21 d and 42 d compared with other groups. The average daily feed intake of the BG group was lower than that of the B group. In the same light color, small intestine villus height grows with age. On days 21 and 42, compared with other groups, the ileal villus height was higher, the crypt depth was lower, and the V/C ratio (villus to crypt ratio) was higher in the BG group. The combination of blue–green composite light was beneficial to increase the content of propionate, isobutyrate, butyrate, isovalerate, and valerate in the cecum of 21-day-old broilers and the content of isobutyrate in the cecum of 42-day-old broilers, and a decrease in cecal short-chain fatty acid concentrations with age. The B group and the BG group had higher abundances of Bacteroidetes at day 21 of age and lower abundances of Phascolarctobacterium at day 42. However, no cecal microbiota differences were detected by the Bonferroni-corrected test. In general, our research results showed that light color could promote the growth of broilers by affecting intestinal morphology, microbiota abundance (needs to be validated by further experiments), and cecal short-chain fatty acid concentrations. And blue and blue–green composite lights are more suitable for broiler growth.

Dietary emodin alleviates lipopolysaccharide-induced intestinal mucosal barrier injury by regulating gut microbiota in piglets.

This study was to determine the effects of dietary emodin (ED) on the intestinal mucosal barrier, nuclear factor kappa-B (NF-κB) pathways, and gut microbial flora in lipopolysaccharide (LPS)-induced piglets. Twenty-four weaned piglets were chosen and 4 treatments were created by randomly distributing piglets into CON, ED, LPS, and ED_LPS groups. Experiments were done in a 2×2 factorial arrangement and maintained for 21d. Dietary treatment (a basal diet or 300mg/kg ED) and immunological challenge (LPS or sterile saline) were 2 major factors. Intraperitoneal injections of LPS or sterilized saline were given to piglets on d 21. Six hours after the LPS challenge, all piglets were euthanized for sample collection and analysis. The results showed that piglets of the ED_LPS group had higher (P<0.05) villus height to crypt depth ratio (VCR), and lower (P<0.05) plasma D-lactate and diamine oxidase (DAO) than the LPS group. Furthermore, ED inhibited (P<0.05) the decrease of glutathione peroxidase (GSH-Px) and catalase (CAT) activities and increase of malonaldehyde level (P<0.05) in jejunal mucosa induced by LPS. The mRNA levels of pro-inflammatory cytokine genes (IL-6, IL-1β, and TNF-α) were significantly reduced (P<0.05), and the mRNA levels of antioxidant enzyme genes (GPX-1, SOD2 and CAT), as well as protein and mRNA levels of tight junction proteins (occludin, claudin-1, and ZO-1), were also significantly increased (P<0.05) by ED addition in LPS-induced piglets. Meanwhile, ED supplementation significantly decreased the LPS-induced protein levels of cyclooxygenase-2 and phosphorylation levels of NF-κB p65 and IκBα in jejunal mucosa. Emodin had a significant effect on the composition of gut microbial flora at various taxonomic positions as indicated by 16S RNA sequencing. The acetic acid, isobutyric acid, valeric acid, and isovaleric acid concentrations in the cecum were also increased by ED addition in pigs (P<0.05). Furthermore, the correlation analysis revealed that some intestinal microbiota had a potential relationship with jejunal VCR, plasma D-lactate and DAO, jejunal mucosa GSH-Px and CAT activity, and cecal short-chain fatty acid concentration. These data suggest that ED is effective in alleviating LPS-induced intestinal mucosal barrier injury by modulating gut microbiota in piglets.

