Multi-omics Uncover Neonatal Cecal Cell Development Potentials

BackgroundAlthough, the cecum plays vital roles in absorption of water, electrolytes, and other small molecules, and harbors trillions of commensal bacteria to shape large intestine immune functions, it is unknown the cecum development potentials at single cell level during the very crucial neonatal developmental period.ResultsUsing singe cell RNA-seq and proteomics, we have characterized six major types of cecal epithelial cells: undifferentiated cells; immune cells (Ims); cecumocytes (CCs); goblet, Paneth like cells (PLCs), and enteroendocrine cells (EECs) with specific marker genes. CCs mature with a gradual decrease in number; however, Ims develop with a continuing increase in number. Meanwhile secretory cells (goblet, PLCs, EECs) reduce in number during the neonatal developmental period. The cells exhibit specific development and maturation trends controlled by transcriptional factors, ligand-receptor pairs, and other factors. As piglets grow, cecal content and mucosal microbial diversity increases dramatically with population of beneficial microbiota, such as lactobacillus, increasing significantly. Moreover, cecal mucosal-associated and cecal content microbiota are positively correlated and both show significant correlation with different types of cecal epithelial cells and plasma metabolites. ConclusionsThis is the first presentation of neonatal cecal cell development and maturation naturally at single cell level with transcript, protein, microbiota and metabolism perspectives. Furthermore, this study provides an important tool for the determination of novel interventions in cecal drug delivery and metabolism studies.

Dietary Fiber Influences Bacterial Community Assembly Processes in the Gut Microbiota of Durco × Bamei Crossbred Pig

Several studies have shown that dietary fiber can significantly alter the composition and structure of the gut bacterial community in humans and mammals. However, few researches have been conducted on the dynamics of the bacterial community assembly across different graded levels of dietary fiber in different gut regions. To address this, 24 Durco × Bamei crossbred pigs were randomly assigned to four experimental chows comprising graded levels of dietary fiber. Results showed that the α-and β-diversity of the bacterial community was significantly different between the cecum and the jejunum. Adding fiber to the chow significantly increased the α-diversity of the bacterial community in the jejunum and cecum, while the β-diversity decreased. The complexity of the bacterial network increased with the increase of dietary fiber in jejunal content samples, while it decreased in cecal content samples. Furthermore, we found that stochastic processes governed the bacterial community assembly of low and medium dietary fiber groups of jejunal content samples, while deterministic processes dominated the high fiber group. In addition, deterministic processes dominated all cecal content samples. Taken together, the variation of gut community composition and structure in response to dietary fiber was distinct in different gut regions, and the dynamics of bacterial community assembly across the graded levels of dietary fiber in different gut regions was also distinct. These findings enhanced our knowledge on the bacterial community assembly processes in gut ecosystems of livestock.

A Comparison of Production Performance, Egg Quality, and Cecal Microbiota in Laying Hens Receiving Graded Levels of Vitamin B12

The objective of the study was to investigate the effect of fortified diets with standard vs. high levels of vitamin B12 on cecal microbiota composition, production performance, and eggshell quality of laying hens. Dietary treatments consisted of a basal diet with no supplementation of vitamin B12 or supplemented with 25, 100, and 400 μg/kg vitamin B12, respectively. A total of 432 laying hens were randomly assigned to four treatments with six replicates per treatment. No significant effect of dietary treatments on the production performance of hens was detected. The shell thickness of eggs from hens fed diet supplemented with 100 μg/kg of vitamin B12 was higher (P < 0.01) than that of eggs from hens fed control diet or supplemented with 25 μg/kg vitamin B12. The shell percentage of eggs from hens fed diet supplemented with 400 μg/kg of vitamin B12 was higher (P < 0.01) than that of eggs from hens fed other treatment diets. Dietary vitamin B12 did not modulate diversity of the cecal microbiota of the layers. At genus level, the cecal content from layers fed diet with supplemental level of 100 or 400 μg/kg of vitamin B12 had higher (P < 0.01) abundance of Faecalibacterium and lower (P < 0.05) abundance of Acinetobacter compared with the cecal content from layers fed other two diets. The abundance of Lactobacillus in the cecal samples from layers fed 100 μg/kg of supplemental level of vitamin B12 was higher (P < 0.05) than that from layers fed other three diets. The abundance of Butyricicoccus was higher (P < 0.05), while Bilophila was lower (P < 0.05) in the cecal content of layers fed 400 μg/kg of vitamin B12 diet compared with those from layers fed other three diets. The results of PICRUSt analysis indicated that 10 predicted metabolic functions of the cecal microbial communities were positively correlated to dietary vitamin B12 level. Overall, dietary supplementation of 100 or 400 μg/kg of vitamin B12 had equivalent effects and caused the significant change in composition and metabolic functions of cecal microorganisms, which could positively impact eggshell quality, metabolism, and gut health of laying hens.

