Performance and intestinal coliform counts in weaned piglets fed a probiotic culture (Lactobacillus casei subsp. casei CECT 4043) or an antibiotic

bulgaricus, as a Substitute for Antibiotics on the Gastrointestinal Tract Microbiota and Metabolomics Profile of Female Growing-Finishing Pigs

Lactobacillus delbrueckii subsp. bulgaricus (LDB) is an approved feed additive on the Chinese ‘Approved Feed Additives’ list. However, the possibility of LDB as an antibiotic replacement remains unclear. Particularly, the effect of LDB on microbiota and metabolites in the gastrointestinal tract (GIT) requires further explanation. This study aimed to identify the microbiota and metabolites present in fecal samples and investigate the relationship between the microbiota and metabolites to evaluate the potential of LDB as an antibiotic replacement in pig production. A total of 42 female growing-finishing pigs were randomly allocated into the antibiotic group (basal diet + 75 mg/kg aureomycin) and LDB (basal diet + 3.0 × 109 cfu/kg LDB) groups. Fecal samples were collected on days 0 and 30. Growth performance was recorded and assessed. 16S rRNA sequencing and liquid chromatography-mass spectrometry-based non-targeted metabolomics approaches were used to analyze the differences in microbiota and metabolites. Associations between the differences were calculated using Spearman correlations with the Benjamini−Hochberg adjustment. The LDB diet had no adverse effect on feed efficiency but slightly enhanced the average daily weight gain and average daily feed intake (p > 0.05). The diet supplemented with LDB increased Lactobacillus abundance and decreased that of Prevotellaceae_NK3B31_group spp. Dietary-supplemented LDB enhanced the concentrations of pyridoxine, tyramine, D-(+)-pyroglutamic acid, hypoxanthine, putrescine and 5-hydroxyindole-3-acetic acid and decreased the lithocholic acid concentration. The Lactobacillus networks (Lactobacillus, Peptococcus, Ruminococcaceae_UCG-004, Escherichia-Shigella, acetophenone, tyramine, putrescine, N-methylisopelletierine, N1-acetylspermine) and Prevotellaceae_NK3B31_group networks (Prevotellaceae_NK3B31_group, Treponema_2, monolaurin, penciclovir, N-(5-acetamidopentyl)acetamide, glycerol 3-phosphate) were the most important in the LDB effect on pig GIT health in our study. These findings indicate that LDB may regulate GIT function through the Lactobacillus and Prevotellaceae_NK3B31_group networks. However, our results were restrained to fecal samples of female growing-finishing pigs; gender, growth stages, breeds and other factors should be considered to comprehensively assess LDB as an antibiotic replacement in pig production.

Probiotic bacteria maintain normal growth mechanisms of heat stressed broiler chickens

Probiotics have growth promoting effects even under periods of heat stress challenge. More information is needed to understand the mechanisms by which probiotics maintain the growth performance. The aim of this study was to evaluate the effect of a probiotic based on Bacillus subtilis bacteria on growth related mechanisms of broilers under heat stress conditions. Specifically, growth performance, skeletal bone characteristics, skeletal muscles size, intestinal villus-crypt structure, intestinal bacteria, growth hormone (GH), insulin-like growth factor-1 (IGF-1), cholesterol, and glucose. A total of 1200 one day old Ross 308 male broilers were randomly distributed into 4 treatments, with 12 replicates per treatment and 25 birds per replicate. A 2 × 2 factorial arrangement was used; the main factors were environmental temperature (thermoneutral or heat stress) and diet (control or control + B. subtilis; 3 × 10⁷ cfu/kg of feed). From d 22 to 35 of age, birds were either exposed to thermoneutral conditions (21 °C) or chronic heat stress (30 °C). During the same period, each group was divided into 2 subgroups and fed either the control diet or the B. subtilis supplemented diet. The results demonstrated that B. subtilis had positive effects (P < 0.05) on the body weight gain, feed conversion ratio, villus height, crypt depth, villus surface area, absorptive epithelial cell area and viable counts of intestinal beneficial bacteria. B. subtilis increased (P < 0.05) serum GH, IGF-1 and maintain normal levels of cholesterol and glucose under heat stress conditions. In addition, broilers fed B. subtilis under heat stress conditions exhibited higher (P < 0.05) skeletal muscles size and improved (P < 0.05) tibia traits and lower (P < 0.05) abdominal fat pads deposition compared with the controls. B. subtilis had no effect on rectal temperature under thermoneutral or heat stress conditions. It is concluded that B. subtilis can be used as growth promoters in broilers, particularly during the periods of heat stress conditions.

