Bacillus subtilis KC1 prevents Mycoplasma gallisepticum-induced lung injury by enhancing intestinal Bifidobacterium animalis and regulating indole metabolism in chickens

It has been reported that dietary administration of Bacillus subtilis KC1 is effective in alleviating lung injury induced by Mycoplasma gallisepticum (MG) infection in chickens. However, the underlying molecular mechanism of B. subtilis KC1 against MG infection is still unclear. The purpose of this study was to determine whether B. subtilis KC1 could alleviate MG infection-induced lung injury in chickens by regulating their gut microbiota. The results of this study indicate that B. subtilis KC1 supplementation has the potential to alleviate MG infection-induced lung injury as reflected by reduced MG colonization, reduced pathologic changes, and decreased production of pro-inflammatory cytokines. In addition, B. subtilis KC1 supplementation was partially effective in alleviating the gut microbiota disorder caused by MG infection. Importantly, B. subtilis KC1 enriched the beneficial Bifidobacterium animalis in gut and thus reversed indole metabolic dysfunction caused by MG infection. B. subtilis KC1 supplementation increased levels of indole, which enhanced aryl hydrocarbon receptor activation, improving barrier function and alleviating lung inflammation caused by MG. Overall, this study indicates that B. subtilis KC1 has a "gut-lung axis" mechanism that can reduce the severity of MG infection by enriching intestinal B. animalis and regulating indole metabolism.

Allium-Derived Compound Propyl Propane Thiosulfonate (PTSO) Reduces Vibrio Populations and Increases Body Weight of European Seabass (Dicentrarchus labrax) Juveniles

The global demand for fish products is continuously increasing as the population grows, and aquaculture plays an important role in supplying this demand. However, industrial antibiotic misuse has contributed to the spread of antimicrobial resistance among pathogenic bacteria, therefore, several antibiotic alternatives have been proposed. In this study, we have analyzed the effects of Allium-derived propyl propane thiosulfonate (PTSO) in European seabass juveniles' growth and performance. These effects were tested by measuring the body weight and analyzing the gut microbiome of fish after 89 days of feeding trial. The relative abundance of potentially pathogenic Vibrio in the foregut and hindgut of supplemented fish decreased, while Pseudomonas and Kocuria increased significantly. Alpha diversity indices significantly decreased in both gut regions of fish fed with Allium-derived PTSO supplemented diet, as well as between bacterial community composition. These results may indicate a positive effect of the supplementation in the diet with Allium-derived PTSO, reducing potentially pathogenic Vibrio and increasing body weight at the end of the experiment (89 days). However, this supplementation with Allium-derived PTSO produces changes in the diversity and composition of microbial communities, so further experiments would be necessary to explore bacterial community composition and health relationship.

Beneficial Shifts in the Gut Bacterial Community of Gilthead Seabream (Sparus aurata) Juveniles Supplemented with Allium-Derived Compound Propyl Propane Thiosulfonate (PTSO)

Simple Summary

Aquaculture plays an important role in supplying global food demand and protein sources. The increasing restriction of drugs in fish production has forced this sector to carry out changes in the management of farms. Functional feed additives such as probiotics, prebiotics, and phytogenics have been proposed in order to maintain or improve productive levels and general health status of fish. In this study, we explore the effects of Allium-derived food additives in the bacterial community and growth of gilthead seabream (Sparus aurata) juveniles. We found that this additive produced significant changes in bacterial community of the hindgut. In this sense, this shift occurred towards a more diverse microbiota. Especially relevant is the decrease in the populations of potential pathogenic bacteria as Vibrio and Pseudomonas, while this additive enhanced Lactobacillus, a well-known beneficial genus. Our work shows that the addition of PTSO has beneficial effects on bacterial communities while keeping productive parameters on fish growth.

