Inclusion of Lactobacillus salivarius strain revealed a positive effect on improving growth performance, fecal microbiota and immunological responses in chicken

Dietary eubiotics of microbial muramidase and glycan improve intestinal villi, ileum microbiota composition and production trait of broiler

BACKGROUND

Optimal gut health is important to maximize growth performance and feed efficiency in broiler chickens. A total of 1,365 one-day-old male Ross 308 broiler chickens were randomly divided into 5 treatments groups with 21 replicates, 13 birds per replicate. The present research investigated effects of microbial muramidase or a precision glycan alone or in combination on growth performance, apparent total tract digestibility, total blood carotenoid content, intestinal villus length, meat quality and gut microbiota in broiler chickens. Treatments included: NC: negative control (basal diet group); PC: positive control (basal diet + 0.02% probiotics); MR: basal diet + 0.035% microbial muramidase; PG: basal diet + 0.1% precision glycan; and MRPG: basal diet + 0.025% MR + 0.1% PG, respectively.

RESULTS

MRPG group increased the body weight gain and feed intake (P < 0.05) compared with NC group. Moreover, it significantly increased total serum carotenoid (P < 0.05) and MRPG altered the microbial diversity in ileum contents. The MRPG treatment group increased the abundance of the phylum Firmicutes, and family Lachnospiraceae, Ruminococcaceae, Oscillospiraceae, Lactobacillaceae, Peptostreptococcaceae and decreased the abundance of the phylum Campilobacterota, Bacteroidota and family Bacteroidaceae. Compared with the NC group, the chickens fed MRPG showed significantly increased in duodenum villus length at end the trial.

CONCLUSION

In this study, overall results showed that the synergetic effects of MR and PG showed enhancing growth performance, total serum carotenoid level and altering gut microbiota composition of broilers. The current research indicates that co-supplementation of MR and PG in broiler diets enhances intestinal health, consequently leading to an increased broiler production.

Effect of Lactobacillus salivarius SNK-6 on egg quality, intestinal morphology, and cecal microbial community of laying hens

The objective of this study was to investigate the effect of Lactobacillus salivarius (L. salivarius) SNK-6 supple-mentation on the laying performance, egg quality, blood parameters, intestinal morphology, and cecal microbial community of laying hens. A total of 432 healthy 30-wk-age laying hens were randomly divided into 3 groups with 6 replicates under the same husbandry and dietary regimes: control (CON); 2.0 × 108 CFU/kg L. salivarius supplementation (T1); 2.0 × 109 CFU/kg L. salivarius supplementation (T2). The experiment lasted for 10 wk. The results indicated that the supplementation resulted in a significant reduction in the broken egg and unqualified egg ratios, and a significant increase in the eggshell strength, eggshell relative weight, albumen height, and Haugh units (P < 0.05). The L. salivarius-treated hens exhibited significantly reduced serum malondialdehyde levels (P < 0.05); significantly increased total protein, phosphorus, calcitonin, and immunoglobulin M (P < 0.05); significantly increased cecal secretory immunoglobulin A concentration (P < 0.05); significantly improved villus height (VH) in the duodenum and VH to crypt depth ratio in the jejunum (P < 0.05). The serum globulin and interleukin-1β, immunoglobulin G concentrations, and catalase activity significantly increased in T2 (P < 0.05). Furthermore, the serum interferon-α level in T1 was significantly higher than that of the CON (P < 0.05). The intestinal barrier-related mRNA gene ZO-1, CLDN1, and MUC2 expression in the jejunum was significantly upregulated in the T1 and T2 groups (P < 0.05). The Firmicutes/Bacteroidetes ratio was higher and the relative abundances of Flavonifractor and Clostridiales_noname were significantly higher in the T1 group (P < 0.05). In conclusion, dietary supplementation with L. salivarius SNK-6 may improve hen egg quality, serum antioxidant capacity, immune function, and intestinal health.

Host genetic background rather than diet-induced gut microbiota shifts of sympatric black-necked crane, common crane and bar-headed goose

Introduction

Gut microbiota of wild birds are affected by many factors, and host genetic background and diet are considered to be two important factors affecting their structure and function.

