Displaying publications 1 - 20 of 231 in total

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  1. Lee YY, Erdogan A, Rao SS
    J Neurogastroenterol Motil, 2014 Apr 30;20(2):265-70.
    PMID: 24840380 DOI: 10.5056/jnm.2014.20.2.265
    Assessment of transit through the gastrointestinal tract provides useful information regarding gut physiology and patho-physiology. Although several methods are available, each has distinct advantages and limitations. Recently, an ingestible wire-less motility capsule (WMC), similar to capsule video endoscopy, has become available that offers a less-invasive, standardized, radiation-free and office-based test. The capsule has 3 sensors for measurement of pH, pressure and temperature, and collec-tively the information provided by these sensors is used to measure gastric emptying time, small bowel transit time, colonic transit time and whole gut transit time. Current approved indications for the test include the evaluation of gastric emptying in gastroparesis, colonic transit in constipation and evaluation of generalised dysmotility. Rare capsule retention and malfunc-tion are known limitations and some patients may experience difficulty with swallowing the capsule. The use of WMC has been validated for the assessment of gastrointestinal transit. The normal range for transit time includes the following: gastric empty-ing (2-5 hours), small bowel transit (2-6 hours), colonic transit (10-59 hours) and whole gut transit (10-73 hours). Besides avoiding the use of multiple endoscopic, radiologic and functional gastrointestinal tests, WMC can provide new diagnoses, leads to a change in management decision and help to direct further focused work-ups in patients with suspected disordered motility. In conclusion, WMC represents a significant advance in the assessment of segmental and whole gut transit and mo-tility, and could prove to be an indispensable diagnostic tool for gastrointestinal physicians worldwide.
    Matched MeSH terms: Gastrointestinal Microbiome
  2. Khosravi Y, Dieye Y, Loke MF, Goh KL, Vadivelu J
    PLoS One, 2014;9(11):e112214.
    PMID: 25386948 DOI: 10.1371/journal.pone.0112214
    Helicobacter pylori (H. pylori) is a major gastric pathogen that has been associated with humans for more than 60,000 years. H. pylori causes different gastric diseases including dyspepsia, ulcers and gastric cancers. Disease development depends on several factors including the infecting H. pylori strain, environmental and host factors. Another factor that might influence H. pylori colonization and diseases is the gastric microbiota that was overlooked for long because of the belief that human stomach was a hostile environment that cannot support microbial life. Once established, H. pylori mainly resides in the gastric mucosa and interacts with the resident bacteria. How these interactions impact on H. pylori-caused diseases has been poorly studied in human. In this study, we analyzed the interactions between H. pylori and two bacteria, Streptococcus mitis and Lactobacillus fermentum that are present in the stomach of both healthy and gastric disease human patients. We have found that S. mitis produced and released one or more diffusible factors that induce growth inhibition and coccoid conversion of H. pylori cells. In contrast, both H. pylori and L. fermentum secreted factors that promote survival of S. mitis during the stationary phase of growth. Using a metabolomics approach, we identified compounds that might be responsible for the conversion of H. pylori from spiral to coccoid cells. This study provide evidences that gastric bacteria influences H. pylori physiology and therefore possibly the diseases this bacterium causes.
    Matched MeSH terms: Gastrointestinal Microbiome
  3. Shahjahan M, Kitahashi T, Parhar IS
    PMID: 24723910 DOI: 10.3389/fendo.2014.00036
    Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts.
    Matched MeSH terms: Gastrointestinal Microbiome
  4. Yap IK, Kho MT, Lim SH, Ismail NH, Yam WK, Chong CW
    Mol Biosyst, 2015 Jan;11(1):297-306.