Abstract

This study analyzes the potential use of an Allium-derived compound, propyl propane thiosulfonate (PTSO), as a functional feed additive in aquaculture. Gilthead seabream (Sparus aurata) juveniles had their diet supplemented with this Allium-derived compound (150 mg/kg of PTSO) and were compared with control fish. The effects of this organosulfur compound were tested by measuring the body weight and analyzing the gut microbiota after 12 weeks. The relative abundance of potentially pathogenic Vibrio and Pseudomonas in the foregut and hindgut of supplemented fish significantly decreased, while potentially beneficial Lactobacillus increased compared to in the control fish. Shannon’s alpha diversity index significantly increased in both gut regions of fish fed with a PTSO-supplemented diet. Regarding beta diversity, significant differences between treatments only appeared in the hindgut when minority ASVs were taken into account. No differences occurred in body weight during the experiment. These results indicate that supplementing the diet with Allium-derived PTSO produced beneficial changes in the intestinal microbiota while maintaining the productive parameters of gilthead seabream juveniles.

Effects of Different Levels of Garlic Straw Powder on Growth Performance, Meat Quality, Antioxidant and Intestinal Mucosal Morphology of Yellow-Feathered Broilers

The full utilization of garlic straw can partially alleviate shortage of feedstuff and waste of resources. The purpose of this study was to investigate the effects of garlic straw as an unconventional feed on yellow-feathered broilers. 360 28-day-old yellow-feathered broilers were randomly divided into 4 groups with 6 replicates (cage) per group, 15 per cage. The 4 groups were as follows: control group (basal diet) and experimental group I (basal diet supplemented with 3% garlic straw powder), II (basal diet supplemented with 6% garlic straw powder) and III (basal diet supplemented with 9% garlic straw powder). There was no significant difference in the initial body weight of the broilers among groups (p > 0.05). The test period was 28 days in total. The experiment results showed that there were no significant difference in the average final weight, ADG, ADFI and F/G among groups (p > 0.05). On the one hand, for the breast muscle, the drip loss of experimental group I, II and III were reduced by 17.24% (p <0.05), 20.11% (p <0.05) and 20.50% (p <0.05), respectively, compared with the control group; the redness a* of the experimental groups had a trend of improvement (0.05 <p < 0.1). On the other hand, compared with the control group, the redness a* of the experimental group II increased significantly by 23.18% for the leg muscles (p < 0.05). Furthermore, compared with the control group, GSH-Px of the experimental group III significantly increased by 21.38% (p < 0.05), and SOD of the experimental group I significantly increased by 21.85% (p < 0.05). Finally, there were no significant differences in the intestinal villus height, crypt depth, V/C and intestinal wall thickness among four groups (p >0.05). In conclusion, dietary supplementation of different levels of garlic straw powder can improve meat quality and antioxidant capacity of yellow-feathered broilers without affecting growth performance and intestinal mucosal morphology.

Comparative Efficacy of Postbiotic, Probiotic, and Antibiotic Against Necrotic Enteritis in Broiler Chickens

Prevention of necrotic enteritis (NE), caused by Clostridium perfringens (C. perfringens), is one of the most important goals to improve the profitability of broiler chickens. This work aimed to compare the efficacy of 2 antibiotic alternatives including a postbiotic (dry feed additive and aqueous nonviable Lactobacillus (L.) species fermentation) and a probiotic (dry feed additive and aqueous Bacillus (B.) subtilis and B. lischeniformis mixture) with an antibiotic (amoxicillin in water) against NE. Four hundred, day-old broiler chicks were divided into 8 equal groups (Gs), n = 50 each (5 replicates; 10 each). Chickens of G1 (postbiotic dry-feed additive), G2 (postbiotic and antibiotic in drinking water), G3 (postbiotic dry and aqueous), G4 (probiotic dry-feed additive), G5 (probiotic and antibiotic in drinking water), G6 (probiotic dry and aqueous), and G7 (nontreated) were orally inoculated with a toxigenic C. perfringens type A on the d 19 to 21 of age and predisposed with 3X coccidial vaccine for induction of NE. However, chickens of G8 were kept nontreated or challenged. The severity of NE signs was markedly decreased in G3 in comparison with other challenged treatment groups, and the mortality rates were 22%, 10%, 16%, 22%, 12%, 20%, and 36% in Gs 1, 2, 3, 4, 5, 6, and 7, respectively. The best significant (P ≤ 0.05) feed conversion ratio was detected in G3 (1.51), G6 (1.54), and G2 and G8 (1.61). In addition, the European production efficiency factor was significantly (P ≤ 0.05) improved in G3 (279.33) and G2 (266.67), but it was decreased in G7 (177.33) when compared with G8 (339.33). An improvement in intestinal and hepatic pathology and liver function tests, as well as a significant (P ≤ 0.05) decrease in bacterial counts were observed in Gs 2, 5, 3, 6, 1, and 4, respectively in comparison with G7. Immunologically, the highest significant (P ≤ 0.05) hemagglutination inhibition antibody titers for Newcastle disease virus vaccine were in Gs 1 and 3 (6.4 log₂). In conclusion, the combined feed and water postbiotic treatment demonstrated promising results in ameliorating the severity of NE and improving the hepatic and the immune status of broiler chickens when compared with the commonly used probiotic and antibiotic.

