赤藓糖醇对变异链球菌产酸作用影响的研究

目的研究赤藓糖醇对变异链球菌产酸作用的影响,为赤藓糖醇的防龋应用提供依据。方法观察变异链球菌分别在质量分数1%、2%、4%、8%的赤藓糖醇、木糖醇和蔗糖胰蛋白胨-多价蛋白-酵母提取物（tryptone-polypeptone-yeast extract,TPY）液体培养基中培养24 h后pH值的变化;测定在以上浓度条件下,体外菌斑糖酵解模型产酸液的pH值变化。结果浓度为2%（q=5.63）、4%（q=4.12）、8%（q=5.77）时,变异链球菌在赤藓糖醇中pH值变化均小于蔗糖组,且差异均有统计学意义（P〈0.05）;浓度为8%时,赤藓糖醇组的pH值变化较木糖醇组小,具有统计学意义（q=6.53,P〈0.05）;浓度为2%（q=6.73）、4%（q=6.11）、8%（q=6.98）时,赤藓糖醇对体外菌斑糖酵解模型的产酸pH值大于蔗糖组,具有统计学意义（P〈0.05）;浓度为2%（q=5.46）、4%（q=6.49）、8%（q=6.01）时,赤藓糖醇对体外菌斑糖酵解模型的产酸pH值小于木糖醇组,差异有统计学意义（P〈0.05）。结论一定浓度的赤藓糖醇对变异链球菌产酸代谢和体外菌斑糖酵解模型产酸代谢具有较明显的抑制作用。     

赤藓糖醇和木糖醇对变异链球菌黏附的影响

目的对比赤藓糖醇和木糖醇对变异链球菌黏附的影响。方法变异链球菌分别在阴性对照组以及含质量分数2％、4％、6％、8％赤藓糖醇和木糖醇的TPY液体培养基试管内厌氧培养24h,用磷酸缓冲盐溶液（PBS）冲洗含变异链球菌生物膜的试管3次,加入PBS超声震荡。分别收集各组原液并将其稀释至10％,各取50μL分别接种于TPY固体培养基中,厌氧培养48h,行平皿菌落计数并绘制变异链球菌集落生成单位（CFU）计数曲线图。结果赤藓糖醇组和木糖醇组的变异链球菌CFU计数低于阴性对照组,且差异有统计学意义;随着赤藓糖醇和木糖醇质量分数的增加,变异链球菌的CFU计数逐渐降低,且差异有统计学意义。在同一质量分数下,木糖醇组变异链球菌的CFU计数少于赤藓糖醇组。在质量分数为2％和4％时,组间差异无统计学意义;在质量分数为6％和8％时,组间差异有统计学意义。结论赤藓糖醇和木糖醇对变异链球菌的黏附有抑制作用,随其质量分数的增加,抑制效果增强。在质量分数为2％和4％时,赤藓糖醇和木糖醇对变异链球菌黏附的抑制作用没有明显的差异,在质量分数为6％和8％时,木糖醇对变异链球菌黏附抑制效果优于赤藓糖醇。     

赤藓糖醇抑制变异链球菌在牛奶中产酸的实验研究

目的:比较变异链球菌在不同浓度赤藓糖醇-牛奶混合液中的产酸情况.方法:配制含赤藓糖醇质量分数为2％、4％、6％、8％的赤藓糖醇-牛奶混合液,设纯牛奶作为阴性对照,磷酸盐缓冲液作为空白对照,各组溶液经灭菌处理,并经涂板检验无细菌生长后,分别接种变异链球菌菌悬液厌氧培养;培养0、2、4、6、8、10、12h测量各组溶液的pH值,数据用SPSS16.0统计软件进行重复测量设计方差分析.结果:培养0～4h各组的pH值均急速下降;6h以后,阴性组和空白组的pH值仍继续下降,而4个浓度赤藓糖醇—牛奶组的pH值变化微小.各时间点的pH值均以空白对照组最高,阴性对照组最低.培养2h时阴性对照组pH值低于8％赤藓糖醇—牛奶组(P ＜0.05);4 h后各时间点均低于赤藓糖醇—牛奶各浓度组(P＜0.05).不同浓度赤藓糖醇—牛奶组相比,4h前各组间均无统计学差异(P＞0.05);6h后各时间点,除6％与8％组相比无统计学差异(P＞0.05)外,其他各组间差异均有统计学意义(P＜0.05).结论:赤藓糖醇能够有效抑制变异链球菌在牛奶中产酸,且高浓度较低浓度效果更强.     

