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Among transplantable organs, the intestine is one of the most challenging organs to transplant. While there is considerable research on the effects of brain death (BD), little is known about the specific intestinal changes that occur, particularly in females. Here we investigated the role of female sex hormones in the BD-induced intestinal inflammation, using an ovariectomy (OVx) model for sex hormones depletion. Wistar rats (female) were divided into four experimental groups: Control non-OVx - non-manipulated; Control-OVx -ovariectomized; BD non-OVx - animals submitted to BD (6h); BD-OVx -ovariectomized animals submitted to BD. OVx was performed 10 days before BD induction. non-OVx groups were chosen during proestrus phase (heat period). Inflammatory mediators and white blood cell count were quantified in the blood. Intestine tissue was sampled for histopathological analysis, myeloperoxidase (MPO) activity, Evans blue dye extravasation assay and immunohistochemistry. Results show higher intestinal injury in BD-OVx than BD non-OVx animals, presenting reduced crypt depth and increased serum inflammatory mediators. Independently from the previous hormonal status, BD increased intestinal inflammation, with higher leukocyte infiltration, MPO activity, ICAM-1 expression, and higher serum MIP-1α. In summary, BD modulates intestinal inflammation by increasing leukocyte mobilization. Whereas OVx, and its consequences on the female hormonal profile, influences homeostasis and BD-induced inflammation, increasing inflammatory mediators and altering intestinal morphology.

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Members of the genus Oncicola Travassos, 1916 are generalist parasites able to infect a broad spectrum of carnivorous hosts, such as marsupials, procyonids, felids, and canids, and are distributed globally. Adult specimens were collected from the intestines of three white-nosed coatis (N. narica), whereas cystacanths (larval form) were found in the body cavities of two amphibian species (paratenic hosts) in localities from northern and southeastern Mexico. Morphologically, both stages were identified as O. luehei (Travassos, 1917) on the basis of the following features: trunk cylindrical, narrow anteriorly, enlarging midbody, tapering gradually to narrow posteriorly; proboscis globular with six circular rows of hooks with six hooks each, decreasing in size posteriorly; neck short with sensory papilla; tubular lemnisci long, extending to the posterior region; protonephridia dendritic type; and eight cement glands, compact with a single giant nuclei. Sequences from cytochrome c oxidase subunit 1 from mtDNA were aligned and compared with sequences available in GenBank. Phylogenetic analyses revealed that adults and cystacanths formed a clade with two other isolates identified as Oncicola sp. and O. luehei from Mexico. The intraspecific genetic divergence among the isolates was low, ranging from 0.0% to 3.0%, indicating that the two stages of the life cycle belong to the same species. The haplotype network was inferred with 11 sequences and revealed a lack of shared haplotypes between populations, suggesting a reduced recombination rate and a high pattern of genetic variation among individuals. Finally, these new records of O. luehei increase the distribution range of O. luehei on both coasts of Mexico.

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Necrotizing enterocolitis (NEC) is a severe intestinal disease of multifactorial origin that primarily affects premature infants. Approximately 27% of NEC babies develop short gut (SG) secondary to extensive intestinal resection, and 10% will have chronic dependence on total parenteral nutrition. We evaluated the Botox treatment in SG model rats. Twenty-day-old weanling male rats (weight range 38-70 g, n=72) were divided into four groups (n=18 each): 1) Control (fed a regular liquid diet); 2) Botox (Control submitted to laparotomy and intestinal injection of Botox®); 3) SG (short gut); and 4) SG and Botox (SG+Botox®). After seven post-operative days, samples were collected for biometrics [body weight (BW), intestine weight (IW) and IW/BW ratio (IBR), and intestine length (IL) and height (IH)], histometric analysis [villous height (VH), crypt depth (CD), muscular thickness (MT), and PCNA index)], and intestinal transit time (ITT). BW, IW, and IL decreased in SG (P<0.05). IH, VH, and PCNA index increased in Botox groups [Control = SG < Botox and SG+Botox (P<0.05)], CD increased in Botox, SG, and SG+Botox (P<0.005), and MT was higher in SG and SG+Botox. Botox groups had lower ITT (P<0.05). Botox provided dilatation and histological changes in SG. These findings suggested that Botox improved adaptation and might be applied in SG with promising results.

