Subject: Biology, Anatomy & Morphology Keywords: probiotic; pig; poultry; microbiota; microbiome; intestine
Online: 19 November 2020 (10:26:23 CET)
The intestinal microbiota and its functions are regarded as critical for host health and disease. Probiotics can influence the gut microbiome and its interactions with the host, and are currently defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Probiotics have become common components of strategies to promote livestock health, welfare and productivity, not least due to restrictions on the use of antimicrobial drugs. Common probiotic organisms are considered commensals and are ‘generally recognized as safe’ (GRAS) via oral administration. This review outlines potential probiotic mechanisms, including recent findings. These mechanisms include those interactions primarily occurring between the supplemented probiotic microorganisms and the indigenous intestinal microbiota, perhaps within the gut lumen, as well as more direct interactions with the host via mucosal receptors or more distally following absorption of microbial components. There is good evidence that the gut microbiome is relatively stable in ‘healthy’ individuals and resistant to ‘colonisation’ by exogenous microbes, which helps exclude pathogens, but has implications for the establishment of probiotics, and could increase the importance of microbe-microbe interactions. However, such microbiomes may be receptive to complementary microbes or functions, while supplemented probiotics may dominate luminal populations, particularly in less populated regions of the intestine. Moreover, host-adapted microbes or microbiomes may elicit different host responses and/or be more effective. Some considerations for the interpretation of study results, including extrapolation from different models or microbial strains, are also included. In addition, notable mechanistic and/or pathogen challenge studies from pigs and poultry are highlighted to underline the recognised potential of probiotics in these species, particularly as the appropriate selection of microorganisms and their application continues to be better understood and improve.
ARTICLE | doi:10.20944/preprints202008.0120.v1
Subject: Life Sciences, Microbiology Keywords: intestine microbiota; Cattle Egret; Pied Crows; Kinshasa
Online: 5 August 2020 (09:59:45 CEST)
Purpose: Our study focused on Pied Grow and Cattle Egret, two commensal and ubiquitous birds feeding in dumps and frequenting our homes. Our aim was to identify the bacteria that birds bring to our homes and could be a potential risk to Congolese health. Method: We have done bacteriological analyses of bird feces for to explore its gut micriobiota composition. The feces were collected in the uricotelic cloaca by using a swab in 52 Cattle Egrets (Bubulcus ibis) and 23 Pied Crows (Corvus albus) from Kinshasa city. Results: Bacteriological analyses revealed the presence of Proteus vulgaris (3.8%) and Klebsiella pneumoniae (5.8%) on Cattle Egret, Salmonella sp. (8.7%), Klebsiella pneumoniae (8.7%), Pseudomonas aeruginosa (21.7%), Proteus vulgaris (30.4%) on Pied Crow, Citrobacter spp and Escherichia coli (100%) on both Cattle Egret and Pied Crow respectively. Conclusion: The presence of these pathogenic germs, suggesting these commensal and ubiquitous birds may be potential vectors of various Diseases which pose serious health problems in the region.
ARTICLE | doi:10.20944/preprints201803.0051.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: glutamine; perioperative period; bypass surgery; intestine surgery; HPLC
Online: 7 March 2018 (05:21:29 CET)
Glutamine is the main amino acid which is substrate for gluconeogenesis in postoperative period. It is suggested that this leads to a substantial and a long-term decline in glutamine concentration. Glutamine is a source of energy for the synthesis of nucleotides, lymphocytes and cells of gastrointestinal tract. In this study, 79 patients were qualified to a coronary artery bypass surgery (Group I) or a surgery in the large intestine area (Group II). The objectives of this study were: evaluation of the impact of surgical procedures on the serum concentration of glutamine of the operated patients, assessment of gender, weight and BMI impact on glutamine concentration and analysis of the correlation between glutaminę serum concentration and laboratory parameters. The mean concentration of glutamine before surgery, the 3rd and 5th day after surgery was higher in Group I. CRP level in the 3rd and 5th postoperative day was higher in Group II. There were no significant differences betweengroups when it comes to BMI and the concentration of CRP (p <0.05). Glutamine concentration depends on the severity of inflammation, the operated body cavity and the intensified catabolism which results from different pathophysiology of digestive system diseases and coronary arterial disease.
