scholarly journals Carboxymethyl chitosan perturbs inflammation profile and colonic microbiota balance in mice

2020 ◽  
Vol 28 (1) ◽  
pp. 175-182
Author(s):  
Yuting Liu ◽  
Shuai Zong ◽  
Jinglei Li
Keyword(s):  
Carboxymethyl Chitosan ◽  
Colonic Microbiota

Intestinal microbiota balance modulates host susceptibility to infection with enteric pathogenss

2007 ◽  
Vol 30 (4) ◽  
pp. 93
Author(s):  
I Sekirov ◽  
N Tam ◽  
M Robertson ◽  
C Lupp ◽  
B Finlay
Keyword(s):  
Intestinal Microbiota ◽  
Small Animal ◽  
Host Susceptibility ◽  
Morphological Development ◽  
Future Design ◽  
Susceptibility To Infection ◽  
Colonic Microbiota ◽  
Food Borne ◽  
Serovar Typhimurium ◽  
Intestinal Pathogens

Background: During our lifetimes we develop a very complex set of interactions with the multitude of microorganisms colonizing our bodies. In the gastrointestinal system, the microbiota is highly important for morphological development, nutrition, and protection against infectious diseases. The gastrointestinal pathogens, enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) and Salmonella enterica serovar Typhimurium (ST) are food-borne pathogens that cause much morbidity and mortality worldwide. Citrobacter rodentium (Cr) is a mouse pathogen that is used in small animal models to mimic EHEC and EPEC infections. Methods: We began to characterize the contribution of intestinal microbiota to the progression of these infections. Two main phyla comprise the majority of mouse intestinal microbiota: Bacteroidetes and Firmicutes. Bacteria from a number of additional phyla are also present in smaller numbers; among them γ-Proteobacteria class, belonging to Proteobacteria phylum, is note-worthy as this class harbours many intestinal pathogens, such as ST and Cr. The mouse intestinal microbiota was perturbed using tetracycline (Tet) and streptomycin (Sm) to increase the proportion of Bacteroidetes in the colonic microbiota, and using vancomycin (Vanc) to create a predominance of Firmicutes. The mice with this perturbed microbiota were infected with ST to investigate the resultant pathology and virulence characteristics, and any additional shifts in microbiota as a result of infection. Results: Treatment of mice with Sm and Vanc was found to decrease the resistance of mice to colonization with ST, while Tet-treated mice exhibited unchanged colonization resistance. Treatment of mice with gradually increasing doses of Sm, which gradually augmented the proportion of CFB bacteria in the microbiota, resulted in progressively increasing colonization of mice by ST, as well as a step-wise increase in the ST-induced typhlitis, associated with higher levels of inflammatory markers IL-6 and KC. The increasing levels of ST colonization following both Sm and Vanc treatment were associated with an increase in the proportion of γ-Proteobacteria in the cecal and colonic microbiota, as well as a decrease in the total bacterial numbers in both organs. Conclusions: It is evident that the intestinal microbiota plays a significant role in the host’s response to infection with enteric pathogens, and its composition and numbers are also affected by the offending bacteria. Elucidation of the details regarding the contribution of the microbiota to infectious disease progression will offer novel targets for the future design of superior prevention and treatment methods.

The Consumption of Galactomannan Effervescent Drinks made from Coconut Pulp Waste and Colonic Microbiota in Wistar Rats

2020 ◽  
Vol 15 (1) ◽  
pp. 52-56
Author(s):  
Sri Winarti ◽  
Agung Pasetyo
Keyword(s):  
Fatty Acids ◽  
Gut Microbiota ◽  
Wistar Rats ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
E Coli ◽  
Colonic Microbiota ◽  
Male Wistar Rats ◽  
Lactobacillus Spp ◽  
Chain Fatty Acids

The consumption of prebiotics is known to affect the balance of gut microbiota. The purpose of this study was to explore how a galactomannan-rich effervescent drink can affect the population of Lactobacillus, Bifidobacterium, E. coli, and the concentration of short-chain fatty acids in the cecum of rats. Twenty-eight male Wistar rats (aged 2 months) were divided equally into 7 groups and treated orally each day for 15 days with 2 mL effervescent drinks with increasing levels of prebiotic galactomannan. The dosage of 500 mg galactomannan increased the growth of Lactobacillus spp. and Bifidobacterium spp. with inhibition of the growth of E.coli with increased formation of short-chain fatty acids such as acetate, propionate, and butyrate in the cecum of rats.

