Synergistic Effect of Retinoic Acid and Lactoferrin in the Maintenance of Gut Homeostasis

Lactoferrin (LF) is a glycoprotein that binds to iron ions (Fe2+) and other metallic ions, such as Mg2+, Zn2+, and Cu2+, and has antibacterial and immunomodulatory properties. The antibacterial properties of LF are due to its ability to sequester iron. The immunomodulatory capability of LF promotes homeostasis in the enteric environment, acting directly on the beneficial microbiota. LF can modulate antigen-presenting cell (APC) biology, including migration and cell activation. Nonetheless, some gut microbiota strains produce toxic metabolites, and APCs are responsible for initiating the process that inhibits the inflammatory response against them. Thus, eliminating harmful strains lowers the risk of inducing chronic inflammation, and consequently, metabolic disease, which can progress to type 2 diabetes mellitus (T2DM). LF and retinoic acid (RA) exhibit immunomodulatory properties such as decreasing cytokine production, thus modifying the inflammatory response. Their activities have been observed both in vitro and in vivo. The combined, simultaneous effect of these molecules has not been studied; however, the synergistic effect of LF and RA may be employed for enhancing the secretion of humoral factors, such as IgA. We speculate that the combination of LF and RA could be a potential prophylactic alternative for the treatment of metabolic dysregulations such as T2DM. The present review focuses on the importance of a healthy diet for a balanced gut and describes how probiotics and prebiotics with immunomodulatory activity as well as inductors of differentiation and cell proliferation could be acquired directly from the diet or indirectly through the oral administration of formulations aimed to maintain gut health or restore a eubiotic state in an intestinal environment that has been dysregulated by external factors such as stress and a high-fat diet.

Fecal Microbiota and Associated Volatile Organic Compounds Distinguishing No-Adenoma from High-Risk Colon Adenoma Adults

Microbiota and the metabolites they produce within the large intestine interact with the host epithelia under the influence of a range of host-derived metabolic, immune, and homeostatic factors. This complex host-microbe interaction affects intestinal tumorigenesis, but established microbial or metabolite profiles predicting colorectal cancer (CRC) risk are missing. Here, we aimed to identify fecal bacteria, volatile organic compounds (VOC), and their associations that distinguish healthy (non-adenoma, NA) from CRC prone (high-risk adenoma, HRA) individuals. Analyzing fecal samples obtained from 117 participants ≥15 days past routine colonoscopy, we highlight the higher abundance of Proteobacteria and Parabacteroides distasonis, and the lower abundance of Lachnospiraceae species, Roseburia faecis, Blautia luti, Fusicatenibacter saccharivorans, Eubacterium rectale, and Phascolarctobacterium faecium in the samples of HRA individuals. Volatolomic analysis of samples from 28 participants revealed a higher concentration of five compounds in the feces of HRA individuals, isobutyric acid, methyl butyrate, methyl propionate, 2-hexanone, and 2-pentanone. We used binomial logistic regression modeling, revealing 68 and 96 fecal bacteria-VOC associations at the family and genus level, respectively, that distinguish NA from HRA endpoints. For example, isobutyric acid associations with Lachnospiraceae incertae sedis and Bacteroides genera exhibit positive and negative regression lines for NA and HRA endpoints, respectively. However, the same chemical associates with Coprococcus and Colinsella genera exhibit the reverse regression line trends. Thus, fecal microbiota and VOC profiles and their associations in NA versus HRA individuals indicate the significance of multiple levels of analysis towards the identification of testable CRC risk biomarkers.

Alterations in gut microbiota are related to metabolite profiles in spinal cord injury