Supplemental enzymes and probiotics on the gut health of broilers fed with a newly harvested corn diet

Gut health is important for digestion and absorption of nutrient for animals. The purpose of this study was to investigate the therapeutic effect of enzymes and probiotics alone or in combination on the gut health of broilers fed with newly harvested corn diets. A total of 624 Arbor Acres Plus male broiler chickens were randomly divided into 8 treatment groups (PC: normal corn diet, NC: newly harvested corn diet, DE: NC+glucoamylase, PT: NC+protease, XL: NC+xylanase, BCC: NC+Pediococcus acidilactici BCC-1, DE+PT: NC+glucoamylase+protease, XL+BCC: NC+xylanase+Pediococcus acidilactici BCC-1). Each group was divided into 6 replicates, with 13 birds each. On d 21, intestinal morphological, intestinal tight junction and aquaporins gene expression, cecal short-chain fatty acid concentrations, and microflora were measured. Compared with the newly harvested corn diets (NC), supplemental glucoamylase (DE) significantly increased the relative abundance of Lachnospiraceae (P < 0.05) and decreased the relative abundance of Moraxellaceae (P < 0.05). Supplemental protease (PT) significantly increased the relative abundance of Barnesiella (P < 0.05), but the relative abundance of Campylobacter decreased by 44.4%. Supplemental xylanase (XL) significantly increased the jejunal mRNA expressions of MUC2, Claudin-1, and Occludin (P < 0.01), as well as the cecal digesta contents of acetic acid, butyric acid, and valeric acid (P < 0.01). Supplemental DE combined with PT increased the ileal mRNA expressions of aquaporins (AQP) 2, AQP5, and AQP7 (P < 0.01). Supplemental BCC significantly increased the jejunal villus height and crypt depth (P < 0.01), the jejunal mRNA expressions of MUC2, Claudin-1 and Occludin (P < 0.01), and the relative abundance of Bacteroides (P < 0.05). Supplemental xylanase in combination with BCC significantly increased jejunal villus height and crypt depth (P < 0.01), the ileal mRNA expressions of AQP2, AQP5 and AQP7 (P < 0.01), and the cecal digesta contents of acetic acid, butyric acid, and valeric acid (P < 0.01). This suggests that inclusions of supplemental protease (12,000 U/kg), glucoamylase (60,000 U/kg), or Pediococcus acidilactici BCC-1 (109 cfu/kg) individually or in combination with xylanase (4,800 U/kg) in the newly harvested corn diets can alleviate diarrhea in broilers, and be beneficial for the gut health.

Effect of riboflavin deficiency on intestinal morphology, jejunum mucosa proteomics, and cecal microbiota of Pekin ducks.

This study was to determine the effects of riboflavin deficiency (RD) on intestinal development, jejunum mucosa proteome, cecal short-chain fatty acids (SCFA) profiling, and cecal microbial diversity and community of starter Pekin ducks. Male white Pekin ducks (1d old, n=240) were allocated into 2 groups, with 12 replicates and 10 birds per replicate in each group. For 21d, all ducks had ad libitum access to either an RD or a riboflavin adequate (control, CON) diet, formulated by supplementing a basal diet with 0 or 10mg riboflavin per kg of diet, respectively. Compared to the CON group, growth retardation, high mortality, and poor riboflavin status were observed in the RD group. Furthermore, RD reduced the villus height and the ratio of villus height to crypt depth of jejunum and ileum (P<0.05), indicating morphological alterations of the small intestine. In addition, dietary RD enhanced relative cecum weight and decreased cecal SCFA concentrations (P<0.05), including propionate, isobutyrate, butyrate, and isovalerate. The jejunum mucosa proteomics showed that 208 proteins were upregulated and 229 proteins were downregulated in the RD group compared to those in the CON group. Among these, RD mainly suppressed intestinal absorption and energy generation processes such as glycolysis and gluconeogenesis, fatty acid beta oxidation, tricarboxylic acid cycle, and oxidative phosphorylation, leading to impaired ATP generation. In addition, RD decreased the community richness and diversity of the bacterial community in the cecum of ducks. Specifically, RD reduced the abundance of butyrate-producing bacteria in the cecum (P<0.05), such as Eubacterium coprostanoligenes, Prevotella and Faecalibacterium. Dietary RD resulted in growth depression and intestinal hypofunction of Pekin ducks, which could be associated with impaired intestinal absorption and energy generation processes in intestinal mucosa, as well as gut microbiota dysbiosis. These findings contribute to our understanding of the mechanisms of intestinal hypofunction due to RD.

