Intestinal microbiota differentially affect brush border enzyme activity and gene expression in the neonatal gnotobiotic pig

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.

Gut microb-aging and its relevance to frailty aging

This review explores 'microb-aging' in the gut and its potential link to frailty aging. We explore this connection through alterations in microbiota's taxonomy and metabolism, as well as with concepts of ecological resilience, pathobionts emergence, and biogeography. We examine microb-aging in interconnected body organs, emphasizing the bidirectional relationship with 'inflammaging'. Finally, we discuss how targeting microb-aging could improve screening, diagnostic, and therapeutic approaches in geriatrics.

Meta-analysis reveals the predictable dynamic development of the gut microbiota in commercial pigs

IMPORTANCE

The swine gut microbiome undergoes an age-dependent assembly pattern with a developmental phase at early ages and a stabilization phase at later ages. Shorter time intervals and a wider range of data sources provided a clearer understanding of the gut microbiota colonization and succession and their associations with pig growth and development. The rapidly changing microbiota of suckling and weaning pigs implies potential time targets for growth and health regulation through gut microbiota manipulation. Since swine gut microbiota development is predictable, swine microbiota age can be calculated and compared between animal treatment groups rather than relying only on static time-matched comparisons.

Comparison of the Microbiome-Metabolome Response to Copper Sulfate and Copper Glycinate in Growing Pigs

This study aims to compare the fecal microbiome-metabolome response to copper sulfate (CuSO₄) and copper glycinate (Cu-Gly) in pigs. Twelve Meishan gilts were allocated into the CuSO₄ group and the Cu-Gly group (fed on a basal diet supplemented with 60 mg/kg copper from CuSO₄ or Cu-Gly) paired in litter and body weight. After a two-week feeding trial, the Cu-Gly group had a higher copper digestibility, blood hemoglobin, and platelet volume and higher levels of plasma iron and insulin-like growth factor-1 than the CuSO₄ group. The Cu-Gly treatment increased the abundance of the Lachnospiraceae family and the genera Lachnospiraceae XPB1014, Corprococcus_3, Anaerorhabdus_furcosa_group, Lachnospiraceae_FCS020_group, and Lachnospiraceae_NK4B4_group and decreased the abundance of the Synergistetes phylum and Peptostreptococcaceae family compared to the CuSO₄ treatment. Moreover, the Cu-Gly group had a lower concentration of 20-Oxo-leukotriene E4 and higher concentrations of butyric acid, pentanoic acid, isopentanoic acid, coumarin, and Nb-p-Coumaroyl-tryptamine than the CuSO₄ group. The abundance of Synergistetes was positively correlated with the fecal copper content and negatively correlated with the fecal butyric acid content. The abundance of the Lachnospiraceae_XPB1014_group genus was positively correlated with the plasma iron level and fecal contents of coumarin and butyric acid. In conclusion, Cu-Gly and CuSO₄ could differentially affect fecal microbiota and metabolites, which partially contributes to the intestinal health of pigs in different manners.

Microbial influences on gut development and gut-brain communication

The developmental programs that build and sustain animal forms also encode the capacity to sense and adapt to the microbial world within which they evolved. This is abundantly apparent in the development of the digestive tract, which typically harbors the densest microbial communities of the body. Here, we review studies in human, mouse, zebrafish and Drosophila that are revealing how the microbiota impacts the development of the gut and its communication with the nervous system, highlighting important implications for human and animal health.

Gut microbiota absence and transplantation affect growth and intestinal functions: An investigation in a germ-free pig model

This study was conducted to investigate host–microbiota interactions and explore the effects of maternal gut microbiota transplantation on the growth and intestinal functions of newborns in a germ-free (GF) pig model. Twelve hysterectomy-derived GF Bama piglets were reared in 6 sterile isolators. Among them, 6 were considered as the GF group, and the other 6 were orally inoculated with healthy sow fecal suspension as fecal microbiota transplanted (FMT) group. Another 6 piglets from natural birth were regarded as the conventional (CV) group. The GF and FMT groups were hand-fed with Co60-γ-irradiated sterile milk powder, while the CV group was reared by lactating Bama sows. All groups were fed for 21 days. Then, all piglets and then were switched to sterile feed for another 21 days. Results showed that the growth performance, nutrient digestibility, and concentrations of short-chain fatty acids in the GF group decreased (P < 0.05). Meanwhile, the serum urea nitrogen concentration and digesta pH values in the GF group increased compared with those in the FMT and CV groups (P < 0.05). Compared with the CV group, the GF group demonstrated upregulation in the mRNA expression levels of intestinal barrier function-related genes in the small intestine (P < 0.05). In addition, the mRNA abundances of intestinal development and absorption-related genes in the small intestine and colon were higher in the GF group than in the CV and FMT groups (P < 0.05). The FMT group exhibited greater growth performance, lipase activity, and nutrient digestibility (P < 0.05), higher mRNA expression levels of intestinal development and barrier-related genes in the small intestine (P < 0.05), and lower mRNA abundances of pro-inflammatory factor in the colon and jejunum (P < 0.05) than the CV group. In conclusion, the absence of gut microbes impaired the growth and nutrient digestibility, and healthy sow gut microbiota transplantation increased the growth and nutrient digestibility and improved the intestinal development and barrier function of newborn piglets, indicating the importance of intestinal microbes for intestinal development and functions.

Lactobacillus rhamnosus GG modifies the metabolome of pathobionts in gnotobiotic mice

Background

Lactobacillus rhamnosus GG (LGG) is the most widely used probiotic, but the mechanisms underlying its beneficial effects remain unresolved. Previous studies typically inoculated LGG in hosts with established gut microbiota, limiting the understanding of specific impacts of LGG on host due to numerous interactions among LGG, commensal microbes, and the host. There has been a scarcity of studies that used gnotobiotic animals to elucidate LGG-host interaction, in particular for gaining specific insights about how it modifies the metabolome. To evaluate whether LGG affects the metabolite output of pathobionts, we inoculated with LGG gnotobiotic mice containing Propionibacterium acnes, Turicibacter sanguinis, and Staphylococcus aureus (PTS).

