Effects of Early Intervention with Sodium Butyrate on Gut Microbiota and the Expression of Inflammatory Cytokines in Neonatal Piglets

Associations between gut microbiota and osteoporosis or osteopenia in a cohort of Chinese Han youth

Osteoporosis (OP) is a common metabolic bone disease characterized by low bone mass and microstructural deterioration of bone. Changes in the composition and structure of gut microbiota (GM) are related to changes of bone mass and bone microstructure. However, the relationship between GM and bone mineral density (BMD) is complex, and data are especially scarce for Chinese Han youth. Therefore, 62 Chinese Han youth participants were recruited. Furthermore, according to the T-score evaluation criteria of the World Health Organization (WHO), we divided the BMD levels of participants into three groups: osteoporosis\BDL, osteopenia\BDM, normal bone density\BDH, and the associations between GM community and BMD groups were conducted. According to alpha and beta diversity analysis, significant differences were found in the microbial richness and composition between groups. The dominant phyla of GM in a cohort of Chinese Han youth were Bacteroidota (50.6%) and Firmicutes (41.6%). Anaerobic microorganisms, such as g_Faecalibacterium and g_Megamonas, account for the largest proportion in the gut, which were mainly Firmicutes phylum. The dominant genera and species in the three BMD groups were g_Prevotella, g_Bacteroides, g_Faecalibacterium, g_Megamonas, s_Prevotella copri, s_unclassified_g_Faecalibacterium, s_unclassified_g_Prevotella, s_unclassified_g_Bacteroides and s_Bacteroides plebeius. g_Faecalibacterium, g_Bacteroides and g_Ruminococcus differed between the BDH and BDL groups as well as between the BDH and BDM groups. LEfSe showed three genus communities and eight species communities were enriched in the three BMD groups, respectively. The associations between microbial relative abundance and T-score was not statistically significant by Spearman and regression analysis. In conclusion, the alpha diversity indexes in the BDH group were higher than in the BDL group, and several taxa were identified that may be the targets for diagnosis and therapy of OP.

Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets

Weaning is a critical transitional point in the life cycle of piglets. Early weaning can lead to post-weaning syndrome, destroy the intestinal barrier function and microbiota homeostasis, cause diarrhea and threaten the health of piglets. The nutritional components of milk and solid foods consumed by newborn animals can affect the diversity and structure of their intestinal microbiota, and regulate post-weaning diarrhea in piglets. Therefore, this paper reviews the effects and mechanisms of different nutrients, including protein, dietary fiber, dietary fatty acids and dietary electrolyte balance, on diarrhea and health of piglets by regulating intestinal function. Protein is an essential nutrient for the growth of piglets; however, excessive intake will cause many harmful effects, such as allergic reactions, intestinal barrier dysfunction and pathogenic growth, eventually aggravating piglet diarrhea. Dietary fiber is a nutrient that alleviates post-weaning diarrhea in piglets, which is related to its promotion of intestinal epithelial integrity, microbial homeostasis and the production of short-chain fatty acids. In addition, dietary fatty acids and dietary electrolyte balance can also facilitate the growth, function and health of piglets by regulating intestinal epithelial function, immune system and microbiota. Thus, a targeted control of dietary components to promote the establishment of a healthy bacterial community is a significant method for preventing nutritional diarrhea in weaned piglets.

Dietary sodium acetate and sodium butyrate improve high-carbohydrate diet utilization by regulating gut microbiota, liver lipid metabolism, oxidative stress, and inflammation in largemouth bass (Micropterus salmoides)

BACKGROUND

Adequate level of carbohydrates in aquafeeds help to conserve protein and reduce cost. However, studies have indicated that high-carbohydrate (HC) diet disrupt the homeostasis of the gut-liver axis in largemouth bass, resulting in decreased intestinal acetate and butyrate level.

METHOD

Herein, we had concepted a set of feeding experiment to assess the effects of dietary sodium acetate (SA) and sodium butyrate (SB) on liver health and the intestinal microbiota in largemouth bass fed an HC diet. The experimental design comprised 5 isonitrogenous and isolipidic diets, including LC (9% starch), HC (18% starch), HCSA (18% starch; 2 g/kg SA), HCSB (18% starch; 2 g/kg SB), and HCSASB (18% starch; 1 g/kg SA + 1 g/kg SB). Juvenile largemouth bass with an initial body weight of 7.00 ± 0.20 g were fed on these diets for 56 d.

RESULTS

We found that dietary SA and SB reduced hepatic triglyceride accumulation by activating autophagy (ATG101, LC3B and TFEB), promoting lipolysis (CPT1α, HSL and AMPKα), and inhibiting adipogenesis (FAS, ACCA, SCD1 and PPARγ). In addition, SA and SB decreased oxidative stress in the liver (CAT, GPX1α and SOD1) by activating the Keap1-Nrf2 pathway. Meanwhile, SA and SB alleviated HC-induced inflammation by downregulating the expression of pro-inflammatory factors (IL-1β, COX2 and Hepcidin1) through the NF-κB pathway. Importantly, SA and SB increased the abundance of bacteria that produced acetic acid and butyrate (Clostridium_sensu_stricto_1). Combined with the KEGG analysis, the results showed that SA and SB enriched carbohydrate metabolism and amino acid metabolism pathways, thereby improving the utilization of carbohydrates. Pearson correlation analysis indicated that growth performance was closely related to hepatic lipid deposition, autophagy, antioxidant capacity, inflammation, and intestinal microbial composition.

CONCLUSIONS

In conclusion, dietary SA and SB can reduce hepatic lipid deposition; and alleviate oxidative stress and inflammation in largemouth bass fed on HC diet. These beneficial effects may be due to the altered composition of the gut microbiota caused by SA and SB. The improvement effects of SB were stronger than those associated with SA.

Effect of Low Protein Diets Supplemented with Sodium Butyrate, Medium-Chain Fatty Acids, or n-3 Polyunsaturated Fatty Acids on the Growth Performance, Immune Function, and Microbiome of Weaned Piglets

This study aimed to investigate the effects of low-protein (LP) diets supplemented with sodium butyrate (SB), medium-chain fatty acids (MCT), or n-3 polyunsaturated fatty acids (n-3 PUFA) on the growth performance, immune function, and the microbiome of weaned piglets. A total of 120 healthy weaned piglets ((Landrace × Large White × Duroc); 7.93 ± 0.7 kg initial body weight), were randomly divided into five groups. Each group consisted of six replications with four piglets per replication. Dietary treatments included control diet (CON); LP diet (LP); LP + 0.2% SB diet (LP + SB); LP + 0.2% MCT diet (LP + MCT); and LP + PUFA diet (LP + PUFA). The experimental period lasted for 4 weeks. Compared with the CON diet, LP, LP + SB, LP + MCT, and LP + PUFA diets decreased the final weight and average daily gain (ADG) of piglets (p < 0.05). There were lower (p < 0.05) concentrations of IL-8 and higher (p < 0.05) Glutathione peroxidase (GSH-Px) activity in the plasma of piglets fed with LP + SB, LP + MCT, and LP + PUFA diets than those fed with the LP diet. The piglets in the LP + SB and LP + PUFA groups had lower IKK-alpha (IKKa) mRNA expression in the colonic mucosa compared with those in the CON and LP groups (p < 0.05). The mRNA expression of TLR4 in the colonic mucosa of piglets in the LP + SB, LP + MCT, and LP + PUFA groups was decreased when compared with the CON and LP groups (p < 0.05). The LP + MCT diets increased the gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in the colonic mucosa of piglets compared with CON, LP, and LP + SB diets (p < 0.05). The abundance of Erysipelotrichaceae in the colonic microbiome of piglets in the LP group was higher than that in the other four groups (p < 0.05). Collectively, this study showed that LP diets supplemented with SB, MCT, or n-3 PUFA reduced plasma inflammatory factor levels, increased plasma GSH-Px activity, and declined mRNA expression of TLR4 and IKKa in the colonic epithelium, whereas it reduced the abundance of Erysipelotrichaceae in the colon of piglets.

Bacillus coagulans prevents the decline in average daily feed intake in young piglets infected with enterotoxigenic Escherichia coli K88 by reducing intestinal injury and regulating the gut microbiota

Background

Enterotoxigenic Escherichia coli (ETEC), an important intestinal pathogen, poses a significant threat to the intestinal health of piglets. Bacillus coagulans (BC), a potential feed additive, can improve the intestinal function of piglets. However, the effects of BC on growth performance and intestinal function in ETEC-infected piglets are still unclear. In this study, 24 7-day-old piglets were randomly assigned to three treatment groups: control group (fed a basal diet), ETEC group (fed a basal diet and challenged with ETEC K88) and BC+ETEC group (fed a basal diet, orally administered BC, challenged with ETEC K88). During Days 1-6 of the trial, piglets in the BC+ETEC group were orally administered BC (1×108CFU/kg). On Day 5 of the trial, piglets in the ETEC and BC+ETEC groups were orally administered ETEC K88 (5×109CFU/piglet). Blood, intestinal tissue, and content samples were collected from the piglets on Day 7 of the trial.

Results

The average daily feed intake in the ETEC group was significantly reduced compared to that of the control group. Further research revealed that ETEC infection significantly damaged the structure of the small intestine. Compared to the control group, the villus height and surface area of the jejunum, the ratio of villus height to crypt depth in the duodenum and jejunum, and the activities of catalase and total superoxide dismutase in the jejunum were significantly reduced. Additionally, the levels of myeloperoxidase in the jejunum, malondialdehyde in the plasma and jejunum, and intestinal epithelial apoptosis were significantly increased in the ETEC group. However, BC supplementation had significantly mitigated these negative effects in the BC+ETEC group by Day 7 of the trial. Moreover, BC supplementation improved the gut microbiota imbalance by reversing the decreased numbers of Enterococcus, Clostridium and Lactobacillus in jejunum and Escherichia coli, Bifidobacterium and Lactobacillus in the colon, as well as the increased number of Escherichia coli in the jejunum induced by ETEC K88.

Conclusions

Overall, BC supplementation reduced the decline in average daily feed intake in ETEC K88-infected piglets by attenuating intestinal epithelial apoptosis and oxidative stress and regulating the gut microbiota. This suggests that BC may be used to prevent intestinal infections caused by ETEC in piglets.

Seabuckthorn Wuwei Pulvis attenuates chronic obstructive pulmonary disease in rat through gut microbiota-short chain fatty acids axis

ETHNOPHARMACOLOGICAL RELEVANCE

Seabuckthorn Wuwei Pulvis (SWP) is a traditional Mongolian medicine used in China. It is composed of Hippophae rhamnoides (berries, 30 g), Aucklandiae costus Falc. (dry root, 25 g), Vitis vinifera F. Cordifolia (berries, 20 g), Glycyrrhiza uralensis Fisch. (dry root, 15 g), and Gardenia jasminoides J. Ellis (desiccative ripe fruit, 10 g). It is clinically applied in the treatment of chronic cough, shortness of breath and phlegm, and chest distress. Past studies demonstrated that Seabuckthorn Wuwei Pulvis improved lung inflammation and chronic bronchitis in mice. However, the effect of Seabuckthorn Wuwei Pulvis on chronic obstructive pulmonary disease (COPD) in rats and the underlying action mechanism is not fully understood.

