Standardized Preparation for Fecal Microbiota Transplantation in Pigs

A multi-omic assessment of the mechanisms of intestinal microbes used to treat diarrhea in early-weaned lambs

Transplant of donor microbiota can significantly alter the structure of the host's intestinal microbiota and alleviate early weaning stress. Screening for alternative-resistant products by transplanting fecal bacteria from healthy lambs is a current research trend in the livestock industry. In the present study, fecal microbiota transplantation was performed in lambs with diarrhea during early weaning. The transplanted fecal microbiota greatly reduced the diarrhea and serum inflammatory factor levels caused by early weaning. Transcriptome sequencing revealed that fecal microbiota transplantation alleviated colonic inflammation and increased the expression of colonic ion transport proteins. In addition, the levels of Streptococcus, Enterococcus, and Escherichia Shigella decreased in the jejunum, cecum, and colon of the lambs; meanwhile, the levels of Bifidobacterium and multiple secondary bile acids, such as ursodeoxycholic acid, increased in the colon. Furthermore, the abundance of Bifidobacterium was significantly negatively correlated with the diarrhea index. The fecal microbiota transplantation reshaped the intestinal microbiota of early-weaned lambs, protected the intestinal physiology and immune barrier, and reduced weaning stress. In addition to making available bacteriological products for controlling intestinal inflammation in young lambs, this study offers a theoretical framework and technical system for the mechanisms by which microbiota transplantation regulates intestinal health in young lambs.IMPORTANCEBefore weaning, the digestive system of lambs is not well developed; hence, its resistance to infectious diseases is weak. Under intensive feeding systems, lambs can easily be stressed and the risk of bacterial infection is high, which causes diarrhea, which in turn may cause mortality and significant economic losses to the livestock industry. With the elimination of antibiotics in animal feed, the incidence of mortality due to intestinal illnesses in lambs has gradually increased. There are several types of probiotics routinely used in young animals, but the effects and processes of their usage have only been assessed in monogastric animals. The lack of data on ruminants, particularly sheep, has severely hampered the process of efficient and healthy sheep breeding. Therefore, there is an urgent need to identify effective and safe functional supplements for lambs.

Effect of direct-fed microbials on growth performance, blood biochemical indices, and immune status of female goats

The effect of direct-feed microbial (DFM) treatment on body weight, serum biochemical indexes, serum immunoglobulins, and serum cytokines was studied. The study was a completely randomized design with 20 growing females Beichuan white goats, weighing 25.11 ± 1.96 kg, divided into two groups of 10 goats per treatment. Goats were offered (1) 10 mL saline solution (Control group) (2) or 10 mL microbials solution (DFM group) on days 0 and 7 for two times. No effect on final body weight and body size was observed between DFM and control group (p > 0.05). DFM treatment had greater serum total protein, globulin, and albumin/globulin ratio than the control treatment (p < 0.05). The concentrations of IgA, IgG, IgM, INF-γ, and IL-2 in DFM group were significantly higher than those in the control group on days 7, 14, and 21 (p < 0.05), and the highest content was detected on day 14 of the experiment. The concentrations of IgA, IgG, IgM, IL-2, INF-γ, INF-α, IL-4, and IL-5 in DFM group on day 14 were higher than those on day 0 (p < 0.05). In conclusion, DFM enhanced serum immunoglobulins and cytokines without affecting body weight, body size, and normal serum metabolism.

Review: Effect of Experimental Diets on the Microbiome of Productive Animals

The microorganisms that inhabit the gastrointestinal tract are responsible for multiple chains of reactions that affect their environment and modify the internal metabolism, their study receives the name of microbiome, which has become more relevant in recent years. In the near future, the challenges related to feeding are anticipated to escalate, encompassing the nutritional needs to sustain an overpopulated world. Therefore, it is expected that a better understanding of the interactions between microorganisms within the digestive tract will allow their modulation in order to provide an improvement in the immune system, feed efficiency or the promotion of nutritional characteristics in production animals, among others. In the present study, the main effects of experimental diets in production animals were described, emphasizing the diversity of the bacterial populations found in response to the diets, ordering them between polygastric and monogastric animals, and then describing the experimental diets used and their effect on the microorganisms. It is hoped that this study will help as a first general approach to the study of the role of the microbiome in production animals under different diets.

Fecal microbiota transplantation holds the secret to youth

Aging shows itself not just at the cellular level, with shortened telomeres and cell cycle arrest, but also at the organ and organismal level, with diminished brainpower, dry eyes, intestinal inflammation, muscular atrophy, wrinkles, etc. When the gut microbiota, often called the "virtual organ of the host," fails to function normally, it can lead to a cascade of health problems including, but not limited to, inflammatory bowel disease, obesity, metabolic liver disease, type II diabetes, cardiovascular disease, cancer, and even neurological disorders. An effective strategy for restoring healthy gut bacteria is fecal microbiota transplantation (FMT). It can reverse the effects of aging on the digestive system, the brain, and the vision by transplanting the functional bacteria found in the excrement of healthy individuals into the gut tracts of patients. This paves the way for future research into using the microbiome as a therapeutic target for disorders associated with aging.

Gut microbiota-derived 3-phenylpropionic acid promotes intestinal epithelial barrier function via AhR signaling

BACKGROUND

The intestinal epithelial barrier confers protection against the intestinal invasion by pathogens and exposure to food antigens and toxins. Growing studies have linked the gut microbiota to the intestinal epithelial barrier function. The mining of the gut microbes that facilitate the function of intestinal epithelial barrier is urgently needed.

