Acid Absorption Research Articles

Effect of serum diamine oxidase activity derived from response to chemotherapy on adverse events and serum amino acid concentrations for esophageal cancer.

55 Background: The relationship between activity of the small intestinal villi and the effectiveness of chemotherapy remains unclear. This study aimed to investigate how serum diamine oxidase (DAO) activity affects antitumor effects, adverse events, and amino acid absorption. Methods: We performed a single-center prospective cohort study that enrolled 50 patients with esophageal cancer (EC) receiving docetaxel, cisplatin, and 5-fluorouracil therapy. We determined the cut-off value of serum DAO activity contributing to a response to chemotherapy using a generalized additive model. Additionally, we compared adverse events, inflammatory markers, blood amino acid levels, and quality of life between the high and low DAO activity groups during chemotherapy. Results: The cut-off value of serum DAO activity at the first visit that contributed to a chemotherapy response was 6.5 units/L. Leukopenia and neutropenia of Grade ≥3 were significantly higher in the DAO low (<6.5 units/L) group ( p = 0.044, 0.017, respectively). Interleukin-6 was significantly lower in the DAO high (≥6.5 units/L) group at the first visit and at 4 weeks after the end of chemotherapy ( p = 0.039, 0.011, respectively). Glutamine was higher in the DAO high group at all measurement points during chemotherapy. Fatigue was significantly lower in the DAO high group ( p = 0.001). Conclusions: Serum DAO activity may be a predictor of the response to chemotherapy in patients with EC. The absorption capacity of amino acids was maintained in the group with high DAO activity, which may have contributed to the anti-inflammatory effect and provided a background for reducing adverse events. Clinical trial information: UMIN000048273 .

Decreased Amino Acid Transporter LAT2 Is the Main Determinant of Impaired Protein Utilization During Aging

As the global demographic shifts toward an aging population, understanding the efficiency of protein utilization in older adults becomes crucial. Our study explores the intricate relationship between protein intake and aging, with a focus on precision nutrition for older people. Through a meta-analysis, we confirm a decline in protein-utilization capacity in older individuals and examine the different contributions of plant and animal protein. In experiments involving mice of different ages, older mice exhibited decreases in the biological utilization of four proteins (casein, beef protein, soy protein, and gluten), particularly casein. In subsequent research, casein was studied as a key protein. A decline in gastric digestion function was observed through peptidomics and the examination of pepsin levels using casein. Nevertheless, this decline did not significantly affect the overall protein digestion during the aging process. The combined application of targeted amino acid metabolomics identified abnormal absorption of amino acids as the underlying cause of decreased protein utilization during aging, particularly emphasizing a reduction in branched-chain amino acids (BCAAs) in older mice. Delving deeper into the proteomics of the intestinal protein digestion and absorption pathway, a reduction of over 60% in large neutral amino acid transporter 2 (LAT2) protein expression was observed in both older humans and aged mice. The reduction in LAT2 protein was found to be a key factor influencing the diminished BCAA availability. Overall, our study establishes the significance of amino acid absorption through LAT2 in protein utilization during aging and offers a new theoretical foundation for improving protein utilization in the older adults.

Characterization of genes and proteins involved in the absorption of long-chain fatty acids in the gastrointestinal tract of cattle

Characterization of genes and proteins involved in the absorption of long-chain fatty acids in the gastrointestinal tract of cattle

Unraveling the Active Sites on Mesoporous CuFe2O4@N-Carbon Catalysts with Abundant Oxygen Vacancies and M-N-C Content for Boosted Nitrogen Reduction Toward Electrosynthesis of Ammonia.