AIM OF THE STUDY

To evaluate the anti-COPD effect of Seabuckthorn Wuwei Pulvis and investigate whether its ameliorative effect is correlated with the composition of gut microbiota and its metabolites.

MATERIALS AND METHODS

The effects of Seabuckthorn Wuwei Pulvis on a COPD rat model were established by exposure to lipopolysaccharide (LPS) and smoking. These effects were then evaluated by monitoring the animal weight, pulmonary function, lung histological alteration, and the levels of inflammatory factors (tumor necrotic factor [TNF]-α, interleukin [IL]-8, IL-6, and IL-17). Furthermore, the serum LPS and fluorescein isothiocyanate-dextran levels were detected by using an enzyme-linked immunosorbent assay and fluorescence microplate reader, respectively. Tight junction proteins (ZO-1 and occludin-1) in the small intestine were detected by performing real-time quantitative polymerase chain reactions and Western blotting to evaluate the intestinal barrier function. The contents of short-chain fatty acids (SCFAs) in the feces of rats were determined by gas chromatography-mass spectrometry. 16S rDNA high throughput sequencing was used to investigate the effect of SWP on the gut microbiota of COPD rats.

RESULTS

Treatment with low and median doses of SWP significantly increased the pulmonary function (forced expiratory volume [FEV] 0.3, forced vital capacity [FVC], and FEV0.3/FVC), decreased the levels of TNF-α, IL-8, IL-6, and IL-17 in the lung, and attenuated the infiltration of inflammatory cells into the lung. The low and median doses of SWP shaped the composition of gut microbiota, which increased the abundances of Ruminococcaceae, Christensenellaceae, and Aerococcaceae, increased the productions of acetic acid, propionic acid, and butyric acid, and upregulated the expression of ZO-1 and occludin-1 in the small intestine of COPD rats.

CONCLUSION

SWP improved pulmonary functions and inhibited the inflammatory response by shaping the gut microbiota, increasing SCFA production, and strengthening the intestinal barrier function in rats with COPD induced by LPS and smoking.

Dietary supplementation of coated sodium butyrate improves growth performance of laying ducks by regulating intestinal health and immunological performance

Introduction

This study was conducted to assess the effects of dietary supplementation of coated sodium butyrate (CSB) on the growth performance, serum antioxidant, immune performance, and intestinal microbiota of laying ducks.

Methods

A total of 120 48-week-old laying ducks were randomly divided into 2 treatment groups: the control group (group C fed a basal diet) and the CSB-treated group (group CSB fed the basal diet + 250 g/t of CSB). Each treatment consisted of 6 replicates, with 10 ducks per replicate, and the trial was conducted for 60 days.

Results

Compared with the group C, the group CSB showed a significant increase in the laying rate (p&lt;0.05) of the 53-56 week-old ducks. Additionally, the serum total antioxidant capacity, superoxide dismutase activity and immunoglobulin G level were significantly higher (p&lt;0.05), while the serum malondialdehyde content and tumor necrosis factor (TNF)-a level were significantly lower (p&lt;0.05) in the serum of the group CSB compared to the group C. Moreover, the expression of IL-1b and TNF-a in the spleen of the group CSB was significantly lower (p&lt;0.05) compared to that of the group C. In addition, compared with the group C, the expression of Occludin in the ileum and the villus height in the jejunum were significantly higher in the group CSB (p&lt;0.05). Furthermore, Chao1, Shannon, and Pielou-e indices were higher in the group CSB compared to the group C (p&lt;0.05). The abundance of Bacteroidetes in the group CSB was lower than that in the group C (p&lt;0.05), while the abundances of Firmicutes and Actinobacteria were higher in the group CSB compared to the group C (p&lt;0.05).

Conclusions

Our results suggest that the dietary supplementation of CSB can alleviate egg-laying stress in laying ducks by enhancing immunity and maintaining the intestinal health of the ducks.

Viral and Bacterial Profiles in Endemic Influenza A Virus Infected Swine Herds Using Nanopore Metagenomic Sequencing on Tracheobronchial Swabs

Swine influenza A virus (swIAV) plays an important role in porcine respiratory infections. In addition to its ability to cause severe disease by itself, it is important in the multietiological porcine respiratory disease complex. Still, to date, no comprehensive diagnostics with which to study polymicrobial infections in detail have been offered. Hence, veterinary practitioners rely on monospecific and costly diagnostics, such as Reverse Transcription quantitative PCR (RT-qPCR), antigen detection, and serology. This prevents the proper understanding of the entire disease context, thereby hampering effective preventive and therapeutic actions. A new, nanopore-based, metagenomic diagnostic platform was applied to study viral and bacterial profiles across 4 age groups on 25 endemic swIAV-infected German farms with respiratory distress in the nursery. Farms were screened for swIAV using RT-qPCR on nasal and tracheobronchial swabs (TBS). TBS samples were pooled per age, prior to metagenomic characterization. The resulting data showed a correlation between the swIAV loads and the normalized reads, supporting a (semi-)quantitative interpretation of the metagenomic data. Interestingly, an in-depth characterization using beta diversity and PERMANOVA analyses allowed for the observation of an age-dependent interplay of known microbial agents. Also, lesser-known microbes, such as porcine polyoma, parainfluenza, and hemagglutinating encephalomyelitis viruses, were observed. Analyses of swIAV incidence and clinical signs showed differing microbial communities, highlighting age-specific observations of various microbes in porcine respiratory disease. In conclusion, nanopore metagenomics were shown to enable a panoramic view on viral and bacterial profiles as well as putative pathogen dynamics in endemic swIAV-infected herds. The results also highlighted the need for better insights into lesser studied agents that are potentially associated with porcine respiratory disease. IMPORTANCE To date, no comprehensive diagnostics for the study of polymicrobial infections that are associated with porcine respiratory disease have been offered. This precludes the proper understanding of the entire disease landscape, thereby hampering effective preventive and therapeutic actions. Compared to the often-costly diagnostic procedures that are applied for the diagnostics of porcine respiratory disease nowadays, a third-generation nanopore sequencing diagnostics workflow presents a cost-efficient and informative tool. This approach offers a panoramic view of microbial agents and contributes to the in-depth observation and characterization of viral and bacterial profiles within the respiratory disease context. While these data allow for the study of age-associated, swIAV-associated, and clinical symptom-associated observations, it also suggests that more effort should be put toward the investigation of coinfections and lesser-known pathogens (e.g., PHEV and PPIV), along with their potential roles in porcine respiratory disease. Overall, this approach will allow veterinary practitioners to tailor treatment and/or management changes on farms in a quicker, more complete, and cost-efficient way.

Combined Omics Analysis Further Unveils the Specific Role of Butyrate in Promoting Growth in Early-Weaning Animals

Abnormal mutations in the microbial structure of early-weaning mammals are an important cause of enteritis. Based on the multiple known beneficial functions of butyrate, we hypothesized that butyrate would alleviate the imbalance of intestinal homeostasis induced by early weaning in animals. However, the mechanisms of action between butyrate and intestinal microbes are still poorly explored. In this study, we aimed to investigate whether butyrate exerts beneficial effects on the structure of the intestinal flora of weanling rabbits and their intestinal homeostasis, growth and development, and we attempted to elucidate the potential mechanisms of action through a combined omics analysis. We found that dietary butyrate upregulated the transcription of tight junction-related proteins in the epithelial barrier and improved the intestinal microbial structure by suppressing harmful bacteria and promoting beneficial ones. Intestinal and plasma metabolomes were also altered. The bile acid secretion, α-linolenic acid, apoptotic, and prostate cancer pathways responded to the positive dietary butyrate-induced metabolic changes in the weanling rabbits, resulting in the inhibition of inflammation, improved antioxidant capacity, increased rates of cell proliferation and survival, and decreased levels of apoptosis. Additionally, dietary butyrate suppressed the release of pro-inflammatory factors and enhanced positive appetite regulation, which increased the average daily gain of the rabbits. These results demonstrated that dietary butyrate can help maintain the integrity of the intestinal epithelial barrier, improve the structural composition of the intestinal microflora, enhance organismal metabolism, inhibit inflammation, reduce post-weaning anorexia, and promote growth and development in early-weaning rabbits. These positive effects of dietary butyrate were exerted via the modulation of the microbe-gut-brain axis.

Effects of dietary protein content and crystalline amino acid supplementation patterns in low protein diets on intestinal bacteria and their metabolites in weaned pigs raised under Different sanitary conditions

The objective of this experiment was to investigate the effects of dietary crude protein (CP) content and crystalline amino acids (CAA) supplementation patterns in low CP (LCP) diets on intestinal bacteria and their metabolites in weaned pigs raised under clean (CSC) or unclean sanitary conditions (USC). One hundred forty-four piglets (6.35 ± 0.63 kg) were assigned to one of six treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions in a randomized complete block design to give eight replicates with three pigs per pen over a 21-d period. Diets consisted of a high CP (HCP; 21%) and two LCP (18%) diets supplemented with 9 CAA (Lys, Met, Thr, Trp, Val, Ile, Leu, His, and Phe) or only six CAA (Lys, Met, Thr, Trp, Val, and Ile) to meet the requirements. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens from the beginning of the study and was not washed throughout the experiment. Jejunum and colon digesta were sampled on day 21. Both jejunum and colon digesta were analyzed for ammonia nitrogen, short-chain fatty acids, and biogenic amines but only colon digesta was analyzed for microbiome composition (16s rRNA sequencing on MiSeq). Data were analyzed using R software for 16S rRNA and the MIXED procedure of SAS for microbial metabolites. Sanitation, CP content, and CAA supplementation patterns did not affect the diversity of colonic bacterial composition in weaned pigs. Pigs raised under USC had greater (P < 0.05) jejunal ammonia nitrogen concentration than those raised under CSC. Pigs fed LCP diets had reduced (P < 0.05) jejunal ammonia nitrogen concentration compared to those fed the HCP diet. Interactions between sanitation and dietary CP content were observed (P < 0.05) for: (1) jejunal acetate and (2) colonic spermidine and spermine, whereby (1) acetate concentrations decreased from NCP to LCP in pigs raised under the CSC but those concentrations increased under the USC, and (2) spermidine and spermine concentrations increased in LCP diets compared to HCP diet under USC, unlike CSC which did not show any difference between HCP and LCP. In conclusion, reducing dietary CP lowered ammonia nitrogen content regardless of sanitation and increased microbial metabolites in weaned pigs raised under USC. However, LCP diets with different CAA supplementation patterns did not affect bacterial diversity in weaned pigs, regardless of the hygienic conditions where the animals were housed.