Dietary Fibers Differ in Their Effects on Large Bowel Epithelial Proliferation and Fecal Fermentation-Dependent Events in Rats

The effects of different fiber types and processing on putative protective mechanisms for colorectal cancer were evaluated. Rats were fed diets of similar nutrient balance containing either no added fiber or 10% fiber from various sources. The rate of distal colonic epithelial proliferation, measured by the metaphase arrest method, was dependent on fiber type; ranking of fibers from highest to lowest yielded the following order: methylcellulose > coarse wheat bran > fine wheat bran ≈ parboiled and extruded rice brans > no fiber (P = 0.012). Effect on stool output ranked identically. Ranking of effect on fecal pH, from most to least acidic was as follows: coarse wheat bran ≈ the rice brans > fine wheat bran > no fiber ≈ methylcellulose (P = 0.00001). Coarse wheat bran gave significantly higher fecal butyrate concentrations than did the rice brans, which in turn gave higher levels than fine wheat bran, methylcellulose and the no-fiber diet. Proximal colon epithelial proliferation was unaffected by diet although cecal short-chain fatty acid concentrations and pH were affected. Different fibers have different effects on events in the fecal environment and distal colonic epithelium. Putative protective events (increased output, low fecal pH, high butyrate, low proliferation) are not equally affected and are unlikely in themselves to allow prediction of the protective effect of a fiber.

Week-Old Chicks with High Bacteroides Abundance Have Increased Short-Chain Fatty Acids and Reduced Markers of Gut Inflammation.

As important commensals in the chicken intestine, Bacteroides are essential complex carbohydrate degraders, and short-chain fatty acid (SCFA) producers that are highly adapted to the distal gut. Previous studies have shown large variation in Bacteroides abundance in young chickens. However, limited information is available regarding how this variation affects the gut microbiome and host immunity. To investigate how elevated or depleted Bacteroides levels affect gut microbial functional capacity and impact host response, we sampled 7-day-old broiler chickens from 14 commercial production flocks. Week-old broiler chickens were screened and birds with low Bacteroides (LB) and high Bacteroides (HB) abundance were identified via 16S rRNA gene amplicon sequencing and quantitative PCR (qPCR) assays. Cecal microbial functionality and SCFA concentration of chickens with distinct cecal Bacteroides abundance were profiled by shotgun metagenomic sequencing and gas chromatography, respectively. The intestinal immune responses of LB and HB chickens were assessed via reverse transcription qPCR. Results showed that the gut microbiota of the LB group had increased abundance of lactic acid bacteria pyruvate fermentation pathway, whereas complex polysaccharide degradation and SCFA production pathways were enriched in the HB group (P < 0.05), which was supported by increased SCFA concentrations in the ceca of HB chickens (P < 0.05). HB chickens also showed decreased expression of interleukin-1β and increased expression of interleukin-10 and tight-junction protein claudin-1 (P < 0.05). Overall, the results indicated that elevated Bacteroides may benefit the 7-day broiler gut and that further work should be done to confirm the causal role of Bacteroides in the observed positive outcomes. IMPORTANCE To date, limited information is available comparing distinct Bacteroides compositions in the chicken gut microbial communities, particularly in the context of microbial functional capacities and host responses. This study showed that possessing a microbiome with elevated Bacteroides in early life may confer beneficial effects to the chicken host, particularly in improving SCFA production and gut health. This study is among the first metagenomic studies focusing on the early life chicken gut microbiota structure, microbial functionality, and host immune responses. We believe that it will offer insights to future studies on broiler gut microbial population and their effects on host health.

Bacteroides uniformis and its preferred substrate, α-cyclodextrin, enhance endurance exercise performance in mice and human males.