赤藓糖醇对变异链球菌作用机制的实验研究

目的研究赤藓糖醇对变异链球菌细胞壁结构的影响,探讨其抑制变异链球菌生长的机制。方法测定在蔗糖和赤藓糖醇条件下变异链球菌所在的液体培养基中乳酸脱氢酶（LDH）的活性;在扫描电镜下观察变异链球菌表面的形态变化,了解赤藓糖醇对变异链球菌细胞壁的影响。结果在赤藓糖醇组中,变异链球菌所在的液体培养基内LDH的含量和蔗糖组有差别,但差别甚微。扫描电镜显示：在赤藓糖醇组中,变异链球菌的表面形态清晰,没有内容物溢出的迹象。结论赤藓糖醇可能不是通过影响细胞壁结构和功能的完整性而抑制变异链球菌的。     

低聚木糖对变异链球菌生长和产酸影响的体外研究

目的　比较低聚木糖与蔗糖对变异链球菌生长和产酸的影响,为低聚木糖在牙齿保健中的应用提供理论依据。方法　分别采用质量浓度为0、1%、2%、8%、16%和20%的低聚木糖和蔗糖培养基培养变异链球菌24 h,通过Bioscreen C全自动微生物生长曲线分析仪每间隔30 min测定各组培养基的吸光度值（A值）;采用pH计分别于0、5.5、10、24 h测定各组培养基的pH值,运用Origin 2017描绘其变化曲线图。比较变异链球菌培养和发酵前后各组A值及pH值的变化量（ΔA和ΔpH）。结果　（1）低聚木糖组和蔗糖组细菌培养基的ΔA均随着培养时间的延长而增大（F值分别为467.165、3207.610,P < 0.05）;低聚木糖组和蔗糖组不同质量浓度培养基的ΔA比较,差异均有统计学意义（F值分别为11682.528、5483.421,P < 0.05）;且这种差异随着培养时间的延长而增大（F值分别为88.140、41.171,P < 0.05）。（2）变异链球菌培养和发酵24 h后,低质量浓度（1%、2%）低聚木糖在略微或不提高变异链球菌生长水平的同时（P > 0.05）,明显抑制了变异链球菌的产酸能力（P < 0.05）;高质量浓度（16%、20%）低聚木糖在明显抑制变异链球菌生长的同时,变异链球菌的产酸水平略有提升（均P < 0.05）。（3）变异链球菌培养和发酵24 h后,与同质量浓度的蔗糖相比,16%、20%的低聚木糖可明显降低变异链球菌的生长水平（P < 0.05）;1%、2%的低聚木糖细菌培养基的ΔA略高,但差异无统计学意义（P > 0.05）;8%的低聚木糖可提高变异链球菌的生长水平（P < 0.05）;各质量浓度低聚木糖细菌培养基的ΔpH均高于相同质量浓度的蔗糖（均P < 0.05）。（4）与同甜度的蔗糖（质量浓度为8%）比较,低聚木糖（质量浓度为20%）抑制变异链球菌的生长及产酸作用更显著。结论　低质量浓度低聚木糖可抑制变异链球菌产酸,高质量浓度低聚木糖可抑制变异链球菌生长;相较于蔗糖,高质量浓度低聚木糖可降低变异链球菌的生长及产酸水平,提示低聚木糖作为龋病易感人群的食品甜味剂具有良好的应用前景。     

异麦芽酮糖醇对变形链球菌生长、黏附和产酸影响的研究

目的研究异麦芽酮糖醇对变形链球菌致龋因素的影响,探讨其作用机制,为进一步的动物和人体研究提供科学依据。方法以异麦芽酮糖醇为实验组,蔗糖、木糖醇为对照组,观察异麦芽酮糖醇、蔗糖和木糖醇对变形链球菌的生长、黏附及菌液pH值的影响。结果变链在一定浓度的异麦芽酮糖醇与木糖醇培养基上生长数量均受到抑制,与蔗糖相比有显著性差异(P<0.001);其形态也有明显变化。变链在不同浓度的异麦芽酮糖醇、木糖醇培养基中黏附于附着板的数量与蔗糖有明显差异(P<0.001)。变链在不同浓度的异麦芽酮糖醇、木糖醇培养基中所测得的pH值均高于蔗糖培养基(P<0.001)。结论异麦芽酮糖醇与蔗糖相比,其作用与木糖醇相似,可以使变链形态改变、数量减少、黏附和产酸能力均减弱。     

