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Beta 1,3/1,6 glucan decreases upper respiratory tract infection symptoms and improves psychological well-being in moderate to highly-stressed subjects
Abstract
A randomized, placebo-controlled, double blind design study was conducted to evaluate the effect of beta-1,3/1,6 glucan derived from bakers yeast, a commercially available dietary supplement, on symptoms associated with upper-respiratory tract infections and psychological well-being. Moderate to highly stressed subjects (45 men, 105 women) ranging in age from 18-65 (mean age: 39 +/- 11 years) were administered placebo, 250 mg, or 500 mg beta-1,3/1,6 glucan during a 4 week treatment period. Subjects in both treatment groups (250 mg and 500 mg beta-1,3/1,6 glucan per day) reported fewer upper respiratory tract infection symptoms, better overall health and increased vigour, and decreased tension, fatigue, and confusion based on the profile of mood states assessment.
... This effect was predominantly demonstrated through the reduction of incidence and symptoms of common cold, flu and upper respiratory tract infections (RTIs) in general, as observed in subjects with or without chronic respiratory problems (Table 1). In trial participants with a history of recurring RTIs, the positive effects on the immune response to RTIs during beta-glucan supplementation included the reduced number, 19 severity [19][20][21][22] and duration 23 of symptomatic common cold infections. Additionally, supplementation reduced sleeping difficulties caused by the cold episode 19 and improved the ability to "breathe easily". ...
... 26 There were also reports of better overall wellbeing. 21,22 Even though there is some dispersed evidence of similar incidence 23,26 and severity 20,24 of RTIs among the outcomes of trials that used yeast-derived beta-glucans, the positive effect of mushroom-derived beta-glucans in general on the body's potential to defend against invading pathogens is supported by the majority of the retrieved studies at the clinical level. In contrast, the results appear to be incoherent at the molecular and cellular levels. ...
... 41 Consistent with these results were the outcomes of trials studying the effect of the same beta-glucan supplement on moderately to highly stressed subjects for one and three months, and showed similar changes in psychological and emotional factors. 21,22 In addition, people with a history of RTIs who received betaglucan supplements for four months, reported a significant increase in the joy subscore of the Perceived Stress Questionnaire (PSQ20). 20 In terms of anti-viral defense, HSV-1 (herpes labialis virus) positive patients who received beta-glucan derived from P. ostreatus reported a significantly shorter duration of herpes simplex symptoms 48 (Table 2). ...
Introduction:
Beta-glucans are polysaccharides that exhibit a wide range of biological properties as a result of their varying chemical composition. Like all dietary fibers, they avoid catabolism in the upper gastrointestinal tract, and they reach the large intestine undigested. There, they undergo fermentation by the gut microbiota, a process that has potential beneficial effects for the host. The aim of this systematic review is to assess the effects of consumption of beta-(1 → 3,1 → 6)-d-glucans, naturally found in the cell walls of fungi, on health outcomes.
Methods:
A comprehensive literature search was performed on PubMed, Cochrane Library and Web of Science to retrieve studies that applied randomized controlled trials (RCTs) to investigate the impact of exclusive oral administration of fungal beta-glucans in any form and at any dosage to healthy subjects or patients.
Results:
Thirty-four RCTs, of the 917 records retrieved in total, met the eligibility criteria and are included in the present review. The sources of fungal beta-glucans were Saccharomyces cerevisiae, Aureobasidium pullulans, Pleurotus ostreatus, Lentinula edodes and Ganoderma lucidum, and the dosage of supplementation ranged from 2.5 to 1000 mg daily for up to 6.5 months. The primary physiological outcome of the majority of the interventions was immunomodulation, which resulted in (a) strengthened immune defense that reduces the incidence and symptoms of cold, flu and other respiratory infections and (b) improvement of allergic symptoms. However, the findings on the induction of immune response alterations were inconsistent at the cellular and molecular levels. Another aspect is psychological wellbeing, as the cohorts that received the polysaccharides of interest reported improvement in their mood states as well as amelioration of overall wellbeing. At the same time, it might also be useful as a complementary agent to patients undergoing cancer therapies. Furthermore, supplements containing beta-(1 → 3,1 → 6)-d-glucan administered to overweight/obese adults might have the potential to decrease comorbid conditions associated with obesity. Notably, no adverse event causally related to glucans was recorded.
Conclusions:
Supplementation with beta-(1 → 3,1 → 6)-d-glucans is well-tolerated, and health-promoting properties are manifested primarily through the potentiation of the immune system. More studies are required to confirm their additional beneficial effects, to establish the optimal dose, and to reveal the underlying molecular mechanisms.
... Baker's yeast β-glucan (BYBG) has been shown to have immunomodulatory effects and to reduce the incidence of URTI symptoms in adults in previous studies [7][8][9][10]. There are significantly fewer studies on the effects of BYBG on the physical health status of young children. ...
... The immuno-modulatory effect of BYBG and reduced URTI incidence has been demonstrated in adults [7][8][9][10] and this study was intended to evaluate similar benefits for children. There are significantly fewer studies on the effects of BYBG on the physical health of young children and additional support is prudent. ...