RESULTS

Here, we studied a landscape of the gut microbiome of seven pig breeds using metagenomics and 16S rDNA gene amplicon sequencing. The results indicated an obvious difference in the gut microbiome between Congjiang miniature (CM) pigs (a native Chinese breed) and commercial Duroc × [Landrace × Yorkshire] (DLY) pigs. CM finishing pigs had stronger intestinal epithelial barrier function than the DLY finishing pigs. Fecal microbiota transplantation from CM and DLY finishing pigs to germ-free (GF) mice transferred the intestinal epithelial barrier characteristics. By comparing the gut microbiome of the recipient GF mice, we identified and validated Bacteroides fragilis as a microbial species that contributes to the intestinal epithelial barrier. B. fragilis-derived 3-phenylpropionic acid metabolite had an important function on the enhancement of intestinal epithelial barrier. Furthermore, 3-phenylpropionic acid facilitated the intestinal epithelial barrier by activating aryl hydrocarbon receptor (AhR) signaling.

CONCLUSIONS

These findings suggest that manipulation of B. fragilis and 3-phenylpropionic acid is a promising strategy for improving intestinal epithelial barrier. Video Abstract.

Dietary fiber during gestation improves lactational feed intake of sows by modulating gut microbiota

BACKGROUND

The feed intake of sows during lactation is often lower than their needs. High-fiber feed is usually used during gestation to increase the voluntary feed intake of sows during lactation. However, the mechanism underlying the effect of bulky diets on the appetites of sows during lactation have not been fully clarified. The current study was conducted to determine whether a high-fiber diet during gestation improves lactational feed intake (LFI) of sows by modulating gut microbiota.

METHODS

We selected an appropriate high-fiber diet during gestation and utilized the fecal microbial transplantation (FMT) method to conduct research on the role of the gut microbiota in feed intake regulation of sows during lactation, as follows: high-fiber (HF) diet during gestation (n = 23), low-fiber (LF) diet during gestation (n = 23), and low-fiber diet + HF-FMT (LFM) during gestation (n = 23).

RESULTS

Compared with the LF, sows in the HF and LFM groups had a higher LFI, while the sows also had higher peptide tyrosine tyrosine and glucagon-like peptide 1 on d 110 of gestation (G110 d). The litter weight gain of piglets during lactation and weaning weight of piglets from LFM group were higher than LF group. Sows given a HF diet had lower Proteobacteria, especially Escherichia-Shigella, on G110 d and higher Lactobacillus, especially Lactobacillus_mucosae_LM1 and Lactobacillus_amylovorus, on d 7 of lactation (L7 d). The abundance of Escherichia-Shigella was reduced by HF-FMT in numerically compared with the LF. In addition, HF and HF-FMT both decreased the perinatal concentrations of proinflammatory factors, such as endotoxin (ET), lipocalin-2 (LCN-2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). The concentration of ET and LCN-2 and the abundance of Proteobacteria and Escherichia-Shigella were negatively correlated with the LFI of sows.

CONCLUSION

The high abundance of Proteobacteria, especially Escherichia-Shigella of LF sows in late gestation, led to increased endotoxin levels, which result in inflammatory responses and adverse effects on the LFI of sows. Adding HF during gestation reverses this process by increasing the abundance of Lactobacillus, especially Lactobacillus_mucosae_LM1 and Lactobacillus_amylovorus.

Mining chicken ileal microbiota for immunomodulatory microorganisms

The gut microbiota makes important contributions to host immune system development and resistance to pathogen infections, especially during early life. However, studies addressing the immunomodulatory functions of gut microbial individuals or populations are limited. In this study, we explore the systemic impact of the ileal microbiota on immune cell development and function of chickens and identify the members of the microbiota involved in immune system modulation. We initially used a time-series design with six time points to prove that ileal microbiota at different succession stages is intimately connected to immune cell maturation. Antibiotics perturbed the microbiota succession and negatively affected immune development, whereas early exposure to the ileal commensal microbiota from more mature birds promoted immune cell development and facilitated pathogen elimination after Salmonella Typhimurium infection, illustrating that early colonization of gut microbiota is an important driver of immune development. Five bacterial strains, Blautia coccoides, Bacteroides xylanisolvens, Fournierella sp002159185, Romboutsia lituseburensis, and Megamonas funiformis, which are closely related to the immune system development of broiler chickens, were then screened out and validated for their immunomodulatory properties. Our results provide insight into poultry immune system-microbiota interactions and also establish a foundation for targeted immunological interventions aiming to combat infectious diseases and promote poultry health and production.

A study on the method and effect of the construction of a humanized mouse model of fecal microbiota transplantation

The gestation period is critical for the health of the mother and fetus. Malnutrition or over nutrition during pregnancy may cause gestational diseases that can result in adverse pregnancy outcomes. Fecal microbiota transplantation (FMT) can be used to re-establish new gut microbiota to treat a variety of diseases and construct a model to investigate the nutritional health during pregnancy. Therefore, this study investigated whether human-derived gut microbiota during pregnancy could colonize the intestines of mice. Moreover, we determined the time and method of intervention for FMT. Based on this information, a humanized mouse model of FMT was constructed to simulate the human intestinal microecology during pregnancy, and serve as a useful animal model for the study of nutritional health and disease during pregnancy. Germ-free (GF) and specific pathogen free (SPF) C57BL/6J mice were selected for humanized gestational FMT and the transplantation outcomes were evaluated. The results demonstrated that the gestational intestinal microbiota colonized the intestines of mice, allowing researchers to construct a humanized mouse model of gestational FMT. The main intestinal flora of the gestational period were transplanted into GF mice, with the gestational flora being similar to the flora of GF mice after transplantation. However, antibiotics could not eliminate the original microbial flora in SPF mice, and the flora was complex and variable after FMT with little increase in abundance. Background flora had a significant impact on the outcomes assessment. The results were better in GF mice than in SPF mice, and after microbiota transplantation, a superior effect was observed on day 21 compared to days 7 and 14.