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目的研究麦芽糖醇对变形链球菌生长和产酸的影响。方法用含2.5%麦芽糖醇（麦芽糖醇组）、木糖醇（木糖醇组）、蔗糖（蔗糖组,作为阳性对照）的TYE液体培养基以及空白TYE液体培养基（阴性对照组）,厌氧条件下培养变形链球菌,测定在不同时间段各液体培养基的光密度（OD）值和pH值。实验结果采用SPSS13.0统计软件进行数据的输入和分析。结果变形链球菌在麦芽糖醇、木糖醇和空白TYE液体培养基内的生长和产酸受到抑制,而在蔗糖组的生长和产酸非常显著。结论麦芽糖醇可以抑制变形链球菌的生长和产酸,可作为一种理想的防龋甜味剂。     

木糖醇对黏性放线菌生长及产酸影响的体外研究

目的对比不同质量浓度下木糖醇对黏性放线菌生长及产酸的影响。方法分别用含不同质量浓度（128、64、32、16、8、4 g·L^-1）木糖醇的脑心浸液（BHI）液体培养基在厌氧条件下培养黏性放线菌,测定其最小抑菌质量浓度（MIC）;然后测量对照组以及1/2、1/4、1/8 MIC和MIC质量浓度时培养1.5、3、6、12、24、48 h液体培养基的pH值,计算ΔpH值,同时测量2、4、6、8、10、12 h液体培养基的光密度（OD550）值;最后测定抑制50%及 90%黏性放线菌生物膜形成的最低木糖醇质量浓度（即MBIC50和MBIC90）。运用SPSS 19.0进行数据分析。结果木糖醇能抑制黏性放线菌的生长,MIC为64 g·L^-1。培养12 h后,各组之间的ΔpH值差异均有统计学意义（P<0.05）,且ΔpH值随MIC质量浓度的增大而减小;此时,除1/2 MIC以及MIC组之外,其余各组的OD550差异均无统计学意义（P>0.05）,OD550值随MIC质量浓度的增加而减小。提示黏性放线菌在含1/2 MIC及MIC的木糖醇培养基里生长及产酸能力随木糖醇质量浓度的升高而下降。木糖醇的MIBC50为64 g·L^-1,MIBC90为128 g·L^-1,说明木糖醇培养基能抑制黏性放线菌生物膜的形成。结论木糖醇能有效地抑制黏性放线菌的生长、黏附以及产酸,有一定的抑制致龋菌和防治龋病的效果。     

异麦芽酮糖醇对变形链球菌乳酸产物及pH值影响的研究

目的 观察异麦芽酮糖醇对变形链球菌产乳酸能力及菌液pH值的影响,为异麦芽酮糖醇在防龋的应用提供实验依据.方法 以异麦芽酮糖醇为实验组,蔗糖、木糖醇为对照组,观察异麦芽酮糖醇、蔗糖、木糖醇对变形链球菌菌液pH值的影响,并利用酶法乳酸试剂盒检测其乳酸产生量的变化.结果 变形链球菌与异麦芽酮糖醇、蔗糖、木糖醇作用后产生的是L-乳酸(左旋乳酸).异麦芽酮糖醇和木糖醇组所产乳酸量和酸度均低于蔗糖组,但异麦芽酮糖醇高于木糖醇组,经两两比较三组所产L-乳酸含量各组之间差异均具有显著性.其菌液pH值之间也具有显著性差异.结论 在异麦芽酮糖醇作用下,变形链球菌所产乳酸量和酸度低于蔗糖.因此,异麦芽酮糖醇是一种低致龋性的糖替代品.     