Clostridium butyricum and Bifidobacterium pseudolongum Attenuate the Development of Cardiac Fibrosis in Mice

Cardiac fibrosis is an integral aspect of every form of cardiovascular diseases, which is one of the leading causes of death worldwide. It is urgent to explore new effective drugs and treatments. In this paper, transverse aortic constriction (TAC)-induced cardiac fibrosis was significantly alleviated by a cocktail of antibiotics to clear the intestinal flora, indicating that the gut microbiota was associated with the disease process of cardiac fibrosis. We transplanted feces from sham-operated and TAC-treated mice to mice treated with a cocktail of antibiotics. We found that TAC-treated gut microbiota dysbiosis cannot cause cardiac fibrosis on its own. Interestingly, healthy fecal microbiota transplantation could alleviate cardiac fibrosis, indicating that targeted probiotics and related metabolite intervention may restore a normal microenvironment for the treatment or prevention of cardiac fibrosis. We used 16S rRNA sequencing of fecal samples and discovered that butyric acid-producing bacteria and Bifidobacterium pseudolongum were the dominant bacteria in the group with the lowest degree of cardiac fibrosis. Moreover, we demonstrated that sodium butyrate prevented the development of cardiac fibrosis. The effect of Clostridium butyricum (butyric acid-producing bacteria) was better than that of B. pseudolongum on cardiac fibrosis. Surprisingly, the cocktail of two probiotics had a stronger ability than a single probiotic. In conclusion, therapies targeting the gut microbiota and metabolites such as probiotics present new strategies for treating cardiovascular disease. IMPORTANCE Cardiac fibrosis is a basic process in cardiac remodeling. It is related to almost all types of cardiovascular diseases (CVD) and has become an important global health problem. Basic research and a number of clinical studies have shown that myocardial fibrosis can be prevented and reversed to a certain extent. It is urgent to explore new effective drugs and treatments. We indicated a causal relationship between cardiac fibrosis and gut microbiota. Gut microbiota dysbiosis cannot cause cardiac fibrosis on its own. Interestingly, healthy fecal microbiota transplantation could alleviate cardiac fibrosis. According to our findings, the combined use of butyric acid-producing bacteria and B. pseudolongum can help prevent cardiac fibrosis. Therapies targeting the gut microbiota and metabolites, such as probiotics, represent new strategies for treating cardiovascular disease.

TangNaiKang, herbal formulation, alleviates obesity in diabetic SHR/cp rats through modulation of gut microbiota and related metabolic functions

CONTEXT

Tangnaikang (TNK) is a Chinese herbal formulation that has lipid-lowering effects, but its effect on reducing obesity has not been studied.

OBJECTIVE

To observe the effect of TNK on obesity and explore its effect on gut microbiota of obese rats.

MATERIALS AND METHODS

The SHR/NDmcr-cp rats were divided into three groups: (1) 3.24 g/kg TNK (High TNK), (2) 1.62 g/kg TNK (Low TNK), and (3) an untreated control (CON). Wistar-Kyoto rats were used as normal controls (WKY). After 8 weeks of TNK oral administration, body weight, abdominal circumference, triglycerides (TC) and total cholesterol (CHO) were measured. Gut microbiota diversity was studied by 16S rDNA sequencing, and metagenomes analysis was conducted to determine alteration in functional gene expression.

RESULTS

The body weight (496.60 ± 6.0 g vs. 523.40 ± 5.6 g), abdomen circumference (24.00 ± 0.11 cm vs. 24.87 ± 0.25 cm), TC (3.04 ± 0.16 mmol/L vs. 4.97 ± 0.21 mmol/L), CHO (2.42 ± 0.15 mmol/L vs. 2.84 ± 0.09 mmol/L) of rats in the High TNK group were decreased significantly (all p < 0.05). TNK administration regulates intestinal flora, up-regulates Eisenbergiella and down-regulates Clostridium_sensu_stricto_1, which is beneficial to the production of short-chain fatty acids (SCFAs). Metagenomes analysis shows that TNK is closely related to the fatty acid synthesis pathway.

DISCUSSION AND CONCLUSIONS

TNK can regulate gut microbiota to reduce obesity, which may be related to fatty acid metabolism. Our research supports the clinical application of TNK preparation and provides a new perspective for the treatment of obesity.

Lactococcus lactis' Effect on the Intestinal Microbiota of Streptococcus agalactiae-Infected Zebrafish (Danio rerio)

Streptococcus agalactiae is a common pathogen in aquaculture that disrupts the balance of the intestinal microbiota and threatens fish health, causing enormous losses to the aquaculture industry. In this study, we isolated and screened a Lactococcus lactis KUST48 (LLK48) strain with antibacterial effect against S. agalactiae in vitro and used it as a potential probiotic to explore its therapeutic effect on zebrafish (Danio rerio) infected with S. agalactiae. This study divided zebrafish into 3 groups: control group, injected with phosphate-buffered saline; infection group, injected with S. agalactiae; and treatment group, treated with LLK48 after S. agalactiae injection. Then, the 16S rRNA gene sequences of the intestinal microbiota of these 3 groups were sequenced using Illumina high-throughput sequencing technology. The results showed that the relative abundance of intestinal bacteria was significantly decreased in the infection group, and a high relative abundance of S. agalactiae was observed. The relative abundance of the intestinal microbiota was increased in the treatment group, with a decrease in the relative abundance of S. agalactiae compared to that in the control group. In the Cluster of Orthologous Groups of proteins function classification, the relative abundance of each biological function in the infection group was significantly lower than that of the control and treatment groups, showing that LLK48 has a positive therapeutic effect on zebrafish infected with S. agalactiae. This study provides a foundation for exploring the pathogenic mechanism of S. agalactiae on fish and their intestinal symbionts, and also presents a new approach for the treatment of S. agalactiae infections in fish aquaculture systems. IMPORTANCE L. lactis KUST48 (LLK48) with a bacteriostatic effect against S. agalactiae was isolated from tilapia intestinal tracts. S. agalactiae infection significantly reduced the relative abundance of intestinal bacteria and various physiological functions in zebrafish intestines. LLK48 demonstrated infection and subsequent therapeutic effects on the S. agalactiae infection in the zebrafish intestine. Therefore, the potential probiotic LLK48 can be considered as a therapeutic treatment for S. agalactiae infections in aquaculture, which can reduce the use of antibiotics and help maintain fish health.

The emerging role of histone deacetylase 1 in allergic diseases

Histone deacetylase 1 (HDAC1) is a unique member of the classes I HDACs and helps to regulate acute and chronic adaptation to environmental stimuli such as allergen, stress. Allergic diseases are complex diseases resulting from the effect of multiple genetic and interacting foreign substances. Epigenetics play an important role in both pathological and immunomodulatory conditions of allergic diseases. To be consistent with this role, recent evidence strongly suggests that histone deacetylase 1 (HDAC1) plays a critical role in allergic response. HDAC1 expression is stimulated by allergen and attributes to increase T helper 2 (Th2) cytokine levels, decrease Th1/Th17 cells and anti-inflammatory cytokine Interleukin-10 (IL-10), and TWIK-related potassium channel-1 (Trek-1) expression. This review focuses on the contribution of HDAC1 and the regulatory role in characterizing allergic endotypes with common molecular pathways and understanding allergic multimorbidity relationships, as well as addressing their potential as therapeutic targets for these conditions.

Can metagenomics unravel the impact of oral bacteriome in human diseases?

Oral microbial ecosystems are vital in maintaining the health of the oral cavity and the entire body. Oral microbiota is associated with the progression of oral diseases such as dental caries, periodontal diseases, head and neck cancer, and several systemic diseases such as cardiovascular disease, rheumatoid arthritis, adverse pregnancy outcomes, diabetes, lung infection, colorectal cancer, and pancreatic cancer. Buccal mucosa, tongue dorsum, hard palate, saliva, palatine tonsils, throat, keratinized gingiva, supra-gingival plaque, subgingival plaque, dentures, and lips are microbial habitats of the oral cavity. Porphyromonas gingivalis may have a role in the development of periodontal diseases, oral cancer, diabetes, and atherosclerotic disease. Fusobacterium nucleatum showed a higher abundance in periodontal diseases, oral and colon cancer, adverse pregnancy outcomes, diabetes, and rheumatoid arthritis. The higher abundance of Prevotella intermedia is typical in periodontal diseases, rheumatoid arthritis, and adverse pregnancy outcome. S. salivarius displayed higher abundance in both dental caries and OSCC. Oral bacteria may influence systemic diseases through inflammation by releasing pro inflammatory cytokines. Identification of oral bacteria using culture-dependent approaches and next-generation sequencing-based metagenomic approaches is believed to significantly identify the therapeutic targets and non-invasive diagnostic indicators in different human diseases. Oral bacteria in saliva could be exploited as a non-invasive diagnostic indicator for the early detection of oral and systemic disorders. Other therapeutic approaches such as the use of probiotics, green tea polyphenol, cold atmospheric plasma (CAP) therapy, antimicrobial photodynamic therapy, and antimicrobial peptides are used to inhibit the growth of biofilm formation by oral bacteria.

Consumption of Dietary Fiber with Different Physicochemical Properties during Late Pregnancy Alters the Gut Microbiota and Relieves Constipation in Sow Model

Constipation is a common problem in sows and women during late pregnancy. Dietary fiber has potential in the regulation of intestinal microbiota, thereby promoting intestinal motility and reducing constipation. However, the effects of fibers with different physicochemical properties on intestinal microbe and constipation during late pregnancy have not been fully explored. In this study, a total of 80 sows were randomly allocated to control and one of three dietary fiber treatments from day 85 of gestation to delivery: LIG (lignocellulose), PRS (resistant starch), and KON (konjaku flour). Results showed that the defecation frequency and fecal consistency scores were highest in PRS. PRS and KON significantly increased the level of gut motility regulatory factors, 5-hydroxytryptamine (5-HT), motilin (MTL), and acetylcholinesterase (AChE) in serum. Moreover, PRS and KON promoted the IL-10 level and reduced the TNF-α level in serum. Furthermore, maternal PRS and KON supplementation significantly reduced the number of stillborn piglets. Microbial sequencing analysis showed that PRS and KON increased short-chain fatty acids (SCFAs)-producing genera Bacteroides and Parabacteroides and decreased the abundance of endotoxin-producing bacteria Desulfovibrio and Oscillibacter in feces. Moreover, the relative abundance of Turicibacter and the fecal butyrate concentration in PRS were the highest. Correlation analysis further revealed that the defecation frequency and serum 5-HT were positively correlated with Turicibacter and butyrate. In conclusion, PRS is the best fiber source for promoting gut motility, which was associated with increased levels of 5-HT under specific bacteria Turicibacter and butyrate stimulation, thereby relieving constipation. Our findings provide a reference for dietary fiber selection to improve intestinal motility in late pregnant mothers.