Effects of a farm-specific fecal microbial transplant (FMT) product on clinical outcomes and fecal microbiome composition in preweaned dairy calves

Gastrointestinal disease (GI) is the most common illness in pre-weaned dairy calves. Therefore, effective strategies to manipulate the microbiome of dairy calves under commercial dairy operations are of great importance to improve animal health and reduce antimicrobial usage. The objective of this study was to develop a farm-specific FMT product and to investigate its effects on clinical outcomes and fecal microbial composition of dairy calves. The FMT product was derived from feces from healthy donors (5–24 days of age) raised in the same calf ranch facility as the FMT recipients. Healthy and diarrheic calves were randomly enrolled to a control (n = 115) or FMT (n = 112) treatment group (~36 g of processed fecal matter once daily for 3 days). Fecal samples were collected at enrollment and again 9 days later after the first FMT dose. Although the FMT product was rich in organisms typically known for their beneficial probiotic properties, the FMT therapy did not prevent or ameliorate GI disease in dairy calves. In fact, calves that received FMT were less likely to recover from GI disease, and more likely to die due to GI disease complications. Fecal microbial community analysis revealed an increase in the alpha-diversity in FMT calves; however, no major differences across treatment groups were observed in the beta-diversity analysis. Calves that received FMT had higher relative abundance of an uncultured organism of the genus Lactobacillus and Lactobacillus reuteri on day 10. Moreover, FMT calves had lower relative abundance of Clostridium nexile and Bacteroides vulgatus on day 10. Our results indicate the need to have an established protocol when developing FMT products, based on rigorous inclusion and exclusion criteria for the selection of FMT donors free of potential pathogens, no history of disease or antibiotic treatment.

Effects of fecal microbiota transplantation from yaks on weaning diarrhea, fecal microbiota composition, microbial network structure and functional pathways in Chinese Holstein calves

This study was conducted to investigate the effect of fecal microbiota transplantation (FMT) from yaks on weaning diarrhea, fecal microbiota composition, microbial network structure and functional pathways in Chinese Holstein Calves. In this study, 50 calves were randomly divided into five groups of 10 each: NC group (no supplementation), Control group (normal saline), low concentration FMT group (LFMT, 1 × 108 CFU/ml), high concentration FMT group (HMFT, 1 × 109 CFU/ml), and sterilized FMT group (SMFT, sterilized bacterial solution). The test lasted for 30 days. We found that FMT reduced the incidence of diarrhea in weaned calves, and the anti-diarrhea effect of LFMT was stronger than those of HFMT and SFMT. Calf feces were collected by rectal palpation on days 5, 10, 15, and 20 post-weaning, and high-throughput sequencing of bacterial 16S rRNA and fungal internal transcribed spacer region of fecal microbiota was performed. We observed that the richness and diversity of bacterial microbiota in the LFMT, HFMT, and SFMT groups were higher than those in the NC and Control groups at day 20 after weaning. The treatment had a significant effect on bacterial richness (p < 0.05), but not on fungal diversity or richness. The analysis of gut microbiome showed that Firmicutes and Bacteroides were the main bacterial phyla in the feces of weaned calves, and norank_ f Muribaculaceae, UCG-005, Rikenellaceae_RC9_gut_group, Bacteroides, and Blautia were the main genera. Ascomycota and Basidiomycota were the main fungal phyla. Compared to abundance parameters in the Control and NC groups, relative abundances of Firmicutes in the FMT groups increased at different time points after weaning. The relative abundance of Blautia and Lactobacillus in the LFMT group increased significantly after weaning. In addition, abundances of Ruminococcus and Romboutsia, which produce short-chain fatty acids, were also increased in different FMT groups. FMT significantly increased the relative abundance of beneficial bacteria, enhanced the complexity of the fecal microbial network, and promoted important metabolic and cellular processes in weaned calves. In conclusion, our study provides a reference and theoretical basis for FMT to prevent calf weaning diarrhea and other intestinal diseases in ruminants.

Integrated analysis of multi-tissues lipidome and gut microbiome reveals microbiota-induced shifts on lipid metabolism in pigs

Lipid metabolism is very important for meat quality in pigs. Accumulating evidence shows that gut microbiota can contribute to this physiological process. However, the gut microbiota that function in lipid metabolism and adipogenesis remains unclear. Here, we compared the characteristics of fat deposition and gut microbial community between Laiwu pigs and Duroc × (Landrace × Yorkshire) (DLY) pigs. Fecal microbiota transplantation (FMT) was performed to determine the possible impact of gut microbiota on lipid metabolism in pigs. An integrated analysis of the gut microbiome and lipidome of the small intestine, plasma, and liver was conducted to investigate the effects of FMT on host lipid metabolism. The comparative analysis of the gut microbiome showed higher abundance of Bacteroidetes (P = 0.0018) while lower abundance of Firmicutes (P = 0.012) in Laiwu pigs, and the microbial composition can be transferred from Laiwu pigs into DLY pigs. Transmission electron microscope and Oil red-O staining were performed to analyze the effects of FMT on lipid deposition in liver, the main target organ for lipid metabolism. The results showed that FMT significantly increased the number of lipid droplets (P = 0.0035) and lipid accumulation (P = 0.0026) in liver. Furthermore, integrated multi-tissues lipidome analysis demonstrated that the fatty acyls and glycerophospholipids were significantly increased (P < 0.01) in intestine and liver, while glycerolipids and fatty acyls were reduced (P < 0.01) in plasma. In the small intestine, FMT increased (P < 0.01) the relative abundance of polyketides and prenol lipids but reduced (P < 0.01) the saccharolipids. Correlation analysis revealed the potential interactions between microbiota and lipid metabolites. Together, our results indicated that the gut microbiota may regulate the lipid metabolism and enhance the accumulation of lipid droplets in the liver of pigs.

