Saccharomyces cerevisiaeas a probiotic feed additive to non and pseudo‐ruminant feeding: a review

Highly elastic, fatigue-resistant, antibacterial, conductive, and nanocellulose-enhanced hydrogels with selenium nanoparticles loading as strain sensors

The fabrication of highly elastic, fatigue-resistant and conductive hydrogels with antibacterial properties is highly desirable in the field of wearable devices. However, it remains challenging to simultaneously realize the above properties within one hydrogel without compromising excellent sensing ability. Herein, we fabricated a highly elastic, fatigue-resistant, conductive, antibacterial and cellulose nanocrystal (CNC) enhanced hydrogel as a sensitive strain sensor by the synergistic effect of biosynthesized selenium nanoparticles (BioSeNPs), MXene and nanocellulose. The structure and potential mechanism to generate biologically synthesized SeNPs (BioSeNPs) were systematically investigated, and the role of protease A (PrA) in enhancing the adsorption between proteins and SeNPs was demonstrated. Additionally, owing to the incorporation of BioSeNPs, CNC and MXene, the synthesized hydrogels showed high elasticity, excellent fatigue resistance and antibacterial properties. More importantly, the sensitivity of hydrogels determined by the gauge factor was as high as 6.24 when a high strain was applied (400-700 %). This study provides a new horizon to synthesize high-performance antibacterial and conductive hydrogels for soft electronics applications.

Unlocking the power of postbiotics: A revolutionary approach to nutrition for humans and animals

Postbiotics, which comprise inanimate microorganisms or their constituents, have recently gained significant attention for their potential health benefits. Extensive research on postbiotics has uncovered many beneficial effects on hosts, including antioxidant activity, immunomodulatory effects, gut microbiota modulation, and enhancement of epithelial barrier function. Although these features resemble those of probiotics, the stability and safety of postbiotics make them an appealing alternative. In this review, we provide a comprehensive summary of the latest research on postbiotics, emphasizing their positive impacts on both human and animal health. As our understanding of the influence of postbiotics on living organisms continues to grow, their application in clinical and nutritional settings, as well as animal husbandry, is expected to expand. Moreover, by substituting postbiotics for antibiotics, we can promote health and productivity while minimizing adverse effects. This alternative approach holds immense potential for improving health outcomes and revolutionizing the food and animal products industries.

Corn straw-saccharification fiber improved the reproductive performance of sows in the late gestation and lactation via lipid metabolism

With the development of animal husbandry, the shortage of animal feedstuffs has become serious. Dietary fiber plays a crucial role in regulating animal health and production performance. The aim of this study was to investigate the effects of three kinds of corn straw-saccharification fibers (CSSF) such as high-fiber and low-saccharification (HFLS), medium-fiber and medium-saccharification (MFMS), low-fiber and high-saccharification (LFHS) CSSF on the reproductive performance of sows. Thirty-two primiparous Yorkshire sows were randomly assigned to 4 groups, 8 sows for each group. Group A was the basal diet as the control group; groups B - D were added with 6% HFLSCSSF, 6% MFMSCSSF and 6% LFHSCSSF to replace some parts of corn meal and wheat bran in the basal diet, respectively. The experimental period was from day 85 of gestation to the end of lactation (day 25 post-farrowing). The results showed that 6% LFHSCSSF addition significantly increased number of total born (alive) piglets, litter weight at birth (p < 0.05), whereas three kinds of CSSF significantly decreased backfat thickness of sows during gestation (p < 0.001), compared with the control group. Furthermore, CSSF improved the digestibility of crude protein, ether extract and fiber for sows. In addition, the levels of total cholesterol, total triglycerides, and high-density lipoprotein cholesterol in serum of sows were decreased by different kinds of CSSF. Further analysis revealed that CSSF regulated lipid metabolism through adjusting the serum metabolites such as 4-pyridoxic acid, phosphatidyl cholines and L-tyrosine. In summary, CSSF addition to the diets of sows during late gestation and lactation regulated lipid metabolism and improved reproductive performance of sows. This study provided a theoretical basis for the application of corn straw in sow diets.

Enhancing Weaned Piglet Health and Performance: The Role of Autolyzed Yeast (Saccharomyces cerevisiae) and β-Glucans as a Blood Plasma Alternative in Diets

The objective of this study was to evaluate the inclusion of the autolyzed yeast (AY) Saccharomyces cerevisiae with or without an immunomodulator (1,3/1,6 β-glucans) as a total/partial substitute for blood plasma (BP) in the diet of post-weaning piglets; zootechnical performance, intestinal health and microbiota, immune responses and energy metabolism were assessed. A total of 240 castrated male and female piglets, with a mean age of 22 days and mean initial weight of 5.24 ± 0.82 kg, were randomly divided into blocks of four treatments with 12 replicates. The dietary inclusions were blood plasma (BP), autolyzed yeast (AY), autolyzed yeast + immunomodulator (AYI) and 50% BP and 50% AY (BPAY). In pre-initial phase II (29-35 days), piglets fed AY showed better feed conversion (FCR = 1.358) than the piglets in the BP (1.484), AYI (1.379) and BPAY (1.442) groups, i.e., 8.49% (0.126), 1.52% (0.021) and 4.50% (0.084), respectively (p = 0.0293). In the total period (21-42 days), better FCR was observed in the AYI (1.458) group, i.e., 4.64% (0.071), 1.15% (0.017) and 4.58% (0.070), than in the BP (1.529), AY (1.475) and BPAY (1.528) groups, respectively (p = 0.0150). In piglets fed AY (n = 3) and BPAY (n = 2), there was a reduction in the number of medications, i.e., 82.35% (-14n) and 88.23% (-15n), respectively (p = 0.0001), compared with that in the BP group (n = 17). In the AY group (73.83 mg/dL), AYI group (69.92 mg/dL), and BPAY group (69.58 mg/dL), piglets exhibited increases in triglyceride levels of 79.32%, 69.83%, and 69.00%, respectively, in comparison to those in the BP group, which had triglyceride levels of 41.17 mg/dL (p = 0.0400). The beta-hydroxybutyrate concentration in the AY group (79.96 ng/μL) was lower by 31.95%, 22.64%, and 5.89% compared to the BP group (117.50 ng/μL), AYI group (103.36 ng/μL), and BPAY group (84.67 ng/μL), respectively (p = 0.0072). In the AYI group, there was modulation of the microbiota, with an increase in the relative abundance of bacteria of the genera Lactobacillus, Collinsella and Bulleidia. AY, associated or not associated with an immunomodulator, is a potential substitute for BP in diets for piglets in the nursery phase, with positive effects on immune, metabolic, and intestinal microbial performance.

Tracing probiotic producing bacterial species from gut of buffalo (Bubalus bubalis), South-East-Asia

Abstract Due to extensive application of antibiotics as growth promoters in animal feed, antimicrobial resistance has been increased. To overcome this challenge, rumen microbiologists search for new probiotics to improve the rate of livestock production. The present study was aimed to isolate and evaluate breed-specific lactic acid bacteria (LAB) as potential animal probiotics. The current study was conducted during 10 months from July 2020 to April 2021, in which a total of n=12 strains were isolated from different samples including milk, rumen, and feces of Nilli Ravi Buffaloes. These isolates were evaluated for their antimicrobial potential against common animal pathogens (Bacillus spp., E. coli, Staphylococcus aureus, Salmonella spp., Listeria spp.). All the isolates were identified using 16S rRNA gene sequencing and the phylogenetic analyses inferred that these strains showed close relations to the species of various genera; Enterococcus lactis, Pediococcus pentosaceus, Bacillus subtilis Weissella cibaria, Weissella soli, Bacillus tequilensis, Weissella bombi, Bacillus licheniformis, Lactococcus lactis, Bacillus megaterium, Lactobacillus ruminis, and Lactococcus lactis. NMCC-Ru2 has exhibited the enormous potential of antimicrobial activity, 28 mm, for Salmonella typhimurium;23 mm for Listeria monocytogenes 21 mm for E.coil. Highest resistance was seen in NMCC-Ru2 agasint test antbiotic, like 25.5 mm for Tetracycline. Overall results revesl that the probiotic profile of isolates was achieved using standard criteria, particularly with animal probiotic properties