Results

16S rRNA sequencing of fecal samples by Ion Torrent and MinION platforms showed colonization of germ-free mice by PTS or by PTS plus LGG (LTS). Although the body weights and feeding rates of mice remained similar between PTS and LTS groups, co-associating LGG with PTS led to a pronounced reduction in abundance of P. acnes in the gut. Addition of LGG or its secretome inhibited P. acnes growth in culture. After optimizing procedures for fecal metabolite extraction and metabolomic liquid chromatography-mass spectrometry analysis, unsupervised and supervised multivariate analyses revealed a distinct separation among fecal metabolites of PTS, LTS, and germ-free groups. Variables-important-in-projection scores showed that LGG colonization robustly diminished guanine, ornitihine, and sorbitol while significantly elevating acetylated amino acids, ribitol, indolelactic acid, and histamine. In addition, carnitine, betaine, and glutamate increased while thymidine, quinic acid and biotin were reduced in both PTS and LTS groups. Furthermore, LGG association reduced intestinal mucosal expression levels of inflammatory cytokines, such as IL-1α, IL-1β and TNF-α.

Conclusions

LGG co-association had a negative impact on colonization of P. acnes, and markedly altered the metabolic output and inflammatory response elicited by pathobionts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02178-2.

Microbial sensing in the neonatal pig gut: effect of diet-independent and diet-dependent factors1

There is considerable agreement that the gastrointestinal microbiota contributes to the performance and health of the neonate, and this relationship includes an ability of the host animal to “sense” changes in the microbial community. Identifying the mechanisms used by the host to sense microbiota is one approach to developing methods to manipulate the microbiota to improve pig health and performance. Diet-independent microbial products are molecules unique to the microbial community and sensed by host pattern recognition receptors stimulating inflammation. Common among all members of the microbial community, their presence is unaffected by diet, but the nature of the response does depends on factors affecting the microenvironment in which the molecule is detected. Diet-dependent microbial products arise as products of fermentation of dietary components and include short-chain fatty acids, ammonia, phenols, hydrogen sulfide, amines, and many other compounds. A plethora of sensing mechanisms exists that include enzymatic metabolism as well as membrane receptors that have evolved to respond to microbial products (e.g., short-chain fatty acid receptors), or simply cross-react with microbial products. This review focuses on host mechanisms used to sense the intestinal microbiota and attempts to establish practical considerations for neonatal gut health based on current understanding.

Porcine colonoids and enteroids keep the memory of their origin during regeneration

The development of alternative in vitro culture methods has increased in the last decade as three-dimensional organoids of various tissues, including those of the small and large intestines. Due to their multicellular composition, organoids offer advantages over traditionally used immortalized or primary cell lines. However, organoids must be accurate models of their tissues of origin. This study compared gene expression profiles with respect to markers of specific cell types (stem cells, enterocytes, goblet, and enteroendocrine cells) and barrier maturation (tight junctions) of colonoid and enteroid cultures with their tissues of origin and colonoids with enteroids. Colonoids derived from three healthy pigs formed multilobed structures with a monolayer of cells similar to the crypt structures in colonic tissue. Colonoid and enteroid gene expression signatures were more similar to those found for the tissues of their origin than to each other. However, relative to their derived tissues, organoids had increased gene expression levels of stem cell markers Sox9 and Lgr5 encoding sex-determining region Y-box 9 and leucine-rich repeat-containing G protein-coupled rector 5, respectively. In contrast, expression levels of Occl and Zo1 encoding occludin and zonula occludens 1, respectively, were decreased. Expression levels of the cell lineage markers Atoh1, Cga, and Muc2 encoding atonal homolog 1, chromogranin A, and mucin 2, respectively, were decreased in colonoids, whereas Sglt1 and Apn encoding sodium-glucose transporter 1 and aminopeptidase A, respectively, were decreased in enteroids. These results indicate colonoid and enteroid cultures were predominantly comprised of undifferentiated cell types with decreased barrier maturation relative to their tissues of origin.

The impact of probiotics on gut health via alternation of immune status of monogastric animals

The intestinal immune system is affected by various factors during its development, such as maternal antibodies, host genes, intestinal microbial composition and activity, and various stresses (such as weaning stress). Intestinal microbes may have an important impact on the development of the host immune system. Appropriate interventions such as probiotics may have a positive effect on intestinal immunity by regulating the composition and activity of intestinal microbes. Moreover, probiotics participate in the regulation of host health in many ways; for instance, by improving digestion and the absorption of nutrients, immune response, increasing the content of intestinal-beneficial microorganisms, and inhibiting intestinal-pathogenic bacteria, and they participate in regulating intestinal diseases in various ways. Probiotics are widely used as additives in livestock and the poultry industry and bring health benefits to hosts by improving intestinal microbes and growth performance, which provides more choices for promoting strong and efficient productivity.

Evidence for the Contribution of Gut Microbiota to Age-Related Anabolic Resistance

Globally, people 65 years of age and older are the fastest growing segment of the population. Physiological manifestations of the aging process include undesirable changes in body composition, declines in cardiorespiratory fitness, and reductions in skeletal muscle size and function (i.e., sarcopenia) that are independently associated with mortality. Decrements in muscle protein synthetic responses to anabolic stimuli (i.e., anabolic resistance), such as protein feeding or physical activity, are highly characteristic of the aging skeletal muscle phenotype and play a fundamental role in the development of sarcopenia. A more definitive understanding of the mechanisms underlying this age-associated reduction in anabolic responsiveness will help to guide promyogenic and function promoting therapies. Recent studies have provided evidence in support of a bidirectional gut-muscle axis with implications for aging muscle health. This review will examine how age-related changes in gut microbiota composition may impact anabolic response to protein feeding through adverse changes in protein digestion and amino acid absorption, circulating amino acid availability, anabolic hormone production and responsiveness, and intramuscular anabolic signaling. We conclude by reviewing literature describing lifestyle habits suspected to contribute to age-related changes in the microbiome with the goal of identifying evidence-informed strategies to preserve microbial homeostasis, anabolic sensitivity, and skeletal muscle with advancing age.

The Role of Metal Oxide Nanoparticles, Escherichia coli, and Lactobacillus rhamnosus on Small Intestinal Enzyme Activity

Engineered nanomaterials (ENMs) have become common in the food industry, which motivates the need to evaluate ENM effects on human health. Gastrointestinal (GI) in vitro models (e.g. Caco-2, Caco-2/HT29-MTX) have been used in nanotoxicology research. However, the human gut environment is composed of both human cells and the gut microbiota. The goal of this study is to increase the complexity of the Caco-2/HT29-MTX in vitro model by co-culturing human cells with the Gram-positive, commensal Lactobacillus rhamnosus or the Gram-negative, opportunistic Escherichia coli; with the hypothesis that the presence of bacteria would ameliorate the effects of exposure to metal oxide nanoparticles (NPs) such as iron oxide (Fe2O3), silicone dioxide (SiO2), titanium dioxide (TiO2), or zinc oxide (ZnO). To understand this relationship, Caco-2/HT29-MTX cell barriers were acutely co-exposed (4 hours) to bacteria and/or NPs (pristine or in vitro digested). The activity of the brush border membrane (BBM) enzymes intestinal alkaline phosphatase (IAP), aminopeptidase-N (APN), sucrase isomaltase (SI) and the basolateral membrane enzyme (BLM) Na+/K+ ATPase were assessed. Findings show that (i) the human digestion process alters the physicochemical properties of NPs, (ii) large agglomerates of NPs remain entrapped on the apical side of the intestinal barrier, which (iii) affects the activity of BBM enzymes. Interestingly, some NPs effects were attenuated in the presence of either bacterial strains. Confocal microscopy detected bacteria-NPs interactions, which may impede the NP-intestinal cell contact. These results highlight the importance of improving in vitro models to closely mimic the complexities of the human body.

