A comparison of methods to extract pure DNA from mammalian intestinal contents and from feces

PURPOSE. To examine the involvement of human SMCT1, a Na+-coupled transporter for short-chain fatty acids, in the transport of nicotinate/structural analogs and monocarboxylate drugs, and to analyze its expression in mouse intestinal tract. We expressed human SMCT1 in X. laevis oocytes and monitored its function by [14C]nicotinate uptake and substrate-induced inward currents. SMCT1 expression in mouse intestinal tract was examined by immunofluorescence. [14C]Nicotinate uptake was several-fold higher in SMCT1-expressing oocytes than in water-injected oocytes. The uptake was inhibited by short-chain/medium-chain fatty acids and various structural analogs of nicotinate. Exposure of SMCT1-expressing oocytes to nicotinate induced Na+-dependent inward currents. Measurements of nicotinate flux and associated charge transfer into oocytes suggest a Na+:nicotinate stoichiometry of 2:1. Monocarboxylate drugs benzoate, salicylate, and 5-aminosalicylate are also transported by human SMCTI. The transporter is expressed in the small intestine as well as colon, and the expression is restricted to the lumen-facing apical membrane of intestinal and colonic epithelial cells. Human SMCTI transports not only nicotinate and its structural analogs but also various monocarboxylate drugs. The transporter is expressed on the luminal membrane of the epithelial cells lining the intestinal tract. SMCT1 may participate in the intestinal absorption of monocarboxylate drugs.

Although the fungus Candida albicans is a commensal colonizer of humans, the organism is also an important opportunistic pathogen. Most infections caused by C. albicans arise from organisms that were previously colonizing the host as commensals, and therefore successful establishment of colonization is a prerequisite for pathogenicity. To elucidate fungal activities that promote colonization, an analysis of the transcription profile of C. albicans cells recovered from the intestinal tracts of mice was performed. The results showed that within the C. albicans colonizing population, cells expressed genes characteristic of the laboratory-grown exponential phase and genes characteristic of post-exponential-phase cells. Thus, gene expression both promoted the ability to grow rapidly (a characteristic of exponential-phase cells) and enhanced the ability to resist stresses (a characteristic of post-exponential-phase cells). Similarities in gene expression in commensal colonizing cells and cells invading host tissue during disease were found, showing that C. albicans cells adopt a particular cell surface when growing within a host in both situations. In addition, transcription factors Cph2p and Tec1p were shown to regulate C. albicans gene expression during intestinal colonization.

ObjectiveTo explore whether stachyose can effectively inhibit the colonization of Clostridium difficile in intestinal tract of mice and analyze the structural change of the intestinal flora using C. difficile infection mouse model. MethodsC57BL/6 female mice were randomly divided into three groups, one group did not receive any treatment (blank group), and the other two groups were daily administrated with stachyose (stachyose group) and phosphate buffered saline (PBS) (PBS group) respectively for 10 days after C. difficile infection. On day 10 after infection, the content of C. difficile in feces was measured with real-time polymerase chain reaction (PCR) and the variation of intestinal flora in mice in different groups was analyzed with 16S rRNA sequencing technique. ResultsOn day 10 after infection, stachyose significantly decreased the colonization of C. difficile in intestinal tract the mice infected with C. difficile. The 16S rRNA sequencing result showed that the ACE index of stachyose group was significantly higher than that of PBS group, but it did not return to normal level. At the phylum level, stachyose treatment resulted in a significant increase in the relative abundance of Bacteroidetes and Firmicutes and a significant decrease in the relative abundance of Proteobacteria in C. difficile-infected mice. At the species level, stachyose treatment resulted in a significant increase in the relative abundance of Parabacteroides goldsteinii, Blautia hansenii, Bacteroides thetaiotaomicron and a significant decrease in the relative abundance of Parasutterella excrementihominis, Parabacteroides distasonis. ConclusionStachyose treatment can effectively reduce the colonization of C. difficile, restore the richness of intestinal flora in intestinal tract of the mice in mice infected with C. difficile, especially the relative abundance of several bacteria, such as Bacteroides thetaiotaomicron and Parabacteroides goldsteinii.