    PMID: 25382376 DOI: 10.1039/c4mb00463a
    Understanding the basal gut bacterial community structure and the host metabolic composition is pivotal for the interpretation of laboratory treatments designed to answer questions pertinent to host-microbe interactions. In this study, we report for the first time the underlying gut microbiota and systemic metabolic composition in BALB/c mice during the acclimatisation period. Our results showed that stress levels were reduced in the first three days of the study when the animals were subjected to repetitive handling daily but the stress levels were increased when handling was carried out at lower frequencies (weekly). We also observed a strong influence of stress on the host metabolism and commensal compositional variability. In addition, temporal biological compartmental variations in the responses were observed. Based on these results, we suggest that consistency in the frequency and duration of laboratory handling is crucial in murine models to minimise the impact of stress levels on the commensal and host metabolism dynamics. Furthermore, caution is advised in consideration of the temporal delay effect when integrating metagenomics and metabonomics data across different biological matrices (i.e. faeces and urine).
    Matched MeSH terms: Gastrointestinal Microbiome*
  5. Loke P, Lim YAL
    Trends Parasitol, 2015 Nov;31(11):534-535.
    PMID: 26604162 DOI: 10.1016/j.pt.2015.10.001
    There is growing interest in treating inflammatory conditions with helminth infection. Recently, Loukas and colleagues have reported promising results from using experimental hookworm infection to reduce gluten sensitivity in celiac disease patients. Analysis of microbiota samples from the trial is contributing to our understanding of the complexity underlying helminth–microbiota–host relationships.
    Matched MeSH terms: Gastrointestinal Microbiome*
  6. Nami Y, Haghshenas B, Haghshenas M, Abdullah N, Yari Khosroushahi A
    Front Microbiol, 2015;6:1317.
    PMID: 26635778 DOI: 10.3389/fmicb.2015.01317
    Enterococcus lactis IW5 was obtained from human gut and the potential probiotic characteristics of this organism were then evaluated. Results showed that this strain was highly resistant to low pH and high bile salt and adhered strongly to Caco-2 human epithelial colorectal cell lines. The supernatant of E. lactis IW5 strongly inhibited the growth of several pathogenic bacteria and decreased the viability of different cancer cells, such as HeLa, MCF-7, AGS, HT-29, and Caco-2. Conversely, E. lactis IW5 did not inhibit the viability of normal FHs-74 cells. This strain did not generate toxic enzymes, including β-glucosidase, β-glucuronidase, and N-acetyl-β-glucosaminidase and was highly susceptible to ampicillin, gentamycin, penicillin, vancomycin, clindamycin, sulfamethoxazol, and chloramphenicol but resistant to erythromycin and tetracyclin. This study provided evidence for the effect of E. lactis IW5 on cancer cells. Therefore, E. lactis IW5, as a bioactive therapeutics, should be subjected to other relevant tests to verify the therapeutic suitability of this strain for clinical applications.
    Matched MeSH terms: Gastrointestinal Microbiome
  7. Chong CW, Ahmad AF, Lim YA, Teh CS, Yap IK, Lee SC, et al.
    Sci Rep, 2015;5:13338.
    PMID: 26290472 DOI: 10.1038/srep13338
    Gut microbiota plays an important role in mammalian host metabolism and physiological functions. The functions are particularly important in young children where rapid mental and physical developments are taking place. Nevertheless, little is known about the gut microbiome and the factors that contribute to microbial variation in the gut of South East Asian children. Here, we compared the gut bacterial richness and composition of pre-adolescence in Northern Malaysia. Our subjects covered three distinct ethnic groups with relatively narrow range of socioeconomic discrepancy. These included the Malays (n = 24), Chinese (n = 17) and the Orang Asli (indigenous) (n = 20). Our results suggested a strong ethnicity and socioeconomic-linked bacterial diversity. Highest bacterial diversity was detected from the economically deprived indigenous children while the lowest diversity was recorded from the relatively wealthy Chinese children. In addition, predicted functional metagenome profiling suggested an over-representation of pathways pertinent to bacterial colonisation and chemotaxis in the former while the latter exhibited enriched gene pathways related to sugar metabolism.