Breed differences in the expression levels of gga-miR-222a in laying hens influenced H2S production by regulating methionine synthase genes in gut bacteria

Background The microbiota in the cecum of laying hens is crucial for host digestion, metabolism, and odor gas production. The results of recent studies have suggested that host microRNAs (miRNAs) can regulate gene expression of the gut microbiota. In the present study, the expression profiles of host-derived miRNAs in the cecal content of two laying hen breeds; Hy-line Gray and Lohmann Pink, which have dissimilar H2S production, were characterized; and their effects on H2S production by regulating the expression of gut microbiota-associated genes were demonstrated. Results The differential expression of microbial serine O-acetyltransferase, methionine synthase, aspartate aminotransferase, methionine-gamma-lyase, and adenylylsulfate kinase between the two hen breeds resulted in lower H2S production in the Hy-line hens. The results also revealed the presence of miRNA exosomes in the cecal content of laying hens, and an analysis of potential miRNA-target relationships between 9 differentially expressed miRNAs and 9 differentially expressed microbial genes related to H2S production identified two methionine synthase genes, Odosp_3416 and BF9343_2953, that are targeted by gga-miR-222a. Interestingly, in vitro fermentation results showed that gga-miR-222a upregulates the expression of these genes, which increased methionine concentrations but decreased H2S production and soluble sulfide concentrations, indicating the potential of host-derived gga-miR-222a to reduce H2S emission in laying hens. Conclusion The findings of the present study reveal both a physiological role by which miRNAs shape the cecal microbiota of laying hens and a strategy to use host miRNAs to manipulate the microbiome and actively express key microbial genes to reduce H2S emissions and breed environmentally friendly laying hens.

PSVI-19 The Association of Benzoic Acid and Essential Oils Increases the Cecal Biodiversity in Weaned Piglets and Improves Growth Performance in Finishing Pigs

Benzoic acid (BA) and essential oils (EO) have antimicrobial properties and can be used in antibiotic restriction situations. The objective of this study was to evaluate the effects of BA and EO on cecal content microbiota in weaned piglets and growth performance from the nursery to finishing phase. One hundred and twenty barrows were weaned at 23 days (6.40 ± 0.53 kg) and assigned into 3 treatments (10 replicates) in randomized block design: basal diet without additives (NC), basal diet with antibiotics (PC), and association of 0,3% benzoic acid and essential oil (BA+EO). Colistin sulphate (200 ppm) in the nursery diets and enramycin (10 and 5 ppm) in the growing and finishing diets were used in the PC treatment. The pigs were weighed 0, 42 and 132 days into the experiment. On day 9, one animal per pen (7 replicates) was euthanized and the cecal content was collected for microbiome analyses. Growth performance was analyzed by MIXED procedure (SAS, 2009) and the Tukey test was used to compare the means (P < 0.050). The averages for biodiversity between treatments were compared using the number of OTUs and the Kruskal Wallis test (P < 0.050), and the statistical program STAMP was used. In the microbiome analyses, the results of the taxonomic classification, by principal components analysis (PCA), showed a marked difference in bacterial communities per treatment and a significant increase in the number of operational taxonomic units (OTUs) was observed in the BA+EO group (P < 0.05). At 132 days, the final weight (P = 0.006) and total average daily gain (P = 0.028) of BA+EO and PC were higher than NC. In conclusion, supplementation with BA+EO increases biodiversity in cecal content in the post-weaning period, resulting in an improvement in the growth performance of finishing pigs.