Microbial fermentation technology for degradation of saponins from peony seed meal

Peony seed meal is a very important feed protein raw material with a high potential for development; however, the presence of some anti-nutritional factors, such as saponins, reduces its reusability. This study aimed to establish ideal microbial fermentation conditions for the degradation of saponins in peony seed meal for its subsequent use in poultry feed. First, saponins were extracted via two methods: ethanol extraction and reflux. Then, response surface methodology and orthogonal array testing were used to establish the optimal conditions for the degradation of saponins by (a) liquid fermentation of single bacteria, (b) liquid fermentation of compound bacteria, and (c) solid-state fermentation. The degradation efficiencies were 40.21% (±1.62), 59.82% (±1.54), and 69.31% (±2.95), respectively. The maximum degradation was obtained via solid-state fermentation, and the soluble protein content for this fermentation product was found to be 14% higher than that of unfermented peony seed meal.

Potential benefits of yeast Saccharomyces and their derivatives in dogs and cats: a review

Yeast Saccharomyces and its derivatives have been largely used in livestock and poultry nutrition for their potential positive impact on growth, performance, and general health. Originally included in animal diets as a source of protein, yeasts can also offer a wide range of by-products with interesting bioactive compounds that would confer uses beyond nutrition. Although its supplementation in livestock, poultry and even in humans is well documented, the available body of literature on the use of yeast and its derivatives in companion animals' food, mainly dogs and cats' diets, is still developing. Despite this, gut microbiota modulation, immune system enhancement or decreasing of potentially pathogenic microorganisms have been reported in pets when using these products, highlighting their possible role as probiotics, prebiotics, and postbiotics. This review attempts to provide the reader with a comprehensive on the effects of Saccharomyces and its derivatives in pets and the possible mechanisms that confer their functional properties.

Fatty Acid Profile and Lipid Quality Indexes of the Meat and Backfat from Porkers Supplemented with EM Bokashi Probiotic

The study aimed to assess the effect of supplementation of pig diet with the Bokashi probiotic on the fatty acid profile of longissimus lumborum (LL) muscles and backfat. The research involved 120 hybrid pigs deriving from Naïma sows and P-76 boars. The experimental group's pigs received probiotics in their feed (containing Saccharomyces cerevisiae, Lactobacillus casei, and Lactobacillus plantarum). To analyze the fatty acid profile in intramuscular fat (IMF) of LL and backfat, 24 pig carcasses from the control group and 26 from the probiotic-supplemented group were randomly selected. Probiotic supplementation increased the Atherogenic Index, reduced the proportion of C20:4, and increased C12:0 and C18:2 n-6 in IMF LL, without affecting ΣSFA, ΣMUFA, and ΣPUFA. In backfat, probiotic supplementation decreased C18:1 and C18:2 n-6 proportion and increased C18:3 n-3, C20:3 n-6, and C20:4 n-6. These changes resulted in significantly higher ΣMUFA, ΣPUFA, PUFA Σn-3/Σn-6, and lower Saturation Index (SI). From a consumer health and technological point of view, probiotic supplementation improved the lipid profile of backfat to a greater extent than LL muscle. Bokashi, at a dose of 3 g/kg of feed in the last stage of pig production, had no significant effect on the fatty acid profile of the meat.

Diversity and functional prediction of fungal communities in different segments of mongolian horse gastrointestinal tracts

BACKGROUND

Anaerobic fungi are effective fibre-degrading microorganisms in the digestive tract of horses. However, our understanding of their diversity and community structure is limited, especially in different parts of the gastrointestinal tract.

RESULTS

For the first time, high-throughput sequencing technology was used to analyse and predict fungal microbial diversity in different parts of the gastrointestinal tract of Mongolian horses. The results revealed that the richness and diversity of fungi in the hindgut of Mongolian horses were much higher than those in the foregut. The foregut was dominated by Basidiomycota and Ascomycota, whereas the hindgut was dominated by Neocallimastigomycota and Basidiomycota. At the genus level, the relative abundance of many pathogenic fungi (Cryptococcus, Cladosporium, Alternaria, and Sarocladium) in the foregut was significantly higher than that in the posterior gut, indicating that Mongolian horses have strong disease resistance. The prediction of fungal function also showed significant differences in the fungal flora between the foregut and the hindgut. The fungi in Mongolian horses' foreguts were mainly pathologically nutritive and contained many animal and plant pathogens, particularly in the small intestine (jejunum and ileum). This indicates that the foregut may be the most important immune site in the digestive system of Mongolian horses, which explains the high disease resistance of Mongolian horses. The number of unassigned functional groups in the posterior gut was significantly higher than that in the anterior gut, indicating that the functions of fungal groups in the posterior gut have not been fully explored, and further studies are required in the future.

CONCLUSIONS

Analysis of high-throughput sequencing results revealed that the fungal composition varied greatly among different gastrointestinal tract segments in Mongolian horses, whose hindgut contains many anaerobic fungi involved in plant cellulose degradation. This provides important basic data for studying fungal diversity in the digestive system of healthy horses, which can be used for the health assessment of horses and provides clues for further research on the disease resistance and digestive capacity of horses, as well as a reference for the early diagnosis of intestinal diseases and innovative treatment methods.

Significance of Limosilactobacillus fermentum and Saccharomyces cerevisiae on the Growth Performance, Haematological Traits, Serum Biochemistry, Faecal and Caeca Microbiota of Broiler Chickens

OBJECTIVE

The aim of the study was to supplement Lactobacillus and yeast in broiler feed by replacing immunomodulators to develop antibiotic free meat and egg production by analyzing broiler performance, haematological traits, serum biochemistry, histopathology, fecal bacterial count, and metagenomic analysis of broiler ceca.

METHOD

Two cultures i.e. KGL4 (Limosilactobacillus fermentum MTCC 25515) and WBS2A (Saccharomyces cerevisiae GI: MG101828) were considered for the evaluation of Broiler chicken's health and growth during 42 days study without supplementing immunomodulators and commercial probiotics in poultry feeds. The 96-day-old broiler chickens were grouped into: T1 [Control: basal diet + immunomodulatory factor and commercial probiotic], T2 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 (108 CFU/mL), T3 [Basal diet without immunomodulatory factor and commercial probiotic + WBS2A (107 CFU/mL), and T4 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 + WBS2A in a 1:1 ratio] (Institutional Animal Ethics Committee (IAEC) No. 365/PRS/2022). The following parameters, i.e., body weight gain, feed consumption ratio (FCR), white blood cell count (WBC), red blood cell count (RBC), hemoglobin content, platelet count, cholesterol content, triglycerides, high density lipoprotein (HDL), very low-density lipoprotein (VLDL), fecal counts and metagenomic analysis of broiler ceca samples, were measured.

RESULTS

In the study, amongst various traits, the overall performance of the group treated along with Limosilactobacillus fermentum (KGL4) showed improved results as compared to control group. Limosilactobacillus fermentum (KGL4) treated group had higher body weight gain (2583.04 ± 35.421 g), FCR (1.60 ± 0.019), WBC (235.60 ± 2.562 × 103/µL), hemoglobin content (14.10 ± 0.442 g/dl), and HDL (131.40 ± 11.400 mg/dl). The investigation did not show significant variations in the relative proportions of genus or phylum among various groups during metagenomic analysis of ceca samples. There was also an improvement in haematological traits; no evidence of necrosis in heart, intestine and liver tissues.