Ruminal Microbiota Determines the High-Fiber Utilization of Ruminants: Evidence from the Ruminal Microbiota Transplant

The rumen, which contains a series of prokaryotes and eukaryotes with high abundance, determines the high ability to degrade complex carbohydrates in ruminants. Using 16S rRNA gene sequencing, we compared the ruminal microbiota of dairy goats with that in the foregut and colon of mice and found more Bacteroides identified in the rumen, which helps ruminants to utilize plant-derived polysaccharides, cellulose, and other structural carbohydrates. Furthermore, high-fiber diets did not significantly increase intestinal fiber-degrading bacteria in mice, but did produce higher levels of ruminal fiber-degrading bacteria in dairy goats. Through rumen microbe transplantation (RMT), we found that rumen-derived fiber-degrading bacteria can colonize the intestines of mice to exert their fiber-degrading function, but their colonization efficiency is affected by diet. Additionally, the colonization of these fiber-degrading bacteria in the colon may involve higher content of butyrate in the colon, protecting the colonic epithelial barrier and promoting energy metabolism. Overall, the fiber degradation function of rumen bacteria through RMT was verified, and our results provide new insights into isolating the functional and beneficial fiber-degrading bacteria in the rumen, providing a theoretical basis for the role of dietary fiber in intestinal health. IMPORTANCE Ruminants have a powerful progastric digestive system that converts structural carbohydrates into nutrients useful to humans. It is well known that this phenomenon is due to the fact that the rumen of ruminants is a natural microbial fermenter, which can ferment structural carbohydrates such as cellulose and hemicellulose and transform them into volatile fatty acids to supply energy for host. However, monogastric animals have an inherent disadvantage in utilizing fiber, so screening rumen-derived fiber-degrading bacteria as a fermentation strain for biological feed is needed in an attempt at improving the fiber digestibility of monogastric animals. In this study, a ruminal microbiota transplant experiment from goats to mice proves that ruminal microbiota could serve as a key factor in utilization of high-fiber diets and provides a new perspective for the development of probiotics with fiber degradation function from the rumen and the importance of the use of prebiotics during the intake of probiotics.

Trans-Species Fecal Transplant Revealed the Role of the Gut Microbiome as a Contributor to Energy Metabolism and Development of Skeletal Muscle

The aim of this study was to investigate the influence of the exogenous gut microbiome at early life stages on the development of mice skeletal muscle in adulthood. First, the characteristics of skeletal muscle and the gut microbiota composition of the gut microbiota donors—Erhualian (EH) pigs (a native Chinese breed)—were studied. EH pigs had significantly higher fiber densities and thinner fiber diameters than Duroc × Landrace × Yorkshire crossed (DLY) pigs (p < 0.05). The expression levels of genes related to oxidized muscle fibers, mitochondrial function, and glucose metabolism in the skeletal muscle of EH pigs were significantly higher than those in DLY pigs (p < 0.05). Moreover, the abundances of 8 gut microbial phyla and 35 genera correlated with the skeletal muscle fiber diameters and densities exhibited significant differences (p < 0.05) between EH and DLY pigs. Subsequently, newborn mice were treated with saline (CG) and fecal microbiota suspensions collected from EH pigs (AG), respectively, for 15 days, starting from the day of birth. In adulthood (60 days), the relative abundances of Parabacteroides, Sutterella, and Dehalobacterium were significantly higher in the feces of the AG mice than those of the CG mice. The microbes contribute to improved functions related to lipid and carbohydrate metabolism. The weight, density, and gene expression related to the oxidized muscle fibers, mitochondrial function, and glucose metabolism of the AG group were significantly higher than those of the CG group (p < 0.05), whereas the fiber diameters in the skeletal muscle of the AG mice were significantly lower (p < 0.05) than those of the CG mice. These results suggested that intervention with exogenous microbiota at early stages of life can affect the fiber size and energy metabolism of their skeletal muscle.

Impacts of Gut Microbiota on the Immune System and Fecal Microbiota Transplantation as a Re-Emerging Therapy for Autoimmune Diseases

The enormous and diverse population of microorganisms residing in the digestive tracts of humans and animals influence the development, regulation, and function of the immune system. Recently, the understanding of the association between autoimmune diseases and gut microbiota has been improved due to the innovation of high-throughput sequencing technologies with high resolutions. Several studies have reported perturbation of gut microbiota as one of the factors playing a role in the pathogenesis of many diseases, such as inflammatory bowel disease, recurrent diarrhea due to Clostridioides difficile infections. Restoration of healthy gut microbiota by transferring fecal material from a healthy donor to a sick recipient, called fecal microbiota transplantation (FMT), has resolved or improved symptoms of autoimmune diseases. This (re)emerging therapy was approved for the treatment of drug-resistant recurrent C. difficile infections in 2013 by the U.S. Food and Drug Administration. Numerous human and animal studies have demonstrated FMT has the potential as the next generation therapy to control autoimmune and other health problems. Alas, this new therapeutic method has limitations, including the risk of transferring antibiotic-resistant pathogens or transmission of genes from donors to recipients and/or exacerbating the conditions in some patients. Therefore, continued research is needed to elucidate the mechanisms by which gut microbiota is involved in the pathogenesis of autoimmune diseases and to improve the efficacy and optimize the preparation of FMT for different disease conditions, and to tailor FMT to meet the needs in both humans and animals. The prospect of FMT therapy includes shifting from the current practice of using the whole fecal materials to the more aesthetic transfer of selective microbial consortia assembled in vitro or using their metabolic products.

Donor age and body weight determine the effects of fecal microbiota transplantation on growth performance, and fecal microbiota development in recipient pigs

Background

The application of fecal microbiota transplantation (FMT) to improve swine growth performance has been sporadically studied. Most of these studies used a single microbiota source and thus the effect of donor characteristics on recipient pigs’ fecal microbiota development and growth performance is largely unknown.