Methods

In order to clarify how these two factors influence the gut microbiota, this study selected the sympatric and closely related and similar-sized Black-necked Crane (Grus nigricollis) and Common Crane (Grus grus), as well as the distantly related and significantly different-sized Bar-headed Goose (Anser indicus). The fecal samples identified using sanger sequencing as the above three bird species were subjected to high-throughput sequencing of rbcL gene and 16S rRNA gene to identify the feeding types phytophagous food and gut microbiota.

Results

The results showed significant differences in food diversity between black-necked cranes and Common Cranes, but no significant differences in gut microbiota, Potatoes accounted for approximately 50% of their diets. Bar-headed Geese mainly feed on medicinal plants such as Angelica sinensis, Alternanthera philoxeroides, and Ranunculus repens. Black-necked cranes and Common Cranes, which have a high-starch diet, have a similar degree of enrichment in metabolism and synthesis functions, which is significantly different from Bar-headed Geese with a high-fiber diet. The differences in metabolic pathways among the three bird species are driven by food. The feeding of medicinal plants promotes the health of Bar-headed Geese, indicating that food influences the functional pathways of gut microbiota. Spearman analysis showed that there were few gut microbiota related to food, but almost all metabolic pathways were related to food.

Conclusion

The host genetic background is the dominant factor determining the composition of the microbiota. Monitoring the changes in gut microbiota and feeding types of wild birds through bird feces is of great reference value for the conservation of other endangered species.

Yijung-tang improves thermogenesis and reduces inflammation associated with gut microbiota in hypothyroid rats

Currently, considerable attention is focused on exploring the potential relationship between herbal medicine (HM) and the gut microbiome in terms of thermoregulation, which is an important aspect of human health, in modern system biology. However, our knowledge of the mechanisms of HM in thermoregulation is inadequate. Here, we demonstrate that the canonical herbal formula, Yijung-tang (YJT), protects against hypothermia, hyperinflammation, and intestinal microbiota dysbiosis in PTU-induced hypothyroid rats. Notably, these properties were associated with alterations in the gut microbiota and signaling crosstalk between the thermoregulatory and inflammatory mediators in the small intestine and brown adipose tissue (BAT). In contrast to the conventional drug L-thyroxine for curing hypothyroidism, YJT has an efficacy for attenuating systematic inflammatory responses, related with depression in intestinal TLR4 and Nod2/Pglyrp1 signaling pathways. Our findings suggest that YJT could promote BAT thermogenesis and prevent systemic inflammation in PTU-induced hypothyroid rats, which was associated with its prebiotic effect on modulating of the gut microbiota and gene expression with relevance in the enteroendocrine function and innate immune systems. These findings may strengthen the rationale of the microbiota-gut-BAT axis for a paradigm shift to enable holobiont-centric medicine.

Mortality, growth, and egg production do not differ between nontransgenic and transgenic female chickens with ubiquitous expression of the 3D8 single chain variable fragment gene

To date, many transgenic (TG) chicken lines have been developed, but few studies have performed a comparative analysis of their mortality, growth, and egg productivity. Previously, we reported the production of 3D8 scFv TG chickens showing antiviral activity. Here, we performed a biometric characterization of TG offspring female chickens. We selected 40 TG and 40 non-TG offspring female chicks among newly hatched chicks produced via artificial insemination of semen from heterotypic 3D8 scFv males into wild-type female chickens. Serum was collected at 14 wk of age, and serum concentrations of biochemical parameters, cytokines, and sex hormones were analyzed. Mortality and growth were monitored daily from 1 to 34 wk, egg productivity was monitored daily from 20 to 34 wk, and the weekly average values were used for analyses. Some serum parameters and cytokines were significantly different between non-TG and TG offspring female chickens. The levels of phosphorus (PHOS), total protein (TP), albumin (ALB), globulin (GLOB), and alanine aminotransferase (ALT) were significantly higher in non-TG chickens (P < 0.05). The levels of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) were significantly higher in TG chickens (P < 0.05). The levels of insulin growth factor-1 (IGF-1), interferon-gamma (INF-γ), interleukin-4 (IL-4), and IL-8 were significantly lower in TG chickens (P < 0.05). Despite these differences, the mortality rates, body weight, egg production rates, and egg weight were not significantly different in the experimental groups of non-TG and TG offspring female chickens (P > 0.05). In conclusion, ubiquitous expression of the 3D8 scFv gene in TG offspring female chickens does not affect some biometric characteristics, including mortality, growth, and egg productivity.