Sending signals - The microbiota's contribution to intestinal epithelial homeostasis

The intestine is inhabited by a diverse range of microorganisms, which requires the host to employ numerous barrier measures to prevent bacterial invasion. However, the intestinal microbiota additionally acts symbiotically with host cells to maintain epithelial barrier function, and perturbation to this interaction plays a pivotal role in intestinal pathogenesis. In this review, we highlight current findings of how the intestinal microbiota influences host intestinal epithelial cells. In particular, we review the roles of numerous microbial-derived products as well as mechanisms by which these microbial products influence the regulation of intestinal epithelial population dynamics and barrier function.

The Effect of Coconut Oil Addition to Feed of Pigs on Rectal Microbial Diversity and Bacterial Abundance

Simple Summary

Looking for non-antibiotic substances that can enhance health by improving the gastrointestinal microbiome of animals is an ongoing task. Among other compounds, medium-chain fatty acids, such as lauric acid, can exert positive effects. Coconut oil is a rich source of lauric acid, and therefore, the aim of this study was to describe the effect of adding coconut oil to the feed of growing pigs on intestinal microbiome diversity and bacterial abundance. Rectal swab samples were analyzed to assess the intestinal microbiomes of pigs. Typically, growing pigs are characterized by continuously changing bacterial communities as a result of aging. However, a significant effect of coconut oil treatment was detected in the presented study. Decreases in Corynebacterium, Pseudomonadales, and Mitsuokella and increases in Alloprevotella, Bifidobacteriales, and Lactobacilli could be attributed to the supplementation of feed with coconut oil. Coconut oil treatment did not have a significant effect on the diversity index of rectal microbiomes, but an abundant increase in probiotics such as Bifidobacterium and Lactobacillus in the gastrointestinal tract is desirable in pig breeding. From this point of view, the addition of coconut oil to the feed of pigs is a good option for improving the microbiome in their gastrointestinal tracts.

Abstract

Coconut oil has a high content of lauric acid, which has selective antibacterial activity. This study aimed to explore the effect of coconut oil ingestion on the gastrointestinal microbiomes of pigs. A 14-day-long feeding experiment included 19 pigs in two groups (9 on a normal diet and 10 on a diet supplemented with coconut oil). At the start and end of the experiment, a rectal swab sample was taken from each pig in both groups, and total bacterial DNA was extracted. We used 16S rRNA high-throughput amplicon sequencing to evaluate the microbiome changes during the feeding experiment. A total of 446 operational taxonomic units (OTUs) were detected in the whole sample set. Shannon’s indices of bacterial diversity did not change significantly during the experiment. Changes in the bacterial community during the study period and in response to the coconut oil treatment were highly significant (p < 0.001). During the study, an increase in the abundance of Lactobacillus was detected in the group treated with coconut oil. An increase in Alloprevotella, Bifidobacteriales, and Lactobacillales and a decrease in Corynebacterium, Mitsuokella, Psychrobacter, and Pseudomonadales were attributed to the coconut oil treatment. Although the addition of coconut oil to pig feed did not affect Shannon’s index of diversity, it had a positive effect on the abundance of bacterial groups that are considered to be commensal and/or probiotic.

Effects of incubation and chick rearing on intestinal morphology, digestive enzyme activities, and mRNA expression of nutrient transporter genes in the pigeon (Columba livia) under artificial farming conditions

The present study investigated the changes in morphology, enzyme activities in the pancreas and mucosa, and nutrient transporter gene expression in the duodenum and jejunum in male and female pigeons during the incubation and chick-rearing periods. Forty-two pairs of White King pigeons with 2 fertile eggs per pair were randomly divided into 7 groups by different breeding stages. The crypt depth of the duodenum and jejunum reached the peak at day 1 (R1) and day 7 (R7) of chick rearing, respectively. The jejunum surface area increased to a maximum value at R1. Amylase activity in the pancreas decreased to the lowest value at R1, whereas trypsin and lipase activities peaked at 17 D of incubation (I17) and R7, respectively. In male pigeons, mucosal Na⁺-K⁺-ATPase activity in the duodenum and jejunum was the highest at R15 and it was at I17 in female pigeons. Jejunum sucrose activity in female pigeons was higher at I4 than that at I17 (P < 0.05). The gene expression of FAT/CD36 and I-FABP in the duodenum gradually increased and then declined in the late chick-rearing period. SGLT1 in the jejunum decreased to a lower level at I17 and R25 in male pigeons (P < 0.05). GLUT2 expression in female duodenum and male jejunum decreased to a lower value at I17 compared with that at R15 (P < 0.05). In the late of incubation (from I10 to I17), expression of duodenum CAT1, B⁰AT1, and PepT1 and jejunum CAT1, ASCT1, and PepT1 in female pigeons was significantly reduced (P < 0.05), whereas opposite results were found in male jejunum CAT1 and duodenum ASCT1. In conclusion, variations of intestinal morphology, activities of pancreatic and mucosal enzymes, and gene expression of nutrient transporters during incubation and chick-rearing periods, underlying potential changes of digestive and absorptive function and intestinal adaptation with sexual effects, may represent a complicated response to stimuli of different breeding stages.

The use of non-rodent model species in microbiota studies

In recent years, tremendous advances have been made in our ability to characterize complex microbial communities such as the gut microbiota, and numerous surveys of the human gut microbiota have identified countless associations between different compositional attributes of the gut microbiota and adverse health conditions. However, most of these findings in humans are purely correlative and animal models are required for prospective evaluation of such changes as causative factors in disease initiation or progression. As in most fields of biomedical research, microbiota-focused studies are predominantly performed in mouse or rat models. Depending on the field of research and experimental question or objective, non-rodent models may be preferable due to better translatability or an inability to use rodents for various reasons. The following review describes the utility and limitations of several non-rodent model species for research on the microbiota and its influence on host physiology and disease. In an effort to balance the breadth of potential model species with the amount of detail provided, four model species are discussed: zebrafish, dogs, pigs, and rabbits.