Although gut microbiota has been linked to exercise, whether alterations in the abundance of specific bacteria improve exercise performance remains ambiguous. In a cross-sectional study involving 25 male long-distance runners, we found a correlation between Bacteroides uniformis abundance in feces and the 3000-m race time. In addition, we administered flaxseed lignan or α-cyclodextrin as a test tablet to healthy, active males who regularly exercised in a randomized, double-blind, placebo-controlled study to increase B. uniformis in the gut (UMIN000033748). The results indicated that α-cyclodextrin supplementation improved human endurance exercise performance. Moreover, B. uniformis administration in mice increased swimming time to exhaustion, cecal short-chain fatty acid concentrations, and the gene expression of enzymes associated with gluconeogenesis in the liver while decreasing hepatic glycogen content. These findings indicate that B. uniformis enhances endurance exercise performance, which may be mediated by facilitating hepatic endogenous glucose production.

Immobilization of Lactobacillus plantarum NCIMB 8826 ameliorates Citrobacter rodentium induced lesions and enhances the gut inflammatory response in C57BL/6 weanling mice

Infectious diarrhea is a major cause of infant mortality in most developing countries. In this research, we evaluated the potential of immobilized Lactobacillus plantarum NCIMB 8826 on weanimix infant cereal and its effectiveness in reducing the severity of Citrobacter rodentium-induced diarrhea in weanling mice. Thirty-six C57BL/6 weanling mice were placed into four groups (n = 9 each; negative, positive, prevention and cure). Mice received either L. plantarum (109 CFU/g) immobilized on weanimix infant cereal 3 days before C. rodentium (109 CFU/ ml) infection (Prevention) or 3 days after C. rodentium infection (Cure). A positive control group was infected with C. rodentium only, while a negative control group received neither L. plantarum nor C. rodentium. Positive control mice showed colonic mucosal and submucosal inflammation, erosion, and mucosal epithelia hyperplasia with the C. rodentium infection. Mice in the prevention and cure groups had less severe histologic alterations in the colon. Some beneficial effect of L. plantarum was observed in cecal short-chain fatty acid concentrations, which stimulates water and electrolytes absorption to reduce diarrhea. Our findings demonstrated that L. plantarum NCIMB 8826 could be immobilized on weanimix infant cereal to help reduce diarrhea during weaning.Graphical

Protease or Clostridium butyricum addition to a low-protein diet improves broiler growth performance

Low-protein (LP) feeds are used in the poultry industry to combat the increasing consumption of protein resources and reduce environmental pollution caused by excessive nitrogen excretion. Dietary supplementation of protease or Clostridium butyricum increases the growth performance of broilers; however, it is unclear whether they counteract the negative effects of LP diets. The effects of protease and C. butyricum on growth performance, intestinal morphology, anti-oxidant capacity, anti-inflammatory response, and microbial community of broilers have not been studied extensively. Here, 450 healthy 1-day-old Cobb500 broilers were allocated to five groups, according to different diets: basal diet (Control); LP diet (LP; 2% less crude protein than the control); LP diet + 200g/t HuPro protease (LPH); LP diet + 1.0 × 109CFU/t C. butyricum (LPC); and basal diet + 200g/t oxytetracycline (Antibiotic). Supplementing both C. butyricum and protease improved the growth performance of broilers. The supplementation of HuPro protease under low-protein conditions could achieve a breeding effect similar to that of the positive control (Antibiotic). Supplementing C. butyricum could maintain intestinal barrier function, alleviate the inflammatory response, and increase ileal and cecal short-chain fatty acid concentrations. Both C. butyricum and protease altered the bacterial diversity in the cecum, increased Bacteroidetes abundance, and resulted in higher abundance of Rikenellaceae RC9 gut spp. and lower abundance of Alistipes spp. in broilers. This study demonstrates the positive effects of proteases and C. butyricum on broilers and serves as a reference for the selection of appropriate supplementation for broilers in the poultry industry. KEY POINTS: • Low-protein diet had a negative effect on growth performance of broilers. • Protease significantly reduced feed conversion rate. • Clostridium butyricum had positive effects on broilers.