    Matched MeSH terms: Gastrointestinal Microbiome
  8. Mohd Shaufi MA, Sieo CC, Chong CW, Gan HM, Ho YW
    Gut Pathog, 2015;7:4.
    PMID: 25806087 DOI: 10.1186/s13099-015-0051-7
    Chicken gut microbiota has paramount roles in host performance, health and immunity. Understanding the topological difference in gut microbial community composition is crucial to provide knowledge on the functions of each members of microbiota to the physiological maintenance of the host. The gut microbiota profiling of the chicken was commonly performed previously using culture-dependent and early culture-independent methods which had limited coverage and accuracy. Advances in technology based on next-generation sequencing (NGS), offers unparalleled coverage and depth in determining microbial gut dynamics. Thus, the aim of this study was to investigate the ileal and caecal microbiota development as chicken aged, which is important for future effective gut modulation.
    Matched MeSH terms: Gastrointestinal Microbiome
  9. Che HL, Tan DM, Meganathan P, Gan YL, Abdul Razak G, Fu JY
    Int J Anal Chem, 2015;2015:357609.
    PMID: 26604927 DOI: 10.1155/2015/357609
    Quantification of tocotrienols in human plasma is critical when the attention towards tocotrienols on its distinctive properties is arising. We aim to develop a simple and practical normal-phase high performance liquid chromatography method to quantify the amount of four tocotrienol homologues in human plasma. Using both the external and internal standards, tocotrienol homologues were quantified via a normal-phase high performance liquid chromatography with fluorescence detector maintained at the excitation wavelength of 295 nm and the emission wavelength of 325 nm. The four tocotrienol homologues were well separated within 30 minutes. A large interindividual variation between subjects was observed as the absorption of tocotrienols is dependent on food matrix and gut lipolysis. The accuracies of lower and upper limit of quantification ranged between 92% and 109% for intraday assays and 90% and 112% for interday assays. This method was successfully applied to quantify the total amount of four tocotrienol homologues in human plasma.
    Matched MeSH terms: Gastrointestinal Microbiome
  10. Hartini Yusof, Mohamad Shafiq Aazmi, Teh Lay Kek, Mohd Zaki Salleh, Ili Ng Abdullah, Aminuddin Ahmad, et al.
    MyJurnal
    Obesity is a growing epidemic due to an accelerated phase of industrialization and urbanization with the overfed people
    now outnumbered the underfed. It is the major public health problem with a lot of research interest as it is associated
    with many complicated chronic disorders such as type-2 diabetes, cardiovascular diseases (CVD) and cancers. A global
    estimation of 2.8 million deaths per year is due to obesity and there are tremendous on-going efforts to identify hosts
    and environmental factors that infl uence the cause and pathogenesis of obesity. Concerted efforts from different research
    groups had successfully shown that obese subjects have altered composition of gut microbiota and transplantation of this
    microbiota infl uences body weight in the germ-free recipient mice. The advancement of technology had made possible
    the study of gut microbiota which was unculturable for better understanding of their impact to human health. Rapid
    deep sequencing of DNA at reasonable cost through various options of platforms followed by data analysis using robust
    bioinformatic tools are an important way of analysing the gut microbiome. Here we review the role of gut microbiota
    which modulates host’s metabolic functions and gene expression, facilitating the extraction and storage of energy from the
    ingested dietary substances and leading to body-weight gain. We will discuss on the different techniques used, focusing
    on the high-defi nition technologies for the determination of the composition, function and ecology of gut microbiota. This
    allows the appropriate selection of platform which becomes the key for success of subsequent research.
    Matched MeSH terms: Gastrointestinal Microbiome
  11. Lee YY
    Malays J Med Sci, 2015 Jan-Feb;22(1):1-3.
