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Nutrients Jan 2022Intestinal dysbiosis has been widely documented in inflammatory bowel diseases (IBDs) and is thought to influence the onset and perpetuation of gut inflammation....
Intestinal dysbiosis has been widely documented in inflammatory bowel diseases (IBDs) and is thought to influence the onset and perpetuation of gut inflammation. However, it remains unclear whether such bacterial changes rely in part on the modification of an IBD-associated lifestyle (e.g., smoking and physical activity) and diet (e.g., rich in dairy products, cereals, meat and vegetables). In this study, we investigated the impact of these habits, which we defined as confounders and covariates, on the modulation of intestinal taxa abundance and diversity in IBD patients. 16S rRNA gene sequence analysis was performed using genomic DNA extracted from the faecal samples of 52 patients with Crohn's disease (CD) and 58 with ulcerative colitis (UC), which are the two main types of IBD, as well as 42 healthy controls (HC). A reduced microbial diversity was documented in the IBD patients compared with the HC. Moreover, we identified specific confounders and covariates that influenced the association between some bacterial taxa and disease extent (in UC patients) or behaviour (in CD patients) compared with the HC. In particular, a PERMANOVA stepwise regression identified the variables "age", "eat yogurt at least four days per week" and "eat dairy products at least 4 days per week" as covariates when comparing the HC and patients affected by ulcerative proctitis (E1), left-sided UC (distal UC) (E2) and extensive UC (pancolitis) (E3). Instead, the variables "age", "gender", "eat meat at least four days per week" and "eat bread at least 4 days per week" were considered as covariates when comparing the HC with the CD patients affected by non-stricturing, non-penetrating (B1), stricturing (B2) and penetrating (B3) diseases. Considering such variables, our analysis indicated that the UC extent differentially modulated the abundance of the , , , , , , and families, while the CD behaviour influenced the abundance of , , , , and families. In conclusion, our study indicated that some covariates and confounders related to an IBD-associated lifestyle and dietary habits influenced the intestinal taxa diversity and relative abundance in the CD and UC patients compared with the HC. Indeed, such variables should be identified and excluded from the analysis to characterize the bacterial families whose abundance is directly modulated by IBD status, as well as disease extent or behaviour.
Topics: Adult; Age Factors; Aged; Case-Control Studies; Colitis, Ulcerative; Crohn Disease; Dairy Products; Diet; Dysbiosis; Exercise; Feces; Gastrointestinal Microbiome; Humans; Life Style; Middle Aged; RNA, Ribosomal, 16S; Sex Factors; Smoking; Yogurt; Young Adult
PubMed: 35057440
DOI: 10.3390/nu14020260 -
BioMed Research International 2022Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease with an increasing incidence rate but few therapies. Shugan Xiaozhi decoction (SX) has demonstrated...
Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease with an increasing incidence rate but few therapies. Shugan Xiaozhi decoction (SX) has demonstrated beneficial effects in treating NAFLD with an unclear mechanism. This study was aimed at investigating the therapeutic mechanism of SX on high-fat diet-induced NAFLD rats via the gut-liver axis. Hepatic steatosis and integrity of intestinal mucosa in NAFLD rats were assessed by histopathological staining. The level of lipid and inflammation were estimated by enzyme-linked immunosorbent assay. Western Blotting was used to detect apolipoprotein (apo) B48 expression. 16S rRNA analysis was used to measure the changes of gut microbial composition after SX treatment. The expressions of zona occludens 1 protein (ZO-1), occludin, and secretory immunoglobulin A (sIgA) in the colon were detected by immunostaining to investigate the intestinal barrier function. Our study found that SX reduced hepatic steatosis, the levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and triglyceride and apoB48 expression but increased peroxisome proliferator activated receptor (PPAR) level. Moreover, SX altered the diversity of gut microbiota, upregulating the relative abundance of , while downregulating , , , , and . By increasing the expression of ZO-1 and occludin and decreasing the level of proinflammatory factors, including sIgA, lipopolysaccharide, tumor necrosis factor-, interleukin-1, monocyte chemotactic protein-1, and transforming growth factor-1, SX improved intestinal mucosal integrity and barrier function. Our study illustrated that the gut-liver axis was a potential way for SX to ameliorate NAFLD, that is, by regulating the expression of PPAR, apoB48, and modulating gut microbiota to protect the intestinal barrier function, and thus alleviate lipid deposition and inflammatory response in the liver.
Topics: Animals; Apolipoprotein B-48; Diet, High-Fat; Immunoglobulin A, Secretory; Liver; Non-alcoholic Fatty Liver Disease; Occludin; PPAR alpha; RNA, Ribosomal, 16S; Rats
PubMed: 35837380
DOI: 10.1155/2022/4801695 -
Frontiers in Microbiology 2019Unabsorbed proteins reach the colon and are fermented by the microbiota, yielding a variety of harmful metabolites. In the present study, a 16S rRNA gene survey...
