Effect of Lactylate and Bacillus subtilis on Growth Performance, Peripheral Blood Cell Profile, and Gut Microbiota of Nursery Pigs

Effects of dietary supplementation with Bacillus subtilis and bacteriophage on growth performance, intestinal morphology and microbiota structure in 0-90 d MaGang geese

Introduction

The expansion of large-scale goose farming under semi-arid conditions has exacerbated bathing pool pollution, adversely affecting goose growth performance and intestinal health. Given the crucial role of gut microbiota in maintaining intestinal homeostasis, and considering the reported beneficial effects of bacteriophages and Bacillus subtilis on gut health, this study investigated their combined application in goose production.

Methods

To investigate the effects of Bacillus subtilis and phage supplementation on goose intestinal health, a 90-day trial was conducted with 288 Magang goslings randomly allocated to four treatment groups: control (A), B. subtilis (1 × 105 CFU/kg; B), bacteriophage (5 × 107 PFU/kg; C), and combined supplementation (D).

Results

The supplementation significantly enhanced body weight (p < 0.05) and feed efficiency without affecting feed intake. Notably, the combined treatment demonstrated synergistic effects in reducing serum and aquatic endotoxin levels while suppressing pathogenic bacteria (Escherichia coli and Salmonella) in water systems. Intestinal morphology improvements included increased villus height and optimized villusto-crypt ratios, accompanied by up-regulated expression of tight junction genes (Zo-1 and Ocln). Cecal microbiota analysis revealed enhanced alpha diversity and a shift toward Bacteroides-dominant communities, with concurrent suppression of Proteobacteria. Immune modulation exhibited a biphasic response, characterized by early anti-inflammatory (Tnf-α) and late-phase antioxidant (Ho-1) activities. Microbialenvironmental correlation analysis identified Firmicutes and Desulfobacterota as growth-promoting but barrier-compromising taxa, while Bacteroidota was associated with improved gut integrity.

Conclusion

This research has shown that adding B. subtilis and bacteriophages to feed significantly enhances the intestinal barrier function of geese. The findings demonstrate that combined supplementation of B. subtilis and bacteriophages during the brooding and rearing stages optimizes growth performance through gut-microbiota-immune interactions, providing an effective antibiotic-free strategy for sustainable poultry production.

Antibiotic Resistance Gene Expression in Veterinary Probiotics: Two Sides of the Coin

The rapid proliferation of antimicrobial resistance has emerged as one of the most pressing animal and public health challenges of our time. Probiotics, extensively employed in human and veterinary medicine, are instrumental in maintaining a balanced microbiome and mitigating its disruption during antibiotic therapy. While their numerous benefits are well documented, probiotics also present potential risks, notably the capacity to harbor antimicrobial resistance genes. This genetic reservoir could contribute to the emergence and spread of antimicrobial resistance by facilitating the horizontal transfer of resistance genes to pathogenic bacteria within the gut. This review critically examines the presence of antimicrobial resistance genes in commonly used probiotic strains, explores the underlying mechanisms of resistance, and provides a balanced analysis of the benefits and risks associated with their use. By addressing these dual aspects, this paper highlights the need for vigilant evaluation of probiotics to preserve their therapeutic potential while minimizing public health risks.

Temporal Changes in Faecal Microbiota Composition and Diversity in Dairy Cows Supplemented with a Lactobacillus-Based Direct-Fed Microbial

The rumen microbiota of dairy cows plays a crucial role in fermenting fibrous material, essential for nutrient extraction and overall productivity, detoxification of anti-nutritional toxic compounds, synthesis of vital nutrients, and is essential for optimal animal health. This study investigated the impact of Lentilactobacillus-, Lactocaseibacillus-, and Lacticaseibacillus-based direct-fed microbial (DFM) supplementation on dairy cows' faecal microbial composition and diversity. The study was carried out on a commercial dairy farm using 50 Holstein-Friesian cows randomly assigned into control (CON) and treatment (TRT) groups. Faecal samples were collected directly from the rectum every two months from September 2021 to January 2023. The bacterial 16S rRNA gene and fungal ITS-1 regions were amplified, sequenced, and analysed. Microbial diversity was assessed through alpha- and beta-diversity metrics. Linear discriminant analysis effect size (LEfSe) was performed to identify which taxa were driving the changes seen in the microbiota over time and treatment. Bacteroidaceae were the most prevalent bacterial family, followed by Lachnospiraceae and Muribaculaceae in both CON and TRT cows. Ascomycota, Basidiomycota, and Mucoromycota were the dominant three fungal phyla in the faeces of both CON and TRT cows. Bacterial genera Fructilactobacillus was abundant in the CON and Absicoccus in the TRT groups. Fungal taxa Chaetothryriales_incertae_sedis and Pseudomentella were absent in the faeces of TRT cows. Significant temporal and specific taxonomic differences were observed between the CON and TRT groups. The study's findings underscore the dynamic nature of microbial communities and the importance of targeted dietary interventions. Further research is necessary to elucidate these microbial shifts, long-term impacts, and functional implications, aiming to optimise ruminant nutrition and enhance dairy cow performance.