Glyceryl butyrate attenuates enterotoxigenic Escherichia coli-induced intestinal inflammation in piglets by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota

The aims of this study were to evaluate whether a diet supplemented with glyceryl butyrate could attenuate the immune-inflammatory response in piglets challenged with enterotoxigenic Escherichia coli (ETEC), and to explore the mechanisms of its regulation. Eighteen weaning piglets were assigned to three diets: basal diet (CON), antibiotics diet (ATB), and 0.5% glyceryl butyrate diet (GB group). Significantly lower concentrations of IL-1β, IL-6 and TNF-α in the jejunum and IL-6 in the ileum were observed in the GB group than that in the CON group (P < 0.05). Moreover, a decreasing trend of IL-1β (P = 0.075) and TNF-α (P = 0.070) was observed in the ileum in the GB group. Correspondingly, the GB group had significantly increased mRNA expression of porcine beta defensins (pBDs) in the jejunum (pBD1, pBD2, pBD114 and pBD129) and ileum (pBD2, pBD3, pBD114 and pBD129) (P < 0.05), and protein abundance of Claudin 1, Occludin, and ZO-1 in the jejunum and ileum (P < 0.05). Further research results showed that the improvement of beta defensins and tight junctions in the GB group was related to the decreased phosphorylation of the NFκB/MAPK pathway. In addition, the results of 16S rDNA sequencing showed that glycerol butyrate supplementation altered the ileal microbiota composition of piglets, increasing the relative abundance of Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus agrilis. In summary, glyceryl butyrate attenuated the immune-inflammatory response in piglets challenged with ETEC by inhibiting the NF-κB/MAPK pathways and modulating the gut microbiota, and thus improved piglet intestinal health.

Role of dietary amino acids and microbial metabolites in the regulation of pig intestinal health

With the rapid development of sequencing technology, research on pigs has focused on intestinal microbes. Accumulating evidence suggests that the metabolites of intestinal microbes are the key medium for interactions between microbes and the host. Amino acid metabolism is involved in the growth and immune processes of pigs. The gut microbes of pigs are heavily involved in the metabolism of amino acids in their hosts. Here, we review the latest relevant literature. Research findings show that microbial metabolites, such as indoles, short-chain fatty acids, and ammonia, play a key role in gut health. Moreover, we summarize the effects of amino acids on the structure of the gut microbial community and the metabolism of amino acids by pig gut microbes. Evidence shows that microbial amino acid metabolites act as signal molecules in the intestine and play an important role in the intestinal health of pigs.

Effect of Two Feed Additives-One Multicomponent Based on Nanosilica and the Second Containing Mycelium of Lentinula edodes Fortified with Selenium-On Production Parameters and Histological Analysis of Calves' Duodenum and Abdominal Rumen

With this study, we aimed to evaluate the effect of two multicomponent feed additives given to animals from 10 to 70 d with milk replacer on the production parameters of reared calves: serum selenium level and histology of duodenum and rumen. The first additive was based on nanosilica (3000 mg) containing pancreatic enzymes (protease (18 mg), lipase (45 mg)), a mixture of fat-coated organic acids (2000 mg) (fumaric, malic, citric, and sorbic acids), and sodium butyrate (10,000 mg) (nanosilica/E/OA/SB), whereas the second was based on the mycelium of L. edodes (7 g) enriched in selenium (0.058 mg/g d.w.) (L. edodes/Se). The study was conducted on 18 male crossbred Holstein dairy calves from birth to 70 days of age, which were randomly assigned to control and experimental groups (six animals in each). From each group, three animals were sacrificed at 70 days of age, and histological analysis of the digestive tract (abdominal rumen and small intestine) was performed. It was observed that the additives used did not have any effect on growth performance and hematological or biochemical parameters. However, higher levels of selenium were found in serum in the calves fed with modified L. edodes mycelium on days 35 and 70 (44.33 and 51.33 µg/L in the control group and 132 and 93 µg/L in the L. edodes/Se group, respectively; p < 0.001). Moreover, we noticed lower average daily milk replacer intake at 35−42 d, which increased significantly from 42 to 70 d in the animals receiving L. edodes/Se.

Butyric and Citric Acids and Their Salts in Poultry Nutrition: Effects on Gut Health and Intestinal Microbiota

Intestinal dysfunction of farm animals, such as intestinal inflammation and altered gut microbiota, is the critical problem affecting animal welfare, performance and farm profitability. China has prohibited the use of antibiotics to improve feed efficiency and growth performance for farm animals, including poultry, in 2020. With the advantages of maintaining gut homeostasis, enhancing digestion, and absorption and modulating gut microbiota, organic acids are regarded as promising antibiotic alternatives. Butyric and citric acids as presentative organic acids positively impact growth performance, welfare, and intestinal health of livestock mainly by reducing pathogenic bacteria and maintaining the gastrointestinal tract (GIT) pH. This review summarizes the discovery of butyric acid (BA), citric acid (CA) and their salt forms, molecular structure and properties, metabolism, biological functions and their applications in poultry nutrition. The research findings about BA, CA and their salts on rats, pigs and humans are also briefly reviewed. Therefore, this review will fill the knowledge gaps of the scientific community and may be of great interest for poultry nutritionists, researchers and feed manufacturers about these two weak organic acids and their effects on intestinal health and gut microbiota community, with the hope of providing safe, healthy and nutrient-rich poultry products to consumers.

Sodium butyrate ameliorates non-alcoholic fatty liver disease by upregulating miR-150 to suppress CXCR4 expression

Sodium butyrate (NaB) in the gut of animals possesses the potential to modulate lipid metabolism, regulate innate immunity and protect intestinal health. Accumulating data have supported the important function of metabolites of intestinal microflora (MIM) in non-alcoholic fatty liver disease (NAFLD). This study intended to investigate the role of NaB in NAFLD and its specific mechanism. Mice were fed a high-fat diet (HFD) for 16 weeks to establish the NAFLD mouse model. The mice were intragastrically administrated MIM (200 µL/day) or NaB (200 mg/kg/day) by gavage for another 8 weeks. The morphology of liver tissues was observed by hematoxylin and eosin (H&E) staining, and the lipid deposition of liver tissues was examined by oil red O staining. The NAFLD cell model was constructed in alpha mouse liver 12 (AML12) cells by 24 hours of stimulation with 0.5 mM free fatty acids. After treatment with 10 mM NaB, AML12 cells were transfected with mimic-miR-150 or inhibitor-miR-150. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to measure the contents of interleukin 1β (IL-1β), IL-6 and tumour necrosis factor α (TNF-α) and the expression of microRNA (miR)-150 and CXCR4 in liver tissues of mice and in AML12 cells. A luciferase reporter assay was applied to verify the binding relationship between miR-150 and CXCR4. The H&E and oil red O staining results showed hepatic steatosis in the liver tissues of HFD-fed mice. There were elevated contents of triacylglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose, enhanced activities of alanine aminotransferase(ALT) and aspartate aminotransferase(AST), increased homeostatic model assessment of insulin resistance scores and increased inflammatory responses in the serum of HFD-fed mice. However, intervention with MIM or NaB reversed the above trends, indicating that MIM or NaB intervention relieved hepatic steatosis in mice. HFD-fed mice had downregulated expression of miR-150, whereas the expression level was upregulated after MIM or NaB treatment. Sodium butyrate attenuated NAFLD progression by regulating miR-150. MiR-150 can negatively target CXCR4. Sodium butyrate mitigates HFD-induced NAFLD in mice by upregulating miR-150 expression to downregulate CXCR4.

Constipation induced gut microbiota dysbiosis exacerbates experimental autoimmune encephalomyelitis in C57BL/6 mice

Background

Constipation is a common gastrointestinal dysfunction which has a potential impact on people's immune state and their quality of life. Here we investigated the effects of constipation on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS).

Methods

Constipation was induced by loperamide in female C57BL/6 mice. The alternations of gut microbiota, permeability of intestinal barrier and blood–brain barrier, and histopathology of colon were assessed after constipation induction. EAE was induced in the constipation mice. Fecal microbiota transplantation (FMT) was performed from constipation mice into microbiota-depleted mice. Clinical scores, histopathology of inflammation and demyelination, Treg/Th17 and Treg17/Teff17 imbalance both in the peripheral lymphatic organs and central nervous system, cytokines include TGF-β, GM-CSF, IL-10, IL-17A, IL-17F, IL-21, IL-22, and IL-23 in serum were assessed in different groups.

Results

Compared with the vehicle group, the constipation mice showed gut microbiota dysbiosis, colon inflammation and injury, and increased permeability of intestinal barrier and blood–brain barrier. We found that the clinical and pathological scores of the constipation EAE mice were severer than that of the EAE mice. Compared with the EAE mice, the constipation EAE mice showed reduced percentage of Treg and Treg17 cells, increased percentage of Th17 and Teff17 cells, and decreased ratio of Treg/Th17 and Treg17/Teff17 in the spleen, inguinal lymph nodes, brain, and spinal cord. Moreover, the serum levels of TGF-β, IL-10, and IL-21 were decreased while the GM-CSF, IL-17A, IL-17F, IL-22, and IL-23 were increased in the constipation EAE mice. In addition, these pathological processes could be transferred via their gut microbiota.

Conclusions

Our results verified that constipation induced gut microbiota dysbiosis exacerbated EAE via aggravating Treg/Th17 and Treg17/Teff17 imbalance and cytokines disturbance in C57BL/6 mice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02995-z.

Effects of Dietary Supplementation with Protected Sodium Butyrate on Gut Microbiota in Growing-Finishing Pigs

Simple Summary

The addition of protected sodium butyrate to the diet of fattening pigs during the whole fattening period (≈90 days) at a dose of 3 kg per ton of feed, did not modify the overall richness of microbiota composition of the pigs at slaughter, but may have caused some significant changes in specific taxa that could be associated with better gut health parameters. In any case, these results should be taken with caution, as the role of a given taxon on the pig’s gut health is influenced by numerous variables such as age, diet, environment, treatments, other taxa present, infections, or even the physiological status of the animal.

Abstract

The study assessed changes in the gut microbiota of pigs after dietary supplementation with protected sodium butyrate (PSB) during the growing-fattening period (≈90 days). One gram of colon content from 18 pigs (9 from the treatment group -TG- and 9 from the control group -CG-) was collected. Bacterial DNA was extracted and 16S rRNA high-throughput amplicon sequencing used to assess microbiota changes between groups. The groups shared 75.4% of the 4697 operational taxonomic units identified. No differences in alpha diversity were found, but significant differences for some specific taxa were detected between groups. The low-represented phylum Deinococcus-Thermus, which is associated with the production of carotenoids with antioxidant, anti-apoptotic, and anti-inflammatory properties, was increased in the TG (p = 0.032). Prevotellaceae, Lachnospiraceae, Peptostreptococcaceae, Peptococcaceae, and Terrisporobacter were increased in the TG. Members of these families have the ability to ferment complex dietary polysaccharides and produce larger amounts of short chain fatty acids. Regarding species, only Clostridium butyricum was increased in the TG (p = 0.048). Clostridium butyricum is well-known as probiotic in humans, but it has also been associated with overall positive gut effects (increased villus height, improved body weight, reduction of diarrhea, etc.) in weanling pigs. Although the use of PSB did not modify the overall richness of microbiota composition of these slaughter pigs, it may have increased specific taxa associated with better gut health parameters.