Results

In this study, we collected feces from six donors with heavy (H) or light (L) body weight and different ages (d 42, nursery; d 96, growing; and d 170, finisher) to evaluate their effects on the growth performance and fecal microbiota development of recipient pigs. Generally, recipients that received two doses of FMT from nursery and finisher stages donor at weaning (21 ± 2 days of age) inherited the donor’s growth pattern, while the pigs gavaged with grower stage material exerted a numerically greater weight gain than the control pigs regardless of donor BW. FMT from heavier donors (NH, GH, and FH) led to the recipients to have numerically increased growth compared to their lighter counterparts (NL, GL, and FL, respectively) throughout the growing and most finishing stages. This benefit could be attributed to the enrichment of ASV25 Faecalibacterium, ASV61 Faecalibacterium, ASV438 Coriobacteriaceae_unclassified, ASV144 Bulleidia, and ASV129 Oribacterium and decrease of ASV13 Escherichia during nursery stage. Fecal microbiota transplantation from growing and finishing donors influenced the microbial community significantly in recipient pigs during the nursery stage. FMT of older donors’ gut microbiota expedited recipients’ microbiota maturity on d 35 and 49, indicated by increased estimated microbiota ages. The age-associated bacterial taxa included ASV206 Ruminococcaceae, ASV211 Butyrivibrio, ASV416 Bacteroides, ASV2 Streptococcus, and ASV291 Veillonellaceae. The body weight differences between GL and GH pigs on d 104 were associated with the increased synthesis of the essential amino acid, lysine and methionine, mixed acid fermentation, expedited glycolysis, and sucrose/galactose degradation.

Conclusions

Overall, our study provided insights into how donor age and body weight affect FMT outcomes regarding growth performance, microbiota community shifts, and lower GI tract metabolic potentials. This study also provided guidance to select qualified donors for future fecal microbiota transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00696-1.

Interspecies microbiome transplantation recapitulates microbial acquisition in mosquitoes

BACKGROUND

Mosquitoes harbor microbial communities that play important roles in their growth, survival, reproduction, and ability to transmit human pathogens. Microbiome transplantation approaches are often used to study host-microbe interactions and identify microbial taxa and assemblages associated with health or disease. However, no such approaches have been developed to manipulate the microbiota of mosquitoes.

RESULTS

Here, we developed an approach to transfer entire microbial communities between mosquito cohorts. We undertook transfers between (Culex quinquefasciatus to Aedes aegypti) and within (Ae. aegypti to Ae. aegypti) species to validate the approach and determine the number of mosquitoes required to prepare donor microbiota. After the transfer, we monitored mosquito development and microbiota dynamics throughout the life cycle. Typical holometabolous lifestyle-related microbiota structures were observed, with higher dynamics of microbial structures in larval stages, including the larval water, and less diversity in adults. Microbiota diversity in recipient adults was also more similar to the microbiota diversity in donor adults.

CONCLUSIONS

This study provides the first evidence for successful microbiome transplantation in mosquitoes. Our results highlight the value of such methods for studying mosquito-microbe interactions and lay the foundation for future studies to elucidate the factors underlying microbiota acquisition, assembly, and function in mosquitoes under controlled conditions. Video Abstract.

Exogenous lipase administration alters gut microbiota composition and ameliorates Alzheimer's disease-like pathology in APP/PS1 mice

Alzheimer's disease (AD) represents the most common form of dementia in the elderly with no available disease modifying treatments. Altered gut microbial composition has been widely acknowledged as a common feature of AD, which potentially contributes to progression or onset of AD. To assess the hypothesis that Candida rugosa lipase (CRL), which has been shown to enhance gut microbiome and metabolite composition, can rebalance the gut microbiome composition and reduce AD pathology, the treatment effects in APPswe/PS1de9 (APP/PS1) mice were investigated. The analysis revealed an increased abundance of Acetatifactor and Clostridiales vadin BB60 genera in the gut; increased lipid hydrolysis in the gut lumen, normalization of peripheral unsaturated fatty acids, and reduction of neuroinflammation and memory deficits post treatment. Finally, we demonstrated that the evoked benefits on memory could be transferred via fecal matter transplant (FMT) into antibiotic-induced microbiome-depleted (AIMD) wildtype mice, ameliorating their memory deficits. The findings herein contributed to improve our understanding of the role of the gut microbiome in AD's complex networks and suggested that targeted modification of the gut could contribute to amelioration of AD neuropathology.

Guidelines for reporting on animal fecal transplantation (GRAFT) studies: recommendations from a systematic review of murine transplantation protocols

Fecal microbiota transplant (FMT) is a powerful tool used to connect changes in gut microbial composition with a variety of disease states and pathologies. While FMT enables potential causal relationships to be identified, the experimental details reported in preclinical FMT protocols are highly inconsistent and/or incomplete. This limitation reflects a current lack of authoritative guidance on reporting standards that would facilitate replication efforts and ultimately reproducible science. We therefore systematically reviewed all FMT protocols used in mouse models with the goal of formulating recommendations on the reporting of preclinical FMT protocols. Search strategies were applied across three databases (PubMed, EMBASE, and Ovid Medline) until June 30, 2020. Data related to donor attributes, stool collection, processing/storage, recipient preparation, administration, and quality control were extracted. A total of 1753 papers were identified, with 241 identified for data extraction and analysis. Of the papers included, 92.5% reported a positive outcome with FMT intervention. However, the vast majority of studies failed to address core methodological aspects including the use of anaerobic conditions (91.7% of papers lacked information), storage (49.4%), homogenization (33.6%), concentration (31.5%), volume (19.9%) and administration route (5.3%). To address these reporting limitations, we developed theGuidelines for Reporting Animal Fecal Transplant (GRAFT) that guide reporting standards for preclinical FMT. The GRAFT recommendations will enable robust reporting of preclinical FMT design, and facilitate high-quality peer review, improving the rigor and translation of knowledge gained through preclinical FMT studies.

The effect of fecal microbial transplant on intestinal microbial composition in short bowel neonatal piglets

BACKGROUND

Short bowel syndrome (SBS) in neonates is associated with microbial dysbiosis due to intestinal surgery, prolonged hospitalization, enteral nutrition, and repeated antibiotic exposure. Sepsis and liver disease, leading causes of morbidity and mortality in SBS, may relate to such intestinal dysbiosis. We investigated the safety and feasibility of fecal microbial transplant (FMT) to alter intestinal microbial composition in SBS piglets.