Dose-Dependent Effects of Supplementing a Two-Strain Bacillus subtilis Probiotic on Growth Performance, Blood Parameters, Fecal Metabolites, and Microbiome in Nursery Pigs

This experiment was conducted to evaluate the effects of dietary supplementation level of a two-strain Bacillus subtilis probiotic on growth performance, blood parameters, fecal metabolites, and microbiome in nursery pigs. A total of 54 weaned piglets were allotted to three treatments in three replicate pens with six pigs/pen for a 28 d feeding trial. The treatments were as follows: control: no probiotic supplementation; Pro1x: B. subtilis supplementation at 1.875 × 105 CFU/g diet; and Pro10x: B. subtilis supplementation at 1.875 × 106 CFU/g diet. Body weight at d 14 postweaning (p = 0.06) and average daily gain for d 0 to 14 postweaning (p < 0.05) were greater in the Pro1x treatment than in the other treatments. Blood glucose levels were greater in both probiotic treatments than in the control treatment at d 14 postweaning (p < 0.05). In the fecal short-chain fatty acid (SCFA) concentrations, the butyrate concentrations were greater in the Pro1x treatment than in the other treatments (p < 0.05), and the acetate, propionate, and total SCFA concentrations were greater in the Pro1x treatment than in the Pro10x treatment (p < 0.05). The beta diversity of fecal microbiome composition at d 14 postweaning based on Unweighted Unifrac analysis was dissimilar between the Pro1x and Pro10x treatments (p < 0.05). In conclusion, dietary B. subtilis supplementation of two strains selected to reduce effects of pathogenic Escherichia coli to nursery diets at 1.875 × 105 CFU/g diet improved the growth rate in the early postweaning period, increased fecal SCFA concentrations and altered the fecal microbial community composition. A higher dose of B. subtilis did not improve the performance parameters over those of the control piglets.

The Effect of Maternal Probiotic or Synbiotic Supplementation on Sow and Offspring Gastrointestinal Microbiota, Health, and Performance

The increasing prevalence of antimicrobial-resistant pathogens has prompted the reduction in antibiotic and antimicrobial use in commercial pig production. This has led to increased research efforts to identify alternative dietary interventions to support the health and development of the pig. The crucial role of the GIT microbiota in animal health and performance is becoming increasingly evident. Hence, promoting an improved GIT microbiota, particularly the pioneer microbiota in the young pig, is a fundamental focus. Recent research has indicated that the sow's GIT microbiota is a significant contributor to the development of the offspring's microbiota. Thus, dietary manipulation of the sow's microbiota with probiotics or synbiotics, before farrowing and during lactation, is a compelling area of exploration. This review aims to identify the potential health benefits of maternal probiotic or synbiotic supplementation to both the sow and her offspring and to explore their possible modes of action. Finally, the results of maternal sow probiotic and synbiotic supplementation studies are collated and summarized. Maternal probiotic or synbiotic supplementation offers an effective strategy to modulate the sow's microbiota and thereby enhance the formation of a health-promoting pioneer microbiota in the offspring. In addition, this strategy can potentially reduce oxidative stress and inflammation in the sow and her offspring, enhance the immune potential of the milk, the immune system development in the offspring, and the sow's feed intake during lactation. Although many studies have used probiotics in the maternal sow diet, the most effective probiotic or probiotic blends remain unclear. To this extent, further direct comparative investigations using different probiotics are warranted to advance the current understanding in this area. Moreover, the number of investigations supplementing synbiotics in the maternal sow diet is limited and is an area where further exploration is warranted.