Carboxymethyl-hexanoyl Chitosan Nanodroplets for Ultrasonic Imaging and Drug Delivery to Tumor

2018 ◽  
Vol 24 (15) ◽  
pp. 1682-1688 ◽  
Author(s):  
Yu Jinsui ◽  
Situ Bing ◽  
Luo Muhua ◽  
Li Yue ◽  
Liao Jianyi ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Tumor Therapy ◽  
Carboxymethyl Chitosan ◽  
Great Promise ◽  
Ovarian Cancer Cells ◽  
Mechanical Index ◽  
Surface Charges ◽  
Particle Structure ◽  
Drug Release Profile ◽  
Hexanoyl Chitosan

Introduction: Although a great many strategies have been proposed for tumor-targeted chemotherapy, current delivery methods of anticancer drugs present limited success with inevitable systemic toxicity. The aim of this study was to develop a new kind of theranostic carrier for targeted tumor therapy. Methods: Prior to prepare CHC-PFP-DOX, carboxymethyl-hexanoyl chitosan (CHC) was synthesized by acylation of carboxymethyl chitosan. To develop CHC-PFP, perfluoropentane (PFP), an ultrasound gas precursor, was simultaneously encapsulated into the hydrophobic inner cores of pre-formulated CHC micelle in aqueous phase via using the oil in water (O/W) emulsion method. The size distribution and surface charges of these nanodroplets were measured and the morphology was observed by transmission electron microscopy (TEM). For ultrasound imaging application, in vitro model was established to evaluate the imaging of CHC-PFP-DOX under different concentration and mechanical index. After that, the anti-tumor effect of ultrasound combined with CHC-PFPDOX on ovarian cancer cells was investigated. Results: The resulting CHC-PFP-DOX had a nano-sized particle structure, with hydrophobic anticancer DOX/PFP inner cores and a hydrophilic carboxymethyl chitosan polymer outer shell. The favorable nano-scaled size offers the potential to extravagate from veins and accumulate in tumor tissues via enhanced permeation and retention (EPR) effect. Additionally, CHC-PFP-DOX showed the ability to serve as ultrasound imaging agent at body temperature. Notably, it exhibited an ultrasound-triggered drug release profile through the external ultrasound irradiation. Further study demonstrated that ultrasound combined with CHC-PFP-DOX can improve the killing effect of chemotherapy for tumor. Conclusion: CHC-PFP-DOX holds great promise in simultaneous cancer-targeting ultrasound imaging and ultrasound- mediated delivery for cancer chemotherapy.

Preparation, Characterization and Antibacterial Activity of Quaternized Carboxymethyl Chitosan/Organic Rectorite Nanocomposites

2013 ◽  
Vol 9 (2) ◽  
pp. 278-282 ◽  
Author(s):  
Xiaoyun Li ◽  
Yang Han ◽  
Haoquan Zhong ◽  
Weijie Ye ◽  
Bo Liu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Carboxymethyl Chitosan

scholarly journals Colonocyte metabolism shapes the gut microbiota

Science ◽  
2018 ◽  
Vol 362 (6418) ◽  
pp. eaat9076 ◽  
Author(s):  
Yael Litvak ◽  
Mariana X. Byndloss ◽  
Andreas J. Bäumler
Keyword(s):  
Gut Microbiota ◽  
Anaerobic Bacteria ◽  
Enteric Pathogens ◽  
Metabolic Reprogramming ◽  
Human Diseases ◽  
Fermentation Products ◽  
Colonic Microbiota ◽  
Obligate Anaerobic ◽  
Control Switch ◽  
Facultative Anaerobic Bacteria

An imbalance in the colonic microbiota might underlie many human diseases, but the mechanisms that maintain homeostasis remain elusive. Recent insights suggest that colonocyte metabolism functions as a control switch, mediating a shift between homeostatic and dysbiotic communities. During homeostasis, colonocyte metabolism is directed toward oxidative phosphorylation, resulting in high epithelial oxygen consumption. The consequent epithelial hypoxia helps to maintain a microbial community dominated by obligate anaerobic bacteria, which provide benefit by converting fiber into fermentation products absorbed by the host. Conditions that alter the metabolism of the colonic epithelium increase epithelial oxygenation, thereby driving an expansion of facultative anaerobic bacteria, a hallmark of dysbiosis in the colon. Enteric pathogens subvert colonocyte metabolism to escape niche protection conferred by the gut microbiota. The reverse strategy, a metabolic reprogramming to restore colonocyte hypoxia, represents a promising new therapeutic approach for rebalancing the colonic microbiota in a broad spectrum of human diseases.

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