两种糖对变异链球菌产酸能力影响的比较研究

目的:通过测量变异链菌代谢高果糖玉米糖浆(high-fructose corn syrup,HFCS)和蔗糖后△pH值的变化,比较两种糖对变异链球菌产酸能力的影响。方法:配制质量浓度为0.25%、0.5%、1%、3%和5%的高果糖玉米糖浆和蔗糖培养基,将变异链球菌UA159于上述各培养基37℃微需氧培养,分别于培养1、4、8、24、48 h各个时间点,用酸度计测量培养前后的pH值,计算ΔpH值,代表变异链球菌的产酸能力。结果:在本研究设定的糖浓度范围和培养时间段内,高果糖玉米糖浆(HFCS)和蔗糖培养基中的ΔpH值均随时间的延长而增大,在培养4～8 h内,HFCS培养基内pH值下降速度快于蔗糖培养基。在培养4、8、24 h时,5种浓度的HFCS培养基中ΔpH值均明显大于蔗糖培养基,差异均有统计学意义(P<0.05),而在培养1 h和48 h时,两种糖培养基中ΔpH值的变化无统计学意义(P>0.05)。结论:在培养4～8 h内,HFCS利于变异链球菌代谢产酸,而在24～48 h内,蔗糖则显示出较强的持续产酸能力。     

Non-cariogenicity of erythritol as a substrate

Erythritol is a sugar alcohol which is obtained through a cultivation of glucose and Aureobasidium sp. The sugar is about 70-80% as sweet as sucrose and is also non-hygroscopic. The effect of erythritol on cariogenicities of mutans streptococci (serotype a-h) and certain oral microorganisms was studies. Erythritol was not utilized as a substrate for the growth, lactic acid production and plaque formation of mutans streptococci (serotype a-h). It did not serve as a substrate for cellular aggregation of mutants streptococci (serotype d, g, h) and was not utilized water-insoluble glucan synthesis and cellular adherence by glucosyltransferase from S. mutans PS-14 (c) or S. sorbrinus 6715 (g). Erythritol was not also utilized for the growth and lactic acid production of certain oral microorganisms although some growth was seen with Actinomyces viscosus. SPF SD rats infected with S. sobrinus 6715 were fed a diet containing 26% erythritol or 26% sucrose for 53 days. A significantly (p less than 0.01) lower caries score (mean +/- SE; 3.1 +/- 0.5) was observed in the rat fed a diet containing erythritol than the control (60.5 +/- 2.0). The caries inhibition rate is 94.9%. Also, rats infected with S. mutans PS-14 were fed a diet containing 56% erythritol chocolate or 56% sucrose chocolate for 58 days. The mean total caries score of rats fed a diet containing 56% erythritol chocolate was 6.7 +/- 0.8, while the mean total caries score of rats fed a diet containing 56% sucrose chocolate was 82.8 +/- 2.8. The value between both groups was significant at 0.01 level, and the caries inhibition rate is 91.9%.     

Xylitol inhibition of acid production and growth of mutans Streptococci in the presence of various dietary sugars under strictly anaerobic conditions

The aim of this study was to investigate the inhibitory effect of xylitol on the growth of and acid production by mutans streptococci in the presence of various dietary sugars, and the relationship between the inhibition and the accumulation of xylitol 5-phosphate (X5P) under strictly anaerobic conditions like those in the deep layers of dental plaque. Xylitol retarded the growth of mutans streptococci in the presence of glucose (G), galactose (Gal), maltose (M), lactose (L) or sucrose (S) as an energy source, though the inhibition of growth on fructose (Fr) was small. Xylitol inhibited acid production by washed cells of Streptococci mutans from G, Gal, M, L or S (12-83% inhibition). S. mutans accumulated X5P intracellularly through activity of the phosphoenolpyruvate-xylitol phosphotransferase system (PEP-xylitol PTS) when they fermented these sugars in the presence of xylitol. However, in the presence of Fr, no inhibition of acid production was observed. In addition, the amounts of X5P during the fermentation of Fr were smaller than those of other sugars in spite of the presence of PEP-xylitol PTS activity. These results suggest that along with the intracellular accumulation of X5P, xylitol decreases the growth and acid production of mutans streptococci in the presence of various dietary sugars except Fr.     