Production of a highly concentrated probiotic culture of Lactococcus lactis CECT 539 containing high amounts of nisin

In this study, probiotic biomass and nisin productions by Lactococcus lactis CECT 539 were followed in two realkalized fed-batch cultures in diluted whey (DW) supplemented with KH₂PO₄ up to a total phosphorus concentration of 0.459 g/L. Increased biomass (5.12 g/L, 2.18 × 10¹⁰ CFU/mL) and nisin (235.23 BU/mL) concentrations were obtained in the culture fed concentrated whey and concentrated mussel processing waste (CMPW) medium supplemented with glucose up to a concentration of 400 g/L (CMPW + G medium) compared with similar fed-batch fermentations in DW medium. In the second fed-batch fermentation, the feeding medium CMPW + G was supplemented with KH₂PO₄ up to a TP concentration of 3.21 g/L. With this approach, increased production of biomass (5.49 g/L, 2.33 × 10¹⁰ CFU/mL) and nisin (257.59 BU/mL) was obtained. Considering the substantial availability of these wastes at very low prices from local dairy and mussel processing plants in Galicia, their use as culture media could offer an attractive alternative for a low-cost production of probiotic biomass and nisin at a high scale.

Weight gain by gut microbiota manipulation in productive animals

Antibiotics, prebiotics and probiotics are widely used as growth promoters in agriculture. In the 1940s, use of Streptomyces aureofaciens probiotics resulted in weight gain in animals, which led to the discovery of chlortetracycline. Tetracyclines, macrolides, avoparcin and penicillins have been commonly used in livestock agriculture to promote growth through increased food intake, weight gain, and improved herd health. Prebiotic supplements including oligosaccharides, fructooligosaccharides, and galactosyl-lactose improve the growth performance of animals. Probiotics used in animal feed are mainly bacterial strains of Gram-positive bacteria and have been effectively used for weight gain in chickens, pigs, ruminants and in aquaculture. Antibiotics, prebiotics and probiotics all modify the gut microbiota and the effect of a probiotic species on the digestive flora is probably determined by bacteriocin production. Regulations governing the introduction of novel probiotics and prebiotics vary by geographical region and bias is very common in industry-funded studies. Probiotic and prebiotic foods have been consumed for centuries, either as natural components of food, or as fermented foods and it is possible to cause the same weight gain effects in humans as in animals. This review presents the use of growth promoters in food-producing animals to influence food intake and weight gain.

Efforts to slacken antibiotic resistance: Labeling meat products from animals raised without antibiotics in the United States

As bacteria and diseases spread due to climatic change, greater amounts of antibiotics will be used thereby exacerbating the problem of antibiotic resistance. To help slacken the development of resistant bacteria, the medical community is attempting to reduce unnecessary and excessive usage of antibiotics. One of the targets is the use of antibiotics for enhancing animal growth and promoting feed efficiency in the production of food animals. While governments can adopt regulations prohibiting nontherapeutic uses of antibiotics in food animals and strategies to reduce antibiotic usage, another idea is to publicize when antibiotics are used in food animal production by allowing labeled meat products. This paper builds upon existing labeling and marketing efforts in the United States to show how a government can develop a verified antibiotic-free labeling program that would allow consumers to purchase meat products from animals that had never received antibiotics.

