Effects of guar gum supplementation on the lipid profile: A systematic review and meta-analysis of randomized controlled trials

Background and aimsGuar gum can be used as an adjuvant in the treatment of dyslipidemia. However, based on data from different studies, the effectiveness of this product is not uniform. Therefore, we conducted a dose–response meta-analysis between guar gum supplementation and lipid profile.Methods and resultsFive databases (Scopus, Web of Science, PubMed/Medline, Embase, and Google Scholar) were searched to identify relevant articles published up to July 2020. The weighted mean difference (WMD) was derived based on the random-effects model. Overall findings were generated from 25 eligible trials. Patients’ conditions included hyperlipidemia, diabetes, metabolic syndrome, hypertension, overweight, carotid endarterectomy, and menopausal women. Prescribed gum dose varied between 100 mg/d and 30 g/d for 1–24 months. Compared with control groups, guar gum supplementation decreased total cholesterol (TC) by −20.41 mg/dL (95% CI: −26.76 to −14.07; P < 0.001) and low-density lipoprotein-cholesterol (LDL-C) by −17.37 mg/dL (95% CI: −23.60 to −11.13; P < 0.001), but did not change triglycerides (TG) (WMD: −6.53 mg/dL, 95% CI: −16.03 to 2.97; P = 0.178) and high-density lipoprotein-cholesterol (HDL-C) (WMD: −0.62 mg/dL, 95% CI: −1.68 to 0.44, P = 0.252).ConclusionsGuar gum supplementation significantly reduced serum LDL-C and TC levels in patients with cardiometabolic problems, but had neutral effects on TG and HDL-C levels.     

2种胶姆糖对菌斑pH值的影响

目的：观察咀嚼2种胶姆糖后口腔菌斑pH值的变化情况.方法：选择8例健康受试者（年龄23～27岁,男4例,女4例）参加3次试验,每次实验开始前停止刷牙24h,在使用10%的蔗糖溶液漱口前以及漱口后5、10、15、20min,用Beetrode pH微电极测量口腔菌斑的pH值,作为基线值.1周后先测量静息pH值,再用蔗糖溶液漱口,1min后给予无糖胶姆糖咀嚼,在5、10、15、20min时间点,分别测量非咀嚼侧的菌斑pH值.1周后重复上述实验,胶姆糖改为含茶多酚胶姆糖.应用SPSS10.0统计软件包对数据进行单因素方差分析和SNK分析.结果：与基线值比较,咀嚼2种胶姆糖都能有效防止由于含漱蔗糖水导致的菌斑pH值下降,并使pH值维持在静息pH值以上.2种胶姆糖之间无显著性差异（P＞0.05）.结论：咀嚼2种胶姆糖均能防止菌斑pH值下降,减少患龋危险.     

咀嚼绿茶多酚胶姆糖对唾液流率及pH值的影响

目的:探讨咀嚼绿茶多酚胶姆糖对唾液分泌及pH值的影响。方法:选取8例受试者,分别检测咀嚼绿茶多酚胶姆糖和对照胶姆糖前后不同时间唾液的流率和pH值。应用单因素方差分析和SNK法进行相关分析。结果:咀嚼2种胶姆糖3min内,唾液流率显著增加,在第1min时达到峰值,实验组和对照组分别为(3.15±1.05)ml和(3.30±0.87)ml。唾液pH值也不断上升,但是与唾液分泌的峰值并非在同一时间,2组之间无显著差异(P>0.05)。结论:咀嚼胶姆糖能促进唾液分泌,提高pH值,有益于口腔健康。     

Development of vaginal rings for sustained release of nonhormonal contraceptives and anti-HIV agents

OBJECTIVES: Construction of vaginal rings to deliver nonhormonal contraceptives and 3'-azido-3'-deoxythymidine (AZT) as an anti-HIV agent and determination of their daily release and efficacy in vitro. MATERIALS AND METHODS: Intravaginal rings of 0.5-0.7 cm rim and 5-5.5 cm in diameter were cast in the molds. The rings were composed of biosoluble acacia gum or nonbiodegradable hydrogel of 2-hydroxyethyl methacrylate (HEMA) and sodium methacrylate (SMA) [P(HEMA-co-SMA)]. The rings were impregnated with nonhormonal contraceptives such as ferrous gluconate to cause spermiostasis, l-ascorbic acid to increase the viscosity of the cervical mucus, and pharmalytes of pH 4-5 or AZT. RESULTS: The daily release rate of nonhormonal contraceptives as well as AZT from the rings was efficacious in vitro. Cumulative effect of nonhormonal contraceptives showed complete spermiostasis within 30 s up to 10 and 28 days, respectively. Daily release of AZT from both rings was also likely to be efficacious to inhibit HIV proliferation in vitro for 10 and 28 days, respectively. CONCLUSION: The data indicate that the rings described here can be developed for intravaginal delivery of nonhormonal contraceptives and/or anti-HIV agents.     

Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum

The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum; however, a context-dependent effect was not found with chewing gum. The findings contradict previous research.     