    PMID: 25892944
    Obesity is a fast-emerging epidemic in the Asia-Pacific region, with numbers paralleling the rising global prevalence within the past 30 years. The landscape of gut diseases in Asia has been drastically changed by obesity. In addition to more non-specific abdominal symptoms, obesity is the cause of gastro-oesophageal reflux disease, various gastrointestinal cancers (colorectal cancer, hepatocellular carcinoma, oesophageal adenocarcinoma, gastric cardia adenocarcinoma, pancreatic cancer and gallbladder cancer) and non-alcoholic fatty liver disease. Abnormal cross-talk between the gut microbiome and the obese host seems to play a central role in the pathogenesis, but more studies are needed.
    Matched MeSH terms: Gastrointestinal Microbiome
  12. Zarkasi KZ, Taylor RS, Abell GC, Tamplin ML, Glencross BD, Bowman JP
    Microb Ecol, 2016 Apr;71(3):589-603.
    PMID: 26780099 DOI: 10.1007/s00248-015-0728-y
    To better understand salmon GI tract microbial community dynamics in relation to diet, a feeding trial was performed utilising diets with different proportions of fish meal, protein, lipid and energy levels. Salmon gut dysfunction has been associated with the occurrence of casts, or an empty hind gut. A categorical scoring system describing expressed digesta consistency was evaluated in relation to GI tract community structure. Faster growing fish generally had lower faecal scores while the diet cohorts showed minor differences in faecal score though the overall lowest scores were observed with a low protein, low energy diet. The GI tract bacterial communities were highly dynamic over time with the low protein, low energy diet associated with the most divergent community structure. This included transiently increased abundance of anaerobic (Bacteroidia and Clostridia) during January and February, and facultatively anaerobic (lactic acid bacteria) taxa from February onwards. The digesta had enriched populations of these groups in relation to faecal cast samples. The majority of samples (60-86 %) across all diet cohorts were eventually dominated by the genus Aliivibrio. The results suggest that an interaction between time of sampling and diet is most strongly related to community structure. Digesta categorization revealed microbes involved with metabolism of diet components change progressively over time and could be a useful system to assess feeding responses.
    Matched MeSH terms: Gastrointestinal Microbiome*
  13. Ramanan D, Bowcutt R, Lee SC, Tang MS, Kurtz ZD, Ding Y, et al.
    Science, 2016 Apr 29;352(6285):608-12.
    PMID: 27080105 DOI: 10.1126/science.aaf3229
    Increasing incidence of inflammatory bowel diseases, such as Crohn's disease, in developed nations is associated with changes to the microbial environment, such as decreased prevalence of helminth colonization and alterations to the gut microbiota. We find that helminth infection protects mice deficient in the Crohn's disease susceptibility gene Nod2 from intestinal abnormalities by inhibiting colonization by an inflammatory Bacteroides species. Resistance to Bacteroides colonization was dependent on type 2 immunity, which promoted the establishment of a protective microbiota enriched in Clostridiales. Additionally, we show that individuals from helminth-endemic regions harbor a similar protective microbiota and that deworming treatment reduced levels of Clostridiales and increased Bacteroidales. These results support a model of the hygiene hypothesis in which certain individuals are genetically susceptible to the consequences of a changing microbial environment.
    Matched MeSH terms: Gastrointestinal Microbiome/immunology*
  14. Cogger VC, Mohamad M, Solon-Biet SM, Senior AM, Warren A, O'Reilly JN, et al.
    Am J Physiol Heart Circ Physiol, 2016 05 01;310(9):H1064-70.