ARTICLE | doi:10.20944/preprints202112.0120.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: aging; NMR spectroscopy; mice; energy metabolism; fat; intestine; metabolomics
Online: 8 December 2021 (12:03:07 CET)
Energy metabolism, including alterations in energy intake and expenditure, is closely related to aging and longevity. Metabolomics studies have recently unraveled changes in metabolite composition in plasma and tissues during aging and have provided critical information to elucidate the molecular basis of aging process. However, the metabolic changes in tissues responsible for food intake and lipid storage have remained unexplored. In this study, we aimed to investigate aging-related metabolic alterations in these tissues. To fill this gap, we employed NMR-based metabolomics in several tissues, including different parts of the intestine (duodenum, jejunum, ileum) and brown/white adipose tissues (BAT, WAT) of young (9-10 weeks) and old (96-104 weeks) wild-type (mixed genetic background of 129/J and C57BL/6) mice. We further included plasma and skeletal muscle of the same mice to verify previous results. Strikingly, we found that duodenum, jejunum, ileum, and WAT do not metabolically age. In contrast, plasma, skeletal muscle, and BAT show a strong metabolic aging phenotype. Overall, we provide first insights into the metabolic changes of tissues essential for nutrient uptake and lipid storage and have identified biomarkers for metabolites that could be further explored to study the molecular mechanisms of aging.
ARTICLE | doi:10.20944/preprints202208.0159.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolomics; NMR; PEMT; knockout; aging; mice; liver; intestine; white/brown adipose tissue
Online: 8 August 2022 (13:36:04 CEST)
Phospholipid metabolism, including phosphatidylcholine (PC) biosynthesis, is crucial for various biological functions and is associated to longevity. Phosphatidylethanolamine N-methyltransferase (PEMT) is a protein that catalyzes the biosynthesis of PC, the levels of which change in various organs such as brain and kidney during aging. However, the role of PEMT for systemic PC supply is not fully understood. To address how PEMT affects aging-associated energy metabolism in tissues responsible for nutrient absorption, lipid storage and energy consumption, we employed NMR-based metabolomics to study liver, plasma, intestine (duodenum, jejunum, ileum), brown/white adipose tissues (BAT, WAT), and skeletal muscle of young (9–10 weeks) and old (96–104 weeks) wild-type (WT) and PEMT knockout (KO) mice. We found that the effect of PEMT-knockout was tissue-specific and age-dependent. Deficiency of PEMT affected the metabolome of all tissues examined, among which the metabolome of BAT from both young and aged KO mice was dramatically changed in comparison to WT mice, whereas the metabolome of jejunum was only slightly affected. As for aging, the absence of PEMT increased the divergence of metabolome during aging of liver, WAT, duodenum and ileum and decreased the impact on skeletal muscle. Overall, our results suggest that PEMT plays a previously unexplored critical role in both aging and energy metabolism.
Subject: Medicine & Pharmacology, Nutrition Keywords: Iron, Zinc, Interactions, DMT1, ZIP4, Pancreas, Metabolism, Homeostasis, Intestine, Caco-2 cells
Online: 9 July 2019 (14:32:11 CEST)
Iron and zinc are essential micronutrients required for growth and health. Deficiencies of these nutrients are highly prevalent among populations, but can be alleviated by supplementation. Cross-sectional studies in humans showed positive association of serum zinc levels with hemoglobin and markers of iron status. Dietary restriction of zinc or intestinal specific conditional knock out of ZIP4 (SLC39A4), an intestinal zinc transporter, in experimental animals demonstrated iron deficiency anemia and tissue iron accumulation. Similarly increased iron accumulation has been observed in cultured cells exposed to zinc deficient media. These results together suggest a potential role of zinc in modulating whole body iron metabolism. Studies in intestinal cell culture models demonstrate that zinc induces iron uptake and transcellular transport via induction of divalent metal iron transporter-1 (DMT1) and ferroportin (FPN) expression, respectively. It is interesting to note that intestinal cells are exposed to very high levels of zinc through pancreatic secretions, which is a major route of zinc excretion from the body. Therefore, zinc appears to be modulating the iron metabolism possibly via regulating the DMT1 and FPN1 levels. Herein we critically reviewed the available evidence to hypothesize novel mechanism of Zinc-DMT1/FPN axis in regulating intestinal iron absorption and tissue iron accumulation to facilitate future research aimed at understanding the yet elusive mechanisms of iron and zinc interactions.
