-
MBio Apr 2023Desulfovibrio vulgaris has been a primary pure culture sulfate reducer for developing microbial corrosion concepts. Multiple mechanisms for how it accepts electrons from...
Desulfovibrio vulgaris has been a primary pure culture sulfate reducer for developing microbial corrosion concepts. Multiple mechanisms for how it accepts electrons from Fe have been proposed. We investigated Fe oxidation with a mutant of in which hydrogenase genes were deleted. The hydrogenase mutant grew as well as the parental strain with lactate as the electron donor, but unlike the parental strain, it was not able to grow on H. The parental strain reduced sulfate with Fe as the sole electron donor, but the hydrogenase mutant did not. H accumulated over time in Fe cultures of the hydrogenase mutant and sterile controls but not in parental strain cultures. Sulfide stimulated H production in uninoculated controls apparently by both reacting with Fe to generate H and facilitating electron transfer from Fe to H. Parental strain supernatants did not accelerate H production from Fe, ruling out a role for extracellular hydrogenases. Previously proposed electron transfer between Fe and via soluble electron shuttles was not evident. The hydrogenase mutant did not reduce sulfate in the presence of Fe and either riboflavin or anthraquinone-2,6-disulfonate, and these potential electron shuttles did not stimulate parental strain sulfate reduction with Fe as the electron donor. The results demonstrate that primarily accepts electrons from Fe via H as an intermediary electron carrier. These findings clarify the interpretation of previous corrosion studies and suggest that H-mediated electron transfer is an important mechanism for iron corrosion under sulfate-reducing conditions. Microbial corrosion of iron in the presence of sulfate-reducing microorganisms is economically significant. There is substantial debate over how microbes accelerate iron corrosion. Tools for genetic manipulation have only been developed for a few Fe(III)-reducing and methanogenic microorganisms known to corrode iron and in each case those microbes were found to accept electrons from Fe via direct electron transfer. However, iron corrosion is often most intense in the presence of sulfate-reducing microbes. The finding that Desulfovibrio vulgaris relies on H to shuttle electrons between Fe and cells revives the concept, developed in some of the earliest studies on microbial corrosion, that sulfate reducers consumption of H is a major microbial corrosion mechanism. The results further emphasize that direct Fe-to-microbe electron transfer has yet to be rigorously demonstrated in sulfate-reducing microbes.
Topics: Iron; Desulfovibrio vulgaris; Hydrogenase; Corrosion; Oxidation-Reduction; Lactic Acid; Sulfates; Desulfovibrio
PubMed: 36786581
DOI: 10.1128/mbio.00076-23 -
Frontiers in Endocrinology 2022As a metabolic disease, one important feature of non-alcoholic fatty liver disease (NAFLD) is the disturbance of the intestinal flora. Spleen-strengthening and... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
As a metabolic disease, one important feature of non-alcoholic fatty liver disease (NAFLD) is the disturbance of the intestinal flora. Spleen-strengthening and liver-draining formula (SLF) is a formula formed according to the theory of "One Qi Circulation" (Qing Dynasty, 1749) of Traditional Chinese Medicine (TCM), which has shown significant therapeutic effect in patients with NAFLD in a preliminary clinical observation. In this study, we aim to explore the mechanism of SLF against NAFLD, especially its effect on glucolipid metabolism, from the perspective of intestinal flora.
METHODS
A prospective, randomized, controlled clinical study was designed to observe the efficacy and safety of SLF in the treatment of NAFLD. The study participants were randomly and evenly divided into control group and treatment group (SLF group). The control group made lifestyle adjustments, while the SLF group was treated with SLF on top of the control group. Both groups were participated in the study for 12 consecutive weeks. Furthermore, the feces of the two groups were collected before and after treatment. The intestinal flora of each group and healthy control (HC) were detected utilizing 16S rRNA gene sequencing.
RESULTS
Compared with the control group, the SLF group showed significant improvements in liver function, controlled attenuation parameter (CAP), and liver stiffness measurement (LSM), meanwhile, patients had significantly lower lipid and homeostasis model assessment of insulin resistance (HOMA-IR) with better security. Intestinal flora 16S rRNA gene sequencing results indicated reduced flora diversity and altered species abundance in patients with NAFLD. At the phylum level, levels were reduced. Although and did not differ significantly between HC and NAFLD, when grouped by alanine transaminase (ALT) and aspartate transaminase (AST) levels in NAFLD, levels were significantly higher in patients with ALT or AST abnormalities, while was significantly lower. Clinical correlation analysis showed that positively correlated with gender, age, ALT, AST, LSM, and Fibroscan-AST (FAST) score, while the opposite was true for . At the genus level, the levels of , , , , group , , , and were reduced, whereas abundance of increased. There was no statistically significant difference in and levels in the SLF group before and after treatment, but both bacteria tended to retrace. At the genus level, ( family), ( family), and ( family) were significantly higher in the SLF group after treatment, and there was also a tendency for ( family) to be back-regulated toward HC.