Reconstitution of the host holobiont in germ-free born male rats acutely increases bone growth and affects marrow cellular content.

Integration of microbiota in a host begins at birth and progresses during adolescence, forming a multidirectional system of physiological interactions. Here, we present an instantaneous effect of natural, bacterial gut colonization on the acceleration of longitudinal and radial bone growth in germ-free born, 7-wk-old male rats. Changes in bone mass and structure were analyzed after 10 days following the onset of colonization through cohousing with conventional rats and revealed unprecedented acceleration of bone accrual in cortical and trabecular compartments, increased bone tissue mineral density, improved proliferation and hypertrophy of growth plate chondrocytes, bone lengthening, and preferential deposition of periosteal bone in the tibia diaphysis. In addition, the number of small in size adipocytes increased, whereas the number of megakaryocytes decreased, in the bone marrow of conventionalized germ-free rats indicating that not only bone mass but also bone marrow environment is under control of gut microbiota signaling. The changes in bone status paralleled with a positive shift in microbiota composition toward short-chain fatty acids (SCFA)-producing microbes and a considerable increase in cecal SCFA concentrations, specifically butyrate. Furthermore, reconstitution of the host holobiont increased hepatic expression of IGF-1 and its circulating levels. Elevated serum levels of 25-hydroxy vitamin D and alkaline phosphatase pointed toward an active process of bone formation. The acute stimulatory effect on bone growth occurred independently of body mass increase. Overall, the presented model of conventionalized germ-free rats could be used to study microbiota-based therapeutics for combatting dysbiosis-related bone disorders.

Qualitative and quantitative profiles of jejunal oligosaccharides and cecal short-chain fatty acids in broiler chickens receiving different dietary levels of fiber, protein and exogenous enzymes.

Dietary supplemental carbohydrases are able to degrade non-starch polysaccharides and generate oligosaccharides in the gastrointestinal tract. This study was conducted to investigate the influence of dietary fiber and protein levels on growth performance, nutrient utilization, digesta oligosaccharides profile and cecal short-chain fatty acid (SCFA) profile in broilers receiving diets supplemented with xylanase or protease individually or in combination. Enzyme supplementation had no effect on growth performance. There was significant (P < 0.05) fiber × protein × xylanase interaction for ileal nitrogen digestibility and significant (P < 0.01) protein × xylanase × protease interaction for nitrogen-corrected apparent metabolizable energy. Birds fed high-fiber diets had higher (P < 0.05) jejunal oligosaccharides and cecal SCFA concentrations. Xylanase and protease combination produced the greatest pentose (Pent) levels in low fiber-adequate protein diets but lowest levels in highfiber-low protein diets. There was significant (P < 0.05) fiber × xylanase × protease interaction explained by the digesta concentrations of (Pent)3 , (Pent)4 and (Pent)5 being greatest (P < 0.5) in protease-only supplemented high-fiber diets but lowest in protease-only supplemented low-fiber diets. These results suggest that, of all the factors investigated, dietary fiber level had the greatest effect on modulating digesta concentration of oligosaccharides and cecal SCFA. Evidence points to the fact that there is considerable capacity for generating pentose oligosaccharides in the digestive tract of broilers receiving diets rich in fibrous feedstuffs, and that this may have a beneficial effect on microbial profile in the digestive tract. © 2021 Society of Chemical Industry.

The Combined Effects of Magnesium Oxide and Inulin on Intestinal Microbiota and Cecal Short-Chain Fatty Acids.