Potential relevance of pig gut content transplantation for production and research

It is becoming increasingly evident that the gastrointestinal microbiota has a significant impact on the overall health and production of the pig. This has led to intensified research on the composition of the gastrointestinal microbiota, factors affecting it, and the impact of the microbiota on health, growth performance, and more recently, behavior of the host. Swine production research has been heavily focused on assessing the effects of feed additives and dietary modifications to alter or take advantage of select characteristics of gastrointestinal microbes to improve health and feed conversion efficiency. Research on faecal microbiota transplantation (FMT) as a possible tool to improve outcomes in pigs through manipulation of the gastrointestinal microbiome is very recent and limited data is available. Results on FMT in humans demonstrating the transfer of phenotypic traits from donors to recipients and the high efficacy of FMT to treat Clostridium difficile infections in humans, together with data from pigs relating GI-tract microbiota composition with growth performance has likely played an important role in the interest towards this strategy in pig production. However, several factors can influence the impact of FMT on the recipient, and these need to be identified and optimized before this tool can be applied to pig production. There are obvious inherent biosecurity and regulatory issues in this strategy, since the donor's microbiome can never be completely screened for all possible non-desirable microorganisms. However, considering the success observed in humans, it seems worth investigating this strategy for certain applications in pig production. Further, FMT research may lead to the identification of specific bacterial group(s) essential for a particular outcome, resulting in the development of banks of clones which can be used as targeted therapeutics, rather than the broader approach applied in FMT. This review examines the factors associated with the use of FMT, and its potential application to swine production, and includes research on using the pig as model for human medical purposes.

Model development: establishing pigs with homogenous microbial profile in the hind gut

The considerable animal-to-animal variation in microbial profiles is a challenge in elucidating the role of gut microbiota in host metabolism. The main purpose of this study was, therefore, to develop a pig model with reduced animal-to-animal variation in gut microbial profile. Twelve piglets from four sows were reared conventionally and 12 piglets from four sows were reared artificially in high efficiency particulate air (HEPA) filtered isolators. All isolator-reared piglets were given an artificial colostrum formula containing the combined fecal material from all eight sows. All piglets were killed at 21 d of age and intestinal contents subjected to 16s rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) profiling. Resulting T-RFLP profiles clustered into two distinct groups representing the two treatment groups. Furthermore, Bray–Curtis dissimilarity distance values and Dice similarity indices showed reduced beta diversity in isolator-reared pigs indicating animal-to-animal variation was reduced in isolator-reared compared to conventional piglets. However, surprisingly, increased alpha diversity was observed in isolator-reared piglets compared with conventional piglets. In conclusion, the study demonstrated that rearing of piglets under conditions of controlled environment reduced animal-to-animal variation in the hindgut microbiota while paradoxically increasing within animal microbial diversity. Isolator rearing may be useful as a model to improve detection of treatment effects on gut microbiota.

Influence of fibre and betaine on development of the gastrointestinal tract of broilers between hatch and 14 d of age

An experiment was designed to determine the influence of fibre and betaine on the development of the intestine, liver and pancreas of broilers from hatch to 14 d of age. A total of 250-day-old Cobb 500 male broilers were allocated to 16 cages with 15 broilers each. Treatments were arranged in a 2 × 4 factorial design, consisting of 2 feed formulations (low and high fibre diets) and 4 levels of betaine (0, 1, 3 or 5 kg/t). At hatch, 10 birds in total were euthanised, and samples of the liver, pancreas, yolk sac and intestine were collected for reference of the analysed parameters before the start of the trial. On d 4, 9 and 14, 5 birds per cage (10 birds per treatment) were selected, euthanised and treated as the same as the birds at hatch. Villus height and width and crypt depth were determined on the duodenum samples, and absorptive area was calculated. The number of enterocytes in mitosis at the villus was determined by a positive reaction to antibody for Ki67 protein, and fused villus was evaluated visually. The relative weight of the yolk sac reduced (P < 0.05) as birds aged while the intestine and liver reached a maximum (P < 0.05) at around d 4 and the pancreas at d 9. Birds fed the high fibre diet had greater feed intake, lower relative weight of the pancreas and higher villus (P < 0.05) than birds fed the low fibre diet. Villus width increased (P < 0.05) at 4 d of age, and this was associated with fused villus. Betaine inclusion reduced (P < 0.05) villus width, increased (P < 0.05) villus size and absorptive area, and reduced (P < 0.05) the number of enterocytes with positive reaction for the antibody Ki-67. Betaine inclusion reduced the width and increased the absorptive area and the villus height of the duodenum of birds up to 14 d of age. The higher fibre diet increased feed intake and villus height, yet reduced pancreas relative weight, while not affecting body weight gain. This response was possibly due to a dilution effect of the fibre, reducing nutrient absorption and consequently stimulating villus growth to improve absorption rates.

Function of capric acid in cyclophosphamide-induced intestinal inflammation, oxidative stress, and barrier function in pigs

The small intestine is not only critical for nutrient absorption, but also serves as an important immune organ. Medium-chain fatty acids have nutritional and metabolic effects and support the integrity of the intestinal epithelium. However, their roles in intestinal immunity in pigs are not fully understood. We investigated the effects of a medium-chain fatty acid, capric acid, on intestinal oxidative stress, inflammation, and barrier function in porcine epithelial cells and miniature pigs after treatment with the immune suppressant cyclophosphamide. Capric acid alleviated inflammatory cytokine production (TNF-α and IL-6) and related gene expression (NF-κB, TNF-α, IFN-γ), alleviated oxidative stress (GSSG/GSH ratio, H₂O₂, and malondialdehyde), and increased oxidative stress-related gene expression (SOD1 and GCLC) in cyclophosphamide-treated IPEC-J2 cells. The permeability of FD-4 and expression of ZO-1 and OCLN in cyclophosphamide-treated IPEC-J2 cells were reduced by capric acid. Dietary capric acid reduced TNF-α, IL-6, and MDA levels and increased SOD, GPx, and the expression of genes related to pro-inflammatory, oxidative stress, and intestinal barrier functions in cyclophosphamide-treated miniature pigs. These results revealed that capric acid has protective effects against cyclophosphamide-induced small intestinal dysfunction in pigs.