... Potential subjects were screened against inclusion and exclusion criteria (see below) during an initial meeting with the investigator. According to the recommendation of CFDA, we chose about one-third dosage of adults (250 mg every day in previous studies [7][8][9][10]), 75 mg as the high dosage and half of high dosage, 35 mg as low dosage in our study. The blinded randomization of enrolled subjects was 1:1:1 to two treatment groups (35 mg or 75 mg of BYBG per day) or placebo group, according to a randomly generated coding allocation produced by the statistical staff. ...
Infections are common in early childhood and create a large economic burden on both the healthcare system and individual family. To solve this problem, we evaluated the ability of baker’s yeast beta glucan (BYBG) to reduce the number of episodes of common childhood illness in 174 Chinese children with 1 to 4 years old in a 12 week randomized, double-blinded, placebo controlled study. We found that children in BYBG group experienced less common childhood infectious illness episodes during the study compared to the placebo group and BYBG were well tolerated for the children with 1 to 4 years old.
... A variety of dietary supplements have been studied for the prevention and treatment of both experimentally induced and naturally occurring colds, including echinacea [8], vitamin C [9,10], ginseng [11], vitamin E [12,13], and zinc [14], with equivocal results. In 3 previously published clinical trials, beta- 1,3/1,6-glucan derived from bakers yeast (beta-glucan) has been shown to reduce the severity and duration of URTI symptoms in healthy subjects [15], physically stressed subjects [16], and healthy-stressed subjects [17]. The mechanism of action by which beta-glucan enhances the activity of innate immune cells has been extensively described181920 with increased survival in animals challenged with a variety of pathogens in vivo212223. ...
... Ninety female subjects were screened for ''moderate'' levels of perceived stress using a screening survey (77 female subjects completed the trial). The stress survey (15 questions) strongly correlates with other measures, such as the POMS [16,17,24,25], and served as a reliable screening tool for identifying subjects undergoing ''moderate'' levels of perceived stress. Subjects scoring 6–10 (indicating moderate stress) on this screening survey were eligible for enrollment. ...
... A possible weakness of the current study is that our assessment of the incidence of upper respiratory symptoms was based on self-reported symptoms. Although symptom selfreports are routinely employed in field studies of URTI incidence15161727282930, others have verified symptomatology using viral identification or clinical examination [31]. Bakers yeast beta-glucan has been shown to bind to specific receptors on innate immune cells (CR3), priming them to be more effective in killing opsonized foreign challenges [20]. ...
Several studies have shown a baker's yeast beta-1,3/1,6-d-glucan, extracted from Saccharomyces cerevisiae, is effective in reducing the incidence of cold and flu symptoms. This study evaluated the effect of a specific beta-glucan supplement (Wellmune) on upper respiratory tract symptoms and psychological well-being in women with moderate levels of psychological stress.
Healthy women (38 ± 12 years old) prescreened for moderate levels of psychological stress, self-administered a placebo (n = 38) or 250 mg of Wellmune (n = 39) daily for 12 weeks. We used the Profile of Mood States (POMS) psychological survey to assess changes in mental/physical energy levels (vigor) and overall well-being (global mood state). A quantitative health perception log was used to track upper respiratory symptoms.
Subjects in the Wellmune group reported fewer upper respiratory symptoms compared to placebo (10% vs 29%), better overall well-being (global mood state: 99 ± 19 vs 108 ± 23, p < 0.05), and superior mental/physical energy levels (vigor: 19.9 ± 4.7 vs 15.8 ± 6.3, p < 0.05).
These data show that daily dietary supplementation with Wellmune reduces upper respiratory symptoms and improves mood state in stressed subjects, and thus it may be a useful approach for maintaining immune protection against daily stressors.
... Previous randomized, double-blinded, placebo-controlled clinical trials of 1/3,1/6 glucopolysaccharide have demonstrated an increased resistance to postoperative infection [25] and a decreased frequency of URTI symptoms in moderately stressed individuals [26] and in physically challenged groups such as marathon runners during the 4-wk period after a race [27]. A significant improvement in psychological mood state has also been noted [26,27]. ...
... Previous randomized, double-blinded, placebo-controlled clinical trials of 1/3,1/6 glucopolysaccharide have demonstrated an increased resistance to postoperative infection [25] and a decreased frequency of URTI symptoms in moderately stressed individuals [26] and in physically challenged groups such as marathon runners during the 4-wk period after a race [27]. A significant improvement in psychological mood state has also been noted [26,27]. However, further studies are required to evaluate the efficacy of 1,3/1,6 glucopolysaccharide on infection. ...
... The present study of a healthy student population taking Wellmune 250 mg/d demonstrated a tendency to a decreased number of days with cold or flu symptoms (18% less) compared with placebo (P ¼ 0.06). This finding is consistent with previous clinical studies in other groups [26,27]. The relatively small number of confirmed URTI episodes was below the expected levels [1,2] and limited the likelihood of achieving statistical significance in the present study. ...