Constipation is a common condition that occurs in many people worldwide. While magnesium oxide (MgO) is often used as the first-line drug for chronic constipation in Japan, dietary fiber intake is also recommended. Dietary fiber is fermented by microbiota to produce short-chain fatty acids (SCFAs). SCFAs are involved in regulating systemic physiological functions and circadian rhythm. We examined the effect of combining MgO and the water-soluble dietary fiber, inulin, on cecal SCFA concentration and microbiota in mice. We also examined the MgO administration timing effect on cecal SCFAs. The cecal SCFA concentrations were measured by gas chromatography, and the microbiota was determined using next-generation sequencing. Inulin intake decreased cecal pH and increased cecal SCFA concentrations while combining MgO increased the cecal pH lowered by inulin and decreased the cecal SCFA concentrations elevated by inulin. When inulin and MgO were combined, significant changes in the microbiota composition were observed compared with inulin alone. The MgO effect on the cecal acetic acid concentration was less when administered at ZT12 than at ZT0. In conclusion, this study suggests that MgO affects cecal SCFA and microbiota during inulin feeding, and the effect on acetic acid concentration is time-dependent.

Bacillus subtilis delivery route: effect on growth performance, intestinal morphology, cecal short-chain fatty acid concentration, and cecal microbiota in broiler chickens

As the poultry industry recedes from the use of antibiotic growth promoters, the need to evaluate the efficacy of possible alternatives and the delivery method that maximizes their effectiveness arises. This study aimed at expounding knowledge on the effect of the delivery method of a probiotic product (Bacillus subtilis fermentation extract) on performance and gut parameters in broiler chickens. A total of 450 fertile eggs sourced from Cobb 500 broiler breeders were randomly allotted to 3 groups: in ovo probiotic (n = 66), in ovo saline (n = 66), and noninjection (n = 200) and incubated for 21 d. On day 18.5 of incubation, 200 μL of either probiotic (10 × 106 cfu) or saline was injected into the amnion. At hatch, chicks were reallotted to 6 new treatment groups: in ovo probiotic, in ovo saline, in-feed antibiotics, in-water probiotic, in-feed probiotics, and control (corn-wheat-soybean diet) in 6 replicate cages and raised for 28 d. Of all hatch parameters evaluated, only percentage pipped eggs was found significant (P < 0.05) with the noninjection group having higher percentage pipped eggs than the other groups. Treatments did not affect the incidence of necrotic enteritis on day 28 (P > 0.05). Irrespective of the delivery method, the probiotic treatments had no significant effect on growth performance. The ileum villus width of the in ovo probiotic treatment was 18% higher than the in ovo saline group (P = 0.05) but not statistically higher than other groups. The jejunum villus height was 23% higher (P = 0.000) in the in ovo probiotic group than in the control group. There was no effect of treatment on total cecal short-chain fatty acid concentration and cecal gut microbiota composition and diversity (P > 0.05), although few unique bacteria differential abundance were recorded per treatment. Conclusively, although probiotic treatments (irrespective of the delivery route) did not affect growth performance, in ovo delivery of the probiotic product enhanced intestinal morphology, without compromising hatch performance and gut homeostasis.

Using of Essential Oil Mixture in Quail Breeders (Coturnix Coturnix Japonica) for Improving Cecal Short-Chain Fatty Acid Concentrations

The aim of this study is to investigate the effect of added to mixture essential oil consist of mint oil, juniper oil, rosemary oil and oregano vulgare oil added in drinking water at on intestinal health in quail breeders. A total of 160 Japanese quail breeders (control group each subgroup 6 females 6 males, experimental groups each subgroup 5 females 5 males) 17 weeks of age were randomly divided into 3 treatment groups and each group was divided into 5 replicates. The experimental period lasted 56 days. Maize and soybean meal-based diets were offered ad libitium to the birds from during the experimental period. Treatments were as follows: C, (Control; without supplementation to the drinking water); E1 (0,1ml/L essential oil mixture supplementation to the drinking water) and E2 (0,3ml/L essential oil mixture supplementation to the drinking water. Acetic acid, butyric acid, isocaproic acid and SCFA values were linearly affected by the increasing level of essential oil mixture (mint oil, juniper oil, rosemary oil and oregano vulgare oil). There were no significant differences in propionic acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid and BCFA concentrations. In conclusion, essential oil mixture consists of mint oil, juniper oil, rosemary oil and oregano vulgare oil can be used to improve intestinal health in quail breeders drinking water.