METHODS

Following a 75% distal small intestinal resection, piglets were fed parenteral nutrition (PN) and elemental diet (ED), and randomized to saline (SAL, n=12) or FMT (n=12) treatments delivered by gastric tube on day 2 (d2). FMT donor was a healthy adult pig. Comparisons were also made to healthy sow-fed littermate controls (SOW, n=6). Stool samples were collected daily, and tissue samples were collected at baseline and termination. Microbial DNA was extracted from stool and analyzed using 16S rRNA sequencing.

RESULTS

All piglets survived to the endpoint. On d2-4, FMT piglets had some differences in microbiota composition, compared to SAL, SOW, and donor. Between base and term, there were transitory changes to alpha and beta diversity in FMT and SAL.

CONCLUSION

FMT treatment in post-surgical neonatal piglets with SBS appears safe, with no increase in sepsis and no mortality. In SBS piglets, FMT induced transient changes to the intestinal microbiota. However, these changes did not persist long-term. This article is protected by copyright. All rights reserved.

Supplementing Glycerol to Inoculum Induces Changes in pH, SCFA Profiles, and Microbiota Composition in In-Vitro Batch Fermentation

Glycerol was generally added to the inoculum as a cryoprotectant. However, it was also a suitable substrate for microbial fermentation, which may produce more SCFAs, thereby decreased pH of the fermentation broth. This study investigated the effect of supplementing glycerol to inoculum on in vitro fermentation and whether an enhanced buffer capacity of medium could maintain the pH stability during in vitro batch fermentation, subsequently improving the accuracy of short chain fatty acids (SCFAs) determination, especially propionate. Two ileal digesta were fermented by pig fecal inoculum with or without glycerol (served as anti-frozen inoculum or frozen inoculum) in standard buffer or enhanced buffer solution (served as normal or modified medium). Along with the fermentation, adding glycerol decreased the pH of fermentation broth (p < 0.05). However, modified medium could alleviate the pH decrement compared with normal medium (p < 0.05). The concentration of total propionic acid production was much higher than that of other SCFAs in anti-frozen inoculum fermentation at 24 and 36 h, thereby increasing the variation (SD) of net production of propionate. The α-diversity analysis showed that adding glycerol decreased Chao1 and Shannon index under normal medium fermentation (p < 0.05) compared to modified medium (p < 0.05) along with fermentation. PCoA showed that all groups were clustered differently (p < 0.01). Adding glycerol improved the relative abundances of Firmicutes, Anaerovibrio, unclassified_f_Selenomonadaceae, and decreased the relative abundance of Proteobacteria (p < 0.05). The relative abundances of Firmicutes, such as Lactobacillus, Blautia and Eubacterium_Ruminantium_group in modified medium with frozen inoculum fermentation were higher than (p < 0.05) those in normal medium at 36 h of incubation. These results showed that adding glycerol in inoculum changed the fermentation patterns, regardless of substrate and medium, and suggested fermentation using frozen inoculum with modified medium could maintain stability of pH, improve the accuracy of SCFA determination, as well as maintain a balanced microbial community.

Early Life Fecal Microbiota Transplantation in Neonatal Dairy Calves Promotes Growth Performance and Alleviates Inflammation and Oxidative Stress during Weaning

This study aimed to evaluate the effects of early life fecal microbiota transplantation (FMT) on the health and performance of neonatal dairy calves. The donor was selected based on health and production records and fecal material testing negative for infectious pathogens. Sixteen healthy newborn Holstein calves were randomized to either a baseline nutritional program (CON) or 1×/d inoculations with 25 g of fecal donor material (FMT) mixed in the milk replacer (n = 8/TRT) from 8 to 12 days of age. Blood and fecal samples were collected weekly, and calves were weaned at 7 weeks of age. A TRT × Week interaction was observed in haptoglobin, which was reflected in a positive quadratic effect in FMT calves but not in CON. A trend for a TRT × Week interaction was observed in the liver function biomarker paraoxonase, which resulted in greater paraoxonase in FMT calves than CON at three weeks of age. Fecal microbial community analysis revealed a significant increase in the alpha-diversity between week 1 and week 5 for the FMT calves. These results suggest that early life FMT in neonatal calves has positive effects in mediating the inflammatory response and gut microbial maturation.

Real-time monitoring of ruminal microbiota reveals their roles in dairy goats during subacute ruminal acidosis

Ruminal microbiota changes frequently with high grain diets and the occurrence of subacute ruminal acidosis (SARA). A grain-induced goat model of SARA, with durations of a significant decrease in the rumen pH value to less than 5.6 and an increase in the rumen lipopolysaccharides concentration, is constructed for real-time monitoring of bacteria alteration. Using 16 S rRNA gene sequencing, significant bacterial differences between goats from the SARA and healthy groups are identified at every hour for six continuous hours after feeding. Moreover, 29 common differential genera between two groups over 6 h after feeding are all related to the altered pH and lipopolysaccharides. Transplanting the microbiota from donor goats with SARA could induce colonic inflammation in antibiotic-pretreated mice. Overall, significant differences in the bacterial community and rumen fermentation pattern between the healthy and SARA dairy goats are real-time monitored, and then tested using ruminal microbe transplantation to antibiotic-treated mice.