CONCLUSIONS

The present study conclude that it is safe to feed Limosilactobacillus fermentum and Saccharomyces cerevisiae to broilers as feed supplements and also supports the current knowledge regarding the use of yeast and lactic acid bacteria as an effective alternative stimulant for maintaining health and growth of broiler chickens.

Enterotypes of the human gut mycobiome

BACKGROUND

The fungal component of the human gut microbiome, also known as the mycobiome, plays a vital role in intestinal ecology and human health. However, the overall structure of the gut mycobiome as well as the inter-individual variations in fungal composition remains largely unknown. In this study, we collected a total of 3363 fungal sequencing samples from 16 cohorts across three continents, including 572 newly profiled samples from China.

RESULTS

We identify and characterize four mycobiome enterotypes using ITS profiling of 3363 samples from 16 cohorts. These enterotypes exhibit stability across populations and geographical locations and significant correlation with bacterial enterotypes. Particularly, we notice that fungal enterotypes have a strong age preference, where the enterotype dominated by Candida (i.e., Can_type enterotype) is enriched in the elderly population and confers an increased risk of multiple diseases associated with a compromised intestinal barrier. In addition, bidirectional mediation analysis reveals that the fungi-contributed aerobic respiration pathway associated with the Can_type enterotype might mediate the association between the compromised intestinal barrier and aging.

CONCLUSIONS

We show that the human gut mycobiome has stable compositional patterns across individuals and significantly correlates with multiple host factors, such as diseases and host age. Video Abstract.

Effects of Lacticaseibacillus casei (Lactobacillus casei) and Saccharomyces cerevisiae mixture on growth performance, hematological parameters, immunological responses, and intestinal microbiome in weaned pigs

Introduction

This study was conducted to evaluate the effects of Lacticaseibacillus casei (Lactobacillus casei) and Saccharomyces cerevisiae mixture on growth performance, hematological parameters, immunological responses, and gut microbiome in weaned pigs.

Methods

A total of 300 crossbred pigs [(Landrace × Yorkshire] × Duroc; 8.87 ± 0.34  kg of average initial body weight [BW]; 4  weeks of age) were divided into two dietary treatments (15 pigs/pen, 10 replicates/treatment) using a randomized complete block design (block = BW): control (CON) and the effective microorganism (MEM). The CON was not treated, while the MEM was treated with the mixture of L. casei (1 × 10⁷ CFU/mL) and S. cerevisiae (1 × 10⁷ CFU/mL) at 3 mL/pig/day for 4  weeks via the drinking water supply. Two feces and one blood sample from the randomly selected pigs in each pen were collected on D1 and D28 after weaning. Pigs were individually weighed, and pen feed intakes were recorded to evaluate pig growth performance. For the gut microbiome analysis, 16S rRNA gene hypervariable regions (V5 to V6) were sequenced using the Illumina MiSeq platform, and Quantitative Insight into Microbial Ecology (QIIME) and Microbiome Helper pipeline were used for 16S rRNA gene sequence analysis.

Results and Discussion

The daily weight gain and feed efficiency of MEM were significantly higher than those of CON (p < 0.001). There were no significant differences in hematological parameters and immune responses between CON and MEM. However, MEM had significantly lower Treponema genus, whereas significantly higher Lactobacillus and Roseburia genera compared to CON. Overall, our data showed that L. casei and S. cerevisiae mixture could promote growth performance through the modulation of gut microbiota in pigs. This study will help to understand the correlation between the growth performance and the gut microbiome.

Combination of glycyrrhizic acid and compound probiotics alleviates deoxynivalenol-induced damage to weaned piglets

Deoxynivalenol (DON) can affect health and growth performance of pigs, resulting in significant economic losses in swine production. The aim of this study was to investigate the effect of glycyrrhizic acid combined with compound probiotics, i.e. Enterococcus faecalis plus Saccharomyces cerevisiae (GAP) on improving growth performance, intestinal health and its fecal microbiota composition change of piglets challenged with DON. A total of 160 42-day-old weaned piglets (Landrace × Large White) were used and the experimental period was 28 d. The results showed that supplementing GAP in the diet significantly improved the growth performance of piglets challenged with DON and alleviate DON-induced intestinal damage by reducing ALT, AST and LDH concentrations in serum, increasing the morphological parameters of jejunum, and decreasing DON residues in serum, liver and feces. Moreover, GAP could significantly decrease the expressions of inflammation and apoptosis genes and proteins (IL-8, IL-10, TNF-α, COX-2, Bax, Bcl-2 and Caspase 3), and increase the expressions of tight-junction proteins and nutrient transport factor genes and proteins (ZO-1, Occludin, Claudin-1, ASCT2 and PePT1). In addition, it was also found that GAP supplementation could significantly increase the diversity of gut microbiota, maintain microbial flora balance and promote piglet growth by significantly increasing the abundance of beneficial bacterium such as Lactobacillus and reducing the abundance of harmful bacterium such as Clostridium_sensu_stricto_1. In conclusion, GAP addition to piglet diets contaminated with DON could significantly promote the health and growth performance of piglets though alleviating DON-induced hazards. This study provided a theoretical basis for the application of GAP to alleviate DON toxicity for animals.

Improving expression and assembly of difficult-to-express heterologous proteins in Saccharomyces cerevisiae by culturing at a sub-physiological temperature

BACKGROUND

Escherichia coli heat labile toxin B subunit (LTB) is one of the most popular oral vaccine adjuvants and intestine adsorption enhancers. It is often expressed as a fusion partner with target antigens to enhance their immunogenicity as well as gut absorbability. However, high expression levels of a fusion protein are critical to the outcome of immunization experiments and the success of subsequent vaccine development efforts. In order to improve the expression and functional assembly of LTB-fusion proteins using Saccharomyces cerevisiae, we compared their expression under culture conditions at a sub-physiological temperature 20 °C with their expression under a standard 30 °C.

RESULTS

The assembled expression of LTB-EDIII₂ (LTB fused to the envelope domain III (EDIII) of Dengue virus serotype 2), which was expressed at the level of 20 µg/L in our previous study, was higher when the expression temperature was 20 °C as opposed to 30 °C. We also tested whether the expression and functional assembly of a difficult-to-express LTB fusion protein could be increased. The assembled expression of the difficult-to-express LTB-VP1 fusion protein (LTB fused to VP1 antigen of Foot-and-Mouth Disease Virus) dramatically increased, although the total amount of expressed protein was still lower than that of LTB-EDIII₂. Slight but significant increase in the expression of well-known reporter protein eGFP, which has previously been shown to be increased by cultivation at 20 °C, was also observed in our expression system. As no significant changes in corresponding transcripts levels and cell growth were observed between 20 °C and 30 °C, we infer that translation and post-translational assembly are responsible for these enhancements.

CONCLUSIONS

The effects of lowering the expression temperature from 30 °C to 20 °C on protein expression and folding levels in S. cerevisiae, using several proteins as models, are reported. When heterologous proteins are expressed at 20 °C, a greater amount of (specially, more assembled) functional proteins accumulated than at 30 °C. Although further studies are required to understand the molecular mechanisms, our results suggest that lowering the expression temperature is a convenient strategy for improving the expression of relatively complexly structured and difficult-to-express proteins in S. cerevisiae.

Postbiotics from Pichia kudriavzevii promote intestinal health performance through regulation of Limosilactobacillus reuteri in weaned piglets

Postbiotics are attractive as alternatives to antibiotics for use against post-weaning diarrhea. However, their beneficial mechanisms are largely unknown. In the current study, we first demonstrated that supplementation with 0.5% Pichia kudriavzevii FZ12 postbiotics in the diet significantly reduced diarrhea incidence, promoted growth performance, improved gut health performance, and significantly enriched beneficial bacteria, particularly Lactobacillus spp., in the intestines of weaned piglets. Importantly, we identified a heat- and proteinase K-sensitive component, cytochrome c, of the postbiotics that significantly promoted the growth and biofilm formation of Limosilactobacillus reuteri FP13. We demonstrated the importance of P. kudriavzevii FZ12 postbiotics in improving the intestinal health of a model animal and revealed that cytochrome c is one of the important components of yeast postbiotics. These findings may provide new insights into microbe-postbiotics interplay that can be applied to guidelines for dietary modulation to alleviate weaning-induced diarrhea.