Studies have shown that gut microbiota metabolites can enter the central nervous system via the blood-spinal cord barrier and cause neuroinflammation, thus constituting secondary injury after spinal cord injury. To investigate the correlation between gut microbiota and metabolites and the possible mechanism underlying the effects of gut microbiota on secondary injury after spinal cord injury, in this study, we established mouse models of T8-T10 traumatic spinal cord injury. We used 16S rRNA gene amplicon sequencing and metabolomics to reveal the changes in gut microbiota and metabolites in fecal samples from the mouse model. Results showed a severe gut microbiota disturbance after spinal cord injury, which included marked increases in pro-inflammatory bacteria, such as Shigella, Bacteroides, Rikenella, Staphylococcus, and Mucispirillum and decreases in anti-inflammatory bacteria, such as Lactobacillus, Allobaculum, and Sutterella. Meanwhile, we identified 27 metabolites that decreased and 320 metabolites that increased in the injured spinal cord. Combined with pathway enrichment analysis, five markedly differential amino acids (L-leucine, L-methionine, L-phenylalanine, L-isoleucine and L-valine) were screened out, which play a pivotal role in activating oxidative stress and inflammatory responses following spinal cord injury. Integrated correlation analysis indicated that the alteration of gut microbiota was related to the differences in amino acids, which suggests that disturbances in gut microbiota might participate in the secondary injury through the accumulation of partial metabolites that activate oxidative stress and inflammatory responses. Findings from this study provide a new theoretical basis for improving the secondary injury after spinal cord injury through fecal microbial transplantation.

Dietary Patterns and Gut Microbiota: The Crucial Actors in Inflammatory Bowel Disease

It is widely believed that diet and the gut microbiota are strongly related to the occurrence and progression of inflammatory bowel disease (IBD), but the effects of the interaction between dietary patterns and the gut microbiota on IBD have not been well elucidated. In this article, we aim to explore the complex relation between dietary patterns, gut microbiota, and IBD. We first comprehensively summarized the dietary patterns associated with IBD and found that dietary patterns can modulate the occurrence and progression of IBD through various signaling pathways, including mammalian target of rapamycin (mTOR), mitogen-activated protein kinases (MAPKs), signal transducer and activator of transcription 3 (STAT3), and NF-κB. Besides, the gut microbiota performs a vital role in the progression of IBD, which can affect the expression of IBD susceptibility genes, such as dual oxidase 2 (DUOX2) and APOA-1 , the intestinal barrier (in particular, the expression of tight junction proteins), immune function (especially the homeostasis between effector and regulatory T cells) and the physiological metabolism, in particular, SCFAs, bile acids (BAs), and tryptophan metabolism. Finally, we reviewed the current knowledge on the interaction between dietary patterns and the gut microbiota in IBD and found that dietary patterns modulate the onset and progression of IBD, which is partly attributed to the regulation of the gut microbiota (especially SCFAs-producing bacteria and Escherichia coli). Faecalibacteria as "microbiomarkers" of IBD could be used as a target for dietary interventions to alleviate IBD. A comprehensive understanding of the interplay between dietary intake, gut microbiota, and IBD will facilitate the development of personalized dietary strategies based on the regulation of the gut microbiota in IBD and expedite the era of precision nutritional interventions for IBD.

Impact of Dietary Sodium Butyrate and Salinomycin on Performance and Intestinal Microbiota in a Broiler Gut Leakage Model

Unfavorable alterations of the commensal gut microbiota and dysbacteriosis is a major health problem in the poultry industry. Understanding how dietary intervention alters the microbial ecology of broiler chickens is important for prevention strategies. A trial was conducted with 672 Ross 308 day-old male broilers fed a basic diet (no additives, control) or the basic diet supplemented with 500 mg/kg encapsulated butyrate or 68 mg/kg salinomycin. Enteric challenge was induced by inclusion of 50 g/kg rye in a grower diet and oral gavage of a 10 times overdose of a vaccine against coccidiosis. Compared to control and butyrate-supplemented birds, salinomycin supplementation alleviated growth depression. Compared to butyrate and non-supplemented control, salinomycin increased potentially beneficial Ruminococcaceae and reduced potentially pathogenic Enterobacteriaceae and counts of Lactobacillus salivarius and Clostridium perfringens. Further, salinomycin supplementation was accompanied by a pH decrease and succinic acid increase in ceca, while coated butyrate (0.5 g/kg) showed no or limited effects. Salinomycin alleviated growth depression and maintained intestinal homeostasis in the challenged broilers, while butyrate in the tested concentration showed limited effects. Thus, further investigations are required to identify optimal dietary inclusion rates for butyrate used as alternative to ionophore coccidiostats in broiler production.