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Intestinal permeability plays a crucial role in intestinal barrier function. Altered intestinal permeability is well documented in numerous chronic diseases and may serve as a risk factor for disease onset as well as a target for innovative therapeutic strategies. While reliable and sensitive approaches for studying intestinal permeability have been established in animal models, such as mice and zebrafish larvae, methods for investigating this in adult zebrafish remain a considerable challenge. The zebrafish has emerged as a valuable model for studying intestinal development, physiology, and disease. Moreover, zebrafish offer certain advantages over rodent models, such as the ability to evaluate the dynamic interactions of labeled markers in vivo and in real time. In this study, we present a comprehensive pipeline for assessing in vivo intestinal permeability in adult zebrafish using fluorescent-labeled dextran. Detailed protocols for fish handling, reagent preparation, optimization of reagent dosage and delivery routes, and quantification of fluorescent markers in extraintestinal sites are provided. Our findings suggest that zebrafish hold promise as an alternative model for in vivo investigations of intestinal permeability induced by genetic, pathophysiological, and/or pharmacological events.

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The objective of this study was to evaluate the effects of three levels of lipids in the diet on growth, metabolism, and intestinal and hepatic histopathology in discus fish (Symphysodon aequifasciatus). Fish were stocked in quadruplicate in aquarium (50L) and were fed experimental diets containing three levels (3%, 10%, and 14%) of dietary lipids (LP). At the end of the trial, no significant differences in growth performance were observed. Fish fed diets with 3% and 10% LP exhibited significantly higher protein efficiency rates compared to those fed the 14% LP diet. A significant increase in lipase and alkaline phosphatase activity was observed in fish fed 14% LP diets. The inclusion of 14% lipids in the diet led to a decrease in albumin activity and an increase in the height of the intestinal villi. Although no significant differences were observed in aspartate aminotransferase, alanine aminotransferase activities, and size of hepatocytes. The histopathology of the liver indicated reduced hepatocyte size, lipid vacuoles, and sinusoidal space in the group fed the 3% LP diet. In conclusion, the use of 10% LP diet was found to be more favorable for liver health and growth performance.

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The objective of this study was to morphologically characterize the structures suggestive of gregarines found in the feces of Triatoma dimidiata collected in five municipalities in Yucatan, Mexico. Three hundred ninety-six specimens of T. dimidiata collected during 2022 and 2023 were analyzed, of which 8.84 % (n = 35) showed evidence of infection by a gregarine in the intestine and 1.77 % (n = 7) of infection with vermiform gregarine in Malpighian tubules. With microscopic examination, it was possible to obtain measurements and micrographs that allowed the rediscovery of Machadoella triatomae (vermiform gregarine) as well as a potential new gregarine species not previously described in T. dimidiata, which, based on its morphological characteristics, could be another Schizogregarina of the genus Caulleryella (flask-shaped). Additionally, the dissections of some specimens helped correctly identify the site where these gregarines parasitized T. dimidiata. Furthermore, of the three staining techniques used in this study, Lugol's solution and Wright's stain provided greater contrast and were therefore useful for visualizing these microorganisms. Scanning electron microscopy of the new gregarine revealed the three-dimensional shape of merozoites inside and outside a ruptured meront in detail. This study provides morphological evidence of two gregarines (Phylum: Apicomplexa) parasitizing Triatoma dimidiata in multiple regions of Yucatan, Mexico. M. triatomae was isolated in Malpighian tubules, and another gregarine, possibly of the genus Caulleryella, was isolated in the intestine.