A strategy of co-fermentation of distillers dried grains with solubles (DDGS) and lignocellulosic feedstocks as swine feed

To meet the sustainable development of the swine feed industry, it is essential to find alternative feed resources and develop new feed processing technologies. Distillers dried grains with solubles (DDGS) is a by-product from the ethanol industry consisting of adequate nutrients for swine and is an excellent choice for the swine farming industry. Here, a strategy of co-fermentation of DDGS and lignocellulosic feedstocks for production of swine feed was discussed. The potential of the DDGS and lignocellulosic feedstocks as feedstock for fermented pig feed and the complementary relationship between them were described. In order to facilitate the swine feed research in co-fermentation of DDGS and lignocellulosic feedstocks, the relevant studies on strain selection, fermentation conditions, targeted metabolism, product nutrition, as well as the growth and health of swine were collected and critically reviewed. This review proposed an approach for the production of easily digestible and highly nutritious swine feed via co-fermentation of DDGS and lignocellulosic feedstocks, which could provide a guide for cleaner swine farming, relieve stress on the increasing demand of high-value swine feed, and finally support the ever-increasing demand of the pork market.

Probiotic cultures as a potential protective strategy against the toxicity of environmentally relevant chemicals: State-of-the-art knowledge

Environmentally relevant toxic substances may affect human health, provoking numerous harmful effects on central nervous, respiratory, cardiovascular, endocrine and reproductive system, and even cause various types of carcinoma. These substances, to which general population is constantly and simultaneously exposed, enter human body via food and water, but also by inhalation and dermal contact, while accumulating evidence suggests that probiotic cultures are able to efficiently adsorb and/or degrade them. Cell wall of probiotic bacteria/fungi, which contains structures such as exopolysaccharide, teichoic acid, protein and peptidoglycan components, is considered the main place of toxic substances adsorption. Moreover, probiotics are able to induce metabolism and degradation of various toxic substances, making them less toxic and more suitable for elimination. Other probable in vivo protective effects have also been suggested, including decreased intestinal absorption and increased excretion of toxic substances, prevented gut microbial dysbiosis, increase in the intestinal mucus secretion, decreased production of reactive oxygen species, reduction of inflammation, etc. Having all of this in mind, this review aims to summarize the state-of-the-art knowledge regarding the potential protective effects of different probiotic strains against environmentally relevant toxic substances (mycotoxins, polycyclic aromatic hydrocarbons, pesticides, perfluoroalkyl and polyfluoroalkyl substances, phthalates, bisphenol A and toxic metals).

Understanding the microbial fibre degrading communities & processes in the equine gut

The equine gastrointestinal tract is a self-sufficient fermentation system, housing a complex microbial consortium that acts synergistically and independently to break down complex lignocellulolytic material that enters the equine gut. Despite being strict herbivores, equids such as horses and zebras lack the diversity of enzymes needed to completely break down plant tissue, instead relying on their resident microbes to carry out fibrolysis to yield vital energy sources such as short chain fatty acids. The bulk of equine digestion occurs in the large intestine, where digesta is fermented for 36-48 h through the synergistic activities of bacteria, fungi, and methanogenic archaea. Anaerobic gut dwelling bacteria and fungi break down complex plant polysaccharides through combined mechanical and enzymatic strategies, and notably possess some of the greatest diversity and repertoire of carbohydrate active enzymes among characterized microbes. In addition to the production of enzymes, some equid-isolated anaerobic fungi and bacteria have been shown to possess cellulosomes, powerful multi-enzyme complexes that further enhance break down. The activities of both anaerobic fungi and bacteria are further facilitated by facultatively aerobic yeasts and methanogenic archaea, who maintain an optimal environment for fibrolytic organisms, ultimately leading to increased fibrolytic microbial counts and heightened enzymatic activity. The unique interactions within the equine gut as well as the novel species and powerful mechanisms employed by these microbes makes the equine gut a valuable ecosystem to study fibrolytic functions within complex communities. This review outlines the primary taxa involved in fibre break down within the equine gut and further illuminates the enzymatic strategies and metabolic pathways used by these microbes. We discuss current methods used in analysing fibrolytic functions in complex microbial communities and propose a shift towards the development of functional assays to deepen our understanding of this unique ecosystem.

The Role of Yeast Saccharomyces cerevisiae in Supporting Gut Health in Horses: An Updated Review on Its Effects on Digestibility and Intestinal and Fecal Microbiota

To support the overall health of horses, it is essential to maintain an optimal gut health (GH) status, which encompasses several physiological and functional aspects, including the balance and functionality of intestinal microbial populations and, accordingly, the effective digestion and absorption of nutrients. Numerous biotic and abiotic stressors can lead to an imbalance of GH, such as the quality of forages and the composition of diet, e.g., the inclusion of high energy-dense feeds to meet the energy requirements of performance horses. To support the digestive function and the intestinal microbial populations, the diet can be supplemented with feed additives, such as probiotic yeasts, that promote the ability of cellulolytic bacteria in the hindgut to digest the available fiber fractions, finally increasing feed efficiency. Among the different yeasts available, S. cerevisiae is the most used in horses' nutrition; however, results of digestibility trials, as well as data on intestinal and fecal microbial populations, are sometimes contradictory. Therefore, the purpose of this review is to summarize the effects of S. cerevisiae on in vivo and in vitro digestibility, providing an updated overview of its effects on the intestinal and fecal microbial population.

Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.

Yeast Probiotic and Yeast Products in Enhancing Livestock Feeds Utilization and Performance: An Overview

The intensive use of antibiotics as growth-promoting agents in animal production has resulted in the spread of animal antibiotic resistance and possibly human antibiotic resistance. Based on this premise, it is significant to explore an alternative approach to preventing infectious diseases and promoting animal growth and health. Yeast as the main natural growth promoter in livestock nutrition has been extensively studied for decades. Numerous yeasts and yeast-containing products are produced, marketed, and used in animal feed as providers of nutrient sources, probiotics, and nutrients or serve distinct nutritional functions. A large amount of scientific research suggests that yeasts and their derivatives may be good for animal growth performance and health, especially when animals are housed in poor sanitation or are suffering from disease. However, when yeasts are used as a surrogate for livestock antibiotics, the results vary according to several factors, including yeast species, yeast product components, feed ingredients, animal category, type of symptoms, and differences in the rearing environment. In this review, the effects of different yeasts on different animals will be reviewed. The types of widely used yeast products, their functional characteristics, and application effects will be discussed in order to provide a reference for the development and application of yeast feed products.

An Electro-Microbial Process to Uncouple Food Production from Photosynthesis for Application in Space Exploration

Here we propose the concept of an electro–microbial route to uncouple food production from photosynthesis, thereby enabling production of nutritious food in space without the need to grow plant-based crops. In the proposed process, carbon dioxide is fixed into ethanol using either chemical catalysis or microbial carbon fixation, and the ethanol created is used as a carbon source for yeast to synthesize food for human or animal consumption. The process depends upon technologies that can utilize electrical energy to fix carbon into ethanol and uses an optimized strain of the yeast Saccharomyces cerevisiae to produce high-quality, food-grade, single-cell protein using ethanol as the sole carbon source in a minimal medium. Crops performing photosynthesis require months to mature and are challenging to grow under the conditions found in space, whereas the electro–microbial process could generate significant quantities of food on demand with potentially high yields and productivities. In this paper we explore the potential to provide yeast-based protein and other nutrients relevant to human dietary needs using only ethanol, urea, phosphate, and inorganic salts as inputs. It should be noted that as well as having potential to provide nutrition in space, this novel approach to food production has many valuable terrestrial applications too. For example, by enabling food production in climatically challenged environments, the electro–microbial process could potentially turn deserts into food bowls. Similarly, surplus electricity generated from large-scale renewable power sources could be used to supplement the human food chain.