Research progress in the role of gut microbiota and its metabolites in intrahepatic cholestasis of pregnancy

INTRODUCTION

Intrahepatic cholestasis of pregnancy (ICP) is a liver disease that occurs during pregnancy. While ICP has a minimal impact on the mother, it primarily affects the pregnancy outcome of fetus, resulting in spontaneous miscarriage and even the intrauterine death of fetus.

AREAS COVERED

This review covers current progress in the role of gut microbiota and bile acids in ICP.

EXPERT OPINION

The causes and pathogenesis of ICP are currently unclear, and the serum bile acid level is the main clinical evidence for ICP diagnosis. The gastrointestinal tract is home to a tremendous number and type of microbes, which play critical roles in the synthesis and metabolism of bile acids. Studies in recent years have shown that the changes in gut microbiota and bile acid metabolic profiles are closely associated with ICP. This review discusses some of the future prospects in this area of research.

Patients with senile pruritus have a distinct skin microbiota and epidermal barrier in comparison with healthy controls

Senile pruritus (SP) is a common skin disease in the elderly. The role of skin dysbacteriosis in the development of various skin diseases has been studied in recent years. However, the research about the skin microbiota of senile pruritus patients is lacking at present. The purpose of this cross-sectional study was to investigate the differences of skin microbiota in senile pruritus patients and their relationship with the epidermal barrier. Thirty patients with senile pruritus and 30 age- and sex-matched healthy controls were enrolled in this study. The skin barrier indexes were recorded by multi-functional skin tester. The skin bacterial diversity was analyzed by using hyper-variable tag sequencing of the V3-V4 region of the 16S rDNA. Compared with the healthy control group, the patients had significantly lower skin hydration (p = 0.014) and higher pH value (p = 0.021). Skin microbial diversity was significantly increased in patients according to the alpha diversity. At the genus level, Acinetobacter (p = 0.002) and Lactobacillus (p = 0.002) increased and Cutibacterium (p = 0.043) decreased. The pH value was positively associated with observed_species diversity (p = 0.026). The transdermal water loss was negatively related to the genus of Lactobacillus (p = 0.036), while the skin hydration was positively associated with the genus of Lactobacillus (p = 0.038). As a result, the damaged skin barrier function and skin dysbacteriosis complemented each other and may be associated with the occurrence of senile pruritus, but their role still needs further study.

Changes and Correlations of the Intestinal Flora and Liver Metabolite Profiles in Mice With Gallstones

There is increasing appreciation for the roles of the gut-liver axis in liver and gall diseases. Specific gut microbes are associated with susceptibility to gallstone diseases, while the relationship between intestinal flora and liver metabolism in the formation of gallstones remains unclear. In this study, an experimental group of model mice was given a lithogenic diet, and a control group was given a normal diet. Both groups were fed for 8 weeks. Integrating 16S rRNA gene sequencing and non-targeted metabolomics to explore the impact of the lithogenic diet on intestinal flora and liver metabolism, Spearman correlation analysis reveals the network of relationships between the intestine and liver. Our findings showed that the gut microbiome and liver metabolome compositions of the test group were significantly changed compared with those of the normal group. Through our research, biomarkers of gallstones were identified at the phylum (5), class (5), order (5), family (7), and genus levels. We predicted the function of the differential flora. We analyzed the liver metabolism of mice with gallstones paired with their flora, and the results showed that there were 138 different metabolites between the two groups. The metabolic pathways enriched by these differential metabolites are highly consistent with the functions of the disordered flora. We focused on an analysis of the relationship between deoxycholic acid, asymmetric dimethylarginine, glucosamine, tauroursodeoxycholic acid, and the disordered flora. This provides a basis for the establishment of the intestine-liver axis in gallstone disease. This research provides a theoretical basis for the research and development of probiotics and prebiotics.