Unabsorbed proteins reach the colon and are fermented by the microbiota, yielding a variety of harmful metabolites. In the present study, a 16S rRNA gene survey identified the bacterial taxa flourishing in 11 batch fermentations with proteins and peptones as the sole fermentable substrates, inoculated with the feces of six healthy adults. Organic acids, ammonia, and indole resulting from protein breakdown and fermentation accumulated in all of the cultures. Analysis of differential abundances among time-points identified Enterobacteriaceae, Burkholderiaceae, and Desulfovibrionaceae (including , , , and ) among the bacteria that especially in the cultures with low inoculation load. Lachnospiraceae and Ruminococcaceae also encompassed many taxa that significantly expanded, mainly in cultures inoculated with high inoculation load, and showed the strongest correlation with the production of ammonium, indole, and -cresol. , , , , , , and were among them. Other Firmicutes (e.g., , , , Erysipelotrichaceae, and Streptococcaceae) and many Bacteroidetes (e.g., Barnesiellaceae, Prevotellaceae, and Rickenelliaceae) decreased. Sequences attributed to , unresolved at the level of species, presented opposite contributions, resulting in no significant changes in the genus. This study sheds light on the multitude of bacterial taxa putatively participating in protein catabolism in the colon. Protein fermentation was confirmed as unfavorable to health, due to both the production of toxic metabolites and the blooming of opportunistic pathogens and pro-inflammatory bacteria.
PubMed: 31803157
DOI: 10.3389/fmicb.2019.02614 -
Nutrients May 2022The gut microbial ecosystem is an important factor that regulates host health and the onset of chronic diseases, such as inflammatory bowel diseases, obesity,...
BACKGROUND
The gut microbial ecosystem is an important factor that regulates host health and the onset of chronic diseases, such as inflammatory bowel diseases, obesity, hyperlipidemia, and diabetes mellitus, which are important risk factors for atherosclerosis. However, the links among diet, microbiota composition, and atherosclerotic progression are unclear.
METHODS AND RESULTS
Four-week-old mice ( mice, C57Bl/6) were randomly divided into two groups, namely, supplementation with culture medium (control, CTR) and (BFS), and were fed a high-fat diet. The gut microbiota abundance in feces was evaluated using the 16S rDNA cloning library construction, sequencing, and bioinformatics analysis. The atherosclerotic lesion was estimated using Oil Red O staining. Levels of CD36, a scavenger receptor implicated in atherosclerosis, and F4/80, a macrophage marker in small intestine, were quantified by quantitative real-time PCR. Compared with the CTR group, the BFS group showed increased food intake, fasting blood glucose level, body weight, low-density lipoprotein level, and aortic atherosclerotic lesions. BFS dramatically reduced (LAC) abundance and increased (DSV) abundance. The mRNA expression levels of CD36 and F4/80 in small intestine and aorta tissue in the BFS group were significantly higher than those in the CTR group.
CONCLUSIONS
gut microbiota dysbiosis was induced by BFS. It was characterized by reduced LAC and increased DSV abundance and led to the deterioration of glucose/lipid metabolic dysfunction and inflammatory response, which likely promoted aorta plaque formation and the progression of atherosclerosis.
Topics: Animals; Aorta; Aortic Diseases; Atherosclerosis; Bacteroides fragilis; Diet, High-Fat; Dietary Supplements; Disease Models, Animal; Dysbiosis; Ecosystem; Gastrointestinal Microbiome; Inflammation; Mice; Mice, Inbred C57BL
PubMed: 35684000
DOI: 10.3390/nu14112199 -
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 -
Evidence-based Complementary and... 2021(Leyss.Fr.) Karst is one of the well-known medicinal macrofungi all over the world, and mounting researches have focused on the polysaccharides derived from the spores...
(Leyss.Fr.) Karst is one of the well-known medicinal macrofungi all over the world, and mounting researches have focused on the polysaccharides derived from the spores of . In the present study, BALB/c mice ( = 8-10) were administered with crude polysaccharides of spores (CPGS) and the refined polysaccharides of spores (RPGS) for 30 days to investigate their effect on the adaptive immune system. Results showed that CPGS and RPGS displayed diverse effects on the lymphocyte activity in the spleen. The splenocyte proliferation activity upon mitogen was suppressed by CPGS and RPGS, while the NK cell's tumor-killing ability was promoted by CPGS. Both CPGS and RPGS could increase the proportion of naïve T cells in thymus, but only RPGS significantly uplifted the percentage of T cells, as well as the T cell subsets, in peripheral blood, and promoted the activation by upregulating the expression of costimulatory factor CD28. Moreover, 16S sequencing results showed that the effects of CPGS and RPGS were closely related to the regulation of gut microbiota. -diversity of the microbiome was evidently changed by CPGS and RPGS. The phytoestrogen/polysaccharide-metabolizing bacteria (, , and ), and an unclassified , were remarkably enriched by CPGS or RPGS, and functions involving carbohydrate metabolism, membrane transport, and lipid metabolism were regulated. Moreover, the enrichments of , , and were positively related to the immune regulation by CPGS and RPGS, while that of displayed a negative correlation. These findings suggested a promising effect of the polysaccharide from sporoderm-broken spore of in immune regulation to promote health control.