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Aflatoxin is a mycotoxin produced by fungi of the genus Aspergillus that is present in various foods. Probiotics are well-established products in aquaculture, and due to their effective contribution to the intestine, they can be used as an aflatoxin adsorbent. This study evaluated the effects of aflatoxin B1 (AFB1) on enzymatic activity and intestinal function in Piaractus mesopotamicus (pacu) fingerlings fed diets containing a probiotic-based adsorbent (PBA). Seventy-two fish with an average weight of 12 ± 1.30 g were used in the study. The experiment was conducted over 15 days using a completely randomized design with six diet treatments (AFB1 per kg of formulated diet) and two replicates. These treatments were: control without AFB1; 25.0 µg of AFB1; 400.0 µg of AFB1; control diet without AFB1 + PBA; 25.0 µg of AFB1 + PBA; and 400.0 µg of AFB1 + PBA. After the experimental period, the digestive enzymes protease, amylase, and lipase from the stomach, pyloric caeca, and intestine were quantified. The height and width of the intestinal villi, pyloric caeca, and stomach wall were measured. Fish fed the 400.0 µg of AFB1 diet showed reduced feed consumption, even though they ingested higher amounts of AFB1 compared to those fed the other experimental diets. The best zootechnical performance parameters were observed in fish fed the control diet without AFB1 + PBA. Changes (p < 0.05) were observed in the amount of protease in the stomach, pyloric caeca, and intestine; in the amount of amylase in the intestine; and the amount of lipase in the pyloric caeca and intestine. Changes were observed (p < 0.05) in the length of the stomach wall and the anterior and posterior intestines. Changes in the width of the stomach and anterior intestine walls were observed as a result of diet. Our results suggest that the use of probiotics as an aflatoxin adsorbent in pacu diets is beneficial from a physiological perspective and may also enhance growth.

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BACKGROUND: The main challenge in new drug development is accurately predicting the human response in preclinical models. METHODS: In this study, we developed three different intestinal barrier models using advanced biofabrication techniques: (i) a manual model containing Caco-2 and HT-29 cells on a collagen bed, (ii) a manual model with a Caco-2/HT-29 layer on a HDFn-laden collagen layer, and (iii) a 3D bioprinted model incorporating both cellular layers. Each model was rigorously tested for its ability to simulate a functional intestinal membrane. RESULTS: All models successfully replicated the structural and functional aspects of the intestinal barrier. The 3D bioprinted intestinal model, however, demonstrated superior epithelial barrier integrity enhanced tight junction formation, microvilli development, and increased mucus production. When subjected to Ibuprofen, the 3D bioprinted model provided a more predictive response, underscoring its potential as a reliable in vitro tool for drug toxicity testing. CONCLUSION: Our 3D bioprinted intestinal model presents a robust and predictive platform for drug toxicity assessments, significantly reducing the need for animal testing. This model not only aligns with ethical testing protocols but also offers enhanced accuracy in predicting human responses, thereby advancing the field of drug development.

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The DAF-2/insulin/insulin-like growth factor signaling (IIS) pathway plays an evolutionarily conserved role in regulating reproductive development, life span, and stress resistance. In Caenorhabditis elegans, DAF-2/IIS signaling is modulated by an extensive array of insulin-like peptides (ILPs) with diverse spatial and temporal expression patterns. However, the release dynamics and specific functions of these ILPs in adapting to different environmental conditions remain poorly understood. Here, we show that the ILP, insulin-3 (INS-3), plays a crucial role in modulating the response to various environmental stressors in C. elegans. ins-3 mutants display increased resistance to heat, oxidative stress, and starvation; however, this advantage is countered by slower reproductive development under favorable conditions. We find that ins-3 expression is downregulated in response to environmental stressors, whereas, the neurohormone tyramine, which is released during the acute flight response, increases ins-3 expression. We show that tyramine induces intestinal calcium (Ca2+) transients through the activation of the TYRA-3 receptor. Our data support a model in which tyramine negatively impacts environmental stress resistance by stimulating the release of INS-3 from the intestine via the activation of a TYRA-3-Gαq-IP3 pathway. The release of INS-3 systemically activates the DAF-2 pathway, resulting in the inhibition of cytoprotective mechanisms mediated by DAF-16/FOXO. These studies offer mechanistic insights into a brain-gut communication pathway that weighs adaptive strategies to respond to acute and long-term stressors.