Intestinal flora differences between patients with ulcerative colitis of different ethnic groups in China

To determine the differences in intestinal flora between Uygur and Han patients with ulcerative colitis (UC).Microbial diversity and structural composition of fecal bacteria from patients with UC and their matched healthy spouses or first-degree relatives were analyzed using high-throughput sequencing technology.The fecal microbial diversity and abundance index of Uygur patients with UC (UUC) were significantly lower compared with the Uygur normal control group, while there was no significant difference between the Han UC patients (HUC) and the Han normal control group (HN). Compared with their respective control groups, Uygur UC patients and Han UC patients had a different main composition of human intestinal flora (P < .05). The abundance of Burkholderia, Caballeronia, Paraburkholderia in the UUC group were higher compared with the HUC group, while Faecalibacterium, Bifidobacterium, and Blautia in the HUC group were higher than those in the UUC group (P < .05). Veillonella in the UUC group was higher than that in the Uygur normal control group group, while Subdoligranulum and Ruminococcaceae_UCG-002 were significantly lower (P < .05). Prevotella_9 in the HUC group was significantly higher than that in HN group, while Blautia, Anaerostipes, and [Eubacterium]_hallii_group were significantly lower. Moreover, the top 6 species in order of importance were Christensenellaceae_R_7_group, Ruminococcae_ucg_005, Ruminococcae_ucg_010, Ruminococcae_ucg_013, Haemophilus, and Ezakiella.The difference in intestinal microflora structure may be one of the reasons for the clinical heterogeneity between Uygur and Han patients with UC. Christensenellaceae_R_7_group, Ruminococcae_ucg_005, Ruminococcae_ucg_010, Ruminococcae_ucg_013, Haemophilus, and Ezakiella could be used as potential biomarkers for predicting UC.

Negative Impact of Pseudomonas aeruginosa Y12 on Its Host Musca domestica

High concentrations of Pseudomonas aeruginosa Y12 significantly inhibit the development of housefly larvae and accelerate larvae death. In this study, the dynamic distribution of the gut microbiota of housefly larvae fed different concentrations of P. aeruginosa Y12 was investigated. Compared with low-concentration P. aeruginosa diets, orally administered high-concentration P. aeruginosa diets caused higher mortality and had a greater impact on the community structure and interaction network of intestinal flora in housefly larvae. The bacterial community of the gut microbiota in housefly larvae was reconstructed in 4 days. Bacterial abundance and diversity were significantly reduced in housefly larvae fed high concentrations of P. aeruginosa. With the growth of larvae, the relative abundances of Providencia, Proteus, Myroides, Klebsiella, and Alcaligenes increased significantly in housefly larvae fed with high concentrations of P. aeruginosa, while the relative abundances of Bordetella, Enterobacter, Morganella, Ochrobactrum, Alcaligenaceae, and Empedobacter were significantly reduced. To analyze the role of the gut microorganisms played on housefly development, a total of 10 cultivable bacterial species belonging to 9 genera were isolated from the intestine of housefly larvae among which Enterobacter hormaechei, Klebsiella pneumoniae, Enterobacter cloacae, Lysinibacillus fusiformis, and Bacillus safensis promoted the growth of larvae through feeding experiments. This study is the first to analyze the influence of high concentrations of P. aeruginosa on the gut microbiota of houseflies. Our study provides a basis for exploring the pathogenic mechanism of high concentrations of P. aeruginosa Y12 in houseflies.

Advances of Mechanisms-Related Metabolomics in Parkinson's Disease

Parkinson’s disease (PD) is a multifactorial disorder characterized by progressively debilitating dopaminergic neurodegeneration in the substantia nigra and the striatum, along with various metabolic dysfunctions and molecular abnormalities. Metabolomics is an emerging study and has been demonstrated to play important roles in describing complex human diseases by integrating endogenous and exogenous sources of alterations. Recently, an increasing amount of research has shown that metabolomics profiling holds great promise in providing unique insights into molecular pathogenesis and could be helpful in identifying candidate biomarkers for clinical detection and therapies of PD. In this review, we briefly summarize recent findings and analyze the application of molecular metabolomics in familial and sporadic PD from genetic mutations, mitochondrial dysfunction, and dysbacteriosis. We also review metabolic biomarkers to assess the functional stage and improve therapeutic strategies to postpone or hinder the disease progression.