PubMed: 33859713
DOI: 10.1155/2021/8842062 -
Nutrients Apr 2022Intestinal fatty acid-binding protein (IFABP; FABP2) and liver fatty acid-binding protein (LFABP; FABP1) are small intracellular lipid-binding proteins. Deficiency of...
Intestinal fatty acid-binding protein (IFABP; FABP2) and liver fatty acid-binding protein (LFABP; FABP1) are small intracellular lipid-binding proteins. Deficiency of either of these proteins in mice leads to differential changes in intestinal lipid transport and metabolism, and to markedly divergent changes in whole-body energy homeostasis. The gut microbiota has been reported to play a pivotal role in metabolic process in the host and can be affected by host genetic factors. Here, we examined the phenotypes of wild-type (WT), LFABP, and IFABP mice before and after high-fat diet (HFD) feeding and applied 16S rRNA gene V4 sequencing to explore guild-level changes in the gut microbiota and their associations with the phenotypes. The results show that, compared with WT and IFABP mice, LFABP mice gained more weight, had longer intestinal transit time, less fecal output, and more guilds containing bacteria associated with obesity, such as members in family . By contrast, IFABP mice gained the least weight, had the shortest intestinal transit time, the most fecal output, and the highest abundance of potentially beneficial guilds such as those including members from , , and . Twelve out of the eighteen genotype-related bacterial guilds were associated with body weight. Interestingly, compared with WT mice, the levels of short-chain fatty acids in feces were significantly higher in LFABP and IFABP mice under both diets. Collectively, these studies show that the ablation of LFABP or IFABP induced marked changes in the gut microbiota, and these were associated with HFD-induced phenotypic changes in these mice.
Topics: Animals; Diet, High-Fat; Fatty Acid-Binding Proteins; Fatty Acids, Volatile; Gastrointestinal Microbiome; Liver; Mice; Mice, Inbred C57BL; Phenotype; RNA, Ribosomal, 16S
PubMed: 35565729
DOI: 10.3390/nu14091762 -
Biomolecules Jun 2020A comparative study of the kinetic characteristics (specific activity, initial and maximum rate, and affinity for substrates) of key enzymes of assimilatory sulfate...
A comparative study of the kinetic characteristics (specific activity, initial and maximum rate, and affinity for substrates) of key enzymes of assimilatory sulfate reduction (APS reductase and dissimilatory sulfite reductase) in cell-free extracts of sulphate-reducing bacteria (SRB) from various biotopes was performed. The material for the study represented different strains of SRB from various ecotopes. Microbiological (isolation and cultivation), biochemical (free cell extract preparation) and chemical (enzyme activity determination) methods served in defining kinetic characteristics of SRB enzymes. The determined affinity data for substrates (i.e., sulfite) were 10 times higher for SRB strains isolated from environmental (soil) ecotopes than for strains from the human intestine. The maximum rate of APS reductase reached 0.282-0.862 µmol/min×mg of protein that is only 10 to 28% higher than similar initial values. The maximum rate of sulfite reductase for corrosive relevant collection strains and SRB strains isolated from heating systems were increased by 3 to 10 times. A completely different picture was found for the intestinal SRB V in the strains Desulfovibrio piger Vib-7 (0.67 µmol/min × mg protein) and Desulfomicrobium orale Rod-9 (0.45 µmol/min × mg protein). The determinant in the cluster distribution of SRB strains is the activity of the terminal enzyme of dissimilatory sulfate reduction-sulfite reductase, but not APS reductase. The data obtained from the activity of sulfate reduction enzymes indicated the adaptive plasticity of SRB strains that is manifested in the change in enzymatic activity.
Topics: Adenosine Phosphosulfate; Biodegradation, Environmental; Desulfovibrio desulfuricans; Desulfovibrio vulgaris; Hydrogen Sulfide; Oxidoreductases Acting on Sulfur Group Donors
PubMed: 32560561
DOI: 10.3390/biom10060921 -
Journal of Physiology and Pharmacology... Dec 2016Clostridium difficile infection (CDI) is the most common cause of infectious diarrhea and represents an important burden for healthcare worldwide. Symptoms of severe CDI...