Protective Effects of Bacillus subtilis HH2 against Oral Enterotoxigenic Escherichia coli in Beagles

This study evaluated the protective effect of Bacillus subtilis HH2 on beagles orally challenged with enterotoxigenic Escherichia coli (ETEC). We assessed the physiological parameters and the severity of diarrhea, as well as the changes in three serum immunoglobulins (IgG, IgA, and IgM), plasma diamine oxidase (DAO), D-lactate (D-LA), and the fecal microbiome. Feeding B. subtilis HH2 significantly reduced the severity of diarrhea after the ETEC challenge (p < 0.05) and increased serum levels of IgG, IgA, and IgM (p < 0.01). B. subtilis HH2 administration also reduced serum levels of DAO at 48 h after the ETEC challenge (p < 0.05), but no significant changes were observed in D-LA (p > 0.05). Oral ETEC challenge significantly reduced the richness and diversity of gut microbiota in beagles not pre-fed with B. subtilis HH2 (p < 0.05), while B. subtilis HH2 feeding and oral ETEC challenge significantly altered the gut microbiota structure of beagles (p < 0.01). Moreover, 14 days of B. subtilis HH2 feeding reduced the relative abundance of Deinococcus-Thermus in feces. This study reveals that B. subtilis HH2 alleviates diarrhea caused by ETEC, enhances non-specific immunity, reduces ETEC-induced damage to the intestinal mucosa, and regulates gut microbiota composition.

Unraveling Membrane-Disruptive Properties of Sodium Lauroyl Lactylate and Its Hydrolytic Products: A QCM-D and EIS Study

Membrane-disrupting lactylates are an important class of surfactant molecules that are esterified adducts of fatty acid and lactic acid and possess industrially attractive properties, such as high antimicrobial potency and hydrophilicity. Compared with antimicrobial lipids such as free fatty acids and monoglycerides, the membrane-disruptive properties of lactylates have been scarcely investigated from a biophysical perspective, and addressing this gap is important to build a molecular-level understanding of how lactylates work. Herein, using the quartz crystal microbalance-dissipation (QCM-D) and electrochemical impedance spectroscopy (EIS) techniques, we investigated the real-time, membrane-disruptive interactions between sodium lauroyl lactylate (SLL)-a promising lactylate with a 12-carbon-long, saturated hydrocarbon chain-and supported lipid bilayer (SLB) and tethered bilayer lipid membrane (tBLM) platforms. For comparison, hydrolytic products of SLL that may be generated in biological environments, i.e., lauric acid (LA) and lactic acid (LacA), were also tested individually and as a mixture, along with a structurally related surfactant (sodium dodecyl sulfate, SDS). While SLL, LA, and SDS all had equivalent chain properties and critical micelle concentration (CMC) values, our findings reveal that SLL exhibits distinct membrane-disruptive properties that lie in between the rapid, complete solubilizing activity of SDS and the more modest disruptive properties of LA. Interestingly, the hydrolytic products of SLL, i.e., the LA + LacA mixture, induced a greater degree of transient, reversible membrane morphological changes but ultimately less permanent membrane disruption than SLL. These molecular-level insights support that careful tuning of antimicrobial lipid headgroup properties can modulate the spectrum of membrane-disruptive interactions, offering a pathway to design surfactants with tailored biodegradation profiles and reinforcing that SLL has attractive biophysical merits as a membrane-disrupting antimicrobial drug candidate.

16S rRNA Gene Amplicon Sequencing of Gut Microbiota Affected by Four Probiotic Strains in Mice

Probiotics, also referred to as "living microorganisms," are mostly present in the genitals and the guts of animals. They can increase an animal's immunity, aid in digestion and absorption, control gut microbiota, protect against sickness, and even fight cancer. However, the differences in the effects of different types of probiotics on host gut microbiota composition are still unclear. In this study, 21-day-old specific pathogen-free (SPF) mice were gavaged with Lactobacillus acidophilus (La), Lactiplantibacillus plantarum (Lp), Bacillus subtilis (Bs), Enterococcus faecalis (Ef), LB broth medium, and MRS broth medium. We sequenced 16S rRNA from fecal samples from each group 14 d after gavaging. According to the results, there were significant differences among the six groups of samples in Firmicutes, Bacteroidetes, Proteobacteria, Bacteroidetes, Actinobacteria, and Desferribacter (p < 0.01) at the phylum level. Lactobacillus, Erysipelaceae Clostridium, Bacteroides, Brautella, Trichospiraceae Clostridium, Verummicroaceae Ruminococcus, Ruminococcus, Prevotella, Shigella, and Clostridium Clostridium differed significantly at the genus level (p < 0.01). Four kinds of probiotic changes in the composition and structure of the gut microbiota in mice were observed, but they did not cause changes in the diversity of the gut microbiota. In conclusion, the use of different probiotics resulted in different changes in the gut microbiota of the mice, including genera that some probiotics decreased and genera that some pathogens increased. According to the results of this study, different probiotic strains have different effects on the gut microbiota of mice, which may provide new ideas for the mechanism of action and application of microecological agents.

