An in vitromodel to quantify interspecies differences in kinetics for intestinal microbial bioactivation and detoxification of zearalenone
Mendez-Catala, Diana M. ; Spenkelink, Albertus ; Rietjens, Ivonne M.C.M. ; Beekmann, Karsten - \ 2020
Toxicology Reports 7 (2020). - ISSN 2214-7500 - p. 938 - 946.
Bioactivation - Detoxification - Interspecies differences - Intestinal microbiota - Zearalenone
Zearalenone (ZEN) is a mycotoxin known for its estrogenic activities. The metabolism of ZEN plays a role in the interspecies differences in sensitivity to ZEN, and is known to occur in the liver and via the intestinal microbiota, although the relative contribution of these two pathways remains to be characterized. In the present study a fecal in vitro model was optimized and used to quantify the interspecies differences in kinetics of the intestinal microbial metabolism of ZEN in rat, pig and human. Vmax, Km, and catalytic efficiencies (kcat) were determined, and results obtained reveal that the kcat values for formation of α-ZEL and β-ZEL amounted to 0.73 and 0.12 mL/h/kg bw for human microbiota, 2.6 and 1.3 mL/h/kg bw for rat microbiota and 9.4 and 6.3 mL/h/kg bw for pig microbiota showing that overall ZEN metabolism increased in the order human < rat < pig microbiota. Expressed per kg bw the kcat for ZEN metabolism by the liver surpassed that of the intestinal microbiota in all three species. In conclusion, it is estimated that the activity of the intestinal colon microbiome may be up to 36 % of the activity of the liver, and that it can additionally contribute to the species differences in bioactivation and detoxification and thus the toxicity of ZEN in pigs and rats but not in humans. The results highlight the importance of the development of human specific models for the assessment of the metabolism of ZEN.
Acute porcine epidemic diarrhea virus infection reshapes the intestinal microbiota
Yang, Shanshan ; Li, Yang ; Wang, Bin ; Yang, Ning ; Huang, Xin ; Chen, Qingbo ; Geng, Shuxian ; Zhou, Yawei ; Shi, Han ; Wang, Leyi ; Brugman, Sylvia ; Savelkoul, Huub ; Liu, Guangliang - \ 2020
Virology 548 (2020). - ISSN 0042-6822 - p. 200 - 212.
Intestinal microbiota - Pathogenicity - Porcine epidemic diarrhea virus
The intestinal microbiota is crucial to intestinal homeostasis. Porcine epidemic diarrhea virus (PEDV) is high pathogenic to intestines, causing diarrhea, even death in piglets. To investigate the detailed relationship between PEDV infection and intestinal microbiota, the composition and distribution of intestinal microbiota from pigs were first analyzed using 16S rRNA sequencing technology. The results demonstrated that the composition and distribution of microbes in different intestinal segments were quite similar between 1-week-old and 2-week-old piglets but different from 4-week-old (weaned) piglets. Then piglets at different ages were inoculated with PEDV. The results showed that the 1-week-old piglets exhibited the most severe pathogenicity comparing to the other age groups. Further investigations indicated that Lactobacillus, Escherichia coli, and Lactococcus in the intestinal microbiota of piglets were significantly changed by PEDV infection. These results strengthen our understanding of viruses influencing intestinal microbes and remind us of the potential association between PEDV and intestinal microbes.
Molecular ecology of the yet uncultured bacterial Ct85-cluster in the mammalian gut
Hynönen, Ulla ; Zoetendal, Erwin G. ; Virtala, Anna Maija K. ; Shetty, Sudarshan ; Hasan, Shah ; Jakava-Viljanen, Miia ; Vos, Willem M. de; Palva, Airi - \ 2020
Anaerobe 62 (2020). - ISSN 1075-9964
16S rRNA - IBS - Intestinal microbiota - Typing - Uncultured
In our previous studies on irritable bowel syndrome (IBS) –associated microbiota by molecular methods, we demonstrated that a particular 16S rRNA gene amplicon was more abundant in the feces of healthy subjects or mixed type IBS (IBS-M) –sufferers than in the feces of individuals with diarrhea-type IBS (IBS-D). In the current study, we demonstrated that this, so called Ct85-amplicon, consists of a cluster of very heterogeneous 16S rRNA gene sequences, and defined six 16S rRNA gene types, a to f, within this cluster, each representing a novel species-, genus- or family level taxon. We then designed specific PCR primers for these sequence types, mapped the distribution of the Ct85-cluster sequences and that of the newly defined sequence types in several animal species and compared the sequence types present in the feces of healthy individuals and IBS sufferers using two IBS study cohorts, Finnish and Dutch. Various Ct85-cluster sequence types were detected in the fecal samples of several companion and production animal species with remarkably differing prevalences and abundances. The Ct85 sequence type composition of swine closely resembled that of humans. One of the five types (d) shared between humans and swine was not present in any other animals tested, while one sequence type (b) was found only in human samples. In both IBS study cohorts, one type (e) was more prevalent in healthy individuals than in the IBS-M group. By revealing various sequence types in the widespread Ct85-cluster and their distribution, the results improve our understanding of these uncultured bacteria, which is essential for future efforts to cultivate representatives of the Ct85-cluster and reveal their roles in IBS.