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The knowledge about the occurrence and biochemical characteristics of key digestive enzymes is crucial for an enhanced understanding of the dietary ecophysiology of the species. On the other hand, integrative studies on digestive physiology and on tissue content of glycogen, glucose, lipid and protein in groups of ecological and economic importance are currently limited. In this work, we determined the occurrence and biochemical characteristics in intestine of key digestive enzymes activities as indexes of the ability to digest different dietary substrates and of functional differentiation for digestion/absorption of nutrients along with the intestinal coefficient as index of dietary habit and digestion efficiency in adults of Odonthtestes argentinensis inhabiting Mar Chiquita Coastal Lagoon (Buenos Aires, Argentina). Furthermore, to identify storage sites, glycogen, triglycerides and protein content in different tissues were also analyzed. The presence and biochemical characteristics of amylase, maltase, sucrase, lipase, trypsin and aminopeptidase-N activity in intestine, as well as the tissue content of glycogen, triglycerides and protein suggests that adults of O.argentinensis exhibit an adequate digestive battery to potentially perform complete hydrolysis of various dietary substrates and capacity for storage and/or utilization of energy reserves. Our study provides novel insights into the digestive/metabolic traits in adults of the resident silverside O. argentinensis from Mar Chiquita Coastal Lagoon.

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The study aimed to investigate the influence of different microalgae used in green water culture on the intestinal morphology of the seahorse Hippocampus reidi during the first 15 days of life. Four treatments were tested in triplicate, consisting of two microalgae (Tisochrysis lutea-ISO and Chaetoceros muelleri-CHO), used either individually (TISO and TCHO) or combined (TIC 1:1) in larval rearing water, and a treatment without microalgae (TWM). Larvae (6.68 ± 0.55 mm) were fed copepods (Parvocalanus crassirrostris; 2 ind mL-1) and rotifers (Brachionus rotundiformis; 8 ind mL-1) from the first to the seventh day, and from the eighth day onwards, with Artemia sp. nauplii (2 ind mL-1). For the analysis of intestinal histomorphometry, histological analysis of the tissue was performed on day 0 (initial) and after 7 and 15 days. The results demonstrate a significant increase in weight and weight gain of the larvae on the 15th day in the treatments with the addition of the microalgae T. lutea, whether alone or combination with other microalgae, compared to TWM. In relation the intestinal histomorphometry of larvae, the ANCOVA revealed that, on the 7th and 15th day, only the treatments with microalgae significantly affected the surface area of the intestinal villi. The intestinal histomorphometry of larvae from TISO showed higher values of villus height (85.29 ± 1.23 µm2) compared to TWM (69.42 ± 2.82 µm2) and TCHO (76.92 ± 2.23 µm2) (P < 0.05) but did not show significant differences compared to TIC (80.127 ± 2.08 µm2), which reflected on the villi surface area. Therefore, larvae from TISO (3603.43 ± 151.31 µm2) and TIC (3550.29 ± 120.99 µm2) showed significantly higher values of this parameter compared to TWM (3026.79 ± 147.64 µm2) and TCHO (3069.09 ± 126.18 µm2) (P < 0.05). In conclusion, the protocol for H. reidi larvae rearing in a green water system with the addition of the microalgae T. lutea resulted in an increase in the intestinal absorption area, resulting in improved performance of the larvae.

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BACKGROUND: Nowdays, more relevant applications of perinatal derivatives, such as amniotic membrane (AM), are emerging in our environment as a source of biomaterials for use in different healing processes. The study of anastomosis healing associated with antimetabolic drugs such as 5-fluorouracil (5-FU) is a potential target of AM. AIMS: To evaluate the healing effects of AM in rats treated with 5-FU at a dose of 20 mg/kg on the seventh day of postoperative evolution, regarding the parameters percentage of type I collagen (mature), cell viability, microvascular density and formation of granulation tissue. METHODS: Thirty-two Wistar rats were used, submitted to colotomy and colorraphy, separated into four groups of eight, which received different treatments daily, intraperitoneally, until the day of sacrifice: saline solution (C), 20 mg/kg 5-FU, 20 mg/kg 5-FU and AM. RESULTS: Treatment with 20 mg/kg of 5-FU, on the seventh postoperative day, induced adverse effects on the anastomotic healing process, evidenced by a decrease in the percentage of type I (mature) collagen, cell viability, microvascular density, fibrin-leukocyte scab formation and angiofibroblast proliferation; the use of AM under these conditions induced an improvement in the percentage of type I (mature) collagen. CONCLUSIONS: Treatment with 20 mg/kg of 5-FU on the seventh postoperative day induced adverse effects on the anastomotic healing process, and the use of AM under these conditions induced an improvement in the percentage of type I (mature) collagen.