Does diet or macronutrients intake drive the structure and function of gut microbiota?

Shift of ingestive behavior is an important strategy for animals to adapt to change of the environment. We knew that shifts in animal dietary habits lead to changes in the structure of the gut microbiota, but we are not sure about if changes in the composition and function of the gut microbiota respond to changes in the nutrient intake or food items. To investigate how animal feeding strategies affect nutrient intakes and thus alter the composition and digestion function of gut microbiota, we selected a group of wild primate group for the study. We quantified their diet and macronutrients intake in four seasons of a year, and instant fecal samples were analyzed by high-throughput sequencing of 16S rRNA and metagenomics. These results demonstrated that the main reason that causes seasonal shifts of gut microbiota is the macronutrient variation induced by seasonal dietary differences. Gut microbes can help to compensate for insufficient macronutrients intake of the host through microbial metabolic functions. This study contributes to a deeper understanding of the causes of seasonal variation in host-microbial variation in wild primates.

Complete genome analysis of Bacillus subtilis derived from yaks and its probiotic characteristics

Probiotics have attracted attention due to their multiple health benefits to the host. Yaks inhabiting the Tibetan plateau exhibit excellent disease resistance and tolerance, which may be associated with their inner probiotics. Currently, research on probiotics mainly focuses on their positive effects on the host, but information regarding their genome remains unclear. To reveal the potential functional genes of Bacillus subtilis isolated from yaks, we sequenced its whole genome. Results indicated that the genomic length of Bacillus subtilis was 866,044,638 bp, with 4,429 coding genes. The genome of this bacteria was composed of one chromosome and one plasmid with lengths of 4,214,774 and 54,527 bp, respectively. Moreover, Bacillus subtilis contained 86 tRNAs, 27 rRNAs (9 16S_rRNA, 9 23S_rRNA, and 9 5S_rRNA), and 114 other ncRNA. KEGG annotation indicated that most genes in Bacillus subtilis were associated with biosynthesis of amino acids, carbon metabolism, purine metabolism, pyrimidine metabolism, and ABC transporters. GO annotation demonstrated that most genes in Bacillus subtilis were related to nucleic acid binding transcription factor activity, transporter activity, antioxidant activity, and biological adhesion. EggNOG uncovered that most genes in Bacillus subtilis were related to energy production and conversion, amino acid transport and metabolism, carbohydrate transport and metabolism. CAZy annotation found glycoside hydrolases (33.65%), glycosyl transferases (22.11%), polysaccharide lyases (3.84%), carbohydrate esterases (14.42%), auxiliary activities (3.36%), and carbohydrate-binding modules (22.59%). In conclusion, this study investigated the genome and genetic properties of Bacillus subtilis derived from yaks, which contributed to understanding the potential prebiotic mechanism of probiotics from the genetic perspective.

Effects of Replacing Alfalfa Hay with Oat Hay in Fermented Total Mixed Ration on Growth Performance and Rumen Microbiota in Lambs