Bombyx mori, the silkworm, is a voracious feeder that relies on digestive enzymes for mulberry digestion and its conversion in to silk. In the current study, fifth-instar larvae were given 2% spirulina supplementation with commercially graded spirulina samples, and a few digestive enzymes and cocoon traits were examined. The treatment groups of silkworms T1-control, T2-supplemented with spirulina powder graded for animal dietary consumption, T3- graded for human dietary consumption and T4-spirulina graded for medicinal applications. Spirulina supplementation was tested in silkworms for digestive protease, carbohydrases and cocoon traits. The results shows that the total protein content percentage difference (PD) in the gut wall was increased by 2.79% in T3, 1.96% in T4, and 0.78% in T2 compared to T1 (control). A similar trend was noticed in the gut content, with the PD of 15.81% in T3, 7.51% in T4, and 3.95% in T2. In total carbohydrate content, observed PD of 16.35% in T2, 11.27% in T3, and 9.38% in T4, while the gut content was 13% both in T2 and T3, and 1.22% in T4. The protease activity PD of gut wall tissue has 21.99% in T3, 5.13% in T2, and 4.30% in T4; similarly, the gut content has a PD of 112.38% in T3, 106.12% in T4, and 86.41% in T2. The amylase activity have shown highest PD in T4 (33.43%), T3 (23.37%), and moderate in T2 (19.23%) in the gut wall, and 93.10% in T3, 66.44% in T2, and 14.92% in T4 of gut content. Enzymes such as sucrase, cellulase, and pectinase have also improved with spirulina fortification. The sucrase activity in the gut wall and gut content were, respectively, 7.99% and 80.73% in T3 treatment. Noteworthy, the T2 showed 37.69% in the gut wall and 24.54% in the gut content for the cellulase activity. Unlike cellulase, pectinase activity has been observed with a PD of 93.15% in the gut wall and 64.63% in gut content. The study further confirms that the additional fortification of spirulina will have a beneficial effect on the digestive cells of the silkworm, Bombyx mori, resulting in the highest rate of enzyme activity and in turn, increasing survivability.

The probiotics and prebiotis as microecological modulator have dramatic effects on the microdysbiosis. We found the effects of Ganoderan (GD) in normal flora in intestinal tract of mice. The mice were divided into normal group, decontaminated (DC) group, GD treated group and Bacillus bifidus praeparatum (LZCL) treated group, in which the three groups were treated per os with Lincomycin to be the DC model. After six‐day treatment, the intestinal flora were detected. Lincomycin decreased the number of Bifidobacterium, Bacteroid and Lactobacillus in intestinal tract of mice. The voltatile fatty acid, acetic acid, propionic acid and butanoic acid in blindgut of mice were decreased, suggesting that the dysbacteria were induced in DC mice. After six‐day treatment, the enteric bacilli and enterococcus of GD treatment group and LZCL group were lower than that of DC group, the Bifidobacterium and Bacteroid of GD treatment Group, while LZCL group were higher than that of DC group. The acetic acid, propionic acid and butanoic acid in blindgut of GD treated group and LZCL group were increased. But the level of acetic acid, propionic acid and butanoic acid in blindgut of DC group were lower than that of normal group. The morphologic data showed that the pathological changes of intestinal mucosa restored to normal state after treatment. These results suggest that the GD is an important microecological modulator.

The authors of the original article “The effects of myeloablative or non-myeloablative total body irradiations on intestinal tract in mice” (Biosci Rep (2021) 41(3):BSR20202993. doi: 10.1042/BSR20202993). would like to correct Figure 2. Due to an error, they had placed an incorrect image in Figure 2A (ERK1/2 bands), and in Figure 2B (ERK1/2 gray levels). A revised version of Figure 2 is present in this Correction. The authors express their sincere apologies for any inconvenience that this error has caused to the readers. The authors declare that this Correction does not alter the conclusions of the study.