Dysbacteriosis of the Intestinal Flora Is an Important Reason for the Death of Adult House Flies Caused by Beauveria bassiana

Beauveria bassiana is one of the most widespread insect pathogens and can be used in the biological control of agricultural, forestry and medical pests. The mechanisms by which B. bassiana leads to mortality in different host insects are also different. For house flies, B. bassiana has strong virulence, but its microecological mechanism is not clear. In this paper, the virulence of three strains of B. bassiana (TB, CB and BB) isolated from different hosts to house flies was studied. The results showed that the three strains of B. bassiana had strong pathogenicity to house fly adults. Specifically, TB was the strongest, CB was the second strongest, and BB was the weakest, with maximum lethal effects on house fly populations 5, 6, and 7 days after infection, respectively. Further study showed that the intestinal flora of house flies was disordered 3, 4, and 5 days after B. bassiana TB, CB and BB strain infection, respectively. Intestinal flora dysbacteriosis may be an important reason for the death of house flies caused by B. bassiana. After infection, the negative interaction ratio of bacteria in the house fly intestine decreased, and the stronger the virulence was, the lower the negative interaction ratio was. The time from B. bassiana infection to intestinal flora dysbacteriosis was not fixed. We named this period the “spring stage”. The stronger the virulence of the B. bassiana strain was, the shorter the “spring stage” was. Therefore, the “spring stage” can be used as a virulence marker for evaluating the pathogenicity of different B. bassiana strains.

Role of pulmonary microorganisms in the development of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic obstructive respiratory disease characterized by irreversible airway limitation and persistent respiratory symptoms. The main clinical symptoms of COPD are dyspnoea, chronic cough, and sputum. COPD is often accompanied by other respiratory diseases, which can cause worsening of the disease. COPD patients with dyspnoea and aggravation of cough and sputum symptoms represent acute exacerbations of COPD (AECOPD). There is mounting evidence suggesting that dysbiosis of pulmonary microbiota participates in the disease. However, investigations of dysbiosis of pulmonary microbiota and the disease are still in initial phases. To screen, diagnose, and treat this respiratory disease, integrating data from different studies can improve our understanding of the occurrence and development of COPD and AECOPD. In this review, COPD epidemiology and the primary triggering mechanism are explored. Emerging knowledge regarding the association of inflammation, caused by pulmonary microbiome imbalance, and changes in lung microbiome flora species involved in the development of the disease are also highlighted. These data will further our understanding of the pathogenesis of COPD and AECOPD and may yield novel strategies for the use of pulmonary microbiota as a potential therapeutic intervention.

Exploring the Role of Gut Bacteria in Health and Disease in Preterm Neonates

The mortality rate of very preterm infants with birth weight <1500 g is as high as 15%. The survivors till discharge have a high incidence of significant morbidity, which includes necrotising enterocolitis (NEC), early-onset neonatal sepsis (EONS) and late-onset neonatal sepsis (LONS). More than 25% of preterm births are associated with microbial invasion of amniotic cavity. The preterm gut microbiome subsequently undergoes an early disruption before achieving bacterial maturation. It is postulated that bacterial gut colonisation at birth and postnatal intestinal dysbacteriosis precede the development of NEC and LONS in very preterm infants. In fact, bacterial colonization patterns in preterm infants greatly differ from term infants due to maternal chorioamnionitis, gestational age, delivery method, feeding type, antibiotic exposure and the environment factor in neonatal intensive care unit (NICU). In this regard, this review provides an overview on the gut bacteria in preterm neonates' meconium and stool. More than 50% of preterm meconium contains bacteria and the proportion increases with lower gestational age. Researchers revealed that the gut bacterial diversity is reduced in preterm infants at risk for LONS and NEC. Nevertheless, the association between gut dysbacteriosis and NEC is inconclusive with regards to relative bacteria abundance and between-sample beta diversity indices. With most studies show a disruption of the Proteobacteria and Firmicutes preceding the NEC. Hence, this review sheds light on whether gut bacteria at birth either alone or in combination with postnatal gut dysbacteriosis are associated with mortality and the morbidity of LONS and NEC in very preterm infants.