CONCLUSIONS
SLF can improve liver function and glucolipid metabolism in patients with NAFLD and lower down liver fat content to some extent. SLF could be carried out by regulating the disturbance of intestinal flora, especially , group, and genus.
Topics: Humans; Clostridiales; Gastrointestinal Microbiome; Non-alcoholic Fatty Liver Disease; RNA, Ribosomal, 16S; Spleen; Drugs, Chinese Herbal
PubMed: 36743913
DOI: 10.3389/fendo.2022.1107071 -
Frontiers in Nutrition 2022To study the prevention and mechanism of oat antimicrobial peptides (AMPs) on enteritis. Oat protein was hydrolyzed by alkaline protease and isolated to obtain oat...
To study the prevention and mechanism of oat antimicrobial peptides (AMPs) on enteritis. Oat protein was hydrolyzed by alkaline protease and isolated to obtain oat antimicrobial peptides. Rat enteritis models were constructed using dextran sodium sulfate (DSS), and a blank group, a negative control group, a positive control group, and an experimental group (low dose, medium dose, and high dose) were established. Through pathological test, antioxidant test, intestinal microbial and metabolite determination, it was found that AMPS can improve the antioxidant capacity of colon, reduce the production of inflammatory cells, and have the effect of preventing enteritis. In addition, the AMPS group is able to change and reduce the abundance of and , increase the abundance of probiotics such as and and the diversity of intestinal microorganisms. Then, the combined analysis of microorganism and metabolites showed that and reduced the contents of amino acid and glucose and promoted the production of phospholipid, while promoted the synthesis of amino acid in the body. From the above, it can be seen that DSS causes damage to the mechanical barrier of the gut. Oat antimicrobial peptides provide a microbial barrier for the gut microbes, which produce acetic acid and succinic acid with small amounts of isobutyric acid, isovaleric acid, and lactic acid. The acidic metabolites produced reduce the pH of the gut and produce substances with antibacterial effects (such as lipophilic molecules, antibiotics, and hydroperoxides). Inhibit the growth and reproduction of other harmful bacteria, , from adhering to and colonizing the intestinal mucosa. Secreted short-chain fatty acids, such as acetate and butyric acid, maintain tight connections between the epithelial cells of the intestinal mucosa, thus protecting the mechanical barrier of the intestinal mucosa. Moreover, amino acids are converted into phospholipid metabolism through protein digestion and absorption to promote the production of phospholipid in the intestine and repair damaged cell membranes.
PubMed: 36712538
DOI: 10.3389/fnut.2022.1095483 -
Preventive Veterinary Medicine Mar 2023Lawsonia intracellularis (LI) is an economically important enteric pathogen in pigs with a worldwide endemic prevalence. The objective of this study was to evaluate the...
Effect of intramuscular vaccination against Lawsonia intracellularis on production parameters, diarrhea occurrence, antimicrobial treatment, bacterial shedding, and lean meat percentage in two Danish naturally infected finisher pig herds.