Postnatal regulation of MAMDC4 in the porcine intestinal epithelium is influenced by bacterial colonization

The MAM domain‐containing 4 (MAMDC4) protein is associated with the unique endocytotic mechanism observed in the intestine of mammals during the immediate postnatal period. Transcriptional expression of MAMDC4 was substantially upregulated at birth in both the piglet jejunum and ileum and its expression decreases after birth. The protein was found localized specifically to the apical region of the luminal epithelium, however, MAMDC4 protein expression was lost at day 10 and 15 in the jejunum and ileum, respectively, and was not associated with “fetal” enterocyte replacement. Although spatial variation in the subcellular localization of Claudin 1 (CLDN1) was noted at day 3, the loss of MAMDC4 at later stages of development did not appear to have any effect on the tight junction structure. Germ‐free (GF) piglets and piglets whose gastrointestinal flora consists exclusively of Escherichia coli (EC) or Lactobacillus fermentum (LF) maintained MAMDC4 protein expression to 14 days of age in distal regions of the small intestine whereas those with conventionalized intestinal flora (CV) showed no MAMDC4 protein at this age. MAMDC4 protein expression was most pronounced in the LF and GF colonized piglets which showed staining in the epithelial cells at 75% and 95% of the length of the small intestine, respectively, which matched that of the newborn. In contrast, EC animals showed only a low abundance at these regions as well as a discontinuous staining pattern. Collectively these results suggest that maturation of MAMDC4 expression in the porcine epithelium occurs more rapidly than what is reported in previously studied rodent species. Furthermore, intestinal bacterial colonization is a major regulator of MAMDC4 in a manner specific to bacterial species and independent of enterocyte turnover.

Human microbiota-associated swine: current progress and future opportunities

Gnotobiotic (GN) rodent models have provided insight into the contributions of the gut microbiota to host health and preventing disease. However, rodent models are limited by several important physiological and metabolic differences from humans, and many rodent models do not dependably replicate the clinical manifestations of human diseases. Due to the high degree of similarity in anatomy, physiology, immunology and brain growth, the domestic pig (Sus scrofa) is considered a clinically relevant model to study factors influencing human gastrointestinal, immune, and brain development. Gnotobiotic piglet models have been developed and shown to recapitulate key aspects of GN rodent models. Human microbiota-associated (HMA) piglets have been established using inocula from infants, children, and adults. The gut microbiota of recipient HMA piglets was more similar to that of the human donor than that of conventionally reared piglets harboring a pig microbiota. Moreover, Bifidobacterium and Bacteroides, two predominant bacterial groups of infant gut, were successfully established in the HMA piglets. Thus, the HMA pig model has the potential to be a valuable model for investigating how the gut microbiota composition changes in response to environmental factors, such as age, diet, vaccination, antibiotic use and infection. The HMA also represents a robust model for screening the efficacy of pre- and probiotic interventions. Lastly, HMA piglets can be an ideal model with which to elucidate microbe-host interactions in human health and disease due to the similarities to humans in anatomy, physiology, developmental maturity at birth, and the pathophysiology of many human diseases.

Development of the Chick Microbiome: How Early Exposure Influences Future Microbial Diversity

The concept of improving animal health through improved gut health has existed in food animal production for decades; however, only recently have we had the tools to identify microbes in the intestine associated with improved performance. Currently, little is known about how the avian microbiome develops or the factors that affect its composition. To begin to address this knowledge gap, the present study assessed the development of the cecal microbiome in chicks from hatch to 28 days of age with and without a live Salmonella vaccine and/or probiotic supplement; both are products intended to promote gut health. The microbiome of growing chicks develops rapidly from days 1–3, and the microbiome is primarily Enterobacteriaceae, but Firmicutes increase in abundance and taxonomic diversity starting around day 7. As the microbiome continues to develop, the influence of the treatments becomes stronger. Predicted metagenomic content suggests that, functionally, treatment may stimulate more differences at day 14, despite the strong taxonomic differences at day 28. These results demonstrate that these live microbial treatments do impact the development of the bacterial taxa found in the growing chicks; however, additional experiments are needed to understand the biochemical and functional consequences of these alterations.

Fatty acids, inflammation and intestinal health in pigs

The intestine is not only critical for nutrient digestion and absorption, but also is the largest immune organ in the body. However, in pig production, inflammation induced by numerous factors, such as pathogen infection and stresses (e.g., weaning), results in intestinal mucosal injury and dysfunction, and consequently results in poor growth of pigs. Dietary fatty acids not only play critical roles in energy homeostasis and cellular membrane composition, but also exert potent effects on intestinal development, immune function, and inflammatory response. Recent studies support potential therapeutic roles for specific fatty acids (short chain and medium chain fatty acids and long chain polyunsaturated fatty acids) in intestinal inflammation of pigs. Results of these new lines of work indicate trophic and cytoprotective effects of fatty acids on intestinal integrity in pigs. In this article, we review the effect of inflammation on intestinal structure and function, and the role of specific fatty acids on intestinal health of pigs, especially under inflammatory conditions.

Development and Evaluation of qPCR Assay for Quantitation of Kazachstania slooffiae and Total Yeasts Occurring in the Porcine Gut

Kazachstania slooffiae is the dominating yeast in pig's gut. No methods others than cultivation were applied for enumeration of yeasts within this ecosystem. Therefore, the aim of this study was to develop a real-time quantitative polymerase chain reaction (qPCR) assay to quantitate total yeasts and K. slooffiae in the porcine gut. This work demonstrated that the copy numbers in gDNA can be determined by qPCR using PCR amplicons as a calibrator and one-point calibration method. The gDNA were then used as a calibrator for further analysis. The values of quantitation cycle and PCR amplification efficiency of gDNA calibrator were highly reproducible. DNA was extracted from feces and from 10 different cultured yeasts found in pigs' intestine. The qPCR results using primers NL1/LS2 encoding 26S rDNA correlated (r = 0.984, P < 0.0001) with cultivation results. From two primer sets developed, one set encoding act1 gene was suitable for quantitation of K. slooffiae. The copy numbers of K. slooffiae could be determined by 40% analyzed animals, amounting to about 70% of total yeasts. The application of this method in next studies will help to get more information about K. slooffiae and total yeasts in the gut of pigs.