Rumen Microbiota Distribution Analyzed by High-Throughput Sequencing After Oral Doxycycline Administration in Beef Cattle

The beef cattle rumen is a heterogenous microbial ecosystem that is necessary for the host to digest food and support growth. The importance of the rumen microbiota (RM) is also widely recognized for its critical roles in metabolism and immunity. The level of health is indicated by a dynamic RM distribution. We performed high-throughput sequencing of the bacterial 16S rRNA gene to compare microbial populations between rumens in beef cattle with or without doxycycline treatment to assess dynamic microbiotic shifts following antibiotic administration. The results of the operational taxonomic unit analysis and alpha and beta diversity calculations showed that doxycycline-treated beef cattle had lower species richness and bacterial diversity than those without doxycycline. Bacteroidetes was the predominant phylum in rumen samples without doxycycline, while Proteobacteria was the governing phylum in the presence of doxycycline. On the family level, the top three predominant populations in group qlqlwy (not treated with doxycycline) were Prevotellaceae, Lachnospiraceae, and Ruminococcaceae, compared to Xanthomonadaceae, Prevotellaceae, and Rikenellaceae in group qlhlwy (treated with doxycycline). At the genus level, the top predominant population in group qlqlwy was unidentified_Prevotellaceae. However, in group qlhlwy, the top predominant population was Stenotrophomonas. The results revealed significant RM differences in beef cattle with or without doxycycline. Oral doxycycline may induce RM composition differences, and bacterial richness may also influence corresponding changes that could guide antibiotic use in adult ruminants. This study is the first to assess microbiota distribution in beef cattle rumen after doxycycline administration.

[The state and role of esophagus, stomach, intestinal microbiota in patients with ulcer disease, chronic gastritis, esophagitis.]

The microflora of 64 biopsies taken during fibrogastroduodenoscopy of the mucous membrane of the esophagus, stomach and duodenum in healthy volunteers and 1120 samples obtained from the same parts of the digestive tract in patients with esophagitis, chronic gastritis and peptic ulcer disease were studied. The patients ranged in age from 18 to 62 years. Traditional bacteriological method was used to isolate and identify microorganisms. Staphylococcus spp., Streptococcus spp., Lactobacillus spp., Bacteroides spp., Stomatococcus spp., Enterobacteriaceae, Corynebacterium spp., Micrococcus spp., Neisseria spp., Veilonella spp. were isolated from biopsies of healthy respondents in an average amount from 3.2 to 4.68 lg CFU/g. H.pylori was found in 60% (5.66 lg CFU/g) in the esophagus, in 33.3% of cases (5.12 lg CFU/g) from the fundal part of the stomach, in 44.4% (5.25 lg CFU/g) from the antral part of the stomach, in 5.5% (4.2 lg CFU/g) in the duodenal mucosa. In samples obtained from the inflamed and eroded mucous membrane of the esophagus, stomach and duodenum, opportunistic bacteria of the genera Klebsiella, Enterobacter, Proteus, Pseudomonas, Peptococcus, Actinomyces, yeast fungi of the genus Candida etc. were detected in an amount exceeding 4 lg CFU/g. H. pylori isolated in 6.3-16.7% of patients (4.25-4.6 lg CFU/g) and did not dominate in relation to other microorganisms, and in most cases had a low frequency of its occurrence. In patients with the recurrence of peptic ulcer disease, exacerbation of chronic gastritis and esophagitis, dysbiosis was developed, characterized by an increase in the species and quantitative composition of opportunistic microflora, an increase in its enzymatic and cytotoxic activity, which can contribute to the maintenance of inflammatory and necrotic processes and inhibit the elimination of the pathological process.

Partially Hydrolyzed Guar Gum Attenuates d-Galactose-Induced Oxidative Stress and Restores Gut Microbiota in Rats

Partially hydrolyzed guar gum (PHGG) has received considerable attention for its various bioactive functions. The injection of d-galactose can cause aging-related injury which is usually resulted from oxidative stress on tissues and cells. In this study, d-galactose (200 mg/kg/day) was injected into rats, and the protective effects of PHGG (500, 1000, and 1500 mg/kg/day) against oxidative damages, as well as its probiotic functions, were analyzed. The results showed that PHGG treatment at a concentration of 1500 mg/kg/day greatly reduced the levels of lactic acid, nitric oxide, inducible nitric oxide synthase, advanced glycation end products, and increased the telomerase activity, by 7.60%, 9.25%, 12.28%, 14.58%, and 9.01%, respectively. Moreover, PHGG significantly elevated the activities of antioxidant enzymes and decreased the content of malondialdehyde in rat serum and brain. The oxidative damage was also significantly alleviated in the liver and hippocampus and the expressions of brain-derived neurotrophic factor and choline acetyltransferase also increased. Furthermore, PHGG treatment could significantly regulated the expression of sirtuin 1, forkhead box O1, and tumor protein p53 in the hippocampus. It also increased the levels of organic acids and improved the composition of intestinal microbiota. These findings demonstrated that PHGG treatment could effectively alleviate the oxidative damage and dysbacteriosis.