Beneficial Effects of Organosulfur Compounds from Allium cepa on Gut Health: A Systematic Review

Dietary changes affect the composition and structure of gut microbiota (GM) in animals and humans. One of the beneficial effects of consuming products derived from plants is the positive influence on immunity and gastrointestinal health. Species belonging to the genus Allium contain many organosulfur compounds (OSCs) that have been widely studied showing their biological properties and beneficial effects on intestinal health and GM. This is the first systematic review of OSCs from Allium performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and it is based on the evidence that we found in literature about the benefits on the GM and intestinal health demonstrated by OSCs from Allium, and specifically from onion. OSCs from Allium cepa have shown a significant antibacterial activity against a broad spectrum of antibiotic-resistant Gram-positive and Gram-negative bacteria. In addition, the intake of OSCs from onion was able to modulate the composition of GM, increasing the beneficial bacterial populations in animal models. Moreover, the beneficial effects observed in murine models of colitis suggest that these compounds could be suitable candidates for the treatment of inflammatory bowel disease (IBD) or reverse the dysbiosis caused by a high-fat diet (HFD). Despite the evidence found both in vitro and in vivo, we have not found any article that tested OSCs different from allicin in clinical trials or dietary intervention studies in humans. In this sense, it would be interesting to conduct new research that tests the benefits of these compounds in human GM.

Effect of Alliaceae Extract Supplementation on Performance and Intestinal Microbiota of Growing-Finishing Pig

Simple Summary

The increasing interest in phytogenics for use with livestock, especially swine and poultry, is mainly due to their antimicrobial, antioxidant, growth-promoting, and gut microbiome modulation properties, which makes them ideal candidates to mitigate the negative effects of the ban on antibiotic growth promoters in the European Union. We tested the ability of Allium spp. extract (containing garlic and onion), one of the best-known phytogenics, used in pig feed, to improve growth performance through modulation of the microbiome and changes in the metabolism of short-chain fatty acids in the gut tract. The promising results obtained in the present study suggested that Allium spp. extracts had the potential to be used in feeding pigs to improve growth performances by modulating the microbiota and metabolism of short-chain fatty acids.

Abstract

The aim of the present study was to ascertain whether an Allium spp. extract rich in organosulfur compounds, such as propyl thiosulfonate (PTSO), added to the feed of growing-finishing pigs at 5 g/kg enhances growth performance or affects the fecal microbiome, the levels of short-chain fatty acids, or the antioxidant capacity of the animals. Fifty male growing pigs (large white) of 23.07 ± 2.87 kg average body weight were randomly allotted to two treatments in a 103-day trial. The trial was divided into two periods, an initial growing phase (56-days) and a finishing phase (47-days). Two dietary treatments for each phase (growing and finishing) were used: a control diet (CON) and an experimental diet consisting of the control diet to which 5 g/kg of Allium spp. extract was added to substitute sepiolite (GAR). Throughout the study, body weight, average daily gain (kg/day, ADG), feed intake (kg/day), and feed conversion ratio (kg/kg) were measured, while the backfat thickness and muscle depth were determined at the end of the study. Besides, feces samples were taken for bacterial counts by means of real-time PCR and short-chain fatty acid (SCFA) profile determination, and the antioxidant capacity was assessed in serum and saliva. In the animals receiving Allium spp. extract (5 g/kg) in the feed, ADG increased (p < 0.05) throughout the trial, Salmonella spp. and Clostridium spp. counts in feces had decreased (p < 0.05) when measured on day 56, and, by day 103, Salmonella spp., Clostridium spp., and Enterobacteriaceae counts had decreased (p < 0.05) and Lactobacillus spp. counts had increased (p < 0.01) in feces. Regarding the SCFA profile in feces and antioxidant capacity measured in serum and saliva, supplementation with Allium spp. extract significantly increased the levels of propionic, isobutyric, and isovaleric acids and the percentage of total branched fatty acids, while the c2/c3 and (c2 + c4)/c3 ratios were lower (p < 0.05) in feces; the Trolox equivalent antioxidant capacity and the cupric reducing antioxidant capacity levels in serum were significantly higher in the same pigs on day 103 than on day 0. Consequently, based on the current results, Allium spp. extract rich in organosulfur compounds, added to the diet at 5 g/kg, had a beneficial effect on the microbiota and would seem to be a possible alternative for increasing the growth performance of growing-finishing pigs. However, further studies on the effects of Allium spp. supplementation on carcass quality are necessary.