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Five metabolism assays were performed to determine the metabolizable energy (ME) content of soybean oil, coconut oil, fish viscera oil, physical mixture of coconut oil and fish viscera oil (3:2, in kg: kg) and structured lipid prepared from interesterification of fish viscera oil and coconut oil (3: 2, in kg: kg), and one assay to evaluate the effects of including these lipid sources in piglet diets on performance, digestibility of diets, incidence of diarrhea and intestinal morphometry at nursery phase. Soybean, coconut, fish viscera, physical mixture and structured lipid oils showed ME values of 8239, 8199, 8839, 8268 and 8523 kcal/kg DM respectively. In the performance trial, a total of 90 piglets with 23 days of age were distributed among 5 diets, differing in the lipid source used (soybean oil, coconut oil, fish viscera oil, physical mixture or structured lipid). Piglets fed diet containing structured lipid showed better feed conversion, higher duodenal goblet cell number and jejunal absorption area (P < 0.05), with better digestibility of ether extract and energy of diets. Interesterification of lipid sources such as coconut oil and fish viscera oil improves intestinal morphology, positively influencing the performance of piglets at nursery phase.

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BACKGROUND: IL-33, a pleiotropic cytokine, has been associated with a plethora of immune-related processes, both inflammatory and anti-inflammatory. T regulatory (Treg) cells, the main leukocyte population involved in immune tolerance, can be induced by the administration of IL-33, the local microbiota, and its metabolites. Here, we demonstrate that IL-33 drastically induces the production of intestinal metabolites involved on tryptophan (Trp) metabolism. METHODS: naïve mice were treated with IL-33 for 4 days and leukocyte populations were analyzed by flow cytometry, and feces were processed for microbiota and intestinal metabolites studies. Using a murine skin transplantation model, the effect of Kynurenic acid (KA) on allograft survival was tested. RESULTS: Under homeostatic conditions, animals treated with IL-33 showed an increment in Treg cell frequencies. Intestinal bacterial abundance analysis indicates that IL-33 provokes dysbiosis, demonstrated by a reduction in Enterobacteria and an increment in Lactobacillus genera. Furthermore, metabolomics analysis showed a dramatic IL-33 effect on the abundance of intestinal metabolites related to amino acid synthesis pathways, highlighting molecules linked to Trp metabolism, such as kynurenic acid (KA), 5-Hydroxyindoleacetic acid (5-HIAA), and 6-Hydroxynicotinic acid (6-HNA), which was supported by an enhanced expression of Ido and Kat mRNA in MLN cells, which are two enzymes involved on KA synthesis. Interestingly, animals receiving KA in drinking water and subjected to skin transplantation showed allograft acceptance, which is associated with an increment in Treg cell frequencies. CONCLUSIONS: Our study reveals a new property for IL-33 as a modulator of the intestinal microbiota and metabolites, especially those involved with Trp metabolism. In addition, we demonstrate that KA favors Tregs in vivo, positively affecting skin transplantation survival.

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A new species of bothriocephalid cestode in the genus Anantrum is described from the intestine of the shorthead lizardfish Synodus scituliceps from the north Pacific coast of Costa Rica. The new species is described based on an integrative taxonomic approach that includes the use of light and scanning electron microscopy, 28S rDNA sequencing, and phylogenetic analysis. Anantrum gallopintoi sp. nov. is the third known member of this genus and can be distinguished from A. tortum (Linton, 1905) and A. histocephalum Jensen & Heckmann, 1977 by a combination of morphological and ecological traits and, in particular, by having a vaginal sphincter, different number of testes, and different type host and type locality. The molecular analysis and the phylogenetic reconstructions supported its status as a new taxon placing it within a well-supported separate branch of Anantrum spp. subclade. According to the present finding, S. scituliceps represents a new host record and Costa Rica a new geographical record for Anantrum species, and, in general, for a bothriocephalid cestode.