Transition metal centers dispersed over nitrogen-doped carbon (M-NC) supports have been widely explored for electrocatalytic reactions; however, sparsely reported for electrochemical nitrogen reduction reaction (ENRR). Particularly, the single-atom catalysts (SACs) have shown reasonable ammonia yield rate and faradaic efficiency (FE), but their complex synthesis and low durability for long-term electrocatalysis runs restrict their use on a larger scale. Importantly, the catalytic active sites in metal nanostructured-based M-NC catalysts toward enhanced N2 adsorption and activation are still not clear as they are highly challenging to reveal. A few studies have predicted that the surface oxygen vacancies (Ovac) favor an enhanced ENRR performance. Herein, a strategy using tailored M-NC content and Ovac in a single catalyst for enhanced ammonia electrosynthesis is devised. A mesoporous bimetallic spinel oxide (CuFe2O4) supported over N-doped carbon (CuFe2O4@NC) derived from Prussian blue analog (PBA) via controlled pyrolysis possess is found to show boosted ENRR activity. Moreover, operando NH3 formation over the catalyst is observed using four electrode set up. This approach enables rapid evaluation ofelectrocatalytic efficacy and avoids false positive results. The rotating disc electrode results reveal that mass transport in acidic media and surface absorption in alkline media primarily regulate ENRR over CuFe2O4@NC electrocatalyst.

The Preventive Effect of Low-Molecular Weight Oyster Peptides on Lipopolysaccharide-Induced Acute Colitis in Mice by Modulating Intestinal Microbiota Communities.

Colitis causes inflammation, diarrhoea, fever, and other serious illnesses, posing a serious threat to human health and safety. Current medications for the treatment of colitis have serious side effects. Therefore, the new strategy of creating a defence barrier for immune function by adding anti-inflammatory foods to the daily diet is worth advocating for. Low-molecular weight oyster peptides (LOPs) are a natural food with anti-inflammatory activity extracted from oysters, so intervention with LOPs is likely to be an effective preventive solution. The aim of this study was to investigate the preventive effect of LOPs on lipopolysaccharide (LPS)-induced acute colitis inflammation in mice and its underlying mechanism. The results showed that LOPs not only inhibited the colonic histopathy in mice induced by LPS-induced inflammation but also reduced the inflammatory response in the blood. In addition, LOPs significantly increased the number of beneficial bacteria (Alistipes, Mucispirillum, and Oscillospira), decreased the number of harmful bacteria (Coprobacillus, Acinetobater) in the intestinal microbiota, and further affected the absorption and utilisation of short-chain fatty acids (SCFAs) in the intestinal tract. In conclusion, dietary supplementation with LOPs is a promising health-promoting dietary supplement and nutraceutical for the prevention of acute colitis by reducing the inflammatory response and modulating the intestinal microbial communities.

Dietary protein splanchnic uptake and digestibility via stable isotope tracers.

Dietary proteins are broken down into peptides across the gastrointestinal tract, with skeletal muscle being a primary deposition site for amino acids in the form of incorporation into, for example, metabolic and structural proteins. It follows that key research questions remain as to the role of amino acid bioavailability, of which protein digestibility and splanchnic sequestration (absorption and utilization) of amino acids are determining factors, impact upon muscle protein synthesis (MPS) in clinical states. Elevated splanchnic amino acid uptake has been implicated in anabolic resistance (i.e. attenuated anabolic responses to protein intake) observed in ageing, though it is unclear whether this limits MPS. The novel 'dual stable isotope tracer technique' offers a promising, minimally invasive approach to quantify the digestion of any protein source(s). Current work is focused on the validation of this technique against established methods, with scope to apply this to clinical and elderly populations to help inform mechanistic and interventional insights. Considerations should be made for all facets of protein quality; digestibility of the protein, absorption/utilization and subsequent peripheral bioavailability of amino acids, and resultant stimulation of MPS. Stable isotope tracer techniques offer a minimally invasive approach to achieve this, with wide-ranging clinical application.