Dietary Saccharomyces cerevisiae improves intestinal flora structure and barrier function of Pekin ducks

This study aimed at investigating the effects of dietary Saccharomyces cerevisiae (SC) on the intestinal flora structure and barrier function of Pekin duck. A total of 180 1-day-old Pekin ducks were randomly divided into 3 groups with 6 replicates in each group and 10 birds per replicate. The birds in the control group (CON) were fed the basal diet, and those in the experimental group were fed the basal diets supplemented with 600 mg/kg SC (LSC) and 1,200 mg/kg (HSC), respectively. The trial lasted for 42 d. Results showed that LSC and HSC treatments tended to improve the feed conversion efficiency during the trial. The ileum length of birds in the LSC and HSC groups was elevated. Additionally, with 600mg/kg SC supplemented, the mRNA levels of villin, claudin3, and MUC 2 in d21 were up-regulated, as well as the mRNA levels of villin, claudin3, occludin, i-FABP, ZO-1, and MUC 2 in d42. In addition, dietary SC supplementation improved the α-diversity of the bacteria in cecal chyme and tended to increase the abundance (RA) of Bacteroidetes (P = 0.071). Besides, the RA of Ruminococcaceae_UCG-014 was raised in the LSC group. Beyond that, the RA of Proteobacteria was descended with two levels of SC added. In conclusion, dietary Saccharomyces cerevisiae, particularly at 600 mg/kg level, improved the intestinal flora structure and barrier function of Pekin duck.

Oral SARS-CoV-2 Spike Protein Recombinant Yeast Candidate Prompts Specific Antibody and Gut Microbiota Reconstruction in Mice

A recent study showed that patients with coronavirus disease 2019 (COVID-19) have gastrointestinal symptoms and intestinal flora dysbiosis. Yeast probiotics shape the gut microbiome and improve immune homeostasis. In this study, an oral candidate of yeast-derived spike protein receptor-binding domain (RBD) and fusion peptide displayed on the surface of the yeast cell wall was generated. The toxicity and immune efficacy of oral administration were further performed in Institute of Cancer Research (ICR) mice. No significant difference in body weights, viscera index, and other side effects were detected in the oral-treated group. The detectable RBD-specific immunoglobulin G (IgG) and immunoglobulin A (IgA) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and more complex microbiota were detected from oral administration mice compared with those of the control group. Interestingly, the recombinant yeast was identified in female fetal of the high-dose group. These results revealed that the displaying yeast could fulfill the agent-driven immunoregulation and gut microbiome reconstitution. The findings will shed light on new dimensions against SARS-CoV-2 infection with the synergistic oral agents as promising non-invasive immunization and restoring gut flora.

Dietary Probiotic Supplementation Suppresses Subclinical Necrotic Enteritis in Broiler Chickens in a Microbiota-Dependent Manner

Background

Chicken meat is one of the most consumed meats worldwide and poultry production is increasing at an exponential rate. Reducing antibiotic usage has resulted in the recurrence of subclinical necrotic enteritis again and influenced global poultry production. Probiotics are potential antibiotic substitutes that can be used to prevent subclinical necrotic enteriti. However, the precise mechanism of action of probiotics and information on which gut microbes confer this efficacy remain elusive.

Methods and results

The subclinical necrotic enteritis animal model was used to reveal the mechanism underlying the effect of probiotics on intestinal health through RNA sequencing and 16S rDNA amplicon sequencing. Bacillus licheniformis H2 feeding significantly reduced the relative abundance of Clostridium perfringens in the ileum and markedly ameliorated the pathological damage in the ileum and liver. In addition, oral administration of B. licheniformis H2 contributed to the enhancement of the intestinal barrier function and epithelial renewal, reducing energy consumption, and improving enteral nutrition absorption. Probiotic B. licheniformis H2 also ameliorated the inflammatory response and increased the immunity of subclinical necrotic enteritis infected broilers. Finally, B. licheniformis H2 feeding regulated liver gene expression to suppress immune response and promoted growth and metabolism depending on the gut microbiota.

Conclusions

These results indicated the mechanism of probiotic action of B. licheniformis H2 in maintaining intestinal health and thus promoting growth and B. licheniformis H2 may serve as an antibiotic substitute to prevent subclinical necrotic enteritis in poultry farming.

Probiotics: Symbiotic Relationship with the Animal Host

Simple Summary

Intestinal health directly influences the profitability of animal production, and so growth-promoting antibiotics have been used in the feed or drinking water to reduce the impact of enteric diseases and improve production parameters. However, these have generated long-term bacterial resistance. In the search for natural alternatives to antibiotics, various probiotic strains have been developed to improve intestinal health and biological indicators in farm animals, which is important to provide the consumer with safe food. This review describes the main probiotic bacteria and yeasts, their in vitro properties and their impact on the antioxidant capacity and intestinal environment of animals. Furthermore, this review outlines the role of probiotics in apparently healthy ruminants, pigs and poultry, including animals with digestive diseases.

Abstract

Antibiotic growth-promoters in animal feeding are known to generate bacterial resistance on commercial farms and have proven deleterious effects on human health. This review addresses the effects of probiotics and their symbiotic relationship with the animal host as a viable alternative for producing healthy meat, eggs, and milk at present and in the future. Probiotics can tolerate the conditions of the gastrointestinal tract, such as the gastric acid, pH and bile salts, to exert beneficial effects on the host. They (probiotics) may also have a beneficial effect on productivity, health and wellbeing in different parameters of animal performance. Probiotics stimulate the native microbiota (microbes that are present in their place of origin) and production of short-chain fatty acids, with proven effects such as antimicrobial, hypocholesterolemic and immunomodulatory effects, resulting in better intestinal health, nutrient absorption capacity and productive responses in ruminant and non-ruminant animals. These beneficial effects of probiotics are specific to each microbial strain; therefore, the isolation and identification of beneficial microorganisms, as well as in vitro and in vivo testing in different categories of farm animals, will guarantee their efficacy, replicability and sustainability in the current production systems.

Effects of Multispecies Probiotic on Intestinal Microbiota and Mucosal Barrier Function of Neonatal Calves Infected With E. coli K99

Altered gut microbiota are implicated in inflammatory neonatal calf diarrhea caused by E. coli K99. Beneficial probiotics are used to modulate gut microbiota. However, factors that mediate host-microbe interactions remain unclear. We evaluated the effects of a combination of multispecies probiotics (MSP) on growth, intestinal epithelial development, intestinal immune function and microbiota of neonatal calves infected with E. coli K99. Twelve newborn calves were randomly assigned as follows: C (control, without MSP); D (E. coli O78:K99 + gentamycin); and P (E. coli O78:K99 + supplemental MSP). All groups were studied for 21 d. MSP supplementation significantly (i) changed fungal Chao1 and Shannon indices of the intestine compared with group D; (ii) reduced the relative abundance of Bacteroides and Actinobacteria, while increasing Bifidobacteria, Ascomycetes, and Saccharomyces, compared with groups C and D; (iii) improved duodenal and jejunal mucosal SIgA and total Short Chain Fatty Acids (SCFA) concentrations compared with group D; (iv) increased relative ZO-1 and occludin mRNA expression in jejunal mucosa compared with group D; and (v) enhanced intestinal energy metabolism and defense mechanisms of calves by reducing HSP90 expression in E. coli K99, thereby alleviating the inflammatory response and promoting recovery of mucosal function. Our research may provide direct theoretical support for future applications of MSP in ruminant production.