Effect of Yeast Culture (Saccharomyces cerevisiae) on Broilers: A Preliminary Study on the Effective Components of Yeast Culture

Simple Summary

The value of yeast culture (YC) as alternative feed additives in poultry farming has been proven. YC is a nutrient-rich and complex micro-ecological fermentation product containing various metabolites. However, the major or specific effective components of YC and their importance in poultry farming are unknown. Herein, we screened the “effective ingredients” of YCs obtained from different fermentation times based on metabolomics and animal feeding experiments. Glycine, fructose, inositol, galactose, and sucrose were identified as potential effective metabolites in YCs. These findings provide an important basis for objective, accurate, and quick evaluation of the quality of YC products, as well as a scientific understanding of their functions.

Abstract

This study was aimed at determining the effective ingredients of yeast culture (YC) for animal breeding. First, the contents of YCs obtained from various fermentation times were detected using gas-chromatography. A total of 85 compounds were identified. Next, 336 Arbor Acres (AA) broilers were randomly divided into seven experimental groups and fed a basal diet, diets supplemented with YCs obtained at various fermentation times, or SZ1 (a commercial YC product). A significant increase in body weight gain (BWG) and a significant decrease in feed conversion ratio (FCR) of AA broiler chicks were observed with YC supplementation. Additionally, most of blood and immunological indices were improved with YC supplementation. According to the production performance and the results of multivariate analysis, glycine, fructose, inositol, galactose, and sucrose were found as the potential effective compounds of YC and were involved in metabolic pathways including glycine, serine, and threonine metabolism. Supplementation with diets based on combinations of effective compounds improved weight gain, feed efficiency, serum immunoglobulin A, and immunoglobulin G, but decreased blood urea concentration. These findings suggest YCs as effective and harmless feed additives with improved nutritional properties for broiler chicks.

The Genus Allium as Poultry Feed Additive: A Review

The genus Allium, belonging to the family Amaryllidaceae has been known since ancient times for their therapeutic potentials. As the number of multi-drug resistant infections has increased due to in-feed antibiotic usage in poultry, the relevance of alliums as feed additives has been critically assessed. Garlic and the other Allium species, such as onions, leek, shallot, scallion, and chives, have been characterized to contain a plethora of bioactive compounds such as organosulfur compounds, polyphenols, saponins, fructans, and fructo-oligosaccharides. Consequently, alliums have been validated to confer antioxidant, antibacterial, antiviral, immunostimulatory, gut homeostasis, and lipid- as well as cholesterol-lowering properties in poultry. This review intends to summarize recent progress on the use of edible alliums as poultry feed additives, their beneficial effects, and the underlying mechanisms of their involvement in poultry nutrition. Perspectives for future research and limitations are also briefly discussed.