Effect of fecal microbiota transplantation on experimental colitis in mice

The aim of the present study was to investigate the effect of fecal microbiota transplantation (FMT) on the acute inflammatory response in a murine model of dextran sulfate sodium (DSS)-induced colitis, and to delineate the putative underlying mechanism(s). Mice were divided into four groups, namely the normal control, DSS, 5-aminosalicylic acid (5-ASA) and FMT group. Mice in the DSS, 5-ASA and FMT groups were orally administered 3% DSS (w/v) solution for 7 days to induce colitis. On days 1, 3, 5 and 7, mice in the DSS, 5-ASA and FMT groups were respectively administered 0.5% carboxymethylcellulose sodium, 5-ASA suspension and fecal suspension by enema. The disease activity index of each mouse was calculated on a daily basis. All mice were sacrificed on day 8, and the length of their colons was measured. Myeloperoxidase (MPO) activity, and the levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-10 in the colon tissues of each group were also measured. Compared with that in the DSS group, FMT ameliorated the severity of inflammation due to ulcerative colitis in mice, which was accompanied by a significantly decreased MPO activity, reduced levels of TNF-α and IL-1β, and an increased level of IL-10 in colon tissue (all P<0.05). Taken together, these results demonstrated that FMT exerted a therapeutic effect on experimental colitis in mice, and the associated mechanism is likely to involve the remodeling of the intestinal flora and regulation of intestinal T-cell immunity homeostasis.

The Complex Puzzle of Interactions Among Functional Food, Gut Microbiota, and Colorectal Cancer

Colorectal cancer exerts a strong influence on the epidemiological panorama worldwide, and it is directly correlated to etiologic factors that are substantiated by genetic and environmental elements. This complex mixture of factors also has a relationship involving the structural dependence and composition of the gut microbiome, leading to a dysbacteriosis process that may evolve to serious modifications in the intestinal lining, eventually causing the development of a neoplasm. The gastrointestinal tract presents defense strategies and immunological properties that interfere in intestinal permeability, inhibiting the bacterial translocation, thus maintaining the integrity of intestinal homeostasis. The modulation of the intestinal microbiome and the extinction of risk factors associated with intestinal balance losses, especially of environmental factors, make cell and defense alterations impossible. This modulation may be conducted by means of functional foods in the diet, especially soluble fibers, polyunsaturated fatty acids, antioxidants and prebiotics that signal immunomodulatory effects in the intestinal microbiota, with preventive and therapeutic action for colorectal cancer. In summary, this review focuses on the importance of dietary modulation of the intestinal microbiota as an instrument for dysbacteriosis and, consequently, for the prevention of colorectal cancer, suggesting anticarcinogenic, and antiangiogenic properties. Among the intestinal modulating agents considered here are functional foods, especially flaxseed, oat and soy, composing a Bioactive Food Compound.

Bacterial Vaginosis and Cervical Intraepithelial Neoplasia: Is there an Association or is Co-Existence Incidental?

Objectives:

To determine associations, if any, of bacterial vaginosis with cervical pre-neoplastic lesions and evaluate any effects of sub-categorization of smears with bacterial vaginosis.

Methods:

All cervico-vaginal smears reported as positive for bacterial vaginosis over a five-year period were reviewed and sub-categorized into ’type I (dysbacteriosis)’ and ’type II (pure Gardenerella infection)’ smears by two cytopathologists (PS, SG). The proportion of smears with healthy flora and pre-neoplastic lesions was compared with those having bacterial vaginosis in conjunction with such changes. In addition, a comparison was also attempted between the frequencies of pre-neoplastic lesions with the two categories of bacterial vaginosis smears.