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Aberrant signaling through damage-associated molecular patterns (DAMPs) has been linked to several health disorders, attracting considerable research interest over the last decade. Adenosine triphosphate (ATP), a key extracellular DAMP, activates the purinergic receptor P2X7, which acts as a danger sensor in immune cells and is implicated in distinct biological functions, including cell death, production of pro-inflammatory cytokines, and defense against microorganisms. In addition to driving inflammation mediated by immune and non-immune cells, the persistent release of endogenous DAMPs, including ATP, has been shown to result in epigenetic modifications. In intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), consequent amplification of the inflammatory response and the resulting epigenetic reprogramming may impact the development of pathological changes associated with specific disease phenotypes. P2X7 is overexpressed in the gut mucosa of patients with IBD, whereas the P2X7 blockade prevents the development of chemically induced experimental colitis. Recent data suggest a role for P2X7 in determining gut microbiota composition. Regulatory mechanisms downstream of the P2X7 receptor, combined with signals from dysbiotic microbiota, trigger intracellular signaling pathways and inflammasomes, intensify inflammation, and foster colitis-associated CRC development. Preliminary studies targeting the ATP-P2X7 pathway have shown favorable therapeutic effects in human IBD and experimental colitis.

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Members of the genus Maritrema Nicoll, 1907 include endoparasites of aquatic birds and mammals, distributed worldwide. Adult specimens were collected from the intestines of three bird species (the great black hawks, Buteogallus urubitinga Gmelin; laughing gull, Leucophaeus atricilla Linnaeus; and the willet, Tringa semipalmata Gmelin) in three localities along the Gulf of Mexico. Photogenophores were sequenced for the large subunit (LSU) from nuclear rDNA, and the new sequences were aligned with other microphalloid sequences available in GenBank. The maximum likelihood and Bayesian inference analyses revealed three independent lineages, one corresponding to a previously described species, Maritrema corai Hernández-Orts, Pinacho-Pinacho, García-Varela & Kostadinova, 2016, and two representing two undescribed species. These two new species are described in the current study. Maritrema itzamnai n. sp. can be morphologically differentiated from its four congeneric species occurring in coastal areas of Mexico by having smaller oral (20-29 × 20-38 µm) and ventral (20-39 × 19-33 µm) suckers. In addition, Maritrema itzamnai n. sp. possess annular vitellarium instead of a horseshoe-shaped vitellarium. Maritrema kukulkanni n. sp. can be distinguished from its congeneric species reported from Mexico by possessing a larger oesophagus (44-117µm) and by having a vitellarium distributed in both the hindbody and forebody. Maritrema corai is the third species recorded in this study parasitizing the great black hawk (Buteogallus urubitinga); this represents a new host and locality record, expanding its distribution range from the Mexican Pacific Ocean to the Gulf of Mexico.

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INTRODUCTION: Short Bowel Syndrome (SBS) is a rare gastrointestinal disorder associated with Intestinal Failure (SBS-IF) that leads to morbidity, mortality, and a burden on healthcare costs. Intestine Transplantation (IT) is a treatment option for patients with SBS-IF as it replaces the missing or diseased intestine and offers the potential for return to normal activities and intestinal function. This study aims to describe the clinical course and demographical and clinical characteristics of subjects with SBS-IF who underwent IT in Brazil. METHODS: This retrospective observational study included all SBS-IF patients who underwent IT in two reference centers in Brazil from April 2011 to December 2021. RESULTS: A total of 7 young male participants were included in the study. The most frequent underlying condition was surgical complications, followed by intestinal volvulus and incisional hernia. The most frequent indication for IT was a hepatic disease associated with total Parenteral Nutrition (PN). The main type of IT performed was intestine only. The median time from underlying condition to IT was 67.3 (16.5‒88.5) months. The mean (SD) number of yearly hospitalizations per patient was 0.5 (0.3). The most common reason for hospitalization was PN-related complications. Sixty exams were performed in-hospital and 53 in the outpatient setting. CONCLUSION: The findings of this study may be helpful to understand better the journey of patients with SBS-IF to IT in Brazil, providing real-world evidence to develop health policy guidelines and improve the quality of life of these patients.