Plasma amino acid profiles in thalassaemia major with iron overload

Introduction: Iron overload in thalassaemia major patients mainly occurs due to periodic transfusions. When iron exceeds transferrin capacity, non-transferrin bound iron accumulates and causes tissue damage, including in the gastrointestinal tract, resulting in impaired enterocyte function and amino acid absorption. The aim of this study was to evaluate amino acid profiles in patients with thalassaemia major after repeated transfusions and chelation. Methods: Whole blood amino acids were analysed from dried blood spots using liquid chromatography tandem mass spectrometry. This study consisted of two parts: a cross-sectional and a cohort study in thalassaemia-β-major patients. In the cross-sectional study, amino acid profiles were analysed in 219 thalassaemia patients who received routine transfusion and chelation therapy, and 60 healthy control subjects. The cohort study included 21 subjects, from whom blood samples were taken at pre-transfusion, 1-day posttransfusion, one and three months post-chelation to evaluate changes in amino acid levels. Results: There were significant differences between amino acid levels in thalassaemia subjects and controls. Positive correlations were found between serum iron and transferrin with age, also between transferrin with proline, valine, phenylalanine, aspartic acid, and glutamic. Phenylalanine and aspartic acid were significantly lower in subjects with transferrin lower than 180 µg/dL. Significant correlations were found between haemoglobin with essential and non-essential amino acid groups. From the cohort study, significant changes were observed in glycine, alanine, leucine, and aspartic acid. Conclusion: Amino acid profiles in thalassaemia patients differed compared to healthy controls, even after transfusion and chelation. Phenylalanine and aspartic acid were significantly lower in subjects with low transferrin levels.

Effects of Different Protein Sources on Amino Acid Absorption and Plasma Appearance of Tryptophan, Large Neutral Amino Acids, and Tryptophan Metabolites in Pigs

BackgroundAbsorption of tryptophan (TRP) across the gut epithelium is potentially modulated by competing large neutral amino acids (LNAAs), which could affect the appearance of TRP and its metabolites in the bloodstream. ObjectivesThis study aimed to determine, in a growing pig model of an adult human, the absorption of TRP and other LNAAs from the gastrointestinal tract, and plasma appearance of TRP, LNAAs, and TRP metabolites, in response to dietary proteins varying in TRP content. MethodsPigs were adapted for 7 d to each of 4 diets that differed in their protein source and TRP content: 1) alpha-lactalbumin (AL; 9.95 mg TRP/g diet DM), 2) whey protein (6.59 mg TRP/g), 3) casein (3.73 mg TRP/g), or 4) zein (0.14 mg TRP/g). On day 8, pigs were euthanised after a 12-h fast (baseline), or 1, 2, 3, 4, or 6 h after they received a test meal consisting of 45 g protein, or a protein-free meal (n = 6 pigs at each time in each meal group). Tryptophan and LNAA absorption from the small intestine, and appearance of TRP, LNAAs, and TRP metabolites (melatonin, serotonin, kynurenine pathway metabolites), in the portal vein and systemic circulation, were determined. ResultsAL intake resulted in sustained elevated plasma TRP concentrations after an overnight fast. The amount of TRP absorbed was dose-dependently related to protein TRP content (P = 0.028), with fastest rates for pigs fed AL (371 mg/h). Portal and systemic plasma TRP, TRP/LNAA, and the TRP metabolites were highest (P ≤ 0.05) after AL intake, and remained above baseline levels for ∼4 h postprandially. Absorption rates of TRP correlated with postprandial plasma TRP and TRP metabolites (P ≤ 0.05). ConclusionsIn adult humans, postprandial plasma TRP and TRP metabolite concentrations can likely be modulated by the TRP content of the meal.

Biodistribution and toxicity assessment of gallic acid (GA)-loaded mesoporous silica nanoparticles coated with lipid in male wistar rats: A comprehensive investigation