The use of the fermented total mixed ration (FTMR) is a promising approach for the preservation of feedstuff, but the effect of FTMR on the between growth performance and ruminal microflora of lambs are still limited. This study aimed to assess the effects of different roughage types in the FTMR on growth performance and rumen microbiota of lambs. Forty-five six-month-old Small tail Han sheep × Ujumqin male lambs were randomly allocated into three groups (three pens per treatment and five lambs per pen) with the initial body weight (BW) of 28.50 ± 1.50 kg. The three treatments were as follows: the low oat percentages group (LO) contained 200 g/kg oat hay + 400 g/kg alfalfa hay, the medium oat percentages group (MO) contained 300 g/kg oat hay + 300 g/kg alfalfa hay, and the high oat percentages group (HO) contained 400 g/kg oat hay + 200 g/kg alfalfa hay. The result revealed that the dry matter intake and average daily gain were markedly (p < 0.05) higher in the MO treatment than in the LO and HO treatments, whereas no significant difference (p > 0.05) was found in the final body weight. There were no significant (p > 0.05) differences on the Shannon and Simpson index among the three treatments. The PCoA score plot illustrated the individual separation in the LO, MO, and HO treatments. At the phylum level, the presence of Bacteroidetes and Firmicutes belonging to the dominant phyla is widely described in rumen communities among the three treatments. The relative abundances of Prevotella, Fibrobacter, and Succinivibrio in the level of the genes were remarkably higher (p < 0.05) in MO treatment than that in LO and HO treatments, while the relative abundance of Sediminispirochaeta was remarkably higher (p < 0.05) in LO treatment than that in MO and HO treatments. These results indicated that the MO treatments could more effectively improve growth performance than the LO and HO treatments, and also revealed that the different forage types in diets reshaped the compositions and function of the rumen microbiota. Consequently, the findings presented in this study provide a reference for the application of FTMR in animal production and the understanding of the interaction between diet, animal performance, and ruminal microbiota.

Joint Application of Lactobacillus plantarum and Bacillus subtilis Improves Growth Performance, Immune Function and Intestinal Integrity in Weaned Piglets

This study was conducted to explore the effects of the joint application of Lactobacillus plantarum and Bacillus subtilis on growth performance, immune function, antioxidant capacity, intestinal integrity, and gut microbiota composition in weaned piglets. The piglets were allocated randomly into 4 dietary groups, which were a control diet (NC), NC + 150 ppm mucilage sulfate (PC), and 3 additional diets containing 1 kg/t (LT), 1.5 kg/t (MT), or 2 kg/t (HT) mixture of Lactobacillus plantarum and Bacillus subtilis, respectively. Results showed that joint application of Lactobacillus plantarum and Bacillus subtilis increased ADFI and ADG of weaned piglets in d 14~28 and d 28~42 (p < 0.05), and decreased serum concentrations of DAO, IL-1β, TNF-α, and IL-2. The LT group increased jejunal and colonic sIgA contents compared with the PC group (p < 0.05). Groups of MT and HT increased colonic mRNA expression of host defense peptides and tight junction proteins compared with the NC and PC groups. The joint application of Lactobacillus plantarum and Bacillus subtilis increased the abundance of colonic Lactobacillus compared with NC and PC groups (p < 0.10). In conclusion, the joint application of Lactobacillus plantarum and Bacillus subtilis as an antibiotics alternative improved growth performance via promoting immune function and intestinal integrity of weaned piglets.

Effect of the Inclusion of Bacillus spp. in Growing-Finishing Pigs' Diets: A Meta-Analysis

This meta-analysis determined the effect of Bacillus spp. on growth performance of growing−finishing pigs and then assessed causes for the heterogeneity of responses detected using meta-regression. A database of 22 articles published from 2000 to 2020 was identified, and 9 articles fitted the selection criteria and were integrated in the final database. Statistical analysis was performed to analyze the effect size for ADG, average daily feed intake (ADFI), and F:G ratio using a standardized means difference (SMD) at a 95% confidence interval. A meta-regression analysis was used to investigate the cause of heterogeneity, using the individual SMD for each study assessment as the outcome and the associated SE as the measure of variance. Dietary Bacillus spp. supplementation had no effect on ADFI (SMD: −0.052, p = 0.138) and numerically increased ADG (SMD: 0.113, p = 0.081) and reduced the F:G ratio SMD: −0.127, p < 0.001). Meta-regression outcomes suggested that the number of animals per group was an essential component promoting heterogeneity in ADG. Overall, the inclusion of Bacillus spp. (median 486 mg/d) in growing−finishing pigs can increase ADG and can decrease the F:G ratio.

Effects of Multi-Strain Probiotics and Perilla frutescens Seed Extract Supplementation Alone or Combined on Growth Performance, Antioxidant Indices, and Intestinal Health of Weaned Piglets

Simple Summary

Weaning piglets face stressors from changes in feed and environment, which affects their growth. To resolve this problem, we explored the separate effects of multi-strain probiotics and Perilla frutescens seed extract and their combined effect on weaning piglets. We found multi-strain probiotics or Perilla frutescens seed extract both improved the gain to feed ratio and antioxidant capacity. In addition, multi-strain probiotics improved jejunal villus height and the villus height/crypt depth ratio. Perilla frutescens seed extract improved ileal villus height. The interactive effects were observed in jejunal villus height and the villus height/crypt depth ratio, ileal villus height, and the gene expression of IL-1β and mucin2 in the intestinal mucosa. This study shows that using either multi-strain probiotics or Perilla frutescens seed extract alone is more effective than their combined use in weaning piglets.