    PMID: 26921440 DOI: 10.1152/ajpheart.00949.2015
    Fenestrations are pores within the liver sinusoidal endothelial cells (LSECs) that line the sinusoids of the highly vascularized liver. Fenestrations facilitate the transfer of substrates between blood and hepatocytes. With pseudocapillarization of the hepatic sinusoid in old age, there is a loss of fenestrations. LSECs are uniquely exposed to gut-derived dietary and microbial substrates delivered by the portal circulation to the liver. Here we studied the effect of 25 diets varying in content of macronutrients and energy on LSEC fenestrations using the Geometric Framework method in a large cohort of mice aged 15 mo. Macronutrient distribution rather than total food or energy intake was associated with changes in fenestrations. Porosity and frequency were inversely associated with dietary fat intake, while fenestration diameter was inversely associated with protein or carbohydrate intake. Fenestrations were also linked to diet-induced changes in gut microbiome, with increased fenestrations associated with higher abundance of Firmicutes and reduced abundance of Bacteroidetes Diet-induced changes in levels of several fatty acids (C16:0, C19:0, and C20:4) were also significantly inversely associated with fenestrations, suggesting a link between dietary fat and modulation of lipid rafts in the LSECs. Diet influences fenestrations and these data reflect both the key role of the LSECs in clearing gut-derived molecules from the vascular circulation and the impact these molecules have on LSEC morphology.
    Matched MeSH terms: Gastrointestinal Microbiome
  15. Zaman SA, Sarbini SR
    Crit Rev Biotechnol, 2016 Jun;36(3):578-84.
    PMID: 25582732 DOI: 10.3109/07388551.2014.993590
    Resistant starch is defined as the total amount of starch and the products of starch degradation that resists digestion in the small intestine. Starches that were able to resist the digestion will arrive at the colon where they will be fermented by the gut microbiota, producing a variety of products which include short chain fatty acids that can provide a range of physiological benefits. There are several factors that could affect the resistant starch content of a carbohydrate which includes the starch granule morphology, the amylose-amylopectin ratio and its association with other food component. One of the current interests on resistant starch is their potential to be used as a prebiotic, which is a non-digestible food ingredient that benefits the host by stimulating the growth or activity of one or a limited number of beneficial bacteria in the colon. A resistant starch must fulfill three criterions to be classified as a prebiotic; resistance to the upper gastrointestinal environment, fermentation by the intestinal microbiota and selective stimulation of the growth and/or activity of the beneficial bacteria. The market of prebiotic is expected to reach USD 198 million in 2014 led by the export of oligosaccharides. Realizing this, novel carbohydrates such as resistant starch from various starch sources can contribute to the advancement of the prebiotic industry.
    Matched MeSH terms: Gastrointestinal Microbiome
  16. Jafari S, Meng GY, Rajion MA, Jahromi MF, Ebrahimi M
    J Agric Food Chem, 2016 Jun 08;64(22):4522-30.
    PMID: 27192629 DOI: 10.1021/acs.jafc.6b00846
    Different solvents (hexane, chloroform, ethyl acetate, butanol, and water) were used to identify the effect of papaya leaf (PL) fractions (PLFs) on ruminal biohydrogenation (BH) and ruminal methanogenesis in an in vitro study. PLFs at a concentration of 0 (control, CON) and 15 mg/250 mg dry matter (DM) were mixed with 30 mL of buffered rumen fluid and were incubated for 24 h. Methane (CH4) production (mL/250 mg DM) was the highest (P < 0.05) for CON (7.65) and lowest for the chloroform fraction (5.41) compared to those of other PLFs at 24 h of incubation. Acetate to propionate ratio was the lowest for PLFs compared to that of CON. Supplementation of the diet with PLFs significantly (P < 0.05) decreased the rate of BH of C18:1n-9 (oleic acid; OA), C18:2n-6 (linoleic acid; LA), and C18:3n-3 (α-linolenic acid; LNA) compared to that of CON after 24 h of incubation. Real time PCR indicated that total protozoa and total methanogen population in PLFs decreased (P < 0.05) compared to those of CON.
    Matched MeSH terms: Gastrointestinal Microbiome/drug effects*
  17. Koh JC, Loo WM, Goh KL, Sugano K, Chan WK, Chiu WY, et al.
    J Gastroenterol Hepatol, 2016 Aug;31(8):1405-13.