Deposition of resistant bacteria and resistome through FMT in germ-free piglets

Faecal microbiota transplantation (FMT) has received considerable attention in recent years due to its remarkable efficacy in restoring a normal gut microbiome. Here, we established the groups of post-FMT recipient piglets using germ-free piglets during early life to characterize the colonization of gut microbiota composition and the enrichment of resistance gene acquisition. By metagenomic analysis, we identified 115 bacterial phyla and 2111 bacterial genera that were acquired by the FMT recipients. We found that early-life microbial colonization and the spread of resistomes in recipient piglets were age dependent. A total of 425, 425 and 358 AR genes primarily belonging to 114, 114 and 102 different types were detected in the donors, post-FMT recipients in the FMT-3D group and post-FMT recipients in the FMT-15D group respectively. Genes that encoded tetracycline, macrolide and chloramphenicol resistance proteins were the most dominant AR genes, and the results corresponded with the exposure of antibiotic consumption at farm. Bacteroides, Escherichia, Clostridium, Parabacteroides, Treponema, Lactobacillus and Enterococcus were significantly correlated with the distribution of AR genes. More importantly, the relative abundance of AR genes was positively correlated with the levels of mobile genetic elements. Our results indicate that early-life microbial colonization can persistently shape the gut microbiota and antibiotic resistome.

Genetically determined hypertensive phenotype affects gut microbiota composition, but not vice versa

OBJECTIVES

Research suggests reciprocal crosstalk between the host and gut bacteria. This study evaluated the interaction between gut microbiota and arterial blood pressure (BP) in rats.

METHODS

Continuous telemetry recordings of BP were started in 7-week-old normotensive Wistar--Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Two weeks later, half of the WKY and SHR were subjected to cross-transplantation of fecal matter, with stools harvested from either WKY or SHR and BP measurements until the age of 14 weeks. The composition of gut bacteria was assessed through analysis of the bacterial 16S ribosomal RNA gene sequence. The concentration of microbiota-derived metabolites was evaluated using HPLC-MS.

RESULTS

There was a significant difference between WKY and SHR in the composition of gut bacteria at the start and end of the study. This was accompanied by significant histological differences in the colon. SHR, but not WKY, showed a gradual increase in BP throughout the experiment. For both WKY and SHR, there was no significant difference in BP or metabolic parameters between animals receiving fecal transplantation from either SHR or WKY.

CONCLUSION

Genetically induced hypertension in SHR is associated with alterations in the composition of gut bacteria and histological morphology of the colon. An inter-strain fecal transplant does not affect BP and does not produce long-term changes in gut bacteria composition. We propose that the impact of the host genotype and/or phenotype on the gut bacteria may be greater than the impact of the gut bacteria on the host BP.

Spatial heterogeneity of bacterial colonization across different gut segments following inter-species microbiota transplantation

BACKGROUND

The microbiota presents a compartmentalized distribution across different gut segments. Hence, the exogenous microbiota from a particular gut segment might only invade its homologous gut location during microbiota transplantation. Feces as the excreted residue contain most of the large-intestinal microbes but lack small-intestinal microbes. We speculated that whole-intestinal microbiota transplantation (WIMT), comprising jejunal, ileal, cecal, and colonic microbiota, would be more effective for reshaping the entire intestinal microbiota than conventional fecal microbiota transplantation fecal microbiota transplantation (FMT).

RESULTS

We modeled the compartmentalized colonization of the gut microbiota via transplanting the microbiota from jejunum, ileum, cecum, and colon, respectively, into the germ-free mice. Transplanting jejunal or ileal microbiota induced more exogenous microbes' colonization in the small intestine (SI) of germ-free mice rather than the large intestine (LI), primarily containing Proteobacteria, Lactobacillaceae, and Cyanobacteria. Conversely, more saccharolytic anaerobes from exogenous cecal or colonic microbiota, such as Bacteroidetes, Prevotellaceae, Lachnospiraceae, and Ruminococcaceae, established in the LI of germ-free mice that received corresponding intestinal segmented microbiota transplantation. Consistent compartmentalized colonization patterns of microbial functions in the intestine of germ-free mice were also observed. Genes related to nucleotide metabolism, genetic information processing, and replication and repair were primarily enriched in small-intestinal communities, whereas genes associated with the metabolism of essential nutrients such as carbohydrates, amino acids, cofactors, and vitamins were mainly enriched in large-intestinal communities of germ-free mice. Subsequently, we compared the difference in reshaping the community structure of germ-free mice between FMT and WIMT. FMT mainly transferred LI-derived microorganisms and gene functions into the recipient intestine with sparse SI-derived microbes successfully transplanted. However, WIMT introduced more SI-derived microbes and associated microbial functions to the recipient intestine than FMT. Besides, WIMT also improved intestinal morphological development as well as reduced systematic inflammation responses of recipients compared with FMT.

CONCLUSIONS

Segmented exogenous microbiota transplantation proved the spatial heterogeneity of bacterial colonization along the gastrointestinal tract, i.e., the microbiota from one specific location selectively colonizes its homologous gut region. Given the lack of exogenous small-intestinal microbes during FMT, WIMT may be a promising alternative for conventional FMT to reconstitute the microbiota across the entire intestinal tract. Video Abstract.

Capsulized faecal microbiota transplantation ameliorates post-weaning diarrhoea by modulating the gut microbiota in piglets

Early weaning-induced stress causes diarrhoea, thereby reducing the growth performance of piglets. Gut bacterial dysbiosis has emerged as a leading cause of post-weaning diarrhoea. The present study aimed to investigate the effect of capsulized faecal microbiota transplantation (FMT) on the gut bacterial community, immune response and gut barrier function of piglets. Thirty-two weaned barrows were randomly divided into two groups. The recipient group was inoculated orally with capsulized faecal microbiota of healthy Tibetan pigs during the whole period of the trial, while the control group was given an empty capsule. The feed-to-gain ratio, diarrhoea ratio, and histological damage score of recipient piglets were significantly decreased. FMT treatment significantly increased the colon length of piglets. Furthermore, the relative abundances of Firmicutes, Euryarchaeota, Tenericutes, Lactobacillus, and Methanobrevibacter in the colon of recipient piglets were increased, and the relative abundances of Campylobacter and Proteobacteria were significantly decreased compared with those in the control group. CD4⁺ lymphocytes and CD4⁺/CD8⁺ ratio in the peripheral blood of recipient piglets were significantly increased. FMT treatment increased the IL-4 and IL-10 levels and decreased the TNF-α and INF-γ levels in the colonic tissue of piglets. The recipient piglets’ mRNA expression of TLR2, TLR8, NF-κB, and iNOS was significantly regulated. In addition, FMT significantly enhanced the gene expression of ZO-1. Overall, treatment with capsulized FMT ameliorated diarrhoea in piglets, with significant effects on limiting colon inflammatory responses, downregulating the TLR signalling pathway and the gene expression of iNOS, and strengthening intestinal barrier function by modulating the constituents of the gut microbiota.