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Intestinal parasites are part of the intestinal ecosystem and have been shown to establish close interactions with the intestinal microbiota. However, little is known about the influence of intestinal protozoa on the regulation of the immune response. In this study, we analyzed the regulation of the immune response of germ-free mice transplanted with fecal microbiota (FMT) from individuals with multiple parasitic protozoans (P) and non-parasitized individuals (NP). We determined the production of intestinal cytokines, the lymphocyte populations in both the colon and the spleen, and the genetic expression of markers of intestinal epithelial integrity. We observed a general downregulation of the intestinal immune response in mice receiving FMT-P. We found significantly lower intestinal production of the cytokines IL-6, TNF, IFN-γ, MCP-1, IL-10, and IL-12 in the FMT-P. Furthermore, a significant decrease in the proportion of CD3+, CD4+, and Foxp3+ T regulatory cells (Treg) was observed in both, the colon and spleen with FMT-P in contrast to FMT-NP. We also found that in FMT-P mice there was a significant decrease in tjp1 expression in all three regions of the small intestine; ocln in the ileum; reg3γ in the duodenum and relmß in both the duodenum and ileum. We also found an increase in colonic mucus layer thickness in mice colonized with FMT-P in contrast with FMT-NP. Finally, our results suggest that gut protozoa, such as Blastocystis hominis, Entamoeba coli, Endolimax nana, Entamoeba histolytica/E. dispar, Iodamoeba bütschlii, and Chilomastix mesnili consortia affect the immunoinflammatory state and induce functional changes in the intestine via the gut microbiota. Likewise, it allows us to establish an FMT model in germ-free mice as a viable alternative to explore the effects that exposure to intestinal parasites could have on the immune response in humans.

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We evaluated the effects of supplementing direct-fed microbials (DFM), containing Bacillus licheniformis and Bacillus subtilis, on performance, rumen morphometrics, intestinal gene expression, and blood and fecal parameters in finishing bulls. Nellore × Angus bulls (n = 144; initial BW = 401 ±â€…45.5 kg) were distributed at random in 36 pens (4 bulls/pen and 18 pens/treatment), following a completely randomized design. A ground corn-based finishing diet was offered for ad libitum intake twice a day for 84 d, containing the following treatments: 1) control (without DFM); 2) DFM (B. licheniformis and B. subtilis) at 6.4 × 109 CFU (2 g) per animal. The data were analyzed using the MIXED procedure of SAS, with a pen representing an experimental unit, the fixed effect of the treatment, and the random effect of pen nested within the treatment. For fecal parameters (two collections made), the collection effect and its interaction with the treatment were included in the model. Bulls that received the DFM had a decreased dry matter intake (P ≤ 0.01), did not differ in average daily gain (2.05 kg; P = 0.39), and had a 6% improvement in gain:feed (P = 0.05). The other performance variables, final BW, hot carcass weight, and hot carcass yield, did not differ (P > 0.10). Plasma urea-N concentration decreased by 6.2% (P = 0.02) in the bulls that received DFM. Glucose, haptoglobin, and lipopolysaccharides were not different between treatments (P > 0.10). Ruminal morphometrics were not affected by the treatment (P > 0.10). The use of DFM tended to reduce fecal starch (P = 0.10). At slaughter, bulls fed DFM had an increased duodenal gene expression of tryptophan hydroxylase-1 (P = 0.02) and of superoxide dismutase-1 (P = 0.03). Overall, supplementation with DFM based on B. licheniformis and B. subtilis to Nellore × Angus bulls in the finishing phase decreased dry matter intake, did not influence ADG, improved gain:feed, and increased the expression of genes important for duodenal function.

One of the main alternatives of additives to modulate the microbial population in the gastrointestinal tract (GIT), especially in the intestine, is the use of direct-fed microbials (DFM). This class of additives comprises all the feed products that contain a live or naturally occurring source of microorganism. The inclusion of DFM in diets of ruminants in the finishing phase may improve gain:feed by modifying the composition of the microbial community in the GIT to bring about a better symbiotic relationship with the host. These effects may be achieved with the use of Bacillus spp. bacteria, such as Bacillus licheniformis and Bacillus subtilis. Mixtures of these bacteria are able to foster positive effects in the finishing phase of beef cattle fed high-energy diets, which reinforces the need for studies that examine the effects and mechanisms of these species. In this study, feedlot Nellore × Angus bulls that received a DFM composed of B. licheniformis and B. subtilis had decreased dry matter intake, no influence on average daily gain, improved gain:feed, and an increase in expression of genes important for duodenal function.