BackgroundThe Blood-Brain Barrier (BBB), which protects the brain from many medications, is the biggest challenge for researchers testing new neurological treatments. Our research uses lipid bilayer-coated (LB) mesoporous silica nanoparticles (MSN) to increase gallic acid (GA) absorption over the BBB and improve its therapeutic benefits. MethodsThe formulations were characterized using Fourier transform infrared, x-ray diffraction (XRD), transmission electron microscopy, drug release, encapsulation efficiency, loading capacity, process yield, and dynamic light scattering to assess particle size and calculate zeta potential. Our investigation divided male Wistar rats into five groups: control, MSN, GA (20 mg/kg GA), MSN-GA, and LB-MSN-GA. HPLC biodistribution, oxidative stress, and cortical and hippocampal histopathology were also done. Key findingsThis study shows gallic acid can be encapsulated into MSN-GA and LB-MSN-GA nanoparticles with good loading capacities and encapsulation efficiency. Fourier transform infrared spectroscopy (FTIR) and XRD confirmed nanoparticle mesoporousness. The study also indicated that LB-MSN-GA may modify cortical and hippocampal histopathological and biochemical parameters. LB-MSN-GA loading altered GA distribution maps across the cortex and hippocampus. ConclusionGallic acid (GA) transfer via LB-MSN-GA substantially impacts rats' cortex and hippocampus. Therefore, one promising method of drug delivery for the brain is LB-MSN-GA.

Obesity-enriched gut microbe degrades myo-inositol and promotes lipid absorption

Numerous studies have reported critical roles for the gut microbiota in obesity. However, the specific microbes that causally contribute to obesity and the underlying mechanisms remain undetermined. Here, we conducted shotgun metagenomic sequencing in a Chinese cohort of 631 obese subjects and 374 normal-weight controls and identified a Megamonas-dominated, enterotype-like cluster enriched in obese subjects. Among this cohort, the presence of Megamonas and polygenic risk exhibited an additive impact on obesity. Megamonas rupellensis possessed genes for myo-inositol degradation, as demonstrated invitro and invivo, and the addition of myo-inositol effectively inhibited fatty acid absorption in intestinal organoids. Furthermore, mice colonized with M.rupellensis or E.coli heterologously expressing the myo-inositol-degrading iolG gene exhibited enhanced intestinal lipid absorption, thereby leading to obesity. Altogether, our findings uncover roles for M.rupellensis as a myo-inositol degrader that enhances lipid absorption and obesity, suggesting potential strategies for future obesity management.

The Possible Effect of Platelet Rich Plasma on Liver and Small intestine in Adult and Aged Male Rats. A Histological and Immunohistochemical Study

Abstract Introduction There is a general modest decline in the function of different organs in the body with aging. In the small intestine, there may be alterations in the intestinal morphology, as well as a decline in the absorption of fatty acids and sugars. The aging process decreases regenerative ability which significantly delays the restoration of liver function. Platelet-rich plasma (PRP) has recently attracted interest in many medical fields. PRP might has benefit effect on aged male rats. Aim of the Work This study aims to investigate the structural changes that might occur during normal aging and the possible effect of PRP intraperitoneal injection on adult and aged male albino rats. Materias and Methods Forty-two male albino rats were classified according to age into adult group and old aged groups. Adult male rats (300 -350 g), their age range between 6-8 months. Aged male rats (570-660 g), their age range between 12-24 months. They were divided randomly into four groups: Group I (Control adult): Included 14 rats that further subdivided into 2 equal subgroups: subgroup IA: untreated rats and subgroup Ib: rats were injected by sterile saline intraperitoneally (0.5 mL/kg by intraperitoneal injection 3 times/week). Group II (Control Aged): Included 14 rat that further subdivided into 2 similar subgroups as group I, Group III (Adult treated): Included 7 rats that received intraperitoneal injection of PRP (0.5 mL/kg by intraperitoneal injection 3 times/week), Group IV (Aged treated): Included 7 rats that received intraperitoneal injection of PRP as group III. Animals were kept under observation and the treated groups received intraperitoneal injections for 21 days. At the end of the experiment, Liver and small intestine specimens were processed for histological and immunohistochemical examination. Morphometric and statistical analysis was also done. Results Group II showed decrease in height of intestinal villi with disruption of their epithelium surface, increase spacing between enterocytes and abundant mononuclear cellular infiltration. Changes in the liver comprised nuclear and cytoplasmic changes that included an increase in nuclei number in hepatocytes with droplets fat infiltration. Treated Groups showed decreasing mononuclear cellular infiltration with decreasing collagen fibres and congested blood vessels. Conclusion Aging process enhanced the vulnerability to injury and inflammation in both the liver and small intestine. PRP had ameliorating effects on these changes.