Pathogen Challenge and Dietary Shift Alter Microbiota Composition and Activity in a Mucin-Associated in vitro Model of the Piglet Colon (MPigut-IVM) Simulating Weaning Transition

Enterotoxigenic Escherichia coli (ETEC) is the principal pathogen responsible for post-weaning diarrhea in newly weaned piglets. Expansion of ETEC at weaning is thought to be the consequence of various stress factors such as transient anorexia, dietary change or increase in intestinal inflammation and permeability, but the exact mechanisms remain to be elucidated. As the use of animal experiments raise more and more ethical concerns, we used a recently developed in vitro model of piglet colonic microbiome and mucobiome, the MPigut-IVM, to evaluate the effects of a simulated weaning transition and pathogen challenge at weaning. Our data suggested that the tested factors impacted the composition and functionality of the MPigut-IVM microbiota. The simulation of weaning transition led to an increase in relative abundance of the Prevotellaceae family which was further promoted by the presence of the ETEC strain. In contrast, several beneficial families such as Bacteroidiaceae or Ruminococcaceae and gut health related short chain fatty acids like butyrate or acetate were reduced upon simulated weaning. Moreover, the incubation of MPigut-IVM filtrated effluents with porcine intestinal cell cultures showed that ETEC challenge in the in vitro model led to an increased expression of pro-inflammatory genes by the porcine cells. This study provides insights about the etiology of a dysbiotic microbiota in post-weaning piglets.

Dietary oregano essential oil supplementation improves intestinal functions and alters gut microbiota in late-phase laying hens

BACKGROUND

Dietary essential oil (EO) supplementation can exert favorable effects on gut health in broilers. However, it is unknown whether EO could improve intestinal functions, consequently beneficial for egg performance and quality in late-phase laying hens. This study was aimed to investigate the potential effects of EO on production performance, egg quality, intestinal health and ileal microbiota of hens in the late phase of production. A total of 288 60-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet (control) or basal diets supplemented with oregano EO at 100, 200 and 400 mg/kg (EO100, EO200 and EO400).

RESULTS

Dietary EO supplementation resulted in a quadratic decrease (P < 0.05) in feed conversion ratio with lower (P < 0.05) feed conversion ratio in EO200 group than the control during weeks 9-12 and 1-12 of the trial. Compared to the control, EO addition resulted in higher (P < 0.05) eggshell thickness at the end of week. 4, 8 and 12 and higher (P < 0.05) chymotrypsin activity. There was a quadratic elevation (P < 0.05) in ileal chymotrypsin and lipase activity, along with a linear increase in villus height to crypt depth ratio. Quadratic declines (P < 0.05) in mRNA expression of IL-1β, TNF-α, IFN-γ and TLR-4, concurrent with a linear and quadratic increase (P < 0.05) in ZO-1 expression were identified in the ileum with EO addition. These favorable effects were maximized at medium dosage (200 mg/kg) of EO addition and intestinal microbial composition in the control and EO200 groups were assessed. Dietary EO addition increased (P < 0.05) the abundances of Burkholderiales, Actinobacteria, Bifidobacteriales, Enterococcaceae and Bacillaceae, whereas decreased Shigella abundance in the ileum.

CONCLUSIONS

Dietary EO addition could enhance digestive enzyme activity, improve gut morphology, epithelial barrier functions and modulate mucosal immune status by altering microbial composition, thus favoring feed efficiency and eggshell quality of late-phase laying hens.

Evaluation of the in vitro effects of the increasing inclusion levels of yeast β-glucan, a casein hydrolysate and its 5 kDa retentate on selected bacterial populations and strains commonly found in the gastrointestinal tract of pigs

Previously, the 5 kDa retentate (5kDaR) of a casein hydrolysate (CH) and yeast β-glucan (YBG) were identified as promising anti-inflammatory dietary supplements for supporting intestinal health in pigs post-weaning. However, their direct effects on intestinal bacterial populations are less well-known. The main objectives of this study were to determine if the increasing concentrations of the CH, 5kDaR and YBG individually, can: (1) alter the bacterial and short-chain fatty acid profiles in a weaned pig faecal batch fermentation assay, and (2) directly influence the growth of selected beneficial (Lactobacillus plantarum, L. reuteri, Bifidobacterium thermophilum) and pathogenic (Enterotoxigenic Escherichia coli, Salmonella Typhimurium) bacterial strains in individual pure culture growth assays. The potential of CH as a comparable 5kDaR substitute was also evaluated. The 5kDaR increased lactobacilli counts and butyrate concentration in the batch fermentation assay (P < 0.05) and increased L. plantarum (linear, P < 0.05), L. reuteri (quadratic, P < 0.05) and B. thermophilum (linear, P < 0.05) counts and reduced S. typhimurium (quadratic, P = 0.058) counts in the pure culture growth assays. CH increased butyrate concentration (P < 0.05) in the batch fermentation assay. YBG reduced Prevotella spp. counts (P < 0.05) and butyrate concentration (P < 0.05) in the batch fermentation assay. Both CH and YBG had no major effects in the pure culture growth assays. In conclusion, the 5kDaR had the most beneficial effects associated with increased counts of Lactobacillus and Bifidobacterium genera and butyrate production and reduced S. typhimurium counts in vitro indicating its potential to promote gastrointestinal health.

Screening of probiotic candidates in a simulated piglet small intestine in vitro model

The CoMiniGut in vitro model mimicking the small intestine of piglets was used to evaluate four probiotic strains for their potential as a preventive measure against development of diarrhea in weaned pigs. In the in vitro system, piglet digesta was inoculated with pathogenic enterotoxigenic Escherichia coli F4 (ETEC F4), and the short-chain fatty acid profile and the gut microbiota composition were assessed. A total of four probiotic strains were evaluated: Enterococcus faecium (CHCC 10669), Lactobacillus rhamnosus (CHCC 11994), Bifidobacterium breve (CHCC 15268) and Faecalibacterium prausnitzii (CHCC 28556). The significant differences observed in metabolite concetration and bacterial enumeration were attributed to variation in inoculating material or pathogen challenge rather than probiotic treatment. Probiotic administration influenced the microbiota composition to a small extend. Learnings from the present study indicate that the experimental setup, including incubation time and choice of inoculating material, should be chosen with care.

Exogenous infusion of short-chain fatty acids can improve intestinal functions independently of the gut microbiota

The present experiment was conducted to investigate the effects of exogenously infused short-chain fatty acids (SCFAs) on the growth development and intestinal functions in a germ-free (GF) pig model. Twelve hysterectomy-derived newborn piglets were reared in six sterile isolators. All piglets were hand-fed Co60-γ-irradiated sterile milk powder for 21 d and then were switched to sterile feed for another 21 d. During the second 21-d period, GF piglets (n = 6) were orally infused with 25 mL/kg sterile saline per day, and SCFA piglets (n = 6) were orally infused with 25 mL/kg SCFAs mixture (acetic, propionic, and butyric acids, 45, 15, and 11 mM, respectively) per day. We observed the concentrations of SCFAs in serum and intestine, and the messenger ribonucleic acid (mRNA) abundance of G-protein-coupled receptor-43 in the ileum was increased (P < 0.05) in the SCFA group. Meanwhile, oral infusion of SCFAs enhanced (P < 0.05) the contents of glucagon-like peptide-2 in the jejunum and serum and tended to increase the villi height in the ileum (P < 0.10). Besides, the activities of lipase, trypsin, sucrase, lactase, Na+-K+-adenosine triphosphatase ([ATPase] P < 0.05), and Ca2+-Mg2+-ATPase (P < 0.10) were stimulated and the mRNA expressions of solute carrier family 7 (SLC7A1) and regeneration protein (REG)-ΙΙΙ γ in the jejunum (P < 0.05) were upregulated in the SCFA group. Additionally, SCFAs infusion downregulated the mRNA abundances of interleukin (IL)-1β and IL-6 in the jejunum, ileum, or colon (P < 0.05) and increased the counts of white blood cell, neutrophils, and lymphocyte in the blood (P < 0.05). Collectively, exogenous infusion of SCFAs might improve intestinal health through promoting intestinal development and absorption function, and enhancing intestinal immune function, and these effects were occur independently of the gut microbiota.

Sodium butyrate can improve intestinal integrity and immunity in juvenile Chinese mitten crab (Eriocheir sinensis) fed glycinin

Butyrate is a fermentation byproduct of gut microbiota and is susceptible to chronic oxidative stress. This study investigates the mitigative effects of sodium butyrate (SBT) on growth inhibition and intestinal damage induced by glycinin in juvenile Chinese mitten crab (Eriocheir sinensis). All four experimental diets containing 80 g/kg glycinin were formulated with 0, 10, 20 and 40 g/kg SBT respectively. There was no glycinin or SBT in the control diet. Juvenile crabs (0.33 ± 0.01g) were respectively fed with these five diets for eight weeks. The diets with 10 and 20 g/kg SBT significantly improved the survival and weight gain of the crabs compared with those in the 0 g/kg SBT group, and showed no difference with the control group. The crabs fed diets containing glycinin without SBT had lower glutathione and glutathione peroxidase activities but higher malondialdehyde in the intestine than those in the control group. Moreover, dietary glycinin decreased the lysozyme and phenoloxidase activities and improved the level of histamine in the intestine compared with the control group, while the supplementation of SBT counteracted these negative effects. The addition of SBT could also restore the impaired immunity and morphological structure of the intestine. Dietary SBT could increase the mRNA expression of antimicrobial peptides genes (anti-lipopolysaccharide factor 1 and 2) and decrease the content of pro-inflammatory factor TNF-α. The SBT could restore the intestinal microbial community disorganized by glycinin. The abundance of pathogenic bacteria (Aeromonas, Vibrio and Pseudomonas) decreased significantly and the potential probiotic bacteria (Bacillus, Lactobacillus, Chitinibacter and Dysgonomonas) increased significantly in the 10 g/kg SBT group. This study suggests that sodium butyrate supplementation can mitigate the negative effects induced by glycinin such as growth inhibition, intestinal inflammation and reduction of beneficial flora in the gut.