    PMID: 27010240 DOI: 10.1111/jgh.13385
    The incidence of obesity is increasing in Asia, with implications on gastrointestinal (GI) and liver diseases. The Gut and Obesity in Asia Workgroup comprises regional experts with the aim of studying relationship between obesity and the GI and liver diseases in Asia. Through literature review and the modified Delphi process, consensus statements examining the impact of obesity on esophageal, gastric, pancreatic, colorectal, and liver diseases, exploring relationship between gut microbiome and obesity, and assessing obesity therapies have been produced by the Gut and Obesity in Asia Workgroup. Sixteen experts participated with 9/15 statements having strong consensus (>80% agreement). The prevalence of obesity in Asia is increasing (100% percentage agreement in brackets), and this increased prevalence of obesity will result in a greater burden of obesity-related GI and liver diseases (93.8%). There was consensus that obesity increases the risk of gastric cancer (75%) and colorectal neoplasia (87.5%). Obesity was also associated with Barrett's esophagus and esophageal adenocarcinoma (66.7%) and pancreatic cancer (66.7%) in Asia. The prevalence of non-alcoholic fatty liver disease (NAFLD) in Asia is on the rise (100%), and the risk of NAFLD in Asia (100%) is increased by obesity. Obesity is a risk factor for the development of hepatocellular carcinoma (93.8%). Regarding therapy, it was agreed that bariatric surgery was an effective treatment modality for obesity (93.8%) but there was less agreement on its benefit for NAFLD (62.5%). These experts' consensus on obesity and GI diseases in Asia forms the basis for further research, and its translation into addressing this emerging issue.
    Matched MeSH terms: Gastrointestinal Microbiome
  18. Hansen TA, Mollerup S, Nguyen NP, White NE, Coghlan M, Alquezar-Planas DE, et al.
    Emerg Microbes Infect, 2016 Aug 17;5(8):e90.
    PMID: 27530749 DOI: 10.1038/emi.2016.90
    Outbreaks of zoonotic diseases in humans and livestock are not uncommon, and an important component in containment of such emerging viral diseases is rapid and reliable diagnostics. Such methods are often PCR-based and hence require the availability of sequence data from the pathogen. Rattus norvegicus (R. norvegicus) is a known reservoir for important zoonotic pathogens. Transmission may be direct via contact with the animal, for example, through exposure to its faecal matter, or indirectly mediated by arthropod vectors. Here we investigated the viral content in rat faecal matter (n=29) collected from two continents by analyzing 2.2 billion next-generation sequencing reads derived from both DNA and RNA. Among other virus families, we found sequences from members of the Picornaviridae to be abundant in the microbiome of all the samples. Here we describe the diversity of the picornavirus-like contigs including near-full-length genomes closely related to the Boone cardiovirus and Theiler's encephalomyelitis virus. From this study, we conclude that picornaviruses within R. norvegicus are more diverse than previously recognized. The virome of R. norvegicus should be investigated further to assess the full potential for zoonotic virus transmission.
    Matched MeSH terms: Gastrointestinal Microbiome*
  19. Saminathan M, Sieo CC, Gan HM, Ravi S, Venkatachalam K, Abdullah N, et al.
    J Sci Food Agric, 2016 Oct;96(13):4565-74.
    PMID: 26910767 DOI: 10.1002/jsfa.7674
    BACKGROUND: Condensed tannin (CT) fractions of different molecular weights (MWs) may affect rumen microbial metabolism by altering bacterial diversity. In this study the effects of unfractionated CTs (F0) and five CT fractions (F1-F5) of different MWs (F1, 1265.8 Da; F2, 1028.6 Da; F3, 652.2 Da; F4, 562.2 Da; F5, 469.6 Da) from Leucaena leucocephala hybrid-Rendang (LLR) on the structure and diversity of the rumen bacterial community were investigated in vitro.

    RESULTS: Real-time polymerase chain reaction assay showed that the total bacterial population was not significantly (P > 0.05) different among the dietary treatments. Inclusion of higher-MW CT fractions F1 and F2 significantly (P 

    Matched MeSH terms: Gastrointestinal Microbiome
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