Lawsonia intracellularis (LI) is an economically important enteric pathogen in pigs with a worldwide endemic prevalence. The objective of this study was to evaluate the effect of an intramuscularly administrated LI vaccine (Porcilis®Lawsonia Vet.) in Danish finisher pigs (30-115 kg) measured on key production figures, antimicrobial (AB) treatments, occurrence of diarrhea and LI shedding. The study was a group-randomized block-trial with parallel groups in two herds, Herd 1 and Herd 2, experiencing a natural subclinical-clinical LI infection in early finisher period. Vaccination occurred at weaning, but the study focused on the first eight weeks in the finisher period. Further, slaughterhouse data were included. In total, 52 and 50 finisher pens comprising 2184 and 2254 finisher pigs were included in each of two herds, respectively. LI vaccination significantly reduced feed conversion ratio (FCR) by 0.05 and 0.09 FU/kg (p = 0.007 and p < 0.001) alongside a significantly increased average daily weight gain (ADWG) by 31 and 43 gr/day (p = 0.001 and p < 0.001) in each of the herds, respectively. In the vaccinated group, less variation was found in ADWG compared to the control group (p < 0.001 in both herds) as an expression of a more uniform growth, which was further confirmed by less variation in lean meat percent in the vaccinated group in one herd (p = 0.007). No significant difference between groups were found in mortality and pigs excluded due to welfare reasons. AB flock treatment against diarrhea was significantly reduced in Herd 1 with all pens treated in the control group compared to 30.8 % in the vaccinated group (p < 0.001). In Herd 2, the difference was non-significant with 68.0 % in the control group compared to 50.0 % in the vaccination group (p = 0.252). Low levels of individual treatments against diarrhea were seen in both herds (≤ 5.0 %) but still significantly reduced in vaccinated pigs compared to control pigs (p < 0.050 in both herds). Mean diarrheic blot counts were significantly reduced in vaccinated pens compared to control pens (p < 0.001 in both herds). In vaccinated pigs, shedding of LI was reduced in both prevalence (p < 0.001 in both herds), excretion level in positive samples (p < 0.001 in both herds) and, in one herd, also in duration (p = 0.003) when compared to control pigs. In conclusion, pigs vaccinated with Porcilis®Lawsonia Vet against LI in both of two high-health and high-productive finisher herds had, compared to non-vaccinated pigs, significantly improved key production figures, and reduced AB treatment, occurrence of diarrhea, LI shedding, and growth variation.
Topics: Swine; Animals; Lawsonia Bacteria; Bacterial Shedding; Swine Diseases; Desulfovibrionaceae Infections; Anti-Infective Agents; Diarrhea; Vaccination; Weight Gain; Denmark
PubMed: 36680993
DOI: 10.1016/j.prevetmed.2023.105837 -
International Journal of Molecular... Jan 2023Apicomplexan infections, such as giardiasis and cryptosporidiosis, negatively impact a considerable proportion of human and commercial livestock populations. Despite...
Apicomplexan infections, such as giardiasis and cryptosporidiosis, negatively impact a considerable proportion of human and commercial livestock populations. Despite this, the molecular mechanisms of disease, particularly the effect on the body beyond the gastrointestinal tract, are still poorly understood. To highlight host-parasite-microbiome biochemical interactions, we utilised integrated metabolomics-16S rRNA genomics and metabolomics-proteomics approaches in a C57BL/6J mouse model of giardiasis and compared these to and uropathogenic (UPEC) infections. Comprehensive samples (faeces, blood, liver, and luminal contents from duodenum, jejunum, ileum, caecum and colon) were collected 10 days post infection and subjected to proteome and metabolome analysis by liquid and gas chromatography-mass spectrometry, respectively. Microbial populations in faeces and luminal washes were examined using 16S rRNA metagenomics. Proteome-metabolome analyses indicated that 12 and 16 key pathways were significantly altered in the gut and liver, respectively, during giardiasis with respect to other infections. Energy pathways including glycolysis and supporting pathways of glyoxylate and dicarboxylate metabolism, and the redox pathway of glutathione metabolism, were upregulated in small intestinal luminal contents and the liver during giardiasis. Metabolomics-16S rRNA genetics integration indicated that populations of three bacterial families- (Up), (Up), and (Down)-were most significantly affected across the gut during giardiasis, causing upregulated glycolysis and short-chained fatty acid (SCFA) metabolism. In particular, the perturbed population seemed to cause oxidative stress responses along the gut-liver axis. Overall, the systems biology approach applied in this study highlighted that the effects of host-parasite-microbiome biochemical interactions extended beyond the gut ecosystem to the gut-liver axis. These findings form the first steps in a comprehensive comparison to ascertain the major molecular and biochemical contributors of host-parasite interactions and contribute towards the development of biomarker discovery and precision health solutions for apicomplexan infections.
Topics: Mice; Animals; Humans; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Giardiasis; Up-Regulation; Proteome; Cryptosporidiosis; Mice, Inbred C57BL; Cryptosporidium; Metabolomics; Metabolome; Microbiota; Liver; Oxidation-Reduction
PubMed: 36675151
DOI: 10.3390/ijms24021636 -
Veterinary Medicine and Science Mar 2023Intestinal infection of many host species with Lawsonia intracellularis are widely reported. Analyses of infections among carnivorous falcons have not previously been...