Effects of tannic acid on the immunity and intestinal health of broiler chickens with necrotic enteritis infection

BACKGROUND

In broiler chickens, necrotic enteritis (NE) infection can reduce production performance. Tannic acid has shown great potential as a treatment of NE in broilers. However, the appropriate dosage of tannic acid in NE of broilers and the improvement effect on intestinal health are not very clear. In this study, we aimed to investigate the effects of different doses of tannic acid on the production performance, immunity, and intestinal health of broilers by constructing an NE model with C. perfringens infection and determining the appropriate dosage of tannic acid with regard to NE.

RESULTS

Challenged birds showed significant reduction in body weight, villus height, and the ratio of villus height to crypt depth (P < 0.05) and increase in the feed consumption gain ratio, intestinal lesion score, and crypt depth (P < 0.05). The infection significantly reduced the relative Bacteroidota and Ligilactobacillus abundance (P < 0.05) and increased the ratio of Firmicutes/Bacteroidota and cecal content of C. perfringens (P < 0.05). Challenged birds fed diets supplemented with tannic acid showed significantly increased mRNA expression of nutrient transport carriers and intestinal barrier genes and growth performance and reduced serum zonulin and endotoxin levels (P < 0.05). Addition of tannic acid to the diet inhibited the inflammatory response by reducing the number of coccidia oocysts in feces and the content of C. perfringens in the cecum. Specifically, tannic acid reduced the serum levels of C reactive protein, myeloperoxidase, and specific IgY and ileal mucosal secretory immunoglobulin A levels in the ileal mucosa compared with those in the NE-infected birds. NE-infected birds fed diets supplemented with tannic acid also showed significantly increased relative Anaerocolumna, Thermoanaerobacterium, and Thermosinus abundance (P < 0.05); their microbial composition and functional predictions were similar to those of the NC group.

CONCLUSIONS

Tannic acid in the diet alleviated NE by enhancing the intestinal barrier and absorption function. The recommended dietary tannic acid additive level is 500-750 mg/kg. Our study findings would be useful in reducing related economic losses in the broiler industry.

Restorative effects of Lactobacillus rhamnosus LR-32 on the gut microbiota, barrier integrity, and 5-HT metabolism in reducing feather-pecking behavior in laying hens with antibiotic-induced dysbiosis

The development of abnormal feather-pecking (FP) behavior, where laying hens display harmful pecks in conspecifics, is multifactorial and has been linked to the microbiota-gut-brain axis. Antibiotics affect the gut microbial composition, leading to gut-brain axis imbalance and behavior and physiology changes in many species. However, it is not clear whether intestinal dysbacteriosis can induce the development of damaging behavior, such as FP. The restorative effects of Lactobacillus rhamnosus LR-32 against intestinal dysbacteriosis-induced alternations need to be determined either. The current investigation aimed to induce intestinal dysbacteriosis in laying hens by supplementing their diet with the antibiotic lincomycin hydrochloride. The study revealed that antibiotic exposure resulted in decreased egg production performance and an increased tendency toward severe feather-pecking (SFP) behavior in laying hens. Moreover, intestinal and blood-brain barrier functions were impaired, and 5-HT metabolism was inhibited. However, treatment with Lactobacillus rhamnosus LR-32 following antibiotic exposure significantly alleviated the decline in egg production performance and reduced SFP behavior. Lactobacillus rhamnosus LR-32 supplementation restored the profile of the gut microbial community, and showed a strong positive effect by increasing the expression of tight junction proteins in the ileum and hypothalamus and promoting the expression of genes related to central 5-HT metabolism. The correlation analysis revealed that probiotic-enhanced bacteria were positively correlated, and probiotic-reduced bacteria were negatively correlated with tight junction-related gene expression, and 5-HT metabolism, and butyric acid levels. Overall, our findings indicate that dietary supplementation with Lactobacillus rhamnosus LR-32 can reduce antibiotic-induced FP in laying hens and is a promising treatment to improve the welfare of domestic birds.