Clostridium difficile infection (CDI) is the most common cause of infectious diarrhea and represents an important burden for healthcare worldwide. Symptoms of severe CDI include watery, foul-smelling diarrhea, peripheral leucocytosis, increased C-reactive protein (CRP), acute renal failure, hypotension and pseudomembranous colitis. Recent studies indicate that the main cause of CDI is dysbiosis, an imbalance in the normal gut microbiota. The restoration of a healthy gut microbiota composition via fecal microbiota transplantation (FMT) recently became more popular. The aim of the present study was to assess the effect of FMT on the healing of CDI and to analyze the changes in the level of pro-inflammatory markers (C-reactive protein, fecal calprotectin) and pro-inflammatory cytokines. Eighteen patients with CDI were included in our study (6 males and 12 females) with recurrent and/or severe CDI. The FMT was performed in 17 patients using colonoscopy, including 16 patients receiving a one-time FMT and 1 patient who needed 2 additional FMTs. One patient was treated with a single round of FMT using push-and-pull enteroscopy. In all CDI patients, before and 3 weeks after FMT, the following parameters were analyzed: C-reactive protein, fecal calprotectin, and plasma interleukin (IL)-6, IL-8 and IL-12, and tumor necrosis factor-alpha (TNF-α). In addition, the plasma level of LL-37, a cathelicidine peptide was assessed by fluorescence-activated cell sorting (FACS) before and 3 months after FMT. Finally, in 7 patients a microbiome analysis was performed by sequencing of 16SrRNA in stool probes obtained before and 3 weeks after FMT. The healing rate of CDI was 94%. In all successfully treated patients no recurrent CDI was observed during follow-up (16 months). The serum level of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8 and IL-12) significantly decreased after FMT. Similarly, CRP and fecal calprotectin normalized after FMT. 3 months after FMT a significant increase of LL-37 in the plasma of successfully treated patients was monitored. The sequencing analysis demonstrated an elevated abundance of beneficial bacterial species such as Lactobacillaceae, Ruminococcaceae, Desulfovibrionaceae, Sutterellaceae and Porphyromonodacea after FMT. No serious side effects were observed. We concluded that FMT represented a very effective and safe treatment of recurrent and/or severe CDI and led to favorable shifts in the composition of gut microbiome.
Topics: Aged; Anti-Bacterial Agents; C-Reactive Protein; Clostridioides difficile; Clostridium Infections; Colonoscopy; Diarrhea; Enterocolitis, Pseudomembranous; Fecal Microbiota Transplantation; Feces; Female; Gastrointestinal Microbiome; Humans; Inflammation; Interleukin-6; Interleukin-8; Male; Treatment Outcome; Tumor Necrosis Factor-alpha
PubMed: 28195066
DOI: No ID Found -
Nutrients Jan 2020Dietary fiber, an important regulator of intestinal microbiota, is a promising tool for preventing obesity and related metabolic disorders. However, the functional links...
Dietary fiber, an important regulator of intestinal microbiota, is a promising tool for preventing obesity and related metabolic disorders. However, the functional links between dietary fiber, intestinal microbiota, and obesity phenotype are still not fully understood. Combined soluble fiber (CSF) is a synthetic mixture of polysaccharides and displays high viscosity, water-binding capacity, swelling capacity, and fermentability. We found that supplementing high-fat diet (HFD) with 6% CSF significantly improved the insulin sensitivity of obese mice without affecting their body weight. Replacing the HFD with normal chow basal diet (NCD), the presence of CSF in the feed significantly enhanced satiety, decreased energy intake, promoted weight and fat loss, and augmented insulin sensitivity. CSF also improved the intestinal morphological integrity, attenuated systemic inflammation, promoted intestinal microbiota homeostasis, and stabilized the production of short-chain fatty acids (SCFAs) that was perturbed during HFD-induced obesity, and these stabilizing effects were more prominent when the basal diet was switched to NCD. The enrichment of bacteria of the S24-7 family and genus increased markedly in the intestine following 6% CSF supplementation- and correlated with decreased adiposity and insulin resistance. Five bacterial genera that were decreased by CSF, including , unclassified Lachonospitaceae, unclassified Clostridiales, unclassified Desulfovibrionaceae, and unclassified Ruminococcae, were subjected to co-occurrence network analysis and were positively correlated to adiposity and insulin resistance, indicating a key role in the microbial response to CSF. Thus, CSF has a potential to promote insulin sensitivity and even reduce obesity via beneficial regulation of the gut microecosystem.
Topics: Animals; Diet, High-Fat; Dietary Fiber; Gastrointestinal Microbiome; Glucose Tolerance Test; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Obesity; Polysaccharides; Specific Pathogen-Free Organisms; Weight Loss
PubMed: 32013093
DOI: 10.3390/nu12020351