Mucin-Derived O-Glycans Act as Endogenous Fiber and Sustain Mucosal Immune Homeostasis via Short-Chain Fatty Acid Production in Rat Cecum

Abstract Objectives Intestinal mucins escape digestion and enter the large bowel where they are degraded by microbiome. To what extent and how mucins impact large-bowel physiology remain unclear. This study examined the large-bowel fermentation characteristics of mucins and mucin-derived O-glycan sugars and whether mucins and N-acetylglucosamine (GlcNAc) affect gut immunity. Methods Mucin secretion from the terminal ileum was determined from feces of ileorectostomized male Wistar rats (age 6 weeks) fed AIN76-based control diet (CD) for 15 d (Expt. 1). Normal male Wistar rats (age 6 weeks; 4 weeks for Expt. 4) were fed CD ± porcine stomach mucin (PM) at 6 or 12g/kg diet, equivalent to 1.5 and 3 times daily mucin secretion, for 14 d (Expt. 2); CD ± GlcNAc, fucose, or N-acetylneuraminic acid at 10g/kg diet for 14 d (Expt. 3); or CD ± PM (15 g/kg diet) or GlcNAc (10 g/kg diet) for 29 d (Expt. 4). Short-chain fatty acids (SCFAs), microbial composition, and cecal O-glycan content were assessed. IgA+ plasma and regulatory T cells and inflammatory cytokine expression in the cecum were evaluated (Expt. 4). Results Daily mucin secretion corresponded to 43.2 mmol of O-glycans. PM was efficiently fermented in the cecum, as evidenced by comparable amounts of cecal O-glycans between groups. PM-fed rats harbored more mucin-degrading bacteria. Cecal SCFA concentrations, particularly n-butyrate, were higher in 12g/kg PM diet-fed rats versus CD (P &amp;lt; 0.05). Among O-glycan sugars, only GlcNAc produced higher n-butyrate concentrations versus CD (P &amp;lt; 0.05), with increased numbers of several butyrate-producing bacteria. GlcNAc increased the abundance of IgA + plasma and regulatory T cells versus CD (P &amp;lt; 0.05). PM produced a similar but less-significant trend. GlcNAc and PM feeding decreased expression of Tnfa and Ifng versus CD (P &amp;lt; 0.05). Conclusions Mucin-derived O-glycans act as endogenous fiber and maintain mucosal immune homeostasis via large-bowel SCFA production in rats. Funding Sources JSPS KAKENHI.

Antibiotic use during pregnancy increases offspring asthma severity in a dose-dependent manner.

The use of antibiotics during pregnancy is associated with increased allergic asthma risk in the offspring, and given that approximately 25% of pregnant women are prescribed antibiotics, it is important to understand the mechanisms contributing to this phenomenon. Currently, there are no studies that directly test this association experimentally. Our objective was to develop a mouse model in which antibiotic treatment during pregnancy results in increased offspring asthma susceptibility. Pregnant mice were treated daily from gestation day 8-17 with an oral solution of the antibiotic vancomycin, and three concentrations were tested. At weaning, offspring were subjected to an adjuvant-free experimental asthma protocol using ovalbumin as an allergen. The composition of the gut microbiome was determined in mothers and offspring with samples collected from five different time points; short-chain fatty acids were also analyzed in allergic offspring. We found that maternal antibiotic treatment during pregnancy was associated with increased offspring asthma severity in a dose-dependent manner. Furthermore, maternal vancomycin treatment during pregnancy caused marked changes in the gut microbiome composition in both mothers and pups at several different time points. The increased asthma severity and intestinal microbiome changes in pups were also associated with significantly decreased cecal short-chain fatty acid concentrations. Consistent with the "Developmental Origins Hypothesis," our results confirm that exposure to antibiotics during pregnancy shapes the neonatal intestinal environment and increases offspring allergic lung inflammation.