Functioning of the Intestinal Ecosystem: From New Technologies in Microbial Research to Practical Poultry Feeding – A Review

Unlike classical microbiology which focuses on bacteria capable of growing in vitro, metagenomics is a study of genetic information originating from microflora which aims to characterise the microbiome, namely the common genome of bacteria, archaea, fungi, protozoa and viruses living in the host. Metagenomics relies on next-generation sequencing (NGS), a large-scale sequencing technique which allows millions of sequential reactions to be carried out in parallel to decode entire communities of microorganisms. Metagenomic analyses support taxonomic analyses (involving gene fragments encoding ribosomal RNAs 5S and 16S in bacteria) or functional analyses for identifying genes encoding proteins that participate in the regulation of metabolic pathways in the body. New metagenomics technologies expand our knowledge of the phylogenetic structure of microflora in the gastrointestinal tract of poultry, and they support the identification of previously unknown groups of microbiota, mainly those occurring in small numbers. Next-generation sequencing also provides indirect information about the quantitative structure of the genes of gut microorganisms, but microbial activity and changes in the proportions of microbial metabolites that affect the host’s intestinal integrity and metabolism remain insufficiently investigated. Therefore, research studies are undertaken to investigate the proportions of the key microbial metabolites in the intestinal contents of poultry relative to changes in the population size of the most important bacterial groups, including those determined by cheaper techniques.

Synthesis of Prebiotic Caramels Catalyzed by Ion-Exchange Resin Particles: Kinetic Model for the Formation of Di-d-fructose Dianhydrides

Caramel enriched in di-d-fructose dianhydrides (DFAs, a family of prebiotic cyclic fructodisaccharides) is a functional food with beneficial properties for health. The aim of this work was to study the conversion of fructose into DFAs catalyzed by acid ion-exchange resin, in order to establish a simplified mechanism of the caramelization reaction and a kinetic model for DFA formation. Batch reactor experiments were carried out in a 250 mL spherical glass flask and afforded up to 50% DFA yields. The mechanism proposed entails order 2 reactions that describe fructose conversion on DFAs or formation of byproducts such as HMF or melanoidines. A third order 1 reaction defines DFA transformation into fructosyl-DFAs or fructo-oligosaccharides. The influence of fructose concentration, resin loading and temperature was studied to calculate the kinetic parameters necessary to scale up the process.

Effect of antibiotic withdrawal in feed on chicken gut microbial dynamics, immunity, growth performance and prevalence of foodborne pathogens

Development of antibiotic resistance in foodborne pathogens, Salmonella spp. and Campylobacter, is a public health concern. Public demand to reduce the use of sub-therapeutic antibiotic growth promoters (AGP) in poultry feeding has resulted in greater adoption of antibiotic-free poultry production systems. There is a need to understand the effects of AGP removal from poultry feed on gut microbiota and its impact on prevalence of foodborne pathogens. The effect of antibiotic withdrawal from poultry feed on gut microbial community, host performance and immunity, and prevalence of Salmonella and Campylobacter was evaluated. Birds were raised on three phase diets (starter [d0-22], grower [d23-35] and finisher [d36-42]) with and without bacitracin dimethyl salicyclate (BMD). At early growth stage, bird performance was improved (P ≤ 0.05) with BMD treatment, whereas performance was better (P ≤ 0.05) in control group (no BMD in the feed) at the time of commercial processing. Acetate and butyrate production was affected (P ≤ 0.05) by age, whereas propionate production was affected (P ≤ 0.05) by both the treatment and age. The bacterial communities in the cecum were more diverse (P ≤ 0.001) and rich compared to the ileal communities, and they shifted in parallel to one another as the chicks matured. Differences in diversity and species richness were not observed (P > 0.05) between the BMD-fed and control groups. Comparing all ages, treatments and diets, the composition of cecal and ileal bacterial communities was different (P ≤ 0.001). Inclusion of BMD in the feed did not affect the bacterial phyla. However, predictable shift in the ileal and cecal bacterial population at lower taxonomic level was observed in control vs BMD-fed group. Cytokines gene expression (IL-10, IL-4, IFN-γ, beta-defensin, and TLR-4) was affected (P≤ 0.05) in the BMD-fed group at early stages of growth. The prevalence of foodborne pathogens, Campylobacter spp. and Salmonella spp. showed higher abundance in the ilea of BMD-fed chicks compared to control group. Overall, this study provided insight of the impact of AGP supplementation in the feed on gut microbial modulations, bird performance, host immunity and pathogen prevalence. This information can assist in designing alternative strategies to replace antibiotics in modern poultry production and for food safety.