Lactobacillus salivarius CML352 Isolated from Chinese Local Breed Chicken Modulates the Gut Microbiota and Improves Intestinal Health and Egg Quality in Late-Phase Laying Hens

Lactobacillus strains with fine probiotic properties are continuously needed in the laying hen industry to improve the animals’ gut health and production performance. In this study, we isolated 57 Lactobacillus strains from the gut microbiota of 17 different chicken breeds in China. We characterized the probiotic features of these isolates, and evaluated the effects of a selected strain, Lactobacillus salivarius CML352, on the production performance and gut health of the late-phase laying hens. The results showed that the isolates varied much in probiotic properties, among which L. salivarius CML352 displayed high acid and bile salt tolerance, high hydrophobicity, auto-aggregation, and antibacterial activities. Whole genome sequencing analysis showed that CML352 was closely related to a strain isolated from human fecal samples, but had different functional potentials. Dietary supplementary of L. salivarius CML352 significantly reduced the Firmicutes to Bacteroidetes ratio, increased the expression of Muc-2, and decreased the expression of MyD88, IFN-γ, and TLR-4. Furthermore, strain CML352 reduced the birds’ abdominal fat deposition, and improved egg quality. Taken together, this study indicated that the newly isolated L. salivarius strain might be a worthy probiotic with positive impacts on the intestinal health and production performance of late-phase laying hens.

Protective Effects of Novel Lactobacillaceae Strains Isolated from Chicken Caeca against Necrotic Enteritis Infection: In Vitro and In Vivo Evidences

The present study aimed to show the benefits of novel lactic acid bacteria (LAB) strains isolated from the caeca of healthy chickens. These novel strains, identified as Limosilactobacillus reuteri and Ligilactobacillus salivarius, displayed high levels of lactic acid production, capability of biofilm formation, high aggregation and adhesion scores, and significant survival rates under conditions mimicking the chicken gastrointestinal tract (GIT). In addition, these novel Lactobacillaceae isolates were neither hemolytic nor cytotoxic. In vivo trials were able to establish their ability to reduce necrotic enteritis. Notably, a significant weight gain was registered, on day 10 of treatment, in the group of chickens fed with a mixture of L. reuteri ICVB416 and L. salivarius ICVB430 strains, as compared with the control group. This group has also shown a reduced number of lesions in the gut compared with other infected chicken groups. This study provides in vitro and in vivo evidence supporting the benefits of these novel Lactobacillaceae isolates for their use in poultry livestock as protective cultures to control the bacterial necrotic enteritis (NE) Clostridium perfringens.

First Report of Fecal Microflora of Wild Bar-Headed Goose in Tibet Plateau

The bar-headed goose (Anser indicus) has two black spots on its head. It is considered an important bird in China. It breeds in plateau lakes, especially saltwater lakes, and swamp areas. However, the intestinal flora of wild bar-headed geese in the Tibet Autonomous Region is currently not known. In this study, 16S rDNA sequencing was performed on the intestinal microbes of wild bar-headed geese. A total of 513,505 reads of raw data were obtained, and the results analyzed the average number of 128,376 ± 2,392 reads per sample. The microbiota of all samples consists of 10 main bacterial phyla, including Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Patescibacteria, Deferribacteres, Planctomy-cetes, Fusobacteria, and Tenericutes. The results indicated that Firmicutes (67.34%) was the predominant phylum, followed by Proteobacteria (29.03%) and Cyanobacteria (1.97%). In our research, we identified the intestinal flora of the wild bar-headed goose, which provides valuable information for further research on the gene function of the bar-headed goose and the intestinal flora of wild animals. These findings are also useful and valuable for genetic and high-altitude research in the Tibet Autonomous Region.

Lactobacillus salivarius and Lactobacillus agilis feeding regulates intestinal stem cells activity by modulating crypt niche in hens

Previously, we found that Lactobacillus salivarius, Lactobacillus agilis, and Lactobacillus aviarius were associated with excellent egg nutrition in native chicken. Next, the optimal Lactobacillus combination is worth studying. Here, a total of 120 HyLine hens (30 hens per group contained 3 replicate cells, 10 hens/cell) in the laying peak period were randomly divided into (1) control, (2) L. salivarius + L. agilis, (3) L. salivarius + L. aviarius, and (4) L. agilis + L. aviarius groups, fed with diet only or with corresponding Lactobacilli (10⁸ colony-forming units/hen/day) for 30 days. As a result, L. salivarius + L. agilis feeding could (1) improve egg-laying rate, egg weight, and albumen's amino acid levels; (2) increase Lactobacillus abundance, decrease Escherichia coli abundance, upregulate the tryptophan metabolism pathway-related molecules, and downregulate the primary bile acid biosynthesis pathway-related molecules in intestinal contents; and (3) upregulate oxidative-phosphorylation pathway-related genes, reactive oxygen species levels, and mRNA abundance of Wnt3a, Dll1, Lgr5, CCDN1, and CDK2 in the crypt. Collectively, L. salivarius + L. agilis feeding in hens could improve intestinal microflora and metabolism profile, promote crypt's local energy metabolism and reactive oxygen species levels, and thus enhance Paneth cells and intestinal stem cells activity.Key points• Lactobacilli co-feeding could improve laying performance and egg nutrition.• Lactobacilli co-feeding could improve intestinal microflora and metabolism profile.• Lactobacilli co-feeding could enhance Paneth cells and intestinal stem cells activity.

