1,590 research outputs found
Dissection of the key intestinal microbiota in residents of Pemba Island in Tanzania and use of Bifidobacterium breve in prevention against colitis in mice.
Pemba Island is located on the eastern coast of Tanzania and is one part of the
Zanzibar Islands. The climate on the island is mild, and the temperature is kept between
24°C and 28°C throughout the year. Therefore, the residents on the island plant plenty
bananas and feed on them. In addition, the residents of the island consume large
amounts of vegetables and fruits, mainly cassava, rice and corn as their staple food, and
fish as the main source of animal food. The parasitic diseases in Africa are highly
prevalent, which seriously endangers the quality of life of the African people. The
prevalence of soil-borne helminthiasis on Pemba Island is relatively high. The research
center Public Health Laboratory Ivo de Carneri (PHL-IdC) hosts researchers from many
countries on Pemba Island to carry out scientific research. The field part of the
investigation reported in this thesis was conducted with the support of the PHL-IdC.
At present, there are very few studies on the dietary structure of African island
residents. Most of the research are carried out on the dietary structure of Western
countries, such as the Mediterranean diet and the typical Western diet. In this study, a
total of 32 pairs (64) of mother and child volunteers on Pemba Island with similar diets
were recruited in three different villages on the Island. First, we used the Food
Frequency Questionnaire (FFQ) to analyze the dietary structure and food composition
of women and their children. At the same time, we used 16S rDNA high-throughput
sequencing technology to study the intestinal flora of the volunteers. Heat maps were
utilized to show the correlation between gut microbiota and diet structure, gut
microbiota and nutrient intake. We found that Pemba women and children’s diets were
characterized by high carbohydrate and high dietary fiber intake, low protein and low fat intake. Supply ratios of carbohydrate, fat and protein were out of balance; The
percentage of carbohydrates supply was too high, the percentage of fat supply was too
low. There was a significant positive correlation between the abundance of
Faecalibacterium and the intake of Cu, and a negative correlation between
Faecalibacterium and the intake of fat in the intestine of healthy Pemba women. There
was a significant positive correlation between Bacteroides and Se, and a significant
negative correlation between Bacteroides and Cu in the intestine of healthy Pemba
children (Chapter 2).
Secondly, we used the gut microbiota of healthy Spanish women and Australian
children as reference to analyze the similarities and differences in the structure and
function of the core intestinal microbiota of healthy women and children from Pemba
Island. We found that Firmicutes and Bacteroidetes were the dominant phyla in the gut
microbiota of Pemba women and children, moreover, Prevotella was the dominant
genus. The structure of the gut microbiota in healthy Pemba women was significantly
different from that of Spanish women, and the structure of the gut microbiota of Pemba
children was also significantly different from the Australian children; PICRUST
prediction analysis revealed that the metabolic pathways "Lipid metabolism" and
"Nucleotide metabolism" showed significantly higher abundance in women and
children from Pemba Island, compared with Spanish women and Australian children
respectively (Chapter 3).
Then, based on the results of the Mini-Flotac parasitological examination, we
divided all volunteers of Pemba Island into four groups, healthy women group,
whipworm-infected women group, healthy children group, whipworm-infected
children group, and used bioinformatics technology to analyze the association between
the intestinal microbiota and whipworm infection. We found that, compared with
healthy women and children, the diversity of the gut microbiota of whipworm-infected
women and children were higher, especially in the microbiota of the infected women,
the alpha diversity and beta diversity of infected women were significantly increased.
Short-chain fatty acid-producing bacteria such as Blautia and Bacteroides showed decreased level in whipworm-infected children, and short-chain fatty acid-producing
bacteria such as Prevotella 2, Prevotella 9 and Ruminococcaceae UCG-005 showed
decreased level in whipworm-infected women volunteers. Opportunistic pathogens
such as Enterococcus showed increased level in whipworm-infected children, and
Campylobacter showed elevated level in whipworm-infected women; the abundance of
Bifidobacterium exerted decreased amount in the gut of healthy women and children
with respect to the infected counterpart. Notably, in the healthy women’s gut, the
abundance of Bifidobacterium presented a significantly reduced level (Chapter 4).