Claudin-4 undergoes age-dependent change in cellular localization on pig jejunal villous epithelial cells, independent of bacterial colonization

Newborn piglets are immunologically naïve and must receive passive immunity via colostrum within 24 hours to survive. Mechanisms by which the newborn piglet gut facilitates uptake of colostral cells, antibodies, and proteins may include FcRn and pIgR receptor-mediated endocytosis and paracellular transport between tight junctions (TJs). In the present study, FcRn gene (FCGRT) was minimally expressed in 6-week-old gut and newborn jejunum but it was expressed at significantly higher levels in the ileum of newborn piglets. pIgR was highly expressed in the jejunum and ileum of 6-week-old animals but only minimally in neonatal gut. Immunohistochemical analysis showed that Claudin-5 localized to blood vessel endothelial cells. Claudin-4 was strongly localized to the apical aspect of jejunal epithelial cells for the first 2 days of life after which it was redistributed to the lateral surface between adjacent enterocytes. Claudin-4 was localized to ileal lateral surfaces within 24 hours after birth indicating regional and temporal differences. Tissue from gnotobiotic piglets showed that commensal microbiota did not influence Claudin-4 surface localization on jejunal or ileal enterocytes. Regulation of TJs by Claudin-4 surface localization requires further investigation. Understanding the factors that regulate gut barrier maturation may yield protective strategies against infectious diseases.

Early changes in microbial colonization selectively modulate intestinal enzymes, but not inducible heat shock proteins in young adult Swine

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but also exert site- and sometimes diet-specific long-term effects on key components of intestinal homeostasis.

Performance, organ zinc concentration, jejunal brush border membrane enzyme activities and mRNA expression in piglets fed with different levels of dietary zinc

This study aimed at investigating the effect of dietary zinc on performance, jejunal brush border membrane enzyme activities and mRNA levels of enzymes and two zinc transporters in piglets. A total of 126 piglets were weaned at 26 ±1 days of age and randomly allocated into three groups fed with diets 50, 150 and 2500 mg zinc/kg. Performance was recorded and at weekly intervals, eight piglets per group were killed. The activities of isolated brush border membrane enzymes including lactase, maltase, sucrase, aminopeptidase-N and intestinal alkaline phosphatase (IAP), and the relative transcript abundance of aminopeptidase-N (APN), sucrase-isomaltase (SUC), IAP and the two zinc transporters SLC39A4 (ZIP4) and SLC30A1 (ZnT1) were investigated in the jejunum. Feeding pharmacological zinc levels increased weight gain (p < 0.001) during the first week, but performance was lower (p < 0.05) in the third week. Organ zinc concentrations were increased by high dietary zinc level. The activity of IAP was higher (p < 0.05) with the highest dietary zinc level, no effects were determined for other enzymes. Dietary zinc level had no effect on transcript abundance of digestive enzymes. The mRNA levels decreased (p < 0.001) for ZIP4, and increased for ZnT1 (p < 0.05) with pharmacological zinc levels. In conclusion, pharmacological zinc levels improved performance in the short-term. Intestinal mRNA level of zinc transporters changed with high zinc supply, but this did not prevent zinc accumulation in tissues, suggesting hampered homoeostatic regulation. This might cause impaired performance during longer supply.

The effect of a Bacillus-based direct-fed microbial supplemented to sows on the gastrointestinal microbiota of their neonatal piglets

Direct-fed microbials (DFM) supplemented in sow diets may confer health benefits to the host and their piglets by reducing pathogens in the sow and environment. In this study we evaluated the effect of a Bacillus-based DFM on the gastrointestinal microbiota of neonatal piglets. A total of 208 sows were divided into 2 treatments: a control diet and the control diet supplemented with a Bacillus subtilis-based DFM (3.75 × 10(5) cfu/g feed). Twenty-one piglets sampled from each sow treatment group were euthanized on d 3 of lactation followed by an additional 15 piglets per treatment on d 10 of lactation. Litters from DFM-supplemented sows had greater (P = 0.02) weaning weights and a tendency (P = 0.09) for improvement in litter ADG. Sows supplemented with the DFM weaned more pigs (P = 0.06) than control sows which was reflected in numerically lower but not statistically different (P = 0.12) decrease in piglet mortality in DFM litters. Terminal RFLP was used to characterize gastrointestinal (GI) microbial populations in the ileum and colon of the piglets. Terminal restriction fragments (T-RF) were compared between control and DFM treatments. There was a greater incidence and quantity of T-RF B423 and H330 (binary P = 0.01, 0.08; quantitative P = 0.01, 0.05, respectively), putatively identified as Lactobacillus gasseri/johnsonii, in the ileum of pigs nursing sows supplemented with DFM at d 3. Terminal restriction fragment peaks B423 and H330 were also greater (binary P = 0.01, 0.08; quantitative P = 0.01, 0.01, respectively) in the colon of pigs nursing sows supplemented with DFM at d 3. Peaks M495 and B394, putatively identified as E. coli, were greater (binary P = 0.01, 0.04; quantitative P = 0.01, 0.01, respectively) in the colon of the control pigs at d 3. At d 10, both the presence and quantity of Lactobacillus species were greater (P < 0.05) in the colon of pigs with the DFM treatment. Additionally, there was a tendency for T-RF B227 and H257 (binary P = 0.07, 0.07, respectively), putatively identified as Clostridium perfringens, to be present in the ileum of the control pigs at d 10 compared with treated pigs. Results of this study reveal that the developing gastrointestinal microbiota of a neonatal piglet can be affected by DFM supplementation to the sow.

Ampicillin-improved glucose tolerance in diet-induced obese C57BL/6NTac mice is age dependent

Ampicillin has been shown to improve glucose tolerance in mice. We hypothesized that this effect is present only if treatment is initiated prior to weaning and that it disappears when treatment is terminated. High-fat fed C57BL/6NTac mice were divided into groups that received Ampicillin at different ages or not at all. We found that both diet and Ampicillin significantly changed the gut microbiota composition in the animals. Furthermore, there was a significant improvement in glucose tolerance in Ampicillin-treated, five-week-old mice compared to nontreated mice in the control group. At study termination, expressions of mRNA coding for tumor necrosis factor, serum amyloid A, and lactase were upregulated, while the expression of tumor necrosis factor (ligand) superfamily member 15 was downregulated in the ileum of Ampicillin-treated mice. Higher dendritic cell percentages were found systemically in high-fat diet mice, and a lower tolerogenic dendritic cell percentage was found both in relation to high-fat diet and late Ampicillin treatment. The results support our hypothesis that a "window" exists early in life in which an alteration of the gut microbiota affects glucose tolerance as well as development of gut immunity and that this window may disappear after weaning.

Zinc competition among the intestinal microbiota

Bioavailable levels of trace metals, such as iron and zinc, for bacterial growth in nature are sufficiently low that most microbes have evolved high-affinity binding and transport systems. The microbe Campylobacter jejuni lives in the gastrointestinal tract of chickens, the principal source of human infection. A high-affinity ABC transporter for zinc uptake is required for Campylobacter survival in chicken intestines in the presence of a normal microbiota but not when chickens are raised with a limited microbiota. Mass spectrometric analysis of cecal contents revealed the presence of numerous zinc-binding proteins in conventional chicks compared to the number in limited-microbiota chicks. The presence of a microbiota results in the production of host zinc-binding enzymes, causing a growth restriction for bacteria that lack the high-affinity zinc transporter. Such transporters in a wide range of pathogenic bacteria make them good targets for the development of broad-spectrum antimicrobials.