Abstract

This study examined the effects of multi-strain probiotics (BL) and Perilla frutescens seed extract (PSE), alone or in combination, on weaning piglets. In total, 96 weaning piglets were allocated into four treatments: CON group (the basal diet), PSE group (basal diet + 1g/kg PSE), BL group (basal diet + 2 g/kg BL), and BL+PSE group (basal diet +1 g/kg PSE + 2 g/kg BL) according to a 2 × 2 factorial arrangement. The supplementation of BL or PSE improved the gain to feed ratio. Dietary BL reduced diarrhea occurrence and Escherichia coli, but increased Lactobacillus counts in the ileal digesta. Dietary PSE tended to increase Lactobacillus counts in the ileal digesta. Interactive effects were found in terms of ileal villus height, the gene expression of IL-1β, and malondialdehyde in the ileal mucosa. Dietary BL lowered malondialdehyde in the spleen, liver, and jejunal mucosa but increased the total antioxidant capacity (T-AOC) in the liver and ileum mucosa. The supplementation of PSE improved superoxide dismutase in serum and T-AOC in the liver, and reduced MDA in liver, spleen, and jejunum mucosa. Taken together, BL or PSE showed positive effects, improving growth and intestinal morphology and enhancing antioxidant capacity. However, their interaction showed no beneficial effects on the antioxidant indices and the intestinal morphology of weaned piglets.

Influence of yeast-based pre- and probiotics in lactation and nursery diets on nursery pig performance and antimicrobial resistance of fecal Escherichia coli

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from d 0 to 7, then concentrations were decreased by 50% from d 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P < 0.05) average daily gain (ADG) from d 0 to 24 and d 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased d 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery there was reduced (P < 0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from d 0 to 38 and NucleoSaf at 0.05% from d 0 to 10 and 0.025% from d 10 to 24; or DFM, 0.10% MicroSaf-S from d 0 to 38 and NucleoSaf at 0.05% from d 0 to 10 and 0.025% from d 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From d 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. While feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2.

Donor age and body weight determine the effects of fecal microbiota transplantation on growth performance, and fecal microbiota development in recipient pigs

Background

The application of fecal microbiota transplantation (FMT) to improve swine growth performance has been sporadically studied. Most of these studies used a single microbiota source and thus the effect of donor characteristics on recipient pigs’ fecal microbiota development and growth performance is largely unknown.

Results

In this study, we collected feces from six donors with heavy (H) or light (L) body weight and different ages (d 42, nursery; d 96, growing; and d 170, finisher) to evaluate their effects on the growth performance and fecal microbiota development of recipient pigs. Generally, recipients that received two doses of FMT from nursery and finisher stages donor at weaning (21 ± 2 days of age) inherited the donor’s growth pattern, while the pigs gavaged with grower stage material exerted a numerically greater weight gain than the control pigs regardless of donor BW. FMT from heavier donors (NH, GH, and FH) led to the recipients to have numerically increased growth compared to their lighter counterparts (NL, GL, and FL, respectively) throughout the growing and most finishing stages. This benefit could be attributed to the enrichment of ASV25 Faecalibacterium, ASV61 Faecalibacterium, ASV438 Coriobacteriaceae_unclassified, ASV144 Bulleidia, and ASV129 Oribacterium and decrease of ASV13 Escherichia during nursery stage. Fecal microbiota transplantation from growing and finishing donors influenced the microbial community significantly in recipient pigs during the nursery stage. FMT of older donors’ gut microbiota expedited recipients’ microbiota maturity on d 35 and 49, indicated by increased estimated microbiota ages. The age-associated bacterial taxa included ASV206 Ruminococcaceae, ASV211 Butyrivibrio, ASV416 Bacteroides, ASV2 Streptococcus, and ASV291 Veillonellaceae. The body weight differences between GL and GH pigs on d 104 were associated with the increased synthesis of the essential amino acid, lysine and methionine, mixed acid fermentation, expedited glycolysis, and sucrose/galactose degradation.