Constraints and opportunities of sweet sorghum (Sorghum bicolor L.) silage production and utilisation by smallholder milk production sector in Zimbabwe

The objective of the scoping research was to evaluate the current situation, constraints and opportunities of sweet sorghum (Sorghum bicolor L.) silage production and utilisation by the smallholder dairy farmers in Zimbabwe. Cross sectional surveys were conducted from 61 households of six milk producers' associations (MPAs) in Chipinge, Gokwe, Mutasa, Seke, and Umzingwane districts, which were in different agro-ecological regions of Zimbabwe. Purposive and stratified random sampling was done to select households to administer structured questionnaires so as to collect data on socio-economic characteristics and dairy production. Key informant' interviews, case studies, and focus group discussions were the other data collection tools used. Total MPA dairy herd size mean differed (P < 0.05) in all MPAs averaging 16, ranging from 1 to 41 herd. Mafumise MPA had the least (P < 0.05) dairy herd size (7), whilst Gokwe, Tsonzo, Marirangwe, Claremont, and Umzingwane MPAs, had similar herd sizes (P > 0.05). There were positive (P < 0.001) relations between MPAs by seasonal milk yields, lactation days, calving intervals, dry days for different dairy breeds. Milk yields across MPAs and breeds were seasonally sensitive, being high in the wet season than dry season. All farmers (100%) had access to formal milk markets such as Milk Collection Centres, large dairy processors, and parallel markets. Farmers indicated non preference of sweet sorghum silage by their cattle as well as recurring drought affected their maize silage production. Farmers lacked knowledge on how to improve utilisation of sweet sorghum silage by using yeast, and bacteria and this justifies the need to use these probiotics in mitigating utilisation challenges for sustainable milk production.

Intestinal microbiota and its interaction to intestinal health in nursery pigs

The intestinal microbiota has gained increased attention from researchers within the swine industry due to its role in promoting intestinal maturation, immune system modulation, and consequently the enhancement of the health and growth performance of the host. This review aimed to provide updated scientific information on the interaction among intestinal microbiota, dietary components, and intestinal health of pigs. The small intestine is a key site to evaluate the interaction of the microbiota, diet, and host because it is the main site for digestion and absorption of nutrients and plays an important role within the immune system. The diet and its associated components such as feed additives are the main factors affecting the microbial composition and is central in stimulating a beneficial population of microbiota. The microbiota–host interaction modulates the immune system, and, concurrently, the immune system helps to modulate the microbiota composition. The direct interaction between the microbiota and the host is an indication that the mucosa-associated microbiota can be more effective in evaluating its effect on health parameters. It was demonstrated that the mucosa-associated microbiota should be evaluated when analyzing the interaction among diets, microbiota, and health. In addition, supplementation of feed additives aimed to promote the intestinal health of pigs should consider their roles in the modulation of mucosa-associated microbiota as biomarkers to predict the response of growth performance to dietary interventions.

Influence of Three Probiotics Strains, Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745 on the Biochemical and Haematological Profiles and Body Weight of Healthy Rabbits

Simple Summary

Currently, probiotics are used as growth promoters on a large scale to improve the productivity of several animals’ species within the aim of reducing the presence of antibiotic residues in animal products consumed by humans. Several reports evidenced the positive effect of probiotic supplementation on the growth performances and health of rabbits, mainly through the balance of the intestinal microbiota of the host animal. Therefore, certain probiotics, including Lactobacilli, Bifidobacteria, Saccharomyces, can improve the biochemical and haematological profiles, especially in production animals. In this context, this study was performed on rabbits for the economic importance they play as a source of meat proteins in developing countries and their use as experimental models in research and biomedicine. This study then aimed to evaluate the effect of three strains of probiotics: Lactobacillus rhamnosus GG Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745, on the biochemical and haematological parameters and their influence on the rabbit’s weight of the ITELV2006 strain. The findings evidenced that the probiotic strain affected the biochemical and haematological parameters. Further, the strains showed a positive effect on the weight gain of the rabbits.

Abstract

This study aimed to investigate the effects of three strains of probiotics, these being Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. Lactis BB-12 and Saccharomyces boulardii CNCM I-745, on the body weight, animal performances and blood parameters of rabbits (male and female) of the ITELV2006 strain. The supplementation of the feed of the rabbits with the three probiotic strains allowed observing positive effects on most of the biochemical and haematological parameters investigated during a period of 60 days (30 days of supplementation and 30 days without treatment). Further, there was a significant improvement in the body weight of the rabbits at the end of the experiment. The effect of the three probiotics investigated in this trial was found to be related to the sex of the rabbits and to the intake period (duration). Ultimately, these findings raise the possibility of using probiotics to investigate in an in-depth and specific manner based on fixed factors such as the strain, the gender and age of the animals, the main underlying mechanisms and effects, which would allow achieving optimal and adapted health benefits and sustainable production. In the context of animal production, it is worth investigating in a targeted study the effect of the three strains on muscle growth and development and finding evidence of the possible consequences on meat quality traits of the rabbits supplemented with probiotics.

KDP, a Lactobacilli Product from Kimchi, Enhances Mucosal Immunity by Increasing Secretory IgA in Mice and Exhibits Antimicrobial Activity

The potential of KDP, a lactic acid bacterial strain of Lactobacillus sakei, to enhance the production of mucosal specific immunoglobulin A (IgA) in mice and thereby enhance gut mucosal immunity was examined. KDP is composed of dead cells isolated from the Korean traditional food kimchi. Female BALB/c mice orally received 0.25 mg KDP once daily for 5 weeks and were co-administrated ovalbumin (OVA) for negative control and cholera toxin for positive control. Mice administered KDP exhibited increased secretory IgA (sIgA) contents in the small intestine, Peyer’s patches, serum, colon, and lungs as examined by ELISA. KDP also significantly increased the gene expression of Bcl-6, IL-10, IL-12p40, IL-21, and STAT4. In addition, KDP acted as a potent antioxidant, as indicated by its significant inhibitory effects in the range of 16.5–59.4% for DPPH, nitric oxide, maximum total antioxidant capacity, and maximum reducing power. Finally, KDP exhibited potent antimicrobial activity as evidenced by a significant decrease in the growth of 7 samples of gram-negative and gram-positive bacteria and Candida albicans. KDP’s adjuvant effect is shown to be comparable to that of cholera toxin. We conclude that KDP can significantly enhance the intestine’s secretory immunity to OVA, as well as act as a potent antioxidant and antimicrobial agent. These results suggest that orally administered KDP should be studied in clinical trials for antigen-specific IgA production.

Effect of Yeast Culture (Saccharomyces cerevisiae) Supplementation on Growth Performance, Excreta Microbes, Noxious Gas, Nutrient Utilization, and Meat Quality of Broiler Chicken

The study was conducted to test the effects of using yeast culture (Saccharomyces cerevisiae) as feed additive on the growth performance, noxious gas emission, utilization of nutrients, excreta microbial count, and meat quality of broilers. In total, 360 one-day-old Ross 308 broilers with average body weight (BW) of 42.90±1.43 g were randomly selected and allotted to two groups; they were fed either a basal diet (control) or a basal diet supplemented with 1% yeast culture (YC). Each treatment group had 10 replication pens and each replication contained 18 birds. The experiment was divided into 3 phases (1 to 7, 8 to 21, and 22 to 35 days) for growth performance observation. In the 1st phase (1 to 7 days), only the body weight gain (BWG) significantly increased (P<0.05) in birds with the YC diet compared to the control diet. Significant effects on BWG (P<0.05) and feed conversion ratio (FCR) (P<0.05) were seen in birds receiving the YC-supplemented diet in the 3rd phase (22 to 35 days) as compared to the control diet. In addition, during the overall period (1-35 d), BWG was significantly higher (P<0.05) and FCR was reduced (P<0.05). Throughout this experiment, the meat quality, nutrient utilization, noxious gas emission, and bacterial count in the excreta did not vary significantly between the groups. This study proved that a higher dose of YC (Saccharomyces cerevisiae) supplementation could maintain the consistent positive effect on broiler growth but eliminated the speculated outcomes on digestibility, bacterial count, or excreta gas emission.