Protein Level and Infantile Diarrhea in a Postweaning Piglet Model

Infantile diarrhea is a serious public health problem around worldwide and results in millions of deaths each year. The levels and sources of dietary protein are potential sources of diarrhea, but the relationship between the pathogenesis causes of infantile diarrhea and protein intake remains poorly understood. Many studies have indicated that the key to understanding the relationship between the protein in the diet and the postweaning diarrhea of piglets is to explore the influences of protein sources and levels on the mammalian digestion system. The current study was designed to control diarrhea control by choosing different protein levels in the diet and aimed at providing efficient regulatory measures for infantile diarrhea by controlling the protein levels in diets using a postweaning piglets model. To avoid influences from other protein sources, casein was used as the only protein source in this study. Fourteen piglets (7.98 ± 0.14 kg, weaned at 28 d) were randomly allotted to two dietary treatments: a control group (Cont, containing 17% casein) and a high protein group (HP, containing 30% casein). The experiment lasted for two weeks and all animals were free to eat and drink water ad libitum. The diarrhea score (1 = normal; 3 = watery diarrhea) and growth performance were recorded daily. The results showed that the piglets in HP group had persistent diarrhea during the whole study, while no diarrhea was noticed in the control groups. Also, the feed intake and body weights were reduced in the HP groups compared with the other group (P < 0.05). The diarrhea-related mRNA abundances were analyzed by real-time PCR; the results showed that HP treatment markedly decreased the expression of aquaporin (AQP, P < 0.05) and the tight junction protein (P<0.05), but increased inflammatory cytokines (P < 0.01) than those in control group. In addition, the Adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway (P < 0.01) was inhibited in the HP group. Intestinal microbiota was tested by 16S sequencing, and we found that the HP group had a low diversity compared the other group. In conclusion, despite being highly digestible, a high casein diet induced postweaning diarrhea and reduced the growth performance of the postweaning piglets. Meanwhile, AQP, tight junction protein, and intestinal immune were compromised. Thus, the mechanism of how a highly digestible protein diet induces diarrhea might be associated with the AMPK signaling pathway and intestinal microbiome.

Sodium Butyrate Protects the Intestinal Barrier by Modulating Intestinal Host Defense Peptide Expression and Gut Microbiota after a Challenge with Deoxynivalenol in Weaned Piglets

This study aims to determine whether sodium butyrate (SB) could antagonize deoxynivalenol (DON)-induced intestinal epithelial dysfunction. In a four-week feeding trial, twenty-eight barrows were randomly divided into four treatments: (1) uncontaminated basal diet (control); (2) 4 mg/kg DON-contaminated diet (DON); (3) basal diet supplemented with 0.2% SB (SB); and (4) 4 mg/kg DON + 0.2% SB (DON + SB). A decrease in performance was observed in DON-exposed animals, which was prevented by the dietary SB supplementation. DON exposure also depressed the expression of host defense peptides (HDPs) in the intestine, impaired the intestinal barrier integrity, and disturbed the gut microbiota homeostasis. These alterations induced by DON were attenuated by SB supplementation. The supplementation of 0.2% SB ameliorated the adverse effects of DON on the liver in terms of hepatic lesions as well as serum concentrations of alkaline phosphatase and aspartate aminotransferase. In IPEC-J2 cells, pretreatment with SB alleviated the DON-induced decreased cell viability. Additionally, the NOD2/caspase-12 pathway participated in the alleviation of SB on DON-induced diminished HDP expression. Taken together, these data demonstrated that SB protected piglets from DON-induced intestinal barrier dysfunction potentially through stimulation of intestinal HDP assembly and regulation in gut microbiota.

Effects of dietary fatty acids on gut health and function of pigs pre- and post-weaning

Fatty acids (FA) play a major role in relation to mucosal immune responses, epithelial barrier functions, oxidative stress, and inflammatory reactions. The dietary FA composition and the molecular structures (chain length and number of double bonds) influence digestion, absorption and metabolism, and the bioactivity of the FA. Piglets post-weaning having an immature intestine and not fully formed immune functions are very vulnerable to invading microorganisms. Manipulation of the milk FA composition via sow nutrition, or inclusion of dietary fat sources in the feed for newly weaned pigs, may be used as a strategic tool to enhance pig performance and their gut health and function pre- and post-weaning. Medium-chain fatty acids (MCFA) are absorbed directly into the portal blood and may contribute to immediate energy for the enterocytes. In addition, the MCFA, similarly to the short-chain fatty acids (SCFA), possess antibacterial effects and may thereby prevent overgrowth of pathogenic bacteria in the gastrointestinal tract. The essential FA, linoleic (LA) and α-linolenic (ALA) FA, form the building blocks for the long-chain polyunsaturated n-3 and n-6 FA. The conversion of ALA and LA into n-3 and n-6 eicosanoids, respectively, influences the molecular structures of metabolites and inflammatory reactions and other immune responses upon bacterial challenges. Dietary manipulation of the lactating sow influences the transfer of the n-3 and n-6 polyunsaturated fatty acids (PUFA) from the sow milk to the piglet and the incorporation of the FA into piglet enteric tissues and cell membranes, which exerts bioactivity of importance for immune responses and the epithelial barrier function. Especially, the n-3 PUFA present in fish oil seem to influence the gut health and function of pigs, and this is of importance during the transition periods such as post-weaning in which piglets are prone to inflammation. The proportion of unsaturated FA in the cell membranes influences the susceptibility to oxidative stress. Oxidative stress accompanies infectious diseases, and the development of lipid peroxides and other reactive oxygen products may be harmful to the epithelial barrier function. Fatty acid peroxides from the feed may also be absorbed with other lipid-solubles and thereby harm the intestinal function. Hence, antioxidative protection is important for the enteric cells. In conclusion, manipulation of the dietary FA composition can influence the gut health and function in pigs and may support a normal immune system and modulate resistance to infectious diseases during especially stressful phases of a pig's life such as post-weaning.

Applicability of an Unmedicated Feeding Program Aimed to Reduce the Use of Antimicrobials in Nursery Piglets: Impact on Performance and Fecal Microbiota

Simple Summary

The need for a reduction in the use of antibiotics in livestock to safeguard their efficacy requires the development of alternatives. In this line, the use of alternative by-products or ingredients, with functional properties brings the opportunity to improve pig health and thus, reduce medicalization. Therefore, in the present study, we aimed to evaluate the impact of an alternative feeding program based on unmedicalized diets formulated with fibrous by-products and functional feed ingredients on performance and fecal microbiota of young pigs compared to a common weaner diet supplemented with antibiotics. The alternative feeding program could anticipate the gut development of young piglets, which at the end of the nursery period presented a fecal microbiota more similar to that found in fattening animals. Moreover, piglets in the unmedicalized diets showed a trend to reduce the course of diarrhea immediately after weaning. The alternative feeding program showed, however, a reduced growth efficiency during the nursery period that needs to be discussed in the frame of the costs-benefits analysis of reducing antibiotics.

Abstract

This study aimed to assess the impact of two different feeding programs, including or not antimicrobials, on gut microbiota development at early ages in commercial pigs. For this, 21-day-old weaned piglets were distributed into 12 pens (6 replicates with 26 pigs each) and fed ad libitum until fattening with: standard commercial formula with antibiotics and zinc oxide (2400 ppm) (AB), and alternative unmedicated feed formula (UN). Subsequently, the animals were moved to the fattening unit (F) receiving a common diet. Pigs were weighed, and feed consumption and diarrhea scores registered. Feces were collected on days 9 (pre-starter), 40 (starter) and 72 (fattening) post-weaning and microbial DNA extracted for 16S rDNA sequencing. Piglets fed UN diets had a worse feed efficiency (p < 0.05) than AB during nursery; however, UN pigs spent less time scouring after weaning (p = 0.098). The structure of fecal community evolved with the age of the animals (p = 0.001), and diet also showed to have a role, particularly in the starter period when UN microbiomes clustered apart from AB, resembling the ecosystems found in the fattening animals. Fibrolytic genera (Fibrobacter, Butyrivibrio, Christellansellaceae) were enriched in UN piglets whereas Lactobacillus characterized AB piglets (adjusted p < 0.05). Overall, this alternative feeding program could anticipate the gut development of piglets despite a lower feed efficiency compared to standard medicalized programs.

Dynamic Changes in Serum Metabolomic Profiles of Growing Pigs Induced by Intravenous Infusion of Sodium Butyrate

This study aimed to explore the dynamic changes in metabolite profiles and metabolism pathways in the serum of growing pigs by intravenous infusion of sodium butyrate (SB). Fourteen crossbred growing barrows (BW = 23.70 ± 1.29 kg) fitted with jugular cannula were randomly allocated to the SB and control (Con) groups, each group consisted of seven replicates (pens), with one pig per pen. At 9:00 of each day during the experimental period, pigs in the SB group were infused with 10 mL of SB (200 mmol/L, pH 7.4, 37 °C) via precaval vein, while the Con group was treated with the same volume of physiological saline. On day 4, the blood of each pig was collected at 0, 30, 60, and 120 min after the intravenous infusion. Metabolites in the serum were detected by gas chromatograph-mass spectrometry analysis. Pathway analysis of metabolomic profiles showed that the differential metabolites mainly enriched in amino acid metabolism, lipid-related metabolism, and the tricarboxylic acid (TCA) cycle. More importantly, the relative concentrations of all eight essential amino acids, five non-essential amino acids, and two amino acid derivatives were decreased by the parenteral SB. In addition, SB significantly increased the relative concentrations of eicosanoic acid and octadecanoic acid and decreased the relative concentration of glycerol-3-phosphate at 0 min (three days after intravenous infusion of SB), which suggests that parenteral SB may increase stearates mobilization and decrease the biosynthesis of stearates. In conclusion, intravenous infusion of SB may induce more amino acids to synthesize proteins and affect fat metabolism through increasing fat mobilization and decreasing the biosynthesis of stearates. However, a further study is needed to understand the mechanism of extensive metabolic pathway changes induced by parenteral SB.

Icariin enhances intestinal barrier function by inhibiting NF-κB signaling pathways and modulating gut microbiota in a piglet model

This study investigated the effects of icariin on intestinal barrier function and its underlying mechanisms. The icariin diet improved the growth rate and reduced the diarrhea rate in piglets. The icariin diet also reduced the levels of plasma and colonic IL-1β, -6, -8, TNF-α, and MDA but increased the plasma and colonic activity of SOD, GPx, and CAT. Besides, the levels of plasma and colonic endotoxin, DAO, d-lactate, and zonulin were markedly reduced in icariin groups. Meanwhile, dietary intake icariin significantly increased the gene and protein expression of ZO-1, Occludin, and Claudin-1 in the colon. Furthermore, the gene and protein expressions of TLR4, MyD88, and NF-κB were significantly inhibited in the colon of icariin fed piglets. The intestinal microbiota composition and function was changed by the icariin diet. Collectively, these findings increase our understanding of the mechanisms by which ICA enhances the intestinal barrier function and promotes the development of nutritional intervention strategies.