Proabsorptive Action of Gum Arabic in Isotonic Solutions Orally Administered to Rats. II. Effects on Solutes Under Normal and Secretory Conditions

Gum arabic (GA) is a natural proteoglycan with proabsorptive capacity attributable to its physico-chemical properties. Previous experiments showed that in rats oral administration of GA in an isotonic solution had a generally positive effect. This study extends the investigation to include acetaminophen and to evaluate whether GA could also act under secretory conditions induced by theophylline. Test solutions were orally administered to rats under CO2 anesthesia and blood concentrations followed for 3 hr. The secretory effects of theophylline were clearly observed for sodium and zinc. Addition of GA resulted in a more rapid rate of glutamate absorption, under normal physiologic conditions, as indicated by the higher area under the curve (AUC). There were no differences in the presence of theophylline. Acetaminophen blood concentrations peaked about 30 min after administration, and the AUC in rats that received GA was higher than in those that got the solution without GA. AUCs for total body water distribution with time and those for glucose concentrations were indistinguishable whether the solutions contained or did not contain either GA or theophylline. The results confirm that oral administration of GA can accelerate absorption of some solutes, including pharmacologic agents.     

An experimental study of Newtonian and non-Newtonian flow dynamics in an axial blood pump model

The head curves of a 1.5:1 new axial blood pump model were measured using five working fluids at five rotational speeds. The working fluids were water, a 39wt% aqueous glycerin solution (GS), and three aqueous xanthan gum solutions (XGSs) with different concentrations. The flow velocities and shear stresses in the mechanical clearance between the casing and rotor were investigated using a laser Doppler velocimeter and hot-film sensor. At every rotational speed, the experiment in which viscous GS was used in the pump model showed a head curve lower than that obtained using water, whereas the head obtained using viscoelastic XGS was higher than that generated using water. A maximum difference of 65.8% between the heads measured in the 0.06% XGS and GS experiments was detected. The higher head produced by the XGS may have originated from the drag-reduction effect of XGS viscoelasticity. The measurements showed that a reverse washout flow at a velocity of 0.05-0.11m/s occurs in the clearance. This reverse washout flow is crucial to preventing flow stagnation and accompanying thrombus formation. The wall shear stress and the Taylor number of the rotating Couette-like flow in the clearance both indicated that it is a turbulent flow.     

Thirty-nine-month xylitol chewing-gum programme in initially 8-year-old school children: a feasibility study focusing on mutans streptococci and lactobacilli

AIM: To investigate the use of xylitol-containing chewing-gums in public elementary schools as a means to affect the growth of salivary and plaque mutans streptococci and salivary lactobacilli. DESIGN: Over a period of 24 months, 750 8- to 9-year-old children chewed xylitol (X group; n = 255) or xylitol-sorbitol (XS group; n = 264) gum on school days (454 days over 2 years), or chewed no gum at all (C group; n = 231). Consumption of xylitol in the X and the XS groups was 6.6 and 5.4g per day, respectively. Use of gum took place at school in four daily episodes of which three were supervised by teachers. Following the 24-month chewing-gum period, the subjects were re-examined after 15 months (total follow-up period: 39 months) at which time an extraneous comparison group (ExC; n = 117) was also examined. The numbers of subjects examined after 39 months were: X, 239; XS, 248; C3 217. METHODS: Salivary and plaque levels of mutans streptococci and the salivary levels of aerobically cultured aciduric bacteria (mostly representing lactobacilli) were determined using the Orion Diagnostica Dentocult SM and LB test kits, respectively. RESULTS: There were statistically significant differences after 24 and 39 months between the two xylitol chewing-gum groups and the C group with regard to salivary and plaque mutans streptococci and salivary lactobacilli: the use of xylitol-containing chewing-gums significantly reduced these bacterial scores. The reductions were statistically more significant in the X group than in the XS group. The bacterial scores of groups C and ExC were similar. CONCLUSIONS: Long-term use of xylitol-containing chewing-gum can reduce the growth of mutans streptococci in saliva and dental plaque, and lactobacilli-type bacteria in saliva, even if xylitol is used only on school days. The results also suggest that xylitol gum use can have a long-term, delayed growth-retarding effect on these micro-organisms, since reduced bacterial growth was still observed 15 months following the termination of xylitol use. The results indicate a close biochemical relationship between xylitol and mutans streptococci, and suggest that a similar relationship may exist regarding aerobically cultured aciduric bacteria present in saliva.     

The safety of gum arabic as a food additive and its Energy Value as an ingredient: a brief review

Gum arabic, the natural exudate from Acacia senegal (L.) Willd., has enjoyed the toxicological status 'ADI not specified' for use in minor proportions as a food additive (E414 in the EEC) since 1982, but it is also used as a major ingredient. Manufacturers may therefore be required to make labelling declarations of its Energy Value and of available/non-available carbohydrate. Although gum arabic complies with the definition for soluble dietary fibre, its Energy Value was accepted by the FAO/WHO International Programme of Food Safety to be 4 kcal/gram on the basis of the evidence available in 1982. Subsequently a French claim for a much lower value attracted the attention of manufacturers of low calorie products but a recent precise experiment establishes that the Digestible Energy Value is 3.5 ± 0.12 kilocalories per gram. The physiological mechanism whereby this value arieses is outlined. The more general dietary implications for other complex carbohydrates which conform to the definition for soluble dietary fibre and yet suffer complete degradation in the large bowel are indicated.     

Hypocholesterolemic effect of gum acacia in men

Fifteen grams of gum acacia administered twice daily to seven hypocholesterolemic subjects for 30 days, reduced their serum cholesterol by approximately 10.4% but had little effect on HDL cholesterol and triglycerides, LDL+VLDL cholesterol was decreased significantly (p<0.05).