Yarrowia lipolytica, health benefits for animals

The yeast Yarrowia lipolytica has been industrially adopted for docosahexaenoic acid and eicosapentaenoic acid production under good manufacturing practices over 2 decades. In recent years, it has claimed attention for novel biotechnological applications, such as a functional feed additive for animals. Studies have demonstrated that this yeast is safe and has probiotic and nutritional properties for mammals, birds, fish, crustaceans, and molluscs. Animals fed Y. lipolytica enhanced productive and immune parameters, as well as modulated microbiome, fatty acid composition, and biochemical profiles. Additionally, some Y. lipolytica-derived compounds have improved productive performance, immune status, and disease resistance in animals. Therefore, the aim of this review is to identify and discuss research advances on the potential use of this yeast for animals of economic interest. Challenges, opportunities, and trends were identified and envisioned in the near future for this industrially produced yeast. KEY POINTS: • Yarrowia lipolytica has probiotic and nutritional effects in animals. • Lipase2, EPA, and β-glucan from Y. lipolytica have health benefits for animals. • Y. lipolytica is envisioned in terrestrial and aquatic animal production systems.

Genomic analysis revealed conserved acid tolerance mechanisms from native micro-organisms in fermented feed

AIMS

Fermented feed is an agricultural practice used in many regions of the world to improve the growth performance of farm animals. This study aimed to identify and evaluate the lactic acid bacteria and yeast involved in the production of fermented feed.

METHODS AND RESULTS

We isolated and described two micro-organisms from autochthonous microbiota origin present in a regional feed product, Lactobacillus paracasei IBR07 (Lacticaseibacillus paracasei) and Kazachstania unispora IBR014 (Saccharomyces unisporum). Genome sequence analyses were performed to characterize both micro-organisms. Potential pathways involved in the acid response, tolerance and persistence were predicted in both genomes. Although L. paracasei and K. unispora are considered safe for animal feed, we analysed the presence of virulence factors, antibiotic resistance and pathogenicity islands. Furthermore, the Galleria mellonella model was used to support the safety of both isolates.

CONCLUSIONS

We conclude that IBR07 and IBR014 strains are good candidates to be used as starter cultures for feed fermentation.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data presented here will be helpful to explore other biotechnological aspects and constitute a starting point for further studies to establish the consumption benefit of fermented feed in farm animal production.

Gut Microbiota Manipulation in Foals-Naturopathic Diarrhea Management, or Unsubstantiated Folly?

Diarrhea in foals is a problem of significant clinical and economic consequence, and there are good reasons to believe microbiota manipulation can play an important role in its management. However, given the dynamic development of the foal microbiota and its importance in health and disease, any prophylactic or therapeutic efforts to alter its composition should be evidence based. The few clinical trials of probiotic preparations conducted in foals to date show underwhelming evidence of efficacy and a demonstrated potential to aggravate rather than mitigate diarrhea. Furthermore, recent studies have affirmed that variable but universally inadequate quality control of probiotics enables inadvertent administration of toxin-producing or otherwise pathogenic bacterial strains, as well as strains bearing transferrable antimicrobial resistance genes. Consequently, it seems advisable to approach probiotic therapy in particular with caution for the time being. While prebiotics show initial promise, an even greater scarcity of clinical trials makes it impossible to weigh the pros and cons of their use. Advancing technology will surely continue to enable more detailed and accurate mapping of the equine adult and juvenile microbiota and potentially elucidate the complexities of causation in dysbiosis and disease. In the meantime, fecal microbiota transplantation may be an attractive therapeutic shortcut, allowing practitioners to reconstruct a healthy microbiota even without fully understanding its constitution.

Unexpected Diversity of Yeast Species in Esophageal Mycosis of Waterfowls

This study was performed to evaluate the diversity and prevalence of yeasts associated with esophageal mycosis in domestic ducks and geese. Fungi were isolated from esophageal lesions of dead animals sent for microbiologic laboratory diagnosis. Species identification using a culture-dependent method was carried out by sequencing of the internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region. The most frequently isolated yeast was Candida albicans (43.1%) followed by Saccharomyces cerevisiae (17.6%), Candida kefyr (11.7%), Kazachstania bovina (11.7%), Candida lambica (3.9%), and single isolates (1.9%) representing Candida inconspicua, Candida rugosa, Candida pelliculosa, Candida krusei, Magnusiomyces capitatus, and Trichosporon asahii. Our results indicate that a number of potentially pathogenic yeast species can be isolated from esophageal mycosis of waterfowls, but additional studies are needed to make conclusions regarding their possible etiologic role in disease.

Effect of a Multispecies Probiotic Mixture on the Growth and Incidence of Diarrhea, Immune Function, and Fecal Microbiota of Pre-weaning Dairy Calves

The effects of different doses of a multispecies probiotic (MSP) mixture on growth performance, the incidence of diarrhea rate and immune function, and fecal microbial diversity and structure were evaluated in pre-weaning Holstein dairy calves at WK2, WK4, WK6, and WK8. Forty Chinese Holstein female newborn calves were randomly assigned to four treatments with 10 calves in each group, C (control group), T1 (0.5 g MSP/calf/day, T2 (1 g MSP/calf/day), and T3 (2 g MSP/calf/day) groups. The experimental period was 56 days. Feed intake and health scoring were recorded every day until the end of the experiment. Fecal contents and blood samples were sampled at WK2, WK4, WK6, and WK8. Growth performance, incidence of diarrhea, and total serum concentrations (IgA, IgG, and IgM) were analyzed. Bacterial 16S rRNA and fungal ITS genes were high-throughput sequenced for fecal microbiota. The relationships among the populations of the principal fecal microbiota at WK2 and the growth performance or serum immunoglobulin concentrations were analyzed using Pearson's rank correlation coefficients. The MSP supplementation reduced the incidence of diarrhea in the first 4 weeks of life, and serum IgA, IgG, and IgM concentrations increased between WK2 and WK8 in the T3 group. There was an increase in growth performance and reduction in the incidence of diarrhea until WK4 after birth in T3 group, compared with the control, T1, and T2 groups. The results of fecal microbiota analysis showed that Firmicutes and Bacteroides were the predominant phyla, with Blautia, Ruminococcaceae_UCG-005, norank_f__Muribaculaceae, Bacteroides, Subdoligranulum, and Bifidobacterium being the dominant genera in calf feces. Aspergillus, Thermomyces, and Saccharomyces were the predominant fungal phyla. Compared with the control, in T1 and T2 groups, the MSP supplementation reduced the relative abundance of Bacteroidetes and increased the relative abundance of Bifidobacterium, Lactobacillus, Collinsella, and Saccharomyces at WK2 in group T3. Thus, the fecal microbial composition and diversity was significantly affected by the MSP mixture during the first 2 weeks of the calves' life. MSP mixtures reduced the incidence of diarrhea in pre-weaning calves (during the first 4 weeks of life). There was a significant improvement in growth performance, reduction in calf diarrhea, balance in the fecal microbiota, and an overall improvement in serum immunity, compared with the control group. We, therefore, recommend adding 2 g/day of multispecies probiotic mixture supplementation in diets of dairy calves during their first 4 weeks of life before weaning.