Finally, we speculated that Bifidobacterium may have the potential to regulate IBD.
Therefore, in the last chapter, we used Bifidobacterium breve to intervene in the mouse
IBD model to explore the potential immune regulation of B. breve. We found that low
concentration of B. breve could reduce the DAI index of DSS-induced mouse colitis,
reduce colon shortening and slice pathological damage, and exert preventive roles. B.
breve could promote the secretion of anti-inflammatory cytokines and inhibit the
expression of pro-inflammatory cytokines in serum, at the same time, it could increase
the number of CD4+CD25+Foxp3+ Treg cells, and inhibit the number of CD3+CD4+
IL-
17+Tcells in mesenteric lymph nodes, to reduce intestinal injury. Low-concentration B.
breve intervention could also improve the composition of the gut microbiota, reduce
the loss of short-chain fatty acid-producing bacteria, reduce the production of pro-
inflammatory bacteria, reshape the intestinal microecology and reduce intestinal
inflammation (Chapter 5)
Third Person Effect and Internet Privacy Risks
The current study tests the third-person effect (TPE) in the context of Internet privacy. TPE refers to the phenomenon that people tend to perceive greater media effects on others than on themselves. The behavioral component of TPE holds that the self-others perceptual gap is positively associated with support for restricting harmful media messages. Using a sample (N=613) from Amazon Mturk, the current research documented firm support for the perceptual and behavioral components of TPE in the context of Internet privacy. Moreover, social distance, perceived Internet privacy knowledge, negative online privacy experiences, and Internet use were found to be significant predictors of the TPE perceptions of Internet privacy risks. There are four novel contributions of the current study. First, this study systematically tests TPE in a new context―Internet privacy. Second, this study examines five antecedents of TPE perceptions, of which perceived Internet privacy knowledge, negative online privacy experiences, and Internet use are novel to TPE studies. Unlike prior studies which assume social distance and desirability of media content, the current study provides direct empirical tests of these two antecedents. Third, prior research primarily examines support for censorship of harmful media messages, a context in which individuals do not have control over policy enforcement. In the case of Internet privacy, people can decide whether to adopt privacy protective measures or not. The current study addresses two types of behavioral intentions to reduce privacy risks: (1) the willingness to adopt online privacy protection measures; and (2) recommend such measures to others. Fourth, unlike prior studies using fear based theories to investigate Internet privacy issues, the current tests Internet privacy from a novel perspective—TPE theory
The Formation and Analysis of the Concept of Tea Horse Ancient Road
Announcement of Retractio
Effect of total flavonoids of Cuscuta chinensis Lam. (Convolvulaceae) on oxidative stress injury in mouse testis and epididymis, and on serum levels of reproductive hormones in oligoasthenospermia mice model
Purpose: To investigate the effect of total flavonoids of Cuscuta chinensis (TFCC) on oxidative stress injury in testis and epididymis, and serum levels of reproductive hormones in an oligoasthenospermia (OAS) mice model.
Methods: Thirty male Wistar mice were randomly assigned to three groups of 10 mice each: control group, OAS group and TFCC group. With the exception of control group, OAS was orally induced in the mice with ornidazole. The TFCC group received TFCC. Reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were also measured.
Results: The levels of ROS and MDA in the testis and epididymis significantly increased in OAS group, when compared to control mice (p < 0.05). However, TFCC administration significantly reduced their levels in these tissues (p < 0.05). In contrast, SOD activity significantly decreased in the testis and epididymis of mice in OAS group, relative to control group, but increased significantly after TFCC exposure (p < 0.05). Serum FSH and LH were markedly elevated in OAS group, but treatment with TFCC significantly reduced the levels of these hormones (p < 0.05).
Conclusion: These results suggest that TFCC effectively improves sperm quality and reduces oxidative damage in testis and epididymis of mice with oligoasthenospermia via a mechanism involving the regulation of serum levels of reproductive hormones. Thus, TFCC may be useful in the treatment of oligoasthenospermia
- …