Intestinal infection of many host species with Lawsonia intracellularis are widely reported. Analyses of infections among carnivorous falcons have not previously been reported. Fifty juvenile captive falcons (Falco spp.) with or without Lawsonia infection were investigated in the United Arab Emirates, including clinical laboratory methods. Fresh intestinal biopsy samples were analysed by microbiological techniques for Lawsonia and other bacteria and by standard parasitological and pathological methods. Lawsonia intracellularis infection was diagnosed by microbiological examination and qPCR in 10 of 50 juvenile falcons at case examination. Seven of these 10 falcons were of normal clinical appearance, and the other three had other contributing factors to ill-thrift. A range of other conditions were noted in 40 case control falcons. This first report of Lawsonia infection in falcons suggests that the agent may have a limited contribution to clinical disease in these birds, including ill-thrift syndromes. This lack of clinical disease association mimics that noted among Lawsonia infections recorded in other avian families.
Topics: Animals; Lawsonia Bacteria; Desulfovibrionaceae Infections; Falconiformes
PubMed: 36639945
DOI: 10.1002/vms3.1063 -
Sheng Li Xue Bao : [Acta Physiologica... Dec 2022The aim of this study was to explore the regulating effects of hyperoside (Hyp) on lipid metabolism in high-fat diet mice. The high-fat diet mouse model was established...
The aim of this study was to explore the regulating effects of hyperoside (Hyp) on lipid metabolism in high-fat diet mice. The high-fat diet mouse model was established by high-fat diet induction. After 5 weeks of Hyp intragastric administration in high-fat diet mice, the serum lipid levels before and after Hyp administration were measured by the corresponding kits. The tissue structure of mouse liver was observed by HE staining before and after Hyp administration. The changes of intestinal flora and transcriptome were measured by Illumina platforms. Liquid chromatography-mass spectrometry (LC-MS) was used to determine non-targeted metabolites. The results showed that Hyp significantly reduced lipid levels in the high-fat diet mice and effectively restored the external morphology and internal structure of liver tissue. Hyp changed the species composition of the intestinal flora in high-fat diet mice, increased the abundance of beneficial flora such as Ruminococcus, and decreased the abundance of harmful flora such as Sutterella. Combined multi-omics analysis revealed that the effect of retinoic acid on lipid metabolism was significant in the high-fat diet mice treated with Hyp, while the increase of retinoic acid content was significantly negatively correlated with the expression of genes such as cyp1a2 and ugt1a6b, positively correlated with AF12 abundance, and significantly negatively correlated with unidentified_Desulfovibrionaceae abundance. These results suggest that Hyp may modulate the abundance of AF12, unidentified_Desulfovibrionaceae and inhibit the expression of genes such as cyp1a2 and ugt1a6b, thus increasing the content of retinoic acid and regulating lipid metabolism in the high-fat diet mice.
Topics: Animals; Mice; Diet, High-Fat; Lipid Metabolism; Cytochrome P-450 CYP1A2; Multiomics; Liver; Lipids; Tretinoin; Mice, Inbred C57BL
PubMed: 36594385
DOI: No ID Found -
Microbiological Research Mar 2023Solidesulfovibrio fructosivorans (formely Desulfovibrio fructosovorans), an anaerobic sulfate-reducing bacterium, possesses six gene clusters encoding six hydrogenases...
Solidesulfovibrio fructosivorans (formely Desulfovibrio fructosovorans), an anaerobic sulfate-reducing bacterium, possesses six gene clusters encoding six hydrogenases catalyzing the reversible oxidation of hydrogen gas (H) into protons and electrons. One of these, named Hnd, was demonstrated to be an electron-bifurcating hydrogenase Hnd (Kpebe et al., 2018). It couples the exergonic reduction of NAD to the endergonic reduction of a ferredoxin with electrons derived from H and whose function has been recently shown to be involved in ethanol production under pyruvate fermentation (Payne 2022). To understand further the physiological role of Hnd in S. fructosivorans, we compared the mutant deleted of part of the hnd gene with the wild-type strain grown on pyruvate without sulfate using NMR-based metabolomics. Our results confirm that Hnd is profoundly involved in ethanol metabolism, but also indirectly intervenes in global carbon metabolism and additional metabolic processes such as the biosynthesis of branched-chain amino acids. We also highlight the metabolic reprogramming induced by the deletion of hndD that leads to the upregulation of several NADP-dependent pathways.