Lactic Acid Bacteria - A Promising Tool for Controlling Chicken Campylobacter Infection

Since 2005, campylobacteriosis has been the most common zoonotic disease in Europe. The main reservoir of pathogenic Campylobacter strains is broilers, which makes raw and undercooked poultry meat two major sources of disease. Infection in chicken flocks is most often asymptomatic, despite a high level of colonization reaching 106-109cfu/g in animal ceca. It is widely believed that controlling the level of colonization of the birds' digestive tract by pathogenic strains is a good way to increase food safety. Many treatments have been proposed to combat or at least reduce the level of colonization in animals reservoirs: probiotics, bacteriophages, vaccines, and anti-Campylobacter bacteriocins. This review focuses on the effects of Campylobacter infection on the chicken microbiome and colonization control strategies using probiotics (mostly lactic acid bacteria, LAB), which are live microorganisms included in the diet of animals as feed additives or supplements. Probiotics are not only an alternative to antibiotics, which were used for years as animal growth promoters, but they also constitute an effective protective barrier against excessive colonization of the digestive system by pathogenic bacteria, including Campylobacter. Moreover, one of the many beneficial functions of probiotics is the ability to manipulate the host's microbiota. Recently, there have also been some promising attempts to use lactic acid bacteria as a delivery system of oral vaccine against Campylobacter. Recombinant LAB strains induce primarily a mucosal immune response against foreign antigens, accompanied by at most a low-level immune response against carrier strains. Since the main barrier against the invasion of pathogens in the gastrointestinal tract is the intestinal mucosal membrane, the development of effective oral vaccines to protect animals against enteric infection is very reasonable.

Supplemental magnolol or honokiol attenuates adverse effects in broilers infected with Salmonella pullorum by modulating mucosal gene expression and the gut microbiota

BACKGROUND

Salmonella pullorum is one of the most harmful pathogens to avian species. Magnolol and honokiol, natural compounds extracted from Magnolia officinalis, exerts anti-inflammatory, anti-oxidant and antibacterial activities. This study was conducted to evaluate the effects of dietary supplemental magnolol and honokiol in broilers infected with S. pullorum. A total of 360 one-day-old broilers were selected and randomly divided into four groups with six replicates: the negative control group (CTL), S. pullorum-infected group (SP), and the S. pullorum-infected group supplemented with 300 mg/kg honokiol (SPH) or magnolol (SPM).

RESULTS

The results showed that challenging with S. pullorum impaired growth performance in broilers, as indicated by the observed decreases in body weight (P < 0.05) and average daily gains (P < 0.05), along with increased spleen (P < 0.01) and bursa of Fabricus weights (P < 0.05), serum globulin contents, and the decreased intestine villus height and villus/crypt ratios (P < 0.05). Notably, supplemental magnolol and honokiol attenuated these adverse changes, and the effects of magnolol were better than those of honokiol. Therefore, we performed RNA-Seq in ileum tissues and 16S rRNA gene sequencing of ileum bacteria. Our analysis revealed that magnolol increased the α-diversity (observed species, Chao1, ACE, and PD whole tree) and β-diversity of the ileum bacteria (P < 0.05). In addition, magnolol supplementation increased the abundance of Lactobacillus (P < 0.01) and decreased unidentified Cyanobacteria (P < 0.05) both at d 14 and d 21. Further study confirmed that differentially expressed genes induced by magnolol and honokiol supplementation enriched in cytokine-cytokine receptor interactions, in the intestinal immune network for IgA production, and in the cell adhesion molecule pathways.

CONCLUSIONS

Supplemental magnolol and honokiol alleviated S. pullorum-induced impairments in growth performance, and the effect of magnolol was better than that of honokiol, which could be partially due to magnolol's ability to improve the intestinal microbial and mucosal barrier.