The effect of polyol-combinant saliva stimulants on S. mutans levels in plaque and saliva of patients with mental retardation

The effect of chewable saliva-stimulants on Streptococcus mutans levels in dental plaque and paraffin-stimulated whole saliva among participants who were mentally disabled was investigated. Over 64-days, 98 participants chewed one of four saliva-stimulating tablets five times/day. The tablets contained one of the following: xylitol (X) or sorbitol (S), or 1:1 mixtures of xylitol and erythritol (XE) or sorbitol and erythritol (SE). Consumption of xylitol and sorbitol in Groups X and S was 5.4 grams/day/ subject, and of each polyol in Groups XE and SE, consumption was 2.7 g/day/subject. Interproximal dental plaque and stimulated whole saliva were sampled at baseline, at Day 36, and Day 64. There was a statistically significant reduction of S. mutans in plaque and saliva counts in Groups X and XE. The percentage of S. mutans in total streptococci increased significantly in dental plaque in Group S but decreased in the other groups. The results suggest that xylitol-containing saliva stimulants may be more effective than sorbitol-containing products in controlling some caries-associated parameters in people who are mentally disabled. Also a relationship may exist between the pentitol-type xylitol and S. mutans , and erythritol may exert a specific biochemical effect on this organism, although further studies are needed.     

壳寡聚糖抑制变形链球菌的致龋能力

目的研究壳寡聚糖(chitooligosaccharide,COS)对变形链球菌生长、产酸及粘附能力的影响。方法选用变形链球菌标准株ATCC 25175,采用对倍稀释法测定COS对变形链球菌的最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC);采用菌落计数法,通过时间—杀菌曲线的变化,分析COS对细菌生长速度的影响;将COS及变形链球菌菌悬液各1 m L接种于无菌试管内厌氧培养,使COS的终浓度分别达到1/2 MIC、1/4 MIC、1/8MIC,测定上清液p H变化并绘制p H曲线;采用液体闪烁计数法测定壳寡聚糖对变形链球菌粘附羟磷灰石能力的影响。结果 COS对变形链球菌的MIC和MBC分别为2.00 g/L和4.00 g/L;COS能有效抑制变形链球菌的生长,较高浓度时对细菌还具有杀菌作用。亚抑菌浓度的COS可显著影响变形链球菌的产酸性和粘附能力,并且这种抑制作用呈浓度依赖性。结论 COS对变形链球菌的生长、产酸和粘附能力均有抑制作用。     

Effect of three-year consumption of erythritol,xylitol and sorbitol candies on various plaque and salivary caries-related variables

Objective

The objective of the present paper is to report results from oral biologic studies carried out in connection with a caries study.

Methods

Samples of whole-mouth saliva and dental plaque were collected from initially 7- to 8-year-old subjects who participated in a 3-year school-based programme investigating the effect of the consumption of polyol-containing candies on caries rates. The subjects were randomized in three cohorts, consumed erythritol, xylitol, or sorbitol candies. The daily polyol consumption from the candies was approximately 7.5 g.

Results

A significant reduction in dental plaque weight from baseline (p < 0.05) occurred in the erythritol group during almost all intervention years while no changes were found in xylitol and sorbitol groups. Usage of polyol candies had no significant or consistent effect on the levels of plaque protein, glucose, glycerol, or calcium, determined yearly in connection with caries examinations. After three years, the plaque of erythritol-receiving subjects contained significantly (p < 0.05) lower levels of acetic acid and propionic acid than that of subjects receiving xylitol or sorbitol. Lactic acid levels partly followed the same pattern. The consumption of erythritol was generally associated with significantly (p < 0.05) lower counts of salivary and plaque mutans streptococci compared with the other groups. There was no change in salivary Lactobacillus levels.

Conclusion

Three-year consumption of erythritol-containing candies by initially 7- to 8-year old children was associated with reduced plaque growth, lower levels of plaque acetic acid and propionic acid, and reduced oral counts of mutans streptococci compared with the consumption of xylitol or sorbitol candies.     

Xylitol inhibition of anaerobic acid production by Streptococcus mutans at various pH levels

Xylitol inhibits the glycolysis and growth of Streptococcus mutans. We studied the inhibitory effect of xylitol on the acid production of S. mutans at several pH levels under the strictly anaerobic conditions found in the deep layer of dental plaque. Xylitol inhibited the rate of acid production from glucose and changed the profile of acidic end products to formate-acetate dominance, with a decrease in the intracellular level of fructose 1,6-bisphosphate and an intracellular accumulation of xylitol 5-phosphate (X5P). These results were notable at pH 5.5-7.0, but were not evident at pH 5.0. Since the activity of phosphoenolpyruvate phosphotransferase for xylitol was greater at higher pH, it is suggested that xylitol could be incorporated more efficiently at higher pH and that the resultant accumulation of X5P could inhibit the glycolysis of S. mutans more effectively.