Investigation on the mechanisms of scorpion venom in hepatocellular carcinoma model mice via untargeted metabolomics profiling

Metabolic reprogramming is frequently accompanied by hepatocellular carcinoma (HCC) progression. Disrupted metabolites act as potential biomarkers and drug therapeutic targets for HCC. Peptide extract of scorpion venom (PESV) induces cytotoxic anti-proliferative effects and apoptosis in tumors. However, the action mechanisms of PESV remain unknown. This study aimed to explore the serum metabolic profiles of tumor-bearing mouse model. We generated an orthotopic HCC xenograft mouse model by implanting H22 cells into the left hepatic lobe of male C57BL/6 mice. After surgery, the mice were assigned to two groups randomly: PESV (PESV-treated 40 mg/kg daily, i.g.; n = 6) and control (treated with the solvent equally for 14 d, n = 6) groups. Based on an untargeted metabolomics approach using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, differential metabolites were screened via univariate and multivariate data analyses. A total of 48 differential metabolites in negative ion mode and 63 in positive ion mode were identified in the serum samples. Furthermore, metabolic pathway analysis revealed that aminoacyl-tRNA biosynthesis, amino acid pathway, glutathione metabolism, protein transports, protein digestion and absorption, and cAMP signaling pathways play vital roles in PESV-induced inhibition of tumors. These findings highlight the distinct changes in the metabolic profiles of HCC-bearing mice after PESV treatment, suggesting the potential of the identified metabolic molecules as therapeutic targets for HCC.

Irisin promotes tilapia muscle cell growth and amino acid uptake via IGF-1 signaling.

Irisin is a recently discovered myokine that facilitates the browning of white adipose tissue, increases glucose uptake in skeletal muscle, and influences metabolic processes in the liver. However, its potential effects on amino acid absorption remained largely unexplored. This study aimed to elucidate the role of irisin in modulating amino acid uptake and delineate the underlying molecular mechanisms involved. To this end, juvenile tilapia were administered intraperitoneal irisin injections at 100 ng/g body weight over 8 weeks. Evaluation of various physiological parameters revealed that irisin supplementation significantly improved the specific growth rate and feed conversion efficiency while reducing feed consumption. Muscle tissue analysis revealed that irisin significantly modified the proximate composition by increasing protein content and reducing lipid levels. It also significantly raised the levels of both essential and non-essential amino acids in the muscle. Histological analysis demonstrated that irisin-stimulated muscle growth through hyperplasia rather than hypertrophy, corroborated by upregulated IGF-1 mRNA and downregulated myostatin mRNA expression. Mechanistic studies in cultured tilapia muscle cells elucidated that irisin activated integrin receptors on muscle cells, which subsequently engaged IGF-1/IGF-1R signaling. Downstream of IGF-1R activation, irisin simultaneously stimulates the ERK1/2 and PI3K/mTORC2/Akt pathways. The convergence of these pathways upregulates L-type amino acid transporter 1 expression, thereby augmenting amino acid uptake into muscle cells. In summary, irisin supplementation in tilapia leads to improved muscle growth, predominantly via hyperplasia and augmented amino acid assimilation, governed by intricate cellular signaling pathways. These findings provide valuable aquaculture applications and novel insights into muscle development.

