| Aging is a physiological phenomenon caused by gene, environment and diets that changes during the body function declines. Many factors contribute to aging, such as free radical theory, telomere theory and mitochondrial DNA damnification. Especially free radical theory focus on that cytomembrane, nucleic acid, protein and other enzymes are damages caused free radical accumulation damage. Aging mechanism is radically divided into two categories, spontaneous aging and passive aging. The former focused on the aging process controlled by gene, and the latter preferred to that negative substances accumulation in vivo accelerated the ageing process, such as reactive oxygen species and inflammation.Recently, scientists pointed out that balance of intestinal flora influce health and disease development, for example obesity, hypertension, irritable bowel syndrome and other diseases. The commensal bacterium changes along with aging process and it has a different compositing in the older and the younger. The gastrointestinal microbiota can also influence active of centre nervous system. The’gut-brain axis’was the concept based on that. The gastrointestinal microbiota was related with nervous system in aging process. The healthy gut flora has can delay aging of animals by reducing inflammation and promoting health which provides a new ideal for disease curing.Probiotics could selectively stimulate one or many species probiotics and be good for health. Specific Prebiotic (SP) using in this study consisted of dietary fiber and polysaccharides from plant. Our research focus on evaluating anti-aging effects of probiotics via interaction with gut flora. SP also increases thermos tolerance ability of worms. We also research on the indigenous populations of the microbial community in worms by high throughput sequencing technology and qPCR. Results are as following.SP delayed aging process in N2 wild type C. elegansObjective:To identify lifespan proving effects of probiotics in worms and evaluated the correlation index.Methods:SP were added to standard NGM of N2 wild type and the total lifespan were evaluated. The variation of lifespan, egg production rate and bending frequency were evaluated to choose the optimal concentratioin.Results:The maximum lifespan and bending frequency of three strains significantly increased in condition of SP(10g/L) feeding while egg production has no difference.Conclusions:SP delayed aging and increased bending frequency in C.elegans but did not affect egg production.The mechanism of SP delaying aging in C.elegansObjective:To analyze the anti-aging mechanisms of SP in worms, changes of gut flora components in SP feeding worms and the stress resistance of worms in thermo condition. To analys lifespan and intestinal tract flora in worms fed on Acinetobacter johnsonii and the effectiveness of SP on OP50.Methods:Making survival curves of two mutation strains of daf-16 and daf-2 in OP50 group and SP plus OP50 group. To Analyze intestinal tract flora in C. elegans by 16S rDNA. Analyze death rate of worms in 35℃ condition,12 hours. Observe expression level of fluorescence in hspl6.2::GFP in ransgenosis worms after 35℃ heat shock for 2 hours. Study proliferation rates of OP50 with or without SP in LB medium and analyse different protein expression using SDS-page and protein profiling.Results:SP can significantly delayed aging in daf-16 and daf-2 mutation with 50% and 47.1% respectively. Moraxellaceae was the prominent bacteria in the gut of N2, daf-2, daf-16 strains with abundances of 93.6%,80.8%,80.0%. The abundances of Enterobacteriaceae were 4.4%,18.8%,13.9% which were much lower than Moraxellaceae. The profiles of intestinal flora abundances in SP added OP50 groups were opposite to control groups. Enterobacteriaceae was the prominent bacteria with the abundances were 93.3%,87.8%,95.2% in three strains. Moraxellaceae abundances were 0.95%,0.96%,0.73% respectively in three strains. The survival rates of N2 were 76% in SP group and 10% in control group after 35℃ heat stress for 12 hours. The GFP fluorescence of hsp-16.2::GFP in SP group were highter than ctrol group. SP could accelerated proliferation rate of OP50. It suggest that aging in C. elegans was likely not due to diet restriction.Conclusions:SP delayed aging process significantly in daf-16 and daf-2. SP influenced abundance of Moraxellaceae low and promoted Enterobacteriaceae proliferating. SP also improved survival ability of worms in heat shock condition and accelerated proliferation ofE. coli.Quantitative analysis of intestinal bacteria in C. elegans using qPCRObjective:To establish a method for detecting intestinal bacterial in Caenorhabditis elegans.Methods:the gut flora number of 1,20, or 50 worms was quantified and compared using Real-time Quantitative PCR (qPCR).Results:The gut flora of a single C. elegans could be detected using qPCR method, which could also reflect the differences in the number of gut bacteria between different samples.Conclusions:The qPCR method can be uased to accurately quantify intestinal bacteria even in only one C. elegans and has the advantages of low-cost, high-sensitivity and good-specificity. |
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