Conclusions

Overall, our study provided insights into how donor age and body weight affect FMT outcomes regarding growth performance, microbiota community shifts, and lower GI tract metabolic potentials. This study also provided guidance to select qualified donors for future fecal microbiota transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00696-1.

Bacillus spp. Probiotic Strains as a Potential Tool for Limiting the Use of Antibiotics, and Improving the Growth and Health of Pigs and Chickens

The pressure to increasingly optimize the breeding of livestock monogastric animals resulted in antimicrobials often being misused in an attempt to improve growth performance and counteract diseases in these animals, leading to an increase in the problem of antibiotic resistance. To tackle this problem, the use of probiotics, also known as direct in-feed microbials (DFM), seems to be one of the most promising strategies. Among probiotics, the interest in Bacillus strains has been intensively increased in recent decades in pigs and poultry. The aim of the present review was to evaluate the effectiveness of Bacillus strains as probiotics and as a potential strategy for reducing the misuse of antibiotics in monogastric animals. Thus, the potential modes of action, and the effects on the performance and health of pigs (weaning pigs, lactation and gestation sows) and broilers are discussed. These searches yielded 131 articles (published before January 2021). The present review showed that Bacillus strains could favor growth in terms of the average daily gain (ADG) of post-weaning piglets and broilers, and reduce the incidence of post-weaning diarrhea in pigs by 30% and mortality in broilers by 6-8%. The benefits of Bacillus strains on these parameters showed results comparable to the benefit obtained by the use of antibiotics. Furthermore, the use of Bacillus strains gives promising results in enhancing the local adaptative immune response and in reducing the oxidative stress of broilers. Fewer data were available regarding the effect on sows. Discordant effects have been reported regarding the effect on body weight (BW) and feed intake while a number of studies have supported the hypothesis that feeding probiotics to sows could benefit their reproductive performance, namely the BW and ADG of the litters. Taken all the above-mentioned facts together, this review confirmed the effectiveness of Bacillus strains as probiotics in young pigs and broilers, favoring their health and contributing to a reduction in the misuse of direct in-feed antibiotics. The continuous development and research regarding probiotics will support a decrease in the misuse of antibiotics in livestock production in order to endorse a more sustainable rearing system in the near future.

Current Applications of Absolute Bacterial Quantification in Microbiome Studies and Decision-Making Regarding Different Biological Questions

High throughput sequencing has emerged as one of the most important techniques for characterizing microbial dynamics and revealing bacteria and host interactions. However, data interpretation using this technique is mainly based on relative abundance and ignores total bacteria load. In certain cases, absolute abundance is more important than compositional relative data, and interpretation of microbiota data based solely on relative abundance can be misleading. The available approaches for absolute quantification are highly diverse and challenging, especially for quantification in differing biological situations, such as distinguishing between live and dead cells, quantification of specific taxa, enumeration of low biomass samples, large sample size feasibility, and the detection of various other cellular features. In this review, we first illustrate the importance of integrating absolute abundance into microbiome data interpretation. Second, we briefly discuss the most widely used cell-based and molecular-based bacterial load quantification methods, including fluorescence spectroscopy, flow cytometry, 16S qPCR, 16S qRT-PCR, ddPCR, and reference spike-in. Last, we present a specific decision-making scheme for absolute quantification methods based on different biological questions and some of the latest quantitative methods and procedure modifications.

Evaluation of Dietary Probiotic (Lactobacillus plantarum BG0001) Supplementation on the Growth Performance, Nutrient Digestibility, Blood Profile, Fecal Gas Emission, and Fecal Microbiota in Weaning Pigs

Simple Summary

Since antibiotics are banned in animal feed in many countries, probiotics have received more attention as reliable alternatives. We mainly study the effect of adding Lactobacillus plantarum BG0001 on the performance of weaned piglets for 42 days. The results: weaning pigs fed diet supplementation with L. plantarum BG0001 significantly improved the growth performance and fecal microbiota, and achieved similar effects as antibiotic growth promoters. Therefore, we consider that L. plantarum BG0001 will have a good role in replacing antibiotic growth promoters in swine feed. It can bring potentially huge economic income to the animal husbandry industry.