Results:

Bacterial vaginosis was diagnosed in 28.6% (7017 of the 24,565) of the 24,565 smears received in the Institute during the study period. Of these 7,017 smears with bacterial vaginosis, 53% (3717) were categorized as type I and 42.7% (3000) as type II by both cytopathologists. Pre-neoplastic lesions were detected in 10.2% of smears with bacterial vaginosis compared to 5.7% of those with healthy flora (P<0.0001). Of the sub-categories of bacterial vaginosis, the risk of detecting precancerous lesion was higher for type II smears (P<0.001).

Conclusion:

Sub-categorization of bacterial vaginosis, as performed in the Dutch coding system, may be worthwhile due to the strikingly different risk of associated preneoplasia.

First detection of Macrorhabdus ornithogaster in wild Eurasian Siskins (Carduelis spinus) in Germany. A case study

OBJECTIVE

The colonization of the gastric ascomycetous yeast Macrorhabdus (M.) ornithogaster could be associated with a chronic wasting disease in several bird species in captivity. The prevalence and clinical relevance of M. ornithogaster in wild birds is unknown in detail.

MATERIAL AND METHODS

In the wintering season 2012/13 injured Eurasian Siskins (Carduelis spinus, n = 8) from the area of Hannover, Lower Saxony, Germany were examined microbiologically and pathologically.

RESULTS

In six out of eight injured Eurasian Siskins M. ornithogaster were detected. The yeast was diagnosed microscopically in wet smears from the gastric isthmus and/or in faecal samples. Histopathological examination (n = 4) of the macroscopically slightly enlarged proventriculus in infected birds demonstrated the growth of M. ornithogaster in the mucosal surface and in the ducts of the glands without an inflammatory reaction. As a possible sign of a lowered fitness, all six infected siskins had a reduced body weight (mean: 11.8 ± 1.64 g) in the lower normal weight range compared to the two injured Eurasian Siskins without M. ornithogaster (15.0 g) as well as to data from the literature. Concurrent intestinal bacterial infections comprised Escherichia coli, Clostridium perfringens or Salmonella Typhimurium, that are regarded as an abnormal bacterial flora for Eurasian Siskins.

CONCLUSION AND CLINICAL RELEVANCE

Infections with M. ornithogaster can be found in the wild population of Eurasian Siskins in Germany. The frequent occurrence of secondary bacterial infections associated with M. ornithogaster infections should be considered in the treatment and rehabilitation of finches.

Disruption of the colonization resistance syndrome in humans in altered habitats and its prevention

Exposure of human subjects to environments with modified parameters is associated with reduced colonization resistance of the intestine and epithelial tissue, which leads to dysbiotic changes. Probiotics - preparations based on protective microflora - are used to correct dysbacteriosis of different etiologies and localizations. However, the effectiveness of probiotics largely depends on the adhesive ability of a probiotic strain and lack of competitive relations with the indigenous microflora, which can be achieved by individual selection of a preparation. We propose to use autochtonous microflora as a probiotic drug to optimize the prevention and treatment results. A personalized approach to probiotic selection will improve therapy efficiency and reduce the risk of adverse effects in each individual patient.

Intestinal dysbacteriosis contributes to decreased intestinal mucosal barrier function and increased bacterial translocation

The purpose of this study was to determine the effect of colistin-induced intestinal dysbacteriosis on intestinal mucosal barrier function and bacterial translocation in a mouse model. Colistin or saline was administered orally for 7 days, and populations of viable organisms from the caecal mucosa and its content, the ileal segments, the mesenteric lymph nodes (MLNs) and the internal organs were prepared for examination. In the intestinal dysbacteriosis model, intestinal barrier dysfunction was observed and associated with increased bacterial translocation to extraintestinal sites. The extent of bacterial translocation to the MLNs and internal organs in the colistin group was significantly higher than in the saline group. Colistin-induced intestinal dysbacteriosis was shown to injure the intestinal mucosa barrier function and increase bacterial dislocation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Colistin has been reported to be effective in selective digestive decontamination (SDD), which is an infection prevention measure used in the treatment of certain patients in intensive care. We are the first to report that colistin-induced intestinal dysbacteriosis can injure intestinal mucosal barrier function and increase bacterial translocation, whereas a high dose of colistin does not damage the intestinal mucosal barrier in germ-free (GF) mice raised in a GF environment. These results may indicate that prolonged use of a high dose of a SDD medication should be carefully considered.