A semi-flexible polybenzimidazole with enhanced comprehensive performance for high-temperature proton exchange membrane fuel cells

Although phosphoric acid-doped PBI holds great promise for application in high-temperature proton exchange membrane fuel cells, the stabilities of phosphoric acid-doped membranes are compromised due to the low absorption capacity of phosphoric acid, poor solubility and difficulty in processing. In this study, by introducing poly (5-phenyl-1H-1,2,3-triazole) monomers into the polybenzimidazole main chains, a semi-flexible polybenzimidazole (PBI-QP) was prepared. The mechanical properties of PBI-QP membranes were better than that of PBI membrane. The tensile strength of PBI-QP-20 reached to 130.9 MPa. Compared with PBI, the solubility of PBI-QP has improved significantly. PBI-QP can be easily dissolved in the solvents of DMF, DMSO and formic acid separately at room temperature. All the membranes exhibited super thermal stability. At 800 °C there is still 72% quantity of residue and the thermal stability of PBI-QP can meet the thermal stability requirements of HT-PEMFCs. The membranes of PBI-QP demonstrated high phosphoric acid absorption (ADL 10.5) and enhanced antioxidant properties. The proton conductivity is 64.3 mS∙cm−1 at 170 °C and the peak power density attains an impressive level of 573.6 mW cm−2 at 180 °C. The results indicate that the synthesized HT-PEMs exhibit excellent solubility and impressive peak power density, underscoring their substantial promise for utilization in HT-PEMs.

Analytical studies on the absorption and metabolism of amino acids by Saccharomyces species

Analytical studies on the absorption and metabolism of amino acids by <i>Saccharomyces</i> species

Role of alkyl chain length on aggregation enhanced two-photon absorption and thermal diffusivity of Carbazole-Barbituric acid D-π-A systems

Aggregation Induced Emission (AIE) luminogens exhibit no or faint emission in dilute solution and are induced to emit when aggregated with restriction of intramolecular motion as the principle mechanism. We investigated the role of hydrophobic interaction in AIE effect by varying the alkyl chain length of Carbazole-Barbituric acid (CBA) D-π-A system. We synthesized six CBA conjugates, studied their photophysical properties and morphological changes upon aggregation by varying water: tetrahydrofuran ratio. We performed thermal lens experiment in all CBA conjugates to understand the variation in radiative and non-radiative decays upon aggregation. Both aggregation and hydrophobic interaction is found to play significant role in tuning thermal diffusivity of CBA conjugates. The knowledge about their energy levels was gained by using DFT in Gaussian 09 program package. Perturbation of energy levels associated with molecular aggregation open up the possibility of such D-π-A system in nonlinear optics. The open aperture Z-scan technique with Nd:YAG laser at 1064 nm was utilized to measure the change in two-photon absorption (TPA) coefficient at different stages of aggregation and as a function of alkyl chain lengths. We observed an aggregation enhanced TPA and could tune the TPA in aqueous solution by changing the alkyl chain length. Experimentally observed TPA coefficient showed the same trend as obtained in DFT calculation for hyperpolarizability. Furthermore, for practical utility we fabricated CBA conjugate doped PMMA thin films for low threshold optical limiting applications.

Clostridium sporogenes increases fat accumulation in mice by enhancing energy absorption and adipogenesis.

The Clostridia clusters have been implicated in energy metabolism, the specific species and underlying mechanisms remain unclear. This present study is the first to report Clostridium sporogenes is able to affect fat accumulation and glycolipid metabolism. We indicated that gavage of C. sporogenes promoted the adipogenesis and fat accumulation in mice by not only increasing the abundance of Clostridium bacteria but by also enhancing the metabolic absorption of carbohydrates and fatty acids significantly. Obviously, changes of gut microbiota caused by the C. sporogenes, especially the significant increase of Clostridium bacteria, contributed to the fat accumulation of mice. In addition, the enhancement of Clostridium genus bacteria remarkably improved the synthesis of hepatic pyruvate, acetyl-CoA, and triglyceride levels, as well as reduced the excretion of fecal carbohydrates, short-chain fatty acids, and free fatty acids remarkably. These findings will help us to understand the relationship of specific bacteria and host energy homeostasis.