Secondary bile acid ursodeoxycholic acid alters weight, the gut microbiota, and the bile acid pool in conventional mice

Ursodeoxycholic acid (commercially available as ursodiol) is a naturally occurring bile acid that is used to treat a variety of hepatic and gastrointestinal diseases. Ursodiol can modulate bile acid pools, which have the potential to alter the gut microbiota community structure. In turn, the gut microbial community can modulate bile acid pools, thus highlighting the interconnectedness of the gut microbiota-bile acid-host axis. Despite these interactions, it remains unclear if and how exogenously administered ursodiol shapes the gut microbial community structure and bile acid pool in conventional mice. This study aims to characterize how ursodiol alters the gastrointestinal ecosystem in conventional mice. C57BL/6J wildtype mice were given one of three doses of ursodiol (50, 150, or 450 mg/kg/day) by oral gavage for 21 days. Alterations in the gut microbiota and bile acids were examined including stool, ileal, and cecal content. Bile acids were also measured in serum. Significant weight loss was seen in mice treated with the low and high dose of ursodiol. Alterations in the microbial community structure and bile acid pool were seen in ileal and cecal content compared to pretreatment, and longitudinally in feces following the 21-day ursodiol treatment. In both ileal and cecal content, members of the Lachnospiraceae Family significantly contributed to the changes observed. This study is the first to provide a comprehensive view of how exogenously administered ursodiol shapes the healthy gastrointestinal ecosystem in conventional mice. Further studies to investigate how these changes in turn modify the host physiologic response are important.

Multiomics analysis reveals the presence of a microbiome in the gut of fetal lambs

ObjectiveMicrobial exposure is critical to neonatal and infant development, growth and immunity. However, whether a microbiome is present in the fetal gut prior to birth remains debated. In this study, lambs delivered by aseptic hysterectomy at full term were used as an animal model to investigate the presence of a microbiome in the prenatal gut using a multiomics approach.DesignLambs were euthanised immediately after aseptic caesarean section and their cecal content and umbilical cord blood samples were aseptically acquired. Cecal content samples were assessed using metagenomic and metatranscriptomic sequencing to characterise any existing microbiome. Both sample types were analysed using metabolomics in order to detect microbial metabolites.ResultsWe detected a low-diversity and low-biomass microbiome in the prenatal fetal gut, which was mainly composed of bacteria belonging to the phyla Proteobacteria, Actinobacteria and Firmicutes. Escherichia coli was the most abundant species in the prenatal fetal gut. We also detected multiple microbial metabolites including short chain fatty acids, deoxynojirimycin, mitomycin and tobramycin, further indicating the presence of metabolically active microbiota. Additionally, bacteriophage phiX174 and Orf virus, as well as antibiotic resistance genes, were detected in the fetal gut, suggesting that bacteriophage, viruses and bacteria carrying antibiotic resistance genes can be transmitted from the mother to the fetus during the gestation period.ConclusionsThis study provides strong evidence that the prenatal gut harbours a microbiome and that microbial colonisation of the fetal gut commences in utero.

Effects of Dietary Defatted Meat Species on Metabolomic Profiles of Murine Liver, Gastrocnemius Muscle, and Cecal Content

In both humans and animals, meat not only constitutes one of the sources of protein, but also includes various water-soluble bioactive substances such as imidazole peptides (carnosine and anserine) and taurine. Previous studies demonstrated that dietary meat species could differently affect physiological functions; however, the mechanisms of this remain unclear. To explore the physiological effects of dietary defatted meat species, especially on metabolism, we investigated their influence on the metabolomic profiles of the liver, gastrocnemius muscle, and cecal content in mice. Casein (control) or a defatted meat species (beef leg, pork leg, chicken leg, or chicken breast) was supplied as the major protein source in the diet for four weeks, and metabolism-related molecules were measured by gas chromatography–mass spectrometry. We found that various metabolite levels in tissues and cecal content differed according to the types of dietary protein consumed. Specifically, differences in carnosine, 1,5-anhydro-glucitol, inositol, butyric acid, and propionic acid were clearly observed. Among them, the highest carnosine intake by dietary pork leg was clearly related to the highest carnosine level in the liver. In addition, taurine intake was suggested to be linked to some metabolic pathways including taurine and hypotaurine metabolism in cecal content. These results provide additional knowledge of the effects of different dietary meat species on human and animal health.