Early-life origin of intestinal inflammatory disorders
Ley, Delphine ; Desseyn, Jean Luc ; Mischke, Mona ; Knol, Jan ; Turck, Dominique ; Gottrand, Frédéric - \ 2017
Nutrition Reviews 75 (2017)3. - ISSN 0029-6643 - p. 175 - 187.
Celiac disease - Epigenetics - Inflammatory bowel disease - Intestinal microbiota - Perinatal programming
A growing body of evidence supports the concept of perinatal programming through which the perinatal environment affects the development of the fetus and infant, thereby modifying the risk profile for disease later in life. Increasing attention is focusing on the role of the early environment in the development of chronic intestinal disorders. Epidemiological studies have highlighted the link between perinatal factors, such as breastfeeding, cesarean delivery, and antibiotic use, and an increased risk for inflammatory bowel disease and/or celiac disease. These links are consistent with the concept of perinatal programming of intestinal inflammatory disorders. Animal models have shown that the early-life environment affects the development of the gastrointestinal tract, but further experimental studies are needed to confirm the long-term effects of the perinatal environment on susceptibility to chronic intestinal disorders later in life. Changes in the development and composition of the intestinal microbiota as well as epigenetic changes are emerging as key mechanisms through which the perinatal environment determines susceptibility to intestinal inflammatory disorders.
Colonic metaproteomic signatures of active bacteria and the host in obesity
Kolmeder, C.A. ; Ritari, Jarmo ; Verdam, F.J. ; Vos, W.M. de - \ 2015
Proteomics 15 (2015)20. - ISSN 1615-9853 - p. 3544 - 3552.
Composition - Intestinal microbiota - Metaproteomics - Microbiology - Obesity
Obesity is associated with the intestinal microbiota in humans but the underlying mechanisms are yet to be fully understood. Our previous phylogenetic study showed that the faecal microbiota profiles of nonobese versus obese and morbidly obese individuals differed. Here, we have extended this analysis with a characterization of the faecal metaproteome, in order to detect differences at a functional level. Proteins were extracted from crude faecal samples of 29 subjects, separated by 1D gel electrophoresis and characterized using RP LC-MS/MS. The peptide data were analyzed in database searches with two complementary algorithms, OMSSA and X!Tandem, to increase the number of identifications. Evolutionary genealogy of genes: nonsupervised orthologous groups (EggNOG) database searches resulted in the functional annotation of over 90% of the identified microbial and human proteins. Based on both bacterial and human proteins, a clear clustering of obese and nonobese samples was obtained that exceeded the phylogenetic separation in dimension. Moreover, integration of the metaproteomics and phylogenetic datasets revealed notably that the phylum Bacteroidetes was metabolically more active in the obese than nonobese subjects. Finally, significant correlations between clinical measurements and bacterial gene functions were identified. This study emphasizes the importance of integrating data of the host and microbiota to understand their interactions.
Multilocus sequence typing of bifidobacterial strains from infant's faeces and human milk : Are bifidobacteria being sustainably shared during breastfeeding?
Makino, H. ; Martin, R. ; Ishikawa, E. ; Knol, J. - \ 2015
Beneficial Microbes 6 (2015)4. - ISSN 1876-2883 - p. 563 - 572.
Bifidobacteria - Breast milk - Infancy - Intestinal microbiota
Bifidobacteria are considered to be one of the most important beneficial intestinal bacteria for infants, contributing to the priming of the mucosal immune system. These microbes can also be detected in mother's milk, suggesting a potential role of human milk in the colonisation of infant's gut. However, little is known about the timing of bacteria appearance in human milk, and whether human milk is the first source of inoculation. Here, we investigated whether specific strains are shared sustainably between maternal milk and infant's gut. Faecal samples and human milk were collected from 102 healthy mother-infant pairs (infant's faeces: meconium, 7, 30 days of age; mother's milk: once before delivery, colostrum, 7, 30 days after delivery). Bifidobacterial strains were isolated from these samples, and were discriminated by means of multilocus sequencing typing. No bifidobacteria were detected from human milk collected before delivery, or colostrum. Strains were isolated only from human milk samples obtained 7 days after birth or later. On the other hand, bifidobacterial strains were obtained from infant's faeces throughout the study period, sometimes as early as the first day of life (meconium). We have found that bifidobacterial species belonging to Bifidobacterium bifidum, Bifidobacterium breve, and Bifidobacterium longum subsp. longum could be identified as monophyletic between infant's faeces and their mother's milk. These strains were confirmed to be sustainably shared between maternal milk and infant's gut. Moreover, monophyletic strains were isolated at the same time point or earlier from infant's faeces than from human milk, and none were isolated earlier from human milk than from infant's faeces. Although it remains unclear whether human milk is the first source of microbes for infants, our results confirm that human milk is a reservoir of bifidobacteria, and specific strains are shared between infant's intestine and human milk during breastfeeding.