Comparative effects of dietary supplementations with sodium butyrate, medium-chain fatty acids, and n-3 polyunsaturated fatty acids in late pregnancy and lactation on the reproductive performance of sows and growth performance of suckling piglets

This study was conducted to compare the effects of adding sodium butyrate (SB), medium-chain fatty acids (MCFAs), or n-3 polyunsaturated fatty acids (n-3 PUFAs) to the diet of sows during late gestation and lactation on the reproductive performance of sows and the growth performance and intestinal health of suckling piglets. Twenty-four sows (Landrace × Large-White hybrid; third parity; 200 ± 15 kg) were randomly assigned to receive 1 of 4 diets: basal diet (control group), basal diet + 1 g SB/kg (SB group), basal diet + 7.75 g MCFA/kg (MCFA group), or basal diet + 68.2 g n-3 PUFA/kg (n-3 PUFA group). The experiment began on day 85 of gestation and ended day 22 of lactation. Colostrum samples were collected from each sow. After the experiment, blood and tissue samples were collected from 1 randomly selected piglet. The results showed that the weaning-to-estrus interval of sows in the SB, MCFA, and n-3 PUFA groups was shorter than that of sows in the control group (P < 0.05). The incidence of diarrhea in suckling piglets in the SB, MCFA, and n-3 PUFA groups was lower than that of piglets in the control group (P < 0.05). The fat, protein, IgA, IgG, and IgM concentration in colostrum from sows increased following dietary supplementation with SB, MCFA, or n-3 PUFA (P < 0.05). Comparison with the control group, the mRNA expression of claudin-1, zona occludens 1, and interleukin-10 increased in the jejunum mucosa of suckling piglets in the SB, MCFA, and n-3 PUFA groups, while that of TLR4 decreased (P < 0.05). Compared with the control group, the Chao1 and ACE indexes of microbial flora in the colon contents of piglets in the SB, MCFA, and MCFA groups increased (P < 0.05), while the relative abundance of Firmicutes, Actinobacteria, and Synergistetes decreased at the phylum level (P < 0.05). In conclusion, during late pregnancy and lactation, dietary SB supplementation had a greater effect on intestinal health and caused a greater decrease in preweaning mortality of suckling piglets than did dietary MCFA or n-3 PUFA supplementation; dietary MCFA supplementation shortened the weaning-to-estrus interval of sows to a greater extent than did dietary SB or n-3 PUFA supplementation; and dietary n-3 PUFA supplementation increased the fat and protein content in the colostrum to the greatest extent.

Response of gastrointestinal fermentative activity and colonic microbiota to protected sodium butyrate and protected sodium heptanoate in weaned piglets challenged with ETEC F4. Arch Anim Nutr 2019;73:339-359. [PMID: 31342760 DOI: 10.1080/1745039x.2019.1641376]

This study aimed to evaluate the potential of two new fat-protected butyrate or heptanoate salts to improve gut health and control post-weaning colibacillosis in weaning piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4⁺, particularly focusing on their impact on intestinal microbiota and fermentative activity along the gastrointestinal tract (GIT). Seventy-two 21-d-old pigs were fed a plain diet (CTR) or supplemented with sodium butyrate (BUT) or sodium heptanoate (HPT), both at 0.3%. After a week of adaptation, animals were orally challenged at days 8 and 9 with 5.8 · 10⁹ and 6.6 · 10¹⁰ cfu, respectively, and were euthanised on d 4 and d 8 post-inoculation (PI) (n = 8) to collect blood, digesta and tissue samples and characterise microbial groups, pathogen loads (qPCR), fermentation, ileal histomorphometry and immune markers. Colonic microbiota was analysed by 16S rRNA gene MiSeq sequencing. Supplementing both acid salts did not compensate clinical challenge effects nor performance impairments and neither histomorphometry nor serum biomarkers. Changes in the gastric fermentative activity were registered, BUT reducing lactic acid concentrations (day 8 PI), and with HPT fewer animals presenting detectable concentrations of propionic, butyric and valeric acids. At ileum BUT increased acetic acid concentration (day 8 PI), and both additives reduced short-chain fatty acids (SCFA) in the colon. Increases in enterobacteria and coliforms counts in ileal digesta (day 4 PI, p < 0.10) and mucosa scrapes (p < 0.05) were registered although E. coli F4 gene copies were unaffected. Regarding changes in the colonic microbiota (day 4 PI), Prevotellaceae and Prevotella were promoted with BUT supplementation whereas only minor groups were modified in HPT-treated animals. Summarising, although the pathogen loads or inflammatory mediators remained unresponsive, butyrate and heptanoate showed a significant impact on microbial fermentation along the whole GIT, being able to modify different bacterial groups at the colon. It could be hypothesised that these effects might be mediated by a carry-over effect of the changes observed in gastric fermentation, but possibly also to a better nutrient digestion in the foregut as a result of the reduced colonic SCFA concentrations.

Probiotic Lactobacillus rhamnosus GG Induces Alterations in Ileal Microbiota With Associated CD3-CD19-T-bet+IFNγ+/- Cell Subset Homeostasis in Pigs Challenged With Salmonella enterica Serovar 4,[5],12:i:

Salmonella enterica serovar 4,[5],12:i:- (S. 4,[5],12:i:-) is an emerging foodborne pathogen causing salmonellosis in humans and animals. Probiotic Lactobacillus rhamnosus GG (LGG) is an effective strategy for controlling enteric infections through maintaining gut microbiota homeostasis and regulating the intestinal innate immune response. Here, LGG was orally administrated to newly weaned piglets for 1 week before S. 4,[5],12:i:- challenge. S. 4,[5],12:i:- challenge led to disturbed gut microbiota, characterized by increased levels of Psychrobacter, Chryseobacterium indoltheticum, and uncultured Corynebacteriaceae populations, as well as an aberrant correlation network in Prevotellaceae NK3B31 group-centric species. The beneficial effect of LGG correlated with attenuating the expansion of Prevotellaceae NK3B31 group. Fusobacterium only found in the pigs treated with LGG was positively correlated with Lactobacillus animalis and Propionibacterium. Administration of LGG induced the expansion of CD3^-CD19^-T-bet⁺IFNγ⁺ and CD3^-CD19^-T-bet⁺IFNγ^- cell subsets in the peripheral blood at 24 h after a challenge of S. 4,[5],12:i:-. S. 4,[5],12:i:- infection increased the population of intraepithelial CD3^-CD19^-T-bet⁺IFNγ⁺ and CD3^-CD19^-T-bet⁺IFNγ^- cells in the ileum; however, this increase was attenuated via LGG administration. Correlation analysis revealed that LGG enriched Flavobacterium frigidarium and Facklamia populations, which were negatively correlated with intraepithelial CD3^-CD19^-T-bet⁺IFNγ⁺ and CD3^-CD19^-T-bet⁺IFNγ^- cells in the ileum. The present data suggest that probiotic LGG alters gut microbiota with associated CD3^-CD19^-T-bet⁺IFNγ^+/- cell subset homeostasis in pigs challenged with S. enterica 4,[5],12:i:-. LGG may be used in potential gut microbiota-targeted therapy regimens to regulate the specific immune cell function and, consequently, control enteric infections.

Exogenous carbohydrases added to a starter diet reduced markers of systemic immune activation and decreased Lactobacillus in weaned pigs1

Although the impact of carbohydrases on performance and nutrient utilization has been well studied, their effects on immune status and intestinal microbiota are less known in pigs. This study aimed to evaluate the impact of xylanase (X) and a carbohydrase enzyme blend (EB; cellulase, ß-glucanase, and xylanase) on the immune profile of the intestine and peripheral system as well as intestinal microbes and microbial metabolites of weaned pigs fed higher fiber diets. Pigs (n = 460; 6.43 ± 0.06 kg BW; F25 × 6.0 Genetiporc) were blocked by initial BW. Pens (n = 48; 12 per treatment; 9 or 10 pigs per pen) were randomly assigned to 1 of 4 dietary treatments, including a higher fiber control diet (CON) and the CON supplemented with 0.01% X, 0.01% EB, or both enzymes (X + EB), arranged in a 2 × 2 factorial. The diets were based on corn, soybean meal, corn distillers dried grains with solubles, and wheat middlings. After 7-d adaptation to the environment, pigs were fed experimental diets ad libitum for 28 d. Blood samples were collected from the same pig within each pen on days 0, 7, 14, and 28. Intestinal tissues and digesta were collected on day 28. Bacteria 16S rRNA gene copy numbers were quantified using qPCR. The mRNA levels of colonic IL-17, occludin (OCLN), and claudin 3 (CLDN3) were greater in pigs fed diets with X + EB, but not X or EB, compared with those fed CON (P < 0.05). The EB in the diet reduced plasma IL-8 over the 28-d trial compared with diets without EB (P < 0.05). There was an X × EB interaction on plasma tumor necrosis factor α and IL-1ß (P < 0.05); their levels were decreased when X and EB were added together, but not individually, compared with CON. The EB decreased cecal propionate, butyrate, and total volatile fatty acids (P < 0.05). Pigs fed X had lower ileal Lactobacillus and greater ileal and cecal Enterobacteriaceae compared with those fed unsupplemented diets (P < 0.05). The EB decreased Lactobacillus (P < 0.05) and tended to decrease (P = 0.065) Enterobacteriaceae in the colon compared with diets without EB. In conclusion, the addition of X and EB together decreased systemic markers of immune activation, potentially diverting energy and nutrients towards growth. The EB reduced colonic Lactobacillus and cecal total volatile fatty acids, probably due to improved prececal fiber and starch degradation and thus reduced substrate availability in the large intestine. These data corroborated previously observed enhanced growth in pigs fed EB-supplemented diets.

Nutritional Intervention for the Intestinal Development and Health of Weaned Pigs

Weaning imposes simultaneous stress, resulting in reduced feed intake, and growth rate, and increased morbidity and mortality of weaned pigs. Weaning impairs the intestinal integrity, disturbs digestive and absorptive capacity, and increases the intestinal oxidative stress, and susceptibility of diseases in piglets. The improvement of intestinal development and health is critically important for enhancing nutrient digestibility capacity and disease resistance of weaned pigs, therefore, increasing their survival rate at this most vulnerable stage, and overall productive performance during later stages. A healthy gut may include but not limited several important features: a healthy proliferation of intestinal epithelial cells, an integrated gut barrier function, a preferable or balanced gut microbiota, and a well-developed intestinal mucosa immunity. Burgeoning evidence suggested nutritional intervention are one of promising measures to enhance intestinal health of weaned pigs, although the exact protective mechanisms may vary and are still not completely understood. Previous research indicated that functional amino acids, such as arginine, cysteine, glutamine, or glutamate, may enhance intestinal mucosa immunity (i.e., increased sIgA secretion), reduce oxidative damage, stimulate proliferation of enterocytes, and enhance gut barrier function (i.e., enhanced expression of tight junction protein) of weaned pigs. A number of feed additives are marketed to assist in boosting intestinal immunity and regulating gut microbiota, therefore, reducing the negative impacts of weaning, and other environmental challenges on piglets. The promising results have been demonstrated in antimicrobial peptides, clays, direct-fed microbials, micro-minerals, milk components, oligosaccharides, organic acids, phytochemicals, and many other feed additives. This review summarizes our current understanding of nutritional intervention on intestinal health and development of weaned pigs and the importance of mechanistic studies focusing on this research area.