Improving the Catalytic Behavior of DFA I-Forming Inulin Fructotransferase from Streptomyces davawensis with Site-Directed Mutagenesis

Previously, a α-d-fructofuranose-β-d-fructofuranose 1,2':2,1'-dianhydride (DFA I)-forming inulin fructotransferase (IFTase), namely, SdIFTase, was identified. The enzyme does not show high performances. In this work, to improve catalytic behavior including activity and thermostability, the enzyme was modified using site-directed mutagenesis on the basis of structure. The mutated residues were divided into three groups. Those in group I are located at central tunnel including G236, A257, G281, T313, and A314S. The group II contains residues at the inner edge of substrate binding pocket including I80, while group III at the outer edge includes G121 and T122. The thermostability was reflected by the melting temperature (T_m) determined by Nano DSC. Finally, the T_m values of G236S/G281S/A257S/T313S/A314S in group I and G121A/T122L in group III were enhanced by 3.2 and 4.5 °C, and the relative activities were enhanced to 140.5% and 148.7%, respectively. The method in this work may be applicable to other DFA I-forming IFTases.

Zinc Oxide Nanoparticles Influence Microflora in Ileal Digesta and Correlate Well with Blood Metabolites

Zinc oxide nanoparticles (ZnO NPs) are used widely in consumer and industrial products, however, their influence on gut microbiota and metabolism and their mutual interactions are not fully understood. In this study, the effects of ZnO NPs on ileal bacterial communities, plasma metabolites, and correlations between them were investigated. Hens were fed with different concentrations of ZnO NPs [based on Zn; 0 mg/kg (control), 25 mg/kg, 50 mg/kg, and 100 mg/kg] for 9 weeks. Subsequently, ileal digesta and blood plasma were collected for analysis of microflora and metabolites, respectively. The V3-V4 region of the 16S rRNA gene of ileal digesta microbiota was sequenced using the Illumina HiSeq 2500 platform. The predominant bacterial community in the ileum belongs to the phylum Firmicutes. The richness of the bacterial community was negatively correlated with increasing amounts of ZnO NPs (r = -0.636, P < 0.01); when ZnO NP levels were at 100 mg/kg, microbiota diversity was significantly decreased (P < 0.05). The community structure determined by LEfSe analysis indicated that Bacilli, Fusobacteria, and Proteobacteria were changed, and Lactobacillus was reduced by ZnO NPs. Moreover, metabolism as analyzed by nuclear magnetic resonance (NMR) indicated that glucose, some amino acids, and other metabolites were changed by ZnO NPs. Choline, lactate, and methionine were positively correlated with bacterial richness. In summary, ZnO NPs could influence the levels of microflora in ileal digesta, particularly Lactobacillus. Furthermore, the richness of the microbiota was related to changes in choline, lactate, and methionine metabolism.

In vitro toxicological assessment of an organosulfur compound from Allium extract: Cytotoxicity, mutagenicity and genotoxicity studies

Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring but also for their antimicrobial activities. These activities are mainly derived from the organosulfur compounds (OSCs). Propyl propane thiosulfinate (PTS) is an OSC with potential use in the active packaging, but its safety should be guaranteed before being commercialized. The aim of this work was to investigate for the first time the cytotoxicity of PTS as well as its in vitro mutagenic/genotoxic potential using the following battery of genotoxicity tests:(1)the bacterial reverse-mutation assay in S. typhimurium (Ames test, OECD 471, 1997); (2) the micronucleus test (MN, OECD 487, 2016); (3) the mouse lymphoma thymidine-kinase assay (MLA, OECD 476, 2015), and (4) the comet assay (standard and modified with restriction enzymes). The results revealed that PTS was not mutagenic neither in the Ames test nor in MLA. However, genotoxic effects were recorded in the MN test on mammalian cells (L5178YTk^+/-cells) after PTS exposure at the highest concentration tested (17.25 μM) without S9, and also its metabolites (+S9, from 20 μM). Moreover, in the comet assay, PTS induced DNA breaks damage in Caco-2 cells at the highest concentration tested (280 μM) but it did not induce oxidative DNA damage.