Popular concerns about blood-stealing, trade in body parts, surreptitious birth control and the deliberate spreading of disease are common across sub-Saharan Africa, and there are indications that they are becoming more common in pace with the process of deprivation that economic and political destructuring has, over the last quarter century, set in motion across most of the continent (Comaroff & Comaroff 2000). Such stories are commonly referred to as ‘rumours’ – by those who observe and dismiss them, but also by those who, usually with due scepticism, pass them on to others. With its connotation of hearsay and gossip, the term is often used in contrast to ‘truth’, much like the equally problematic distinction of ‘belief’ and ‘knowledge’. It is our aim in this paper to move beyond the dismissal of these stories as ‘mere’ rumour, based on erroneous belief or traditional superstition, and to appreciate them as modern commentaries on social relations that involve, and extend far beyond, scientific medical research. If we nevertheless use the words ‘rumour’, ‘story’ and ‘concern’ synonymously, we follow the historian Luise White’s understanding that rumours, such as vampire stories in 20th-century Africa, ‘are neither true nor false, in the sense that they do not have to be proven beyond their being talked about; but as they are told, they contain different empirical elements that carry different weights: stories are told with truths, commentaries, and statements of ignorance’ (White 2000). By telling these stories, relating them to empirical facts in a given locality and at a particular moment, and intertwining them with other seemingly unrelated tales, people make new connections and reveal hitherto unseen links, weaving wide, often global connections into local patterns of relatedness (Geissler 2005). When, below, we speak of ‘rumour’ we are not expressing our scepticism; rather, we are reflecting the scepticism of those who tell these stories: their ambiguity towards formations of knowledge and power that reach deep into their everyday lives, and which are set in a world order that provokes their doubts. Medical research and the ‘trial communities’ it constitutes by linking scientists and subjects, institutions and funders, media and publics, is one of the networks of global connections that has been particularly prolific in the generation of rumours (P.W. Geissler and C. Molyneux, in press). The sort of rumours mentioned above, particularly those about blood, are often directly related to medical research and health interventions. During 15 years of involvement in medical research in Africa we have repeatedly encountered such rumours. From friends and colleagues we have heard many more reports of such rumours, sometimes impeding recruitment to research, affecting adherence to interventions and even threatening the continuation of whole research projects while more commonly providing a background noise without direct impact (Geissler 2005; Molyneux et al. 2005a; Pool & Geissler 2005; Fairhead et al. 2006; for a rare note in a medical paper, see Nchito et al. 2003; for the potential detrimental impact of public debates see most recently Singh & Mills 2005). Most of these rumours follow a relatively limited number of themes, while also showing regional and locally specific variation. On a more general level they merge into related genres such as urban legends and oral traditions (Burke 1998; Ellis & Ter Haar 2001), Tropical Medicine and International Health doi:10.1111/j.1365-3156.2006.01682.x

Biomacromolecules in physiological environments would adsorb onto the nanoparticles (NPs) to form corona layers, in which protein coronas (PCs) are the major constituent. PCs always play diverse influences on the fate of NPs in vitro and in vivo, especially for active-targeting NPs (e.g., transferrin-modified nanoparticles, Tf-NP). In order to eliminate the inhibition of PCs on the efficiency of Tf-NP, the precoated Tf-NP with bovine serum albumin (BSA, B@Tf-NP) was designed to fabricate an "active PCs" (PCs formed by artificial modification) against the "passive PCs" (PCs formed in the biological environments), which was inspired by the formation pattern of PCs. The results indicated that B@Tf-NP had similar particle size, dispersion, and physical stability with Tf-NP. Surprisingly, B@Tf-NP enhanced the cellular uptake in enterocytes and permeability in intestinal tract of mice. Notably, the concentration ratio of BSA to Tf that could ensure Tf revealed timely during the interacted process was considered to be appropriate. These findings provide an easy while efficient design platform for active-targeting NPs to overcome the biomacromolecular barrier in oral administration.