Kazachstania turicensis CAU Y1706 ameliorates atopic dermatitis by regulation of the gut-skin axis

Atopic dermatitis (AD) causes chronic inflammatory skin disease that results in a considerable economic expense and social burden. Certain Lactobacillus strains ameliorate AD, but the effects of probiotic yeast on AD have not been investigated to date. In this study, we isolated Kazachstania turicensis CAU Y1706, commonly known as a kefir yeast, and evaluated its mitigating effects using an ovalbumin-sensitized AD mouse model. Overall, K. turicensis CAU Y1706 was generally effective against AD. Oral administration of K. turicensis CAU Y1706 suppressed T helper type 2 immune response factors by regulatory T cells and upregulation of T helper type 1 cytokine levels. Kazachstania turicensis CAU Y1706 also reduced IgE levels as well as the number of eosinophil and mast cells. Furthermore, feces from K. turicensis CAU Y1706-treated mice had more butyrate-producing bacteria, such as Lactobacillus, Bacteroides, Ruminococcus, and Akkermansia, although the level of Fecalibacterium was significantly reduced. Therefore, K. turicensis CAU Y1706 modulates immune responses as well as gut microbiota, thus indicating that it has potential for application as a supplement for alleviation of AD.

Growth performance, lipid metabolism, and health status of grass carp (Ctenopharyngodon idella) fed three different forms of sodium butyrate

Sodium butyrate (SB) can be coated with fatty acid matrix. In this study, the effects of three SB forms, being zero-lipid-coated (SB-A), half-lipid-coated (SB-B), and 2/3 lipid-coated (SB-C) (w/w), on growth, lipid metabolism, and health status of grass carp (Ctenopharyngodon idella) were investigated. The three forms of SB were added to a control diet to form three SB diets, Con., SB-A, SB-B, and SB-C, where the pure SB in each SB diet was kept at the same level (500 mg kg^-1). A total of 216 C. idella (14.10 ± 0.60 g/fish) were allotted into four groups (triplicate per group) and fed the four diets respectively for 56 days, and then fish were sampled and determined. Fish growth was not affected by any of the three forms of SB. Viscerosomatic index, intraperitoneal fat index, and crude lipid of hepatopancreas and muscle were significantly decreased and villus height of intestine and mRNA expression of MyD88 and TLR22 in hepatopancreas were significantly improved in SB diets compared with control (p < 0.05), respectively. MiSeq sequencing of the V3-V4 region of bacterial 16S rRNA gene revealed that SB increased the relative abundances of intestinal healthy bacteria, Fusobacteria and Bacteroides, and the abundances of Cetobacterium decreased in the SB-C group. In conclusion, the present results showed that three forms of SB, without affecting the growth of fish, respectively decreased lipid accumulation and probably have a beneficial effect on health of C. idella.

Microbial-Driven Butyrate Regulates Jejunal Homeostasis in Piglets During the Weaning Stage

Microbe-derived butyrate plays an important role in the gut health of young mammals during the weaning stage. A greater understanding of how butyrate regulates intestinal development is necessary for overcoming post-weaning diarrheal diseases. We aimed to investigate whether jejunal microbial metabolite butyrate modulates the apoptosis/proliferation balance and immune response in piglets during the post-weaning period of the first 3 weeks of life. On the one hand, during the first week post-weaning, the relative abundances of the dominant bacterial families Erysipelotrichaceae (P < 0.01) and Lachnospiraceae (P < 0.01) were increased, which induced decreases in both butyrate production (P < 0.05) and its receptor (G-protein coupled receptor 43) expression (P < 0.01). The resulting intestinal inflammation (inferred from increased TNF-α and IFN-γ expression) contributed to the onset of cell apoptosis and the inhibition of cell-proliferation along the crypt-villus axis, which were followed by impaired jejunal morphology (i.e., increased crypt-depth) (P < 0.05) and intestinal dysfunction (i.e., decreased creatine kinase, and lactate dehydrogenase) (P < 0.05). On the other hand, during the second week post-weaning, the relative abundances of Lactobacillaceae (P < 0.01) and Ruminococcaceae (P < 0.05) were increased. The increases were accompanied by increased butyrate production (P < 0.05) and its receptor expression (P < 0.01), leading to the inhibition of cell apoptosis and the stimulation of cell proliferation via decreased pro-inflammatory cytokines and thereby the improvement of intestinal development and function. Herein, this study demonstrates that microbial-driven butyrate might be a key modulator in the maintenance of intestinal homeostasis after weaning. The findings suggest that strategies to promote butyrate production can maintain the apoptosis/proliferation balance via minimizing intestinal inflammation, and thereby improving post-weaning jejunal adaptation toward gut health.

Response of Colonic Mucosa-Associated Microbiota Composition, Mucosal Immune Homeostasis, and Barrier Function to Early Life Galactooligosaccharides Intervention in Suckling Piglets

Suckling piglets were used to investigate the response of colonic mucosa-associated microbiota composition, mucosal immune homeostasis, and barrier function to early life galactooligosaccharides (GOS) intervention. Ten milliliter 1 g/kg body weight GOS solutions and physiological saline solutions were fed to the newborn piglets in the GOS group and in the control (CON) group a week time, respectively. Six piglets from each group were euthanized on day 8 and day 21. GOS piglets had a higher abundance of short-chain fatty acids (SCFAs) producer such as Prevotella, Barnesiella, Parabacteroides, and Unclassified Porphyromonadaceae in colonic mucosa ( P < 0.05). In addition, the total SCFAs level in colonic digesta of GOS piglets increased on day 8 ( P < 0.05) and day 21 ( P = 0.064). Meanwhile, a higher SCFAs concentration in colon of the GOS piglets altered the gene expression of inflammatory cytokines (IL-8 and IL-10) and barrier proteins (ZO-1 and Claudin-1) through regulating the phosphorylation of the NFκB and AMPK signaling pathway. In summary, these results provide important insights and understandings to reveal the relationship between the mucosal microbiota colonization and intestinal function at the early life stage of piglets.

Pathobiont release from dysbiotic gut microbiota biofilms in intestinal inflammatory diseases: a role for iron?

Gut microbiota interacting with an intact mucosal surface are key to the maintenance of homeostasis and health. This review discusses the current state of knowledge of the biofilm mode of growth of these microbiota communities, and how in turn their disruptions may cause disease. Beyond alterations of relative microbial abundance and diversity, the aim of the review is to focus on the disruptions of the microbiota biofilm structure and function, the dispersion of commensal bacteria, and the mechanisms whereby these dispersed commensals may become pathobionts. Recent findings have linked iron acquisition to the expression of virulence factors in gut commensals that have become pathobionts. Causal studies are emerging, and mechanisms common to enteropathogen-induced disruptions, as well as those reported for Inflammatory Bowel Disease and colo-rectal cancer are used as examples to illustrate the great translational potential of such research. These new observations shed new light on our attempts to develop new therapies that are able to protect and restore gut microbiota homeostasis in the many disease conditions that have been linked to microbiota dysbiosis.

Gut microbiota was modulated by moxibustion stimulation in rats with irritable bowel syndrome

Background

The pathogenesis of irritable bowel syndrome (IBS) is closely related to intestinal dysbacteriosis and can be controlled by moxibustion treatment. However, the mechanism underlying the therapeutic value of moxibustion in IBS treatment remains unknown.

Methods

An IBS rat model was established by colorectal distention (CRD) stimulus and mustard oil clyster. Sixty-five male rats were randomly divided into six groups: normal, IBS model, moxibustion, electroacupuncture (EA), Bifid-triple Viable Capsule (BTVC) and Pinaverium Bromide (PB) groups. The moxibustion group was treated with mild moxibustion at the bilateral Tianshu (ST25) and Shangjuxu (ST37) for 10 min/day for 7 days, the EA group was given EA at ST25 and ST37 once daily for 7 days, while the BTVC group and PB groups received Bifid-triple Viable Capsule and Pinaverium Bromide solution (at the proportion of 1:0.018) respectively by gavage once daily for 7 days. After the treatment, abdominal withdrawal reflex (AWR) scores were determined based on CRD stimulus, gut microbiota profiling was conducted by 16S rRNA high-throughput sequencing.

Results

Irritable bowel syndrome model rats had significantly increased AWR scores at all intensities (20, 40, 60 and 80 mmHg) compared with the normal group. Moxibustion treatment significantly reduced AWR scores compared with the IBS model group at all intensities. Across all groups the most abundant phyla were Bacteroidetes and Firmicutes followed by Proteobacteria and Candidatus Saccharibacteria. At genus level IBS model rats had a higher abundance of Prevotella, Bacteroides and Clostridium XI and a lower abundance of Lactobacillus and Clostridium XIVa compared with normal rats. These changes in microbiota profiles could however be reversed by moxibustion treatment. Alpha diversity was decreased in IBS model rats compared with normal rats, yet significantly increased in moxibustion- and PB-treated rats compared with IBS rats.

Conclusion

Our findings suggest that moxibustion treats IBS by modulating the gut microbiota.

Sodium butyrate inhibits the production of HMGB1 and attenuates severe burn plus delayed resuscitation-induced intestine injury via the p38 signaling pathway

BACKGROUND

Inflammatory response triggered by high mobility group box-1 (HMGB1) protein and oxidative stress play critical roles in the intestinal injury after severe burn. Sodium butyrate, a histone deacetylase inhibitor, has potential anti-inflammatory properties, inhibiting the expression of inflammatory mediators such as HMGB1 in diverse diseases. This study was designed to investigate the effects of sodium butyrate on severe burn plus delayed resuscitation-induced intestine injury, intestinal expressions of HMGB1 and intracellular adhesion molecule-1 (ICAM-1), oxidative stress, and signal transduction pathway changes in rats.

MATERIALS AND METHODS

Fifty-six Sprague-Dawley rats were divided into 3 groups randomly: (1) sham group, animals underwent sham burn; (2) burn group, rats subjected to full-thickness burns of 30% total body surface area (TBSA) and received 2ml/kg/TBSA lactated Ringer solution for resuscitation at 6, 12, and 36h after burn injury; (3) burn plus sodium butyrate (burn+SB) group, animals received burn injury and lactated Ringer solution with sodium butyrate inside for resuscitation in the same manner. Diamine oxidase (DAO) concentration in plasma was measured by enzyme-linked immunosorbent assay. Intestinal fatty acid binding protein (I-FABP) and ICAM-1 expressions in the intestine were analyzed by immunohistochemical method. HMGB1 and p38 mitogen-activated protein kinase (MAPK) expressions in the intestine tissues were examined by Western blot. The intestinal concentration of malondialdehyde (MDA) was also determined.

RESULTS

Intestinal HMGB1 expression was significantly increased in burn group compared with sham group. Sodium butyrate administration significantly inhibited the HMGB1 expression in the intestine, decreased the DAO concentration in plasma, reduced the intestinal I-FABP expression, and improved the intestinal histologic changes induced by burn injury plus delayed resuscitation. Sodium butyrate treatment also markedly reduced the increase of intestinal ICAM-1 expression and MDA content, and inhibited p38 MAPK activity in the intestine of severely burned rats with delayed resuscitation.

CONCLUSIONS

Sodium butyrate inhibits HMGB1 expression which could be attributed to p38 MAPK signal transduction pathway and decreases intestinal inflammatory responses and oxidative stress, thus attenuates burn plus delayed resuscitation-induced intestine injury.