Topics: Electrons; Fermentation; Hydrogen; Hydrogenase; Oxidation-Reduction; Pyruvic Acid; Desulfovibrionaceae
PubMed: 36592576
DOI: 10.1016/j.micres.2022.127279 -
PeerJ 2022Diet and exercise can affect the gut microbiota (GM); however, the effects of the same amount of exercise on gut microbiota changes in people on a low-fat diet (LFD) and...
BACKGROUND
Diet and exercise can affect the gut microbiota (GM); however, the effects of the same amount of exercise on gut microbiota changes in people on a low-fat diet (LFD) and high-fat diet (HFD) during pregnancy are unknown. Do different nutritional conditions respond equally to exercise intervention? This study aimed to investigate the effects of regular maternal exercise during pregnancy on the GM in mice fed different diets during pregnancy.
METHODS
Six-week-old nulliparous female KunMing mice were fed either a HFD or LFD before and during pregnancy. Each group of mice were then randomly divided into two groups upon confirmation of pregnancy: sedentary (HFD or LFD; = 4 and 5, respectively) and exercised (HFDex or LFDex, = 5 and 6, respectively). Mice were sacrificed on day 19 of gestation and their colon contents were collected. We then performed 16S rDNA gene sequencing of the V3 and V4 regions of the GM.
RESULTS
The pregnancy success rate was 60% for LFDex and 100% for HFDex. Both Chao1 and Simpson indices were not significantly different for either LFD vs. LFDex or HFD vs. HFDex. , , , , , and were markedly decreased after exercise intervention in LFDex vs. LFD, whereas , , , and were significantly increased in LFDex vs. LFD. Furthermore, decreased and and increased were identified in the HFDex vs. HFD group. and were markedly decreased in the LFDex group vs. HFDex group.
CONCLUSIONS
Our data suggested that quantitative maternal exercise during pregnancy resulted in alterations in GM composition, but did not significantly change the diversity of the GM. These findings may have important implications when considering an individual's overall diet when recommending exercise during pregnancy.
Topics: Mice; Pregnancy; Female; Animals; Gastrointestinal Microbiome; Diet, High-Fat; Diet, Fat-Restricted; Physical Conditioning, Animal
PubMed: 36518263
DOI: 10.7717/peerj.14459 -
Biomedicine & Pharmacotherapy =... Jan 2023Polysaccharides from Enteromorpha prolifera (EP) possess important benefits in the management of obesity and associated metabolic diseases, but to date, the underlying...
Polysaccharide-rich fractions from Enteromorpha prolifera improve hepatic steatosis and gut barrier integrity in high-fat diet-induced obese mice linking to modulation of gut microbiota.
Polysaccharides from Enteromorpha prolifera (EP) possess important benefits in the management of obesity and associated metabolic diseases, but to date, the underlying mechanism linking this alleviative effect of EP to gut microbiota remains obscure. This study aimed to investigate the effects of EP in improving lipid metabolism disorders and intestinal barrier disruption in mice with high-fat diet (HFD), and its association with modulation of gut microbiota. C57BL/6 mice were fed a control diet or a HFD with or without 5% EP for 12 weeks. Factors related to lipid metabolism, insulin signaling and intestinal barrier integrity, as well as the involvement of gut microbiota and metabolites, were measured. EP supplementation reduced HFD-induced adiposity and mitigated insulin resistance, hepatic steatosis and elevation of serum lipopolysaccharides (LPS). HFD impaired intestinal barrier integrity while improved due to EP. Moreover, EP administration ameliorated HFD-induced gut dysbiosis, as revealed by the increased short-chain fatty acid (SCFA)-producing bacteria (e.g., Bacteroides, Parabacteroides, Alloprevotella, and Ruminococcus) and gut barrier-protective Akkermansia muciniphila and decreased endotoxin-producing bacteria (e.g., Desulfovibrionaceae and Bilophila), accompanied by enrichment in intestinal SCFA content and reduction in circulating LPS level. The change of dominant bacterial genera is significantly correlated with improved metabolic profiles and intestinal permeability induced by EP. In conclusion, our results indicate that EP can attenuate HFD-induced metabolic disorders along with restoration of gut barrier integrity and lowering of circulating endotoxin, and these improvements are associated with modulation of gut microbiota composition and related metabolites. These data deepen mechanistic understanding of the anti-obesity and metabolic improving effects of EP.
Topics: Mice; Animals; Diet, High-Fat; Mice, Obese; Mice, Inbred C57BL; Gastrointestinal Microbiome; Obesity; Fatty Liver; Metabolic Diseases; Lipopolysaccharides
PubMed: 36434956
DOI: 10.1016/j.biopha.2022.114034