Subject: Life Sciences, Biochemistry Keywords: low intensity exercise; intestine; sodium-dependent glucose transporter; glucose transporter 2; glucagon like peptide 2
Online: 20 April 2021 (11:48:02 CEST)
Exercise affects various organs. However, its effects on nutrient digestion and absorption in the intestinal tract are not well understood. A few studies have reported that exercise training in-creases the expression of carbohydrate digestion and absorption molecules. Exercise was also shown to increase the concentration of blood glucagon like peptide-2(GLP-2), which regulates carbohydrate digestion and absorption in small intestinal epithelium. Therefore, we investigated the effects of exercise on intestinal digestion and absorption molecules and the levels of GLP-2. 6-wk-old of male mice were divided into 2 groups; sedentary (SED) and low-intensity exercise (LEx). LEx mice were required to run on a treadmill (12.5 m/min, 60 min), whereas SED mice rested. All mice were euthanized 1 h after exercise or rest and plasma, jejunum, ileum, and colon were sampled. Samples were analyzed using EIA and immunoblotting. The levels of plasma GLP-2 and the expression of the GLP-2 receptor, sucrase-isomaltase (SI), and glucose transporter (GLUT2) in the jejunum were increased in LEx group. We showed that acute low-intensity exer-cise affects the intestinal carbohydrate digestion and absorption molecules via GLP-2. Our results suggest that exercise might provide new benefits to the small intestine for people with intestinal frailty.
ARTICLE | doi:10.20944/preprints202004.0198.v1
Subject: Keywords: mathematical modelling; peristalsis; smoothed particle hydrodynamics (SPH); fluid dynamics; large intestine; colonl proximal colon; fluid-structure interactions; drug delivery
Online: 12 April 2020 (15:57:17 CEST)
The proximal part of the colon offers opportunities to prolong the absorption window following oral administration of a drug. In this work, we used computer simulations to understand how the hydrodynamics in the proximal colon might affect the release from dosage forms designed to target the colon. For this purpose, we developed and compared three different models: a completely-filled colon, a partially-filled colon and a partially-filled colon with a gaseous phase present (gas-liquid model).The highest velocities of the liquid were found in the completely-filled model, which also shows the best mixing profile, defined by the distribution of tracking particles over time. No significant differences with regard to the mixing and velocity profiles were found between the partially-filled model and the gas-liquid model. The fastest transit time of an undissolved tablet was found in the completely-filled model. The velocities of the liquid in the gas-liquid model are slightly higher along the colon than in the partially-filled model. The filling level has an impact on the exsisting shear forces and shear rates, which are decisive factors in the development of new drugs and formulations.
HYPOTHESIS | doi:10.20944/preprints202004.0153.v1
Subject: Life Sciences, Other Keywords: Severe acute respiratory syndrome coronavirus 2; 2019-nCoV; COVID-19; angiotensin converting enzyme 2; Receptor; Live Attenuated Oral Vaccine; Intestine; proximal and distal enterocytes; herd immunity
Online: 9 April 2020 (13:10:50 CEST)
Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2/2019-nCoV) infection is an emerging pandemic. The virus binds to angiotensin converting enzyme 2 (ACE2) and TMPRSS2 which are abundantly expressed on various human cells including lung epithelial cells and intestinal cells and the virus can infect these cells. Currently no specific treatments or vaccines are available for this disease. A per oral live attenuated vaccine can be beneficial in SARS-Cov-2 infection because the attenuated virus initially infects the gut, stimulates the mucosa associated immune system sparing the respiratory system during the initial immune response. The live virus can also spread in the community boosting herd immunity.