Abstract

A total of 180, 4-week-old crossbred weaning piglets ((Yorkshire × Landrace) × Duroc; 6.67 ± 1.40 kg) were used in a 42 day experiment to evaluate the effect of dietary probiotics (Lactobacillus plantarum BG0001) on growth performance, nutrient digestibility, blood profile, fecal microbiota, and noxious gas emission. All pigs were randomly allotted to one of four treatment diets in a completely randomized block design. Each treatment had nine replicates with five pigs/pen (mixed sex) Designated dietary treatments were as: (1) basal diet (NC), (2) NC + 0.2% antibiotics (chlortetracycline) (PC), (3) NC + 0.1% L. plantarum BG0001 (Lactobacillus plantarum BG0001) (NC1), (4) NC + 0.2% L. plantarum BG0001 (NC2). On d 42, BW and G:F were lower (p < 0.05) in pigs fed NC diet compared with PC diet and probiotic diets. Throughout this experiment, the average daily gain increased (p < 0.05) in pigs when fed with PC and probiotic diets than the NC diet. The average daily feed intake was higher (p < 0.05) in pigs fed PC diet during day 0–7 and 22–42, and probiotic diets during day 0–7 compared with NC diet, respectively. The Lactobacillus count was increased and Escherichia coli count was decreased (p < 0.05) in the fecal microbiota of pigs fed probiotic diets, and E. coli were decreased (p < 0.05) when fed a PC diet compared with the NC diet on day 21. Moreover, the apparent total tract nutrient digestibility, blood profile, and the concentration of noxious gas emission had no negative effects by the probiotic treatments. In conclusion, dietary supplementation with L. plantarum BG0001 significantly improved the growth performance, increased fecal Lactobacillus, and decreased E. coli counts in weaning pigs.

Comprehensive Cultivation of the Swine Gut Microbiome Reveals High Bacterial Diversity and Guides Bacterial Isolation in Pigs

Despite the substantial progress made in human gut culturomics, little is known about the culturability of the swine gut microbiota. In this study, we cultured swine gut microbiota using 53 bacterial cultivation methods with different medium and gas combinations from three pigs at four different growth stages. Both culture-dependent (CD; colony mixtures from each method) and culture-independent (CI; original fecal suspensions) samples were subjected to 16S rRNA gene amplicon sequencing. Increasing microbial diversities were observed in both CI and CD samples from successive growth stages. While a total of 378, 482, 565, and 555 bacterial amplicon sequence variants (ASVs) were observed in the CI samples, higher microbial diversities (415, 675, 808, and 823 observed ASVs) were detected using the CD methods at the lactation, nursery, growing, and finishing stages, respectively. We constructed reference culture maps showing the preferred cultivation conditions for specific bacterial taxa and examined the effects of culturing factors such as oxygen, medium, donor pig age, antibiotics, and blood culture preincubation on swine gut microbiota cultivation. We focused on a wide range of beneficial bacteria, chose 1,299 colonies based on the reference map, and Sanger sequenced their 16S rRNA genes. These isolates clustered into 148 different bacterial taxa covering 28 genera. We observed 11, 19, 33, and 25 pairs of cooccurring ASVs in both CD and CI samples at four successive growth stages. This study provides guidance in culturing the swine gut microbiota of interest, which is critical when characterizing their functions in this important animal species.

IMPORTANCE The swine gut microbiome has been the focus of many investigations due to the fact that pigs serve as both an excellent biomedical model for human diseases and an important protein source. Substantial progress has been made in swine gut microbiome studies using next-generation sequencing-based culture-independent approaches, but little is known about the culturability of the swine gut microbiota. To understand their roles in swine production, it is critical to culture bacterial strains of interest. In this study, we cultured the gut microbiota from pigs at different growth stages using 53 bacterial cultivation methods with different medium and gas combinations. This study provides evidence that the swine gut microbiota is much more diverse based on a culture-dependent approach than previously known. It provides preliminary guidance for isolating certain bacteria of interest from pigs, which is critical in establishing causal relationships between the gut microbiota and the health status of pigs.

Weaning Induced Gut Dysfunction and Nutritional Interventions in Nursery Pigs: A Partial Review

Weaning is one of the most stressful events in the life of a pig. Unsuccessful weaning often leads to intestinal and immune system dysfunctions, resulting in poor growth performance as well as increased morbidity and mortality. The gut microbiota community is a complex ecosystem and is considered an "organ," producing various metabolites with many beneficial functions. In this review, we briefly introduce weaning-associated gut microbiota dysbiosis. Then, we explain the importance of maintaining a balanced gut microbiota. Finally, we discuss dietary supplements and their abilities to restore intestinal balance and improve the growth performance of weaning pigs.