For analyzing the role of the bacterial flagella in colonization in the intestinal tract of mice and adhering to or invading the Intestine 407 cell, a nonflagellated, nonmotile mutant was induced by ultraviolet irradiation of a flagellated, motile wild-type strain of Campylobacter jejuni CF84-340. There was no great difference in the cellular infectivity to the Intestine 407 cells between the wild-type and the mutant strains. Cellular adherence and invasiveness were then compared by fluorescent antibody staining, and an obvious difference was found in the latter. While 21.4% of the organisms of the wied-type strain invaded the cells, only 6.1% of those of the flagella-defective mutant did so. In the experiments in mice involving oral administration, cellular invasiveness was not found with the flagella-defective mutant and no organisms were detected from the blood, although bacteremia is one of the characteristics of infection with C. jejuni. Moreover, no intestinal adherence of the mutant was detected, suggesting early elimination of the organism administered. These results indicate that the bacterial flagella are concerned in not only the cellular adherence and intestinal deposit, but also the intracellular invasiveness and invasion into the blood stream from the intestinal wall in the infected mice.

Field preservation and DNA extraction methods for intestinal microbial diversity analysis in earthworms

MrgprD, a Mas-related G protein-coupled receptor, is initially identified in sensory neurons of mouse dorsal root ganglia (DRG) and has been suggested to participate in somatosensation. However, MrgprD has recently been found to be expressed outside the nervous system such as in aortic endothelia cells and neutrophils. In this study, we used immunohistochemistry to detect the expression and localization of MrgprD in mouse intestinal tract. The immunoreactivity (IR) of MrgprD was found in the smooth muscle layers of small intestine, colon and rectum. In addition, MrgprD IR was colocalized with F4/80-positive macrophages and CD3-positive T lymphocytes resident in the lamina propria of intestinal mucosa. MrgprD was also found to be expressed in primary peritoneal macrophages and splenic T lymphocytes. Furthermore, the presence of MrgprD mRNA and its protein was detected in murine macrophage-like RAW 264.7 and human T lymphocyte Jurkat cell lines. Our study shows, for the first time, the expression and localization of MrgprD in the intestinal tract and in macrophages and T lymphocytes, indicating the potential roles of MrgprD in intestinal mobility and immunity.

The intestinal tract of mammals has a large number of complex microbial flora, which together forms the intestinal microbiome. In recent years, it has been realized that intestinal microbes are closely related to the occurrence and development of some diseases, such as metabolic syndrome, inflammatory bowel disease, cancer, immune system and nervous system disease and so on, which makes intestinal microbiome to be one of the most active research fields. The rapid development of microbial research technologies provides us with efficient and powerful methodology and promotes the systematic understanding of intestinal micro-ecology, and opens up new ideas for the diagnosis and treatment of diseases.. This review aims to summarize and analyze the latest progress and limitation of micro-ecological research techniques, providing a reference for further study of gut microbiota, and simply introduce the representative results of the study on the correlation between micro-ecology and metabolic syndrome in intestinal tract. Key words: Gut microbiota; Single cell analysis; Culture; Metabolic syndrome

A comparison of storage methods for gut microbiome studies in teleosts: Insights from rainbow trout (Oncorhynchus mykiss)

As the saying goes, those who pay the piper call the tune. In most countries where research is publicly funded there are national systems for assessing research outputs. Governments, research councils, charitable bodies and other investors all want value for money. Accordingly, the UK is currently undergoing a research assessment exercise (RAE) in a process which will be familiar to researchers in many countries worldwide. Since 1986, the four UK higher education funding bodies have sponsored successive RAEs, the outcomes of which have been used to inform funding allocations and to provide benchmarking for research quality. The current RAE will report its findings towards the end of 2008.

[6]-Shogaol (6S), one of the major bioactive components in dry ginger, is attracting considerable attention because of its wide spectrum of biological activities, but its metabolic fate is still not fully understood. In the present study, the microbial metabolism of 6S was examined for the first time in in vitro batch fecal fermentation system and in mice. Two major microbial metabolites were detected and identified as 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9) and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11). Our results indicated that reductions of the double bond and the ketone group are the major metabolic pathways of 6S by the human gut microbiota. We also observed the interindividual variability in the metabolism of M11 to M9 by human gut microbiota. In addition, we demonstrated that the glucuronidated form of 6S and its metabolites could be rapidly deconjugated by human gut microbiota and in mice, which can be regarded as a reactive process taking place in the intestinal tract. To our knowledge, this is the first report involving the identification of the microbial metabolites of 6S in an in vitro fermentation system, and the first demonstration of the critical role of gut microbiota in producing the bioactive free form of 6S and its metabolites in the intestinal tract in mice.