Comparison of gut transcriptome and bacterial composition of the yellow peach moth, Conogethes punctiferalis larvae associated with host plants adaptation

The yellow peach moth, Conogethes punctiferalis, is one of the most destructive polyphagous pests to corn crops in the Huang-Huai-Hai summer corn region of China. However, little is known about the host plant adaptation mechanism of C. punctiferalis. In this study, we analyzed the performance of C. punctiferalis on two of its favorable host plants (corn and sorghum). Then, we used RNA-seq and 16S rRNA sequencing to explore the potential adaptation mechanism of C. punctiferalis on these two host plants. Results showed that C. punctiferalis gained more fresh weight on sorghum while its total lipid and triglyceride content was significantly lower than on corn. In total, 2155 genes weredifferentially expressed (DEGs) between corn and sorghum reared C. punctiferalis. Most of the DEGs were involved in nutritional biosynthesis and metabolism including amino acid biosynthesis, protein digestion and absorption, and glycolysis. Enzymatic analyses revealed that C. punctiferalis reared on corn had higher trypsin activity but lower P450 activity than that reared on sorghum. Meanwhile, C. punctiferalis reared on corn harbored more gut bacteria, while its diversity is lower than that reared on sorghum. The potential functional prediction of the gut bacteria revealed that nutritional metabolism functions were differently enriched between two host plants of C. punctiferalis. Taken together, these findings clarify the impact of host plants on the gene expression and gut bacteria in C. punctiferalis. They also suggest that the plasticity of gene expression and gut bacteria cooperatively contribute to insect host adaptation of insects.

Sucrose Solution Ingestion Exacerbates Dinitrofluorobenzene-Induced Allergic Contact Dermatitis in Rats.

Allergic dermatitis is a skin disease with growing prevalence worldwide that has been associated with diets high in fats and sugars. Regular consumption of sucrose-containing beverages may increase the risk for several health problems, including allergic diseases and particularly asthma, but the association between sucrose consumption and allergic dermatitis is understudied. We investigated the effects of sucrose solution intake on allergic contact dermatitis in rats and found early exacerbation of 2,4-dinitrofluorobenzene (DNFB)-induced disease symptoms and altered composition of the gut microbiota after 14 d of intake. The levels of short-chain fatty acids-produced by fermentation by the intestinal microbiota-were not affected in the cecal contents and feces but decreased in the blood; this effect was especially notable for acetate. To restore blood acetate concentrations, triacetin was mixed with a 10% sucrose solution and fed to the rat model. This strategy prevented the early exacerbation of DNFB-induced symptoms. The decreased absorption of short-chain fatty acids from the intestinal lumen was not linked to the decreased expression of short-chain fatty acid transporters in the small intestine; instead, the mechanism involves a reduction in the sodium concentration in the intestinal lumen due to increased expression of sodium-glucose transporter 1 (SGLT1).

Alleviation of fluoride-induced colitis by tea polysaccharides: Insights into the role of Limosilactobacillus vaginalis and butyric acid

Endemic fluorosis has gained increasing attention as a public health concern, and the escalating risk of colitis resulting from excessive fluoride intake calls for effective mitigation strategies. This study aimed to investigate the potential mechanisms underlying the alleviation of fluoride-induced colitis by Tea polysaccharides (TPS). Under conditions of excessive fluoride intake, significant changes were observed in the gut microbiota of rats, leading to aggravated colitis. However, the intervention of TPS exerted a notable alleviating effect on colitis symptoms. Antibiotic intervention and fecal microbiota transplantation (FMT) experiments provided evidence that TPS-mediated relief of fluoride-induced colitis is mediated through its effects on the gut microbiota. Furthermore, TPS supplementation was found to modulate the structure of gut microbiota, enhance the relative abundance of Limosilactobacillus vaginalis in the gut microbiota, and promote the expression of short-chain fatty acid (SCFAs) receptors in colonic tissue. Notably, L. vaginalis played a significant role in alleviating fluoride-induced colitis and facilitating the absorption of butyric acid in the rat colon. Subsequent butyric acid intervention experiments confirmed its remarkable alleviating effect on fluoride-induced colitis. Overall, these findings provide a potential preventive strategy for fluoride-induced colitis by TPS intervention, which is mediated by L. vaginalis and butyric acid.