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Introduction
Published in Lijuan Yuan, Vaccine Efficacy Evaluation, 2022
The detailed technical instructions on how to establish and maintain a Gn pig program, including standard operating procedures for the derivation of Gn pigs and their rearing on sterile commercially available milk, have been provided elsewhere (Yuan et al., 2017). The word gnotobiotic is from Greek roots gnostos means “known” and bios means “life.” A gnotobiotic pig is a pig in which only certain known viruses or bacteria are present. Technically, the term also includes germ-free pigs, as the status of their microbial communities is also known. Germ-free pigs are derived by the surgical procedure hysterectomy one day before the expected delivery date (112–113 days of pregnancy) and moved into a transfer isolator, after which they are transported into rearing isolators where they are kept for the remainder of the experiment. Germ-free pig isolators provide a sterile environment free of bacteria, mycoplasma, molds, fungi, viruses, etc. Once an agent, such as a virus, is introduced into the germ-free isolator, it is no longer truly germ-free and is referred to as being gnotobiotic. In the literature, however, the words germ-free pig, gnotobiotic pig, and isolator pig are often used interchangeably.
Immune Control of Pregnancy
Published in Robert E. Garfield, Thomas N. Tabb, Control of Uterine Contractility, 2019
Gérard Chaouat, Elisabeth Menu, Valentine Djian, Genevieve Delage, Due Can Dang, Aines Assai Meliani, Jacques Martal, Sylvie Ropert
The two models share several characteristics: resorptions become more common with age and with repeated pregnancies with the wrong father; there is a local deficiency of decidua-associated suppressor cells near would-be-resorbed embryos, and the embryos are surrounded by NK cells. The models are environment dependent: Gnotobiotic CBA/J do not abort.156
Peyer’s Patch Epithelium
Published in Shayne C. Gad, Toxicology of the Gastrointestinal Tract, 2018
Gary R. Burleson, Florence G. Burleson
The gut contains 1,000 to 1,500 different bacterial species; however, an individual contains only approximately 160 different species indicating that the makeup of an individual microbiome is quite different between individuals and may be influenced by genetics, diet, lifestyle, age, inflammation, and many other factors (Lee and Mazmanian, 2016; Harmsen and Goffau, 2016). This is emphasized by studies by Hasegawa and Inohara (2014) indicating that mice with the same genotype housed in separate cages within the same facility have different microbiota compositions (Shi et al., 2017). The gut microbiome has been reported to influence susceptibility and severity of a number of diseases (Dietert, 2016). Gnotobiotic mice that harbor known bacterial species and germ-free mice with no bacteria are useful models in studies that attempt to dissect and better understand the effects of the microbiome.
Effects of intestinal flora on pharmacokinetics and pharmacodynamics of drugs
Published in Drug Metabolism Reviews, 2023
Amina Džidić-Krivić, Jasna Kusturica, Emina Karahmet Sher, Nejra Selak, Nejra Osmančević, Esma Karahmet Farhat, Farooq Sher
Moreover, Zimmermann-Kogadeeva et al. (2020) observed changes in drug kinetics in two groups of animals. The first group of gnotobiotic mice was germ-free and the second group had unaltered microbiota. The study showed a significant reduction of drug in the large intestine in the second group confirming the hypothesis that gut microbiota has the power to alter drug pharmacokinetics. It is important to highlight that this process goes bidirectional, meaning that different drugs could alter the bacteria genera in the gut. On the other hand, gut microbiota could also interfere with drug metabolism and, both indirectly and directly, alter their structure and function in the organism as shown in Figure 3. One of the metabolites that gut microbiota produces from dietary choline, marked as Trimethylamine-N-oxide (TMAO), is associated with major cardiovascular events. In addition, the gut enhances the production of some beneficial molecules through food fermentation and their release into the circulation, such as short chain fatty acids (SCFA). These molecules have strong anti-inflammatory properties and they help to maintain the integrity of the intestinal barrier (Zimmermann-Kogadeeva et al. 2020).
Bacterial-fungal metabolic interactions within the microbiota and their potential relevance in human health and disease: a short review
Published in Gut Microbes, 2022
Alexia Lapiere, Mathias L Richard
Currently, only a small fraction of human inhabiting organisms is cultivable in the laboratory,141,142 which means that a wide number of bacteria and fungi are still unstudied. The reasons for the difficulties in their culture are highly related to the challenge of reproducing an identical environment to that in which they usually live. We can also hypothesize that some microorganisms might require, for their growth and survival, the presence of others through some of the metabolic exchanges we described in this review or other yet undescribed ones. Thus, synthetic media and monocultures are presumably inadequate for cultivating such demanding strains. Hence, the gnotobiotic model and coculture with several naturally found coliving strains, potentially from different kingdoms, could facilitate the discovery of original and relevant strains, as well as specific growth conditions and/or multicrossing interactions involving a variety of species that intensify potential exchanges between organisms, which could ultimately be related to human health. Presently, studies only scratch the surface of the bacterial-fungal interactions. We barely appreciate the importance of the impact they represent to our health. Therefore, microbiota-focused studies on health enhancement and on new therapeutic strategies should give more consideration to the significance of bacterial-fungal interactions in human health.
Fusobacterium nucleatum drives a pro-inflammatory intestinal microenvironment through metabolite receptor-dependent modulation of IL-17 expression
Published in Gut Microbes, 2021
Caitlin A. Brennan, Slater L. Clay, Sydney L. Lavoie, Sena Bae, Jessica K. Lang, Diogo Fonseca-Pereira, Kathryn G. Rosinski, Nora Ou, Jonathan N. Glickman, Wendy S. Garrett
Specific-pathogen free (SPF) ApcMin/+ and C57Bl/6J mice were sourced from Jackson Labs and bred in house in a barrier facility under a 12-hour light cycle and with ad libitum food and water. Pregnant SPF C57Bl/6J mice, bred to SPF ApcMin/+ males, were identified at gestational day ~18 and gently orally instilled with either ~5×108 CFU of Fn7-1 (in <100 μl volume) or medium control (sTSB) daily until they gave birth (generally 1–3 times). After birth, pups were orally instilled with ~1×108 colony forming units (CFU) of Fn7-1 (in <20 μl volume) and sprinkled with another ~5×108 CFU per litter at d14. Pups were orally instilled again, as previously at weaning (d18-28). Sham mice were instilled and sprinkled with equivalent amounts of medium control (sTSB) on the same schedule. Mice were aged until 14 weeks for tumor enumeration, or 7–9 weeks for pre-tumoral intestinal gene expression. Gnotobiotic colonization