Stabilized rice bran improves weaning pig performance via a prebiotic mechanism

Stabilized rice bran (SRB) is classified as a "functional food" because of its prebiotic characteristics. With increasing grain prices and the pressure to remove antibiotics from swine diets because of concern over antibiotic resistance, SRB was investigated as a nursery diet ingredient with and without the addition of antibiotics (ANT). Two hundred pigs were weaned at 21 d of age, blocked by BW, and allotted to diets containing 0 or 10% SRB ± ANT according to a 2 × 2 factorial arrangement of treatments. Five animals were housed per pen throughout a 28-d growth period. At the end of the trial, 1 pig from each pen was euthanized for measurement of intestinal morphology. Antibiotic supplementation improved ADG by 6.4% during Phase 2 (d 14 to 28; P = 0.02), but other production variables were unaffected by ANT. During Phase 2 and cumulatively (d 0 to 28), the supplementation of SRB improved G:F by 10% in ANT-free pigs but not in pigs fed ANT (ANT × SRB, P < 0.03). Ileal histology revealed an increase in crypt depth of pigs fed the diet containing ANT plus SRB and corresponding decreases in villi:crypt associated with both ANT and SRB supplementation (P < 0.05). Intraepithelial lymphocytes were increased by 15% in pigs fed SRB without ANT, but were unaffected by SRB in pigs fed ANT (ANT x SRB, P = 0.003). Colonic bifidobacteria tended to increase with SRB supplementation (P < 0.10). Differences in ileal and cecal digesta short-chain fatty acid concentrations were not detected. In summary, SRB improved the efficiency of nutrient utilization in nursery diets lacking antibiotics and tended to increase intestinal bifidobacteria concentrations, indicating that SRB may exert beneficial prebiotic effects in weanling pigs.

The increase of Lactobacillus species in the gut flora of newborn broiler chicks and ducks is associated with weight gain

BACKGROUND

A bacterial role in the obesity pandemic has been suspected based on the ingestion of probiotics that can modify the gut flora. The objective of our study was to determine if increased Lactobacillus sp. in the gut flora of newborn broiler chicks and ducks could result in weight gain increase.

METHODOLOGY

Female broiler chicks (Gallus gallus domesticus) and ducks (Anas platyrhynchos domestica) were separated into one control and two experimental groups, and inoculated once or twice with 4x10(10)Lactobacillus spp. per animal in PBS, or with PBS alone. Fecal samples were collected before and at 24 hours, 2, 4, 8, 16 and 30 days after the inoculation. DNA was extracted from the stools, and qPCR assays were performed on a MX3000 system for the detection and quantification of Lactobacillus sp., Bacteroidetes and Firmicutes, using a quantification plasmid. Animals were measured and sacrificed 60 days after the beginning of the experiment, and livers were collected and measured.

PRINCIPAL FINDINGS

Chicks inoculated once and twice with Lactobacillus weighed 10.2% (p = 0.0162) and 13.5% (p = 0.0064) more than the control group animals, respectively. Similarly, ducks inoculated once and twice weighed 7.7% (p = 0.05) and 14% (p = 0.035) more than those in the control group, respectively. Liver mass was also significantly higher in inoculated animals compared to the control group. Inoculation with Lactobacillus sp. increased the DNA copies of Lactobacillus spp. and Firmicutes in the stools. Bacteroidetes remained stable, and only the second Lactobacillus sp. inoculation significantly decreased its population in chicks. The ratio of DNA copies of Firmicutes to those of Bacteroidetes increased to as much as 6,4 in chicks and 8,3 in ducks.

CONCLUSIONS

Differences in the intestinal microbiota may precede weight increase, as we found that an increase of Lactobacillus sp. in newborn ducks and chicks preceded the development of weight gain.