Importance Zinc is an essential trace element for the growth of most organisms. Quantities of zinc inside cells are highly regulated, as too little zinc does not support growth, while too much zinc is toxic. Numerous bacterial cells require zinc uptake systems for growth and virulence. The work presented here demonstrates that the microbiota in the gastrointestinal tract reduces the quantity of zinc. Without a high-affinity zinc transporter, Campylobacter jejuni, a commensal organism of chickens, is unable to replicate or colonize the gastrointestinal tract. This is the first demonstration of zinc competition between microbiota in the gastrointestinal tract of a host. These results could have profound implications in the field of microbial pathogenesis and in our understanding of host metabolism and the microbiota.

Zinc is an essential trace element for the growth of most organisms. Quantities of zinc inside cells are highly regulated, as too little zinc does not support growth, while too much zinc is toxic. Numerous bacterial cells require zinc uptake systems for growth and virulence. The work presented here demonstrates that the microbiota in the gastrointestinal tract reduces the quantity of zinc. Without a high-affinity zinc transporter, Campylobacter jejuni, a commensal organism of chickens, is unable to replicate or colonize the gastrointestinal tract. This is the first demonstration of zinc competition between microbiota in the gastrointestinal tract of a host. These results could have profound implications in the field of microbial pathogenesis and in our understanding of host metabolism and the microbiota.

Wheat-barley-rye- or corn-fed growing pigs respond differently to dietary supplementation with a carbohydrase complex

Thirty-six pigs (22 kg of BW) were used to evaluate a carbohydrase preparation, with xylanase and β-glucanase as main activities, added to either wheat-barley-rye- (WBR) or corn-based diets on performance, intestinal environment, and nutrient digestibility. Pigs were offered 1 of 4 different dietary treatments for 27 d according to a factorial arrangement of treatments (a 2 × 2) with 2 cereal types (WBR or corn) and 2 levels of supplemental carbohydrase (0 or 0.01%). Pig growth and feed intake were individually measured every week until the end of the experiment when pigs were slaughtered to obtain samples of digesta and tissues. Cereal type affected performance only during wk 1, in which WBR improved ADG (590 vs. 440 g/d; P = 0.008) and G:F (0.61 vs. 0.43; P = 0.045) compared with corn. The WBR also increased the viscosity of the digestive contents in stomach (1.95 vs. 1.23 mPa·s; P = 0.001) and ileum (6.53 vs. 2.80 mPa·s; P = 0.001) and resulted in greater cecal starch digestibility (95.7 vs. 93.9%; P = 0.012). However, trends for a reduction in digestibility were observed for glucose in the nonstarch polysaccharide (NSP) fraction in the ileum (64.4 vs. 75.8%; P = 0.074) and galactose in the NSP fraction in the cecum (1.4 vs. 1.8%; P = 0.055). The use of the enzyme preparation increased ADFI during wk 2 (1,328 vs. 1,215 g/d; P = 0.028), and increased villus height (423 vs. 390 µm; P = 0.045) and tended to reduce relative pancreas weight (0.16 vs. 0.17% BW; P = 0.079) at d 27. The enzyme also improved cecal starch digestibility (95.5 vs. 94.1%; P = 0.043) and tended to improve ileal energy digestibility (61.3 vs. 53.7%; P = 0.090) and cecal glucose digestibility in the NSP fraction (76.0 vs. 54.5%; P = 0.055). However, it reduced the cecal digestibility of mannose in the NSP fraction (27.0 vs. 50.5%; P = 0.016). Interactions (P < 0.05) between cereal type and enzyme supplementation were observed for ADG and G:F during wk 2, BW and ADG during wk 3, and BW and ADFI over the whole trial; and also for villus-height-to-crypt-depth ratio and for cecal DM digestibility. In all instances, whereas the added enzyme had no effect in the case of the corn diet, improvements were observed with WBR. In conclusion, the multi-enzyme tested had different effects depending on the type of cereal present in the diet.

Host-microbe interactions in the neonatal intestine: role of human milk oligosaccharides

The infant intestinal microbiota is shaped by genetics and environment, including the route of delivery and early dietary intake. Data from germ-free rodents and piglets support a critical role for the microbiota in regulating gastrointestinal and immune development. Human milk oligosaccharides (HMO) both directly and indirectly influence intestinal development by regulating cell proliferation, acting as prebiotics for beneficial bacteria and modulating immune development. We have shown that the gut microbiota, the microbial metatranscriptome, and metabolome differ between porcine milk-fed and formula-fed (FF) piglets. Our goal is to define how early nutrition, specifically HMO, shapes host-microbe interactions in breast-fed (BF) and FF human infants. We an established noninvasive method that uses stool samples containing intact sloughed epithelial cells to quantify intestinal gene expression profiles in human infants. We hypothesized that a systems biology approach, combining i) HMO composition of the mother's milk with the infant's gut gene expression and fecal bacterial composition, ii) gene expression, and iii short-chain fatty acid profiles would identify important mechanistic pathways affecting intestinal development of BF and FF infants in the first few months of life. HMO composition was analyzed by HLPC Chip/time-of-flight MS and 3 HMO clusters were identified using principle component analysis. Initial findings indicated that both host epithelial cell mRNA expression and the microbial phylogenetic profiles provided strong feature sets that distinctly classified the BF and FF infants. Ongoing analyses are designed to integrate the host transcriptome, bacterial phylogenetic profiles, and functional metagenomic data using multivariate statistical analyses.

A metagenomic study of diet-dependent interaction between gut microbiota and host in infants reveals differences in immune response

Background

Gut microbiota and the host exist in a mutualistic relationship, with the functional composition of the microbiota strongly affecting the health and well-being of the host. Thus, it is important to develop a synthetic approach to study the host transcriptome and the microbiome simultaneously. Early microbial colonization in infants is critically important for directing neonatal intestinal and immune development, and is especially attractive for studying the development of human-commensal interactions. Here we report the results from a simultaneous study of the gut microbiome and host epithelial transcriptome of three-month-old exclusively breast- and formula-fed infants.