Effect of Fermented Corn-Soybean Meal on Serum Immunity, the Expression of Genes Related to Gut Immunity, Gut Microbiota, and Bacterial Metabolites in Grower-Finisher Pigs

Fermented corn-soybean meal (fermented feed, FF) is commonly used in swine production, but the effects of FF on gut health remain unclear. In this study, serum immunity, mRNA abundances of antimicrobial peptides (AMPs) and Toll-like receptors (TLR1-9), bacterial abundance in the duodenum and colon, and colonic metabolic phenotypes were determined in crossbred barrows (Duroc × Landrace × Large White) fed FF or normal feed (unfermented feed, UF) (n = 6). When compared to the UF group, the results showed that serum levels of IgG and IgM were significantly increased in FF group pigs (P < 0.05). FF significantly decreased the abundances of Bacteroides and Verrucomicrobia in the duodenum and decreased the abundances of Bacteroides, Proteobacteria, and Verrucomicrobia in the colon while it significantly increased the abundances of Firmicutes and Actinobacteria (P < 0.05). Furthermore, a Spearman's correlation analysis showed that serum immunity and the expression of genes related to gut immunity were associated with bacterial strains at the family level. Moreover, differentially abundant colonic microbiota were associated with colonic metabolites. LC-MS data analyses identified a total of 1,351 metabolites that markedly differed between the UF and FF groups. C5-Branched dibasic acid metabolism was significantly upregulated whereas the purine metabolism was significantly downregulated (P < 0.05) in the colonic digesta of pigs in the FF meal group compared to the UF meal group. Collectively, these results indicated that FF meal could influence serum immunity and the expression of genes related to gut immunity, correlating with the gut microbiota and bacterial metabolites in grower-finisher pigs. This study may provide an alternative strategy for improving the intestinal health of grower-finisher pigs.

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.

Active bacterial communities of pig fecal microbiota transplantation suspension prepared and preserved under different conditions

Although fecal microbiota transplantation (FMT) has become a research hotspot, studies on comparison of the active fecal bacteria suspension under different preparation conditions are limited. This study investigated the abundances of active bacterial community in pig FMT suspension that produced under different oxygen concentrations or cryopreservation conditions. Fecal samples from a Landrace × Yorkshire sow were used to prepare fecal bacteria suspension under the anaerobic (AN group) and aerobic conditions (AE group), respectively. And then half of the anaerobic fecal bacteria suspension was cryopreservation in - 80 °C (AN-CR group) for 1 week. The microbial RNA in the fecal bacteria suspension was extracted before and after cryopreservation, and reverse transcribed into cDNA. MiSeq sequencing 16S rRNA gene of bacterial cDNA showed that the bacterial diversity in the AN group was significantly higher than that in the AE group. Comparing with the sows' fecal sample, the relative abundances of Lactobacillus johnsonii, Lactobacillus coleohominis and Parabacteroides merdae in AN, AE and AN-CR groups were reduced. The short-term cryopreservation had low impact on the structure of the active bacterial community in the fecal bacterial suspension. These results suggest that fecal bacteria suspension can be better prepared under strict anaerobic condition, and that fecal bacteria suspension can be cryopreserved in - 80 °C for a short time.

Reducing porcine corneal graft rejection, with an emphasis on porcine endogenous retrovirus transmission safety: a review

Donor cornea shortage is a primary hurdle in the development of corneal transplantation. Of all species, porcine corneas are the ideal transplantation material for humans. However, the xenoimmune rejection induced by porcine corneal xenotransplantation compromises surgical efficacy. Although the binding of IgM/IgG in human serum to a genetically modified porcine cornea is significantly weaker than that of the wild type (WT), genetically modified porcine corneas do not display a prolonged graft survival time in vivo. Conversely, costimulatory blockade drugs, such as anti-CD40 antibodies, can reduce the xenoimmune response and prolong graft survival time in animal experiments. Moreover, porcine endothelial grafts can survive for more than 6mo with only the subconjunctival injection of a steroid-based immunosuppressants regime; therefore, they show great value for treating corneal endothelial disease. In addition, zoonotic transmission is a primary concern of xenotransplantation. Porcine endogenous retrovirus (PERV) is the most significant virus assessed by ophthalmologists. PERV integrates into the porcine genome and infects human cells in vitro. Fortunately, no evidence from in vivo studies has yet shown that PERV can be transmitted to hosts.

Fecal microbiota transplantation as a tool to treat and reduce susceptibility to disease in animals

Fecal microbiota transplantation (FMT) is the process by which fecal microbiota are donated from a healthy individual and subsequently transplanted into a diseased or young individual. The mechanism by which FMT is effective is believed to be due to enhanced beneficial microbes, increased microbiome diversity, and restored normal flora. Beneficial gut microorganisms not only play a role in maintaining an intestinal barrier and metabolizing nutrients, but importantly, these microbes help regulate local and systemic immune function. Although FMT has been described for several centuries, only recently has it been utilized as a mainstream therapy in humans and significantly considered for applications in other species. In humans and animals, gastrointestinal diseases are by far the most widely accepted FMT-treatable conditions; however, recent research has shown exceptional promise for FMT being used to treat or prevent other conditions, including those outside of the gastrointestinal tract. Overall, FMT is likely an underutilized, widely-available, and inexpensive tool for improving the health and response to disease in animals. In this review, the effects of FMT on veterinary diseases and potential applications for FMT in animals are discussed.