Dectin-1-Mediated Production of Pro-Inflammatory Cytokines Induced by Yeast β-Glucans in Bovine Monocytes

Yeast-derived products containing β-glucans have long been used as feed supplements in domesticated animals in an attempt to increase immunity. β-glucans are mainly recognized by the cell surface receptor CLEC7A, also designated Dectin-1. Although the immune mechanisms elicited through Dectin-1 activation have been studied in detail in mice and humans, they are poorly understood in other species. Here, we evaluated the response of bovine monocytes to soluble and particulate purified β-glucans, and also to Zymosan. Our results show that particulate, but not soluble β-glucans, can upregulate the surface expression of costimulatory molecules CD80 and CD86 on bovine monocytes. In addition, stimulated cells increased production of IL-8 and of TNF, IL1B, and IL6 mRNA expression, in a dose-dependent manner, which correlated positively with CLEC7A gene expression. Production of IL-8 and TNF expression decreased significantly after CLEC7A knockdown using two different pairs of siRNAs. Overall, we demonstrated here that bovine monocytes respond to particulate β-glucans, through Dectin-1, by increasing the expression of pro-inflammatory cytokines. Our data support further studies in cattle on the induction of trained immunity using dietary β-glucans.

Effect of Hydrolyzed Yeast Administration on Faecal Microbiota, Haematology, Serum Biochemistry and Cellular Immunity in Healthy Dogs

Fungal microorganisms are regularly found in the gastrointestinal tract of healthy and diseased dogs especially from the phyla Ascomycota and Basidiomycota; however, it is necessary to better understand their role in host health. One of the most commonly studied yeast species in humans or animals is Saccharomyces cerevisiae especially in its live cell form. Scarce knowledge on its hydrolysate product effects in dogs forced us to test diet supplemented with hydrolyzed brewery S. cerevisiae (at a dose 0.3% of the diet) for 14 days to healthy adult dogs. Twenty German Shepherds were randomly divided into 2 groups: control and experimental, ten dogs in each. The experiment lasted 42 days (blood and faeces sample collection at days 0, 14, 28 and 42). The results of this straighforward experiment showed significant increase in the abundance of bifidobacteria (day 14), lactic acid bacteria (day 42) and clostridia (day 42). The faecal pH was significantly increased at day 28. In blood serum, the concentration of triglyceride and cholesterol decreased (day 42) while activities of alanine aminotransferase (at day 14) and aspartate aminotransferase significantly increased (at days 28 and 42). Activities of these enzymes were above reference range top in 7 dogs (ALT) and 4 dogs (AST). Haematological paramaters and activity of phagocytes as well as on percentage of lymphocyte subsets CD4⁺, CD8⁺, CD4⁺CD8⁺ and CD21⁺ were not changed during the experiment. The important point of these results is their onset mostly in the post-supplementation period. The observation of some unexpected effects emphasizes the need for reassessment to use yeasts products for dogs but further studies using different doses are necessary.

Lactobacillus animalis pZL8a: a potential probiotic isolated from pig feces for further research

This study aimed to screen a potential anti-diarrheal probiotic for pigs to meet the growing demand for antibiotic alternatives in livestock. Six intestinal pathogens, Escherichia coli (O157: H7) ATCC 43888, Staphylococcus aureus ATCC 6538, Listeria monocytogenes ATCC 19115, Salmonella Typhimurium ATCC 14028, Shigella boydii ATCC 9207, and Staphylococcus haemolyticus ZSY2 were employed as indicator bacteria. Our result showed that Lactobacillus animalis pZL8a isolated from pig feces had extensive and higher antibacterial activity against indicator pathogens among 9 tested strains. In addition, valuable attributes of pZL8a such as great tolerance of low pH (3.0) and bile salts (0.3%), high-level adhesion to Caco-2 cells, and similar susceptibility to the reference strain Lactobacillus rhamnosus GG (LGG) were observed. Compared with control, pZL8a supplement significantly improved the level of immunoglobulin G (IgG), immunoglobulin M (IgM), and interleukin-2 (IL-2) in mouse serum. Therefore, L. animalis pZL8a was proposed as a potential probiotic for further research and hope to reduce or replace the application of antibiotics in animal production.

Shaping the Future of Probiotics and Prebiotics

Recent and ongoing developments in microbiome science are enabling new frontiers of research for probiotics and prebiotics. Novel types, mechanisms, and applications currently under study have the potential to change scientific understanding as well as nutritional and healthcare applications of these interventions. The expansion of related fields of microbiome-targeted interventions, and an evolving landscape for implementation across regulatory, policy, prescriber, and consumer spheres, portends an era of significant change. In this review we examine recent, emerging, and anticipated trends in probiotic and prebiotic science, and create a vision for broad areas of developing influence in the field.

Aflatoxin Detoxification Using Microorganisms and Enzymes

Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful mycotoxins, which are produced by Aspergillus flavus, Aspergillus parasiticus, and other fungi that are commonly found in the production and preservation of grain and feed. AFs can cause harm to animal and human health due to their toxic (carcinogenic, teratogenic, and mutagenic) effects. How to remove AF has become a major problem: biological methods cause no contamination, have high specificity, and work at high temperature, affording environmental protection. In the present research, microorganisms with detoxification effects researched in recent years are reviewed, the detoxification mechanism of microbes on AFs, the safety of degrading enzymes and reaction products formed in the degradation process, and the application of microorganisms as detoxification strategies for AFs were investigated. One of the main aims of the work is to provide a reliable reference strategy for biological detoxification of AFs.

Impact of Yeast-Derived β-Glucans on the Porcine Gut Microbiota and Immune System in Early Life

Piglets are susceptible to infections in early life and around weaning due to rapid environmental and dietary changes. A compelling target to improve pig health in early life is diet, as it constitutes a pivotal determinant of gut microbial colonization and maturation of the host’s immune system. In the present study, we investigated how supplementation of yeast-derived β-glucans affects the gut microbiota and immune function pre- and post-weaning, and how these complex systems develop over time. From day two after birth until two weeks after weaning, piglets received yeast-derived β-glucans or a control treatment orally and were subsequently vaccinated against Salmonella Typhimurium. Faeces, digesta, blood, and tissue samples were collected to study gut microbiota composition and immune function. Overall, yeast-derived β-glucans did not affect the vaccination response, and only modest effects on faecal microbiota composition and immune parameters were observed, primarily before weaning. This study demonstrates that the pre-weaning period offers a ‘window of opportunity’ to alter the gut microbiota and immune system through diet. However, the observed changes were modest, and any long-lasting effects of yeast-derived β-glucans remain to be elucidated.

Cyberlindnera jadinii Yeast as a Protein Source for Weaned Piglets-Impact on Immune Response and Gut Microbiota

Supplying novel feed ingredients for pig production is crucial to enhance food security and decrease the environmental impact of meat production. Several studies have focused on evaluating the beneficial health effects of yeast in pigs. However, its use as a protein source has been partially addressed. Previously, we have shown that yeast at high inclusion levels maintains growth performance and digestibility, while nutrient digestibility, intestinal villi height and fecal consistency were improved. The present study combined microbiome, short-chain fatty acid, and immune parameter analysis to investigate the effect of high inclusion of yeast in diets for post-weaning piglets. Our results showed that yeast did not have a significant impact on the hematological or biochemical parameters in blood. The different immune cell subpopulations isolated from blood and distal jejunal lymph nodes (DJLN) were analyzed by flow cytometry and showed that yeast diet induced an increased number of the subtype of leukocytes CD45+/CD3-/CD8+, a special type of Natural Killer (NK) cells. Also, a very mild to moderate infiltration of neutrophilic granulocytes and lower IgA level were observed in the colon of yeast fed piglets. The microbiome profiling in different compartments of the gastrointestinal tract of piglets was performed using 16S rRNA metabarcoding. The results showed that 40% replacement of dietary protein had a statistically significant effect on the microbial communities in cecum and colon, while the microbial population in ileum and jejunum were not affected. Analysis of predicted microbial metabolic pathways analysis revealed significant upregulation of short-chain fatty acids, ether lipid metabolisms, secondary bile acids, and several other important biosynthesis pathways in cecum and colon of pigs fed yeast. In conclusion, the results showed that diet containing 40% of yeast protein positively shaped microbial community in the large intestine and increased the number of a specific subpopulation of NK cells in the DJLN. These results showed that yeast modulates the microbiome and decreases the secretion of IgA in the colon of post-weaning pigs.