Results

Variation in both host mRNA expression and the microbiome phylogenetic and functional profiles was observed between breast- and formula-fed infants. To examine the interdependent relationship between host epithelial cell gene expression and bacterial metagenomic-based profiles, the host transcriptome and functionally profiled microbiome data were subjected to novel multivariate statistical analyses. Gut microbiota metagenome virulence characteristics concurrently varied with immunity-related gene expression in epithelial cells between the formula-fed and the breast-fed infants.

Conclusions

Our data provide insight into the integrated responses of the host transcriptome and microbiome to dietary substrates in the early neonatal period. We demonstrate that differences in diet can affect, via gut colonization, host expression of genes associated with the innate immune system. Furthermore, the methodology presented in this study can be adapted to assess other host-commensal and host-pathogen interactions using genomic and transcriptomic data, providing a synthetic genomics-based picture of host-commensal relationships.

Oat β-glucan and dietary calcium and phosphorus differentially modify intestinal expression of proinflammatory cytokines and monocarboxylate transporter 1 and cecal morphology in weaned pigs

Physiologic effects of dietary oat β-glucan and low and high dietary calcium-phosphorus (CaP) on intestinal morphology and gene expression related to SCFA absorption, mucus production, inflammation, and peptide digestion have not been established in weaned mammals. We therefore randomized 32 weaned pigs into 4 equal groups that received a cornstarch-casein-based diet with low (65% of the Ca and P requirement) and high (125 and 115% of the Ca and P requirement, respectively) CaP levels and low- and high-CaP diets supplemented with 8.95% oat β-glucan concentrate for 14 d. High-CaP diets downregulated duodenal expression of IL-1β (P < 0.05) by 30% compared with low-CaP diets. Furthermore, high-CaP diets reduced (P < 0.05) cecal crypt depth by 14% compared with low-CaP diets. Dietary β-glucan upregulated the expression of cecal MCT1 (P < 0.05) by 40% and that of colonic IL-6 (P < 0.05) by 142% compared with the control diet. Correlation analysis indicated that cecal MCT1 (r = 0.99, P < 0.001) and colonic IL-6 (r = 0.84, P < 0.05) expression was positively related to luminal butyrate and total SCFA, respectively, indicating that β-glucan may partly modify gene expression via increased SCFA generation. In conclusion, β-glucan and CaP levels modulated the expression of selected genes and morphology in the postweaning period, but effects were specific to intestinal segment. The present results further indicate that, in addition to being essential nutrients for bone accretion, dietary CaP level may modify the intestinal tissue response in young pigs.

Microarray analysis on germfree mice elucidates the primary target of a traditional Japanese medicine juzentaihoto: acceleration of IFN-α response via affecting the ISGF3-IRF7 signaling cascade

Background

The traditional Japanese medicine juzentaihoto (JTX) is a pharmaceutical grade multi-herbal medicine widely used for the prevention of cancer metastasis and infection in immuno-compromized patients in Japan. The effect of JTX has been supposed to be intimately affected by the immunological properties of host and enteric microflora. The influence of JTX on the gene expression profile in the large and small intestines was investigated by microarray analyses using mice of different strains with or without enteric microflora.

Results

In all types of mice, including germfree (GF) animals, the genes most affected by two-week oral JTX treatment were the type 1 interferon (IFN)-related genes including Stat1, Isgf3g and Irf7, which play a critical role in the feedback loop of IFN-α production cascade. In IQI specific pathogen free (SPF) mice JTX increased the steady state level of the expression of IFN-related genes, but had the opposite effect in IQI GF and BALB/c SPF mice. Promoter analysis suggests that tandem repeated $IRFF (the promoter sequences for interferon regulatory factors) may be a primary target for JTX action. Pre-treatment of JTX accelerated the effects of an oral IFN "inducer" 2-amino-5-bromo-6-methyl-4-pyrimidinol (ABMP) (up-regulation of IFN-α production in IQI strain and down-regulation in BALB/c mice), which is in good accordance with the effect of JTX on gene expression of type 1 IFN-related genes.

Conclusions

Microarray analysis revealed that the target of JTX might be the transcription machinery regulating the steady-state level of genes involved in the ISGF3-IRF7 cascade, whose effect is bi-directional in a strain- and microbiota-dependent manner.

Intrauterine growth restriction modifies the developmental pattern of intestinal structure, transcriptomic profile, and bacterial colonization in neonatal pigs

Neonates with intrauterine growth restriction (IUGR) are prone to suffer from digestive diseases. Using neonatal pigs with IUGR, we tested the hypothesis that IUGR may induce alterations in the developmental pattern of intestinal barrier and thereby may be responsible for IUGR-associated increased morbidity. Piglets with a birth weight near the mean birth weight (+/-0.5 SD) were identified as normal birth weight (control) and piglets with a mean -2 SD lower birth weight (-30%) were defined as piglets with IUGR. The developmental pattern of intestinal structure, transcriptomic profile, and bacterial colonization was investigated from birth to d 5 postnatal. At birth, intestinal weight and length, ileal and colonic weight per unit of length, and villous sizes were lower (P < 0.05) in piglets with IUGR than in same-age control piglets. These IUGR-induced intestinal alterations further persisted, although they were less marked at d 5. Counts of adherent bacteria to ileal and colonic mucosa were greater (P < 0.05) in 2-d-old piglets with IUGR than in same-age control piglets. Dynamic analyses of the transcriptomic profile of the intestine revealed molecular evidence of IUGR-induced intestinal growth impairment that may result from a change in the cell proliferation-apoptosis balance during the first days of life, while a protective process would occur later on. In addition, changes in the expression of several genes suggest a pivotal role of both glucocorticoids and microbiota in driving IUGR intestinal development during the neonatal period.

Noninvasive stool-based detection of infant gastrointestinal development using gene expression profiles from exfoliated epithelial cells

We have developed a novel molecular methodology that utilizes stool samples containing intact sloughed epithelial cells to quantify intestinal gene expression profiles in the developing human neonate. Since nutrition exerts a major role in regulating neonatal intestinal development and function, our goal was to identify gene sets (combinations) that are differentially regulated in response to infant feeding. For this purpose, fecal mRNA was isolated from exclusively breast-fed (n = 12) and formula-fed (n = 10) infants at 3 mo of age. Linear discriminant analysis was successfully used to identify the single genes and the two- to three-gene combinations that best distinguish the feeding groups. In addition, putative "master" regulatory genes were identified using coefficient of determination analysis. These results support our premise that mRNA isolated from stool has value in terms of characterizing the epigenetic mechanisms underlying the developmentally regulated transcriptional activation/repression of genes known to modulate gastrointestinal function. As larger data sets become available, this methodology can be extended to validation and, ultimately, identification of the main nutritional components that modulate intestinal maturation and function.