... Based on title and abstract, 58 articles were discarded and 24 studies were left for full-text screening. Finally, 13 studies were included in qualitative synthesis [41][42][43][45][46][47][48][49][50][51][52][53][54]. One study [49] did not provide any quantitative data, thus 12 studies were included in meta-analysis. ...
... Severity ratings for nasal discharge were significantly lower in both the insoluble and soluble yeast β-glucan groups compared to the placebo group. Additionally, severity rating for sore throat was lower in the insoluble, but not the soluble yeast β-glucan group compared to the placebo group Talbott [52] During the course of the 4 week study, subjects in the treatment groups (250 mg and 500 mg β-glucan per day) reported significantly fewer URTI symptoms, better overall health and decreased confusion, fatigue, tension, and anger, and increased vigor based on the profile of mood states (POMS) survey compared to placebo Talbott [53] Subjects in both treatment groups (250 mg and 500 mg β-glucan per day) reported fewer URTI symptoms, better overall health and increased vigor, and decreased tension, fatigue, and confusion based on the profile of mood states assessment Talbott [54] Subjects in the yeast β-glucan group reported fewer upper respiratory symptoms compared to placebo, better overall well-being, and superior mental/physical energy levels results indicated that particulate yeast β-glucan may provide some protection from URTIs [25]. A recent review, which is wider in scope, summarized the results of 30 RCTs investigating the efficacy and safety of commercial oral and inhalation β-glucan products, for any health claim that was investigated in healthy or ill participants. ...
Purpose
Yeast β-glucans are known for their immune-modulating effects; however, their effects on human upper respiratory tract infections (URTIs) remain unclear. The aim of the present study was to use a systematic review and meta-analysis approach to investigate the effects of yeast β-glucans for the prevention and treatment of URTIs in healthy subjects.
Methods
Databases including Pubmed, Web of Science, EMBASE and the Cochrane Library were searched and 13 RCTs investigating the effects of yeast β-glucans on the incidence, duration, and severity of URTIs in healthy subjects were included.
Results
The results showed that compared to the placebo group, yeast β-glucan could significantly reduce the incidence of URTIs (OR = 0.345, 95% CI = 0.192 to 0.620, p < 0.001), decrease the average number of URTI episodes (SMD = − 0.315, 95% CI = − 0.500 to − 0.130, p < 0.05), and decrease the duration of URTIs (SMD = − 0.312, 95% CI = − 0.561 to − 0.064, p < 0.001). Improved severity of symptoms was found in yeast β-glucan group compared to the placebo group in the majority of included studies. In addition, yeast β-glucan was well tolerated and safe in general.
Conclusion
These findings suggest a positive effect of yeast β-glucans on human URTIs. However, due to the high heterogeneity and small number of included studies, more high-quality research and clinical trials are warranted.
... The benefits include reduction in URTI symptoms and improvements in the ability to resist the effect of stress on human health and well-being [9][10][11][12][13][14][15][16][17]. ...
... A longer washout period may allow subjects further normalization of their daily lifestyle, since intake of the samples or any of the vinegar-based nutritional beverages is not common practice to all subjects. In the present trial, 300 mg of BG was added in consideration of the vinegar beverage formula used, while in previous studies, 250 mg and 500 mg were found to be effective in improving POMS survey scores [9,[11][12][13] when used in a capsule form. ...
ABSTRACT:
Background: Fatigue is attributable to physical and psychological stress; also, fatigue is a common symptom that occurs in both sick and healthy individuals. Although its mechanism of cause is complex, fatigue from stress is known to affect an existent equilibrium of immune system status. Nutrition, such as beta-1,3/1,6 glucan, has been reported to play an important role in regulating stress and fatigue states via modulating a weakened immune system. In this study, a soluble baker’s yeast in black koji vinegar (Moromisu), a popular and healthy beverage in Okinawa, Japan, was provided to healthy subjects with a non-strenuous daily lifestyle.
Results: By performing statistical analysis on the results of the Profile of Mood States (POMS) survey, we observed that the overall study results (n=14) showed significant differences in fatigue and confusion in the POMS factors.
Conclusions: In this study we confirmed that beta-1,3/1,6 glucan improved some of the factors related to stress and fatigue as indicated by evaluation of POMS survey results.
... The main search terms were "controlled clinical trial" AND, "common cold OR respiratory tract infection" in combination with "β-glucan AND yeast". Apart from the clinical trials performed with Yestimun®, we found nine other studies that fit our search criteria [22,[41][42][43][44][45][46][47][48]. The publications by Babineau et al. [21] and Dellinger et al. [41] will not be discussed further, since the β-glucans were applied intravenously and not orally, to a group of high-risk surgical patients. ...
... When stressed women (n = 77) took insoluble bakers' yeast β-glucan before breakfast for 12 weeks, they reported fewer upper respiratory tract symptoms compared to placebo (p < 0.05) and a better overall well-being (p < 0.05) [48]. Similar results have been obtained in moderate to highly stressed subjects (n = 150; placebo n = 50; 250 mg β-glucan/day n = 50; 500 mg β-glucan/day n = 50) [44] as well as healthy stressed subjects (screened for moderate level of psychological stress n = 122) [45]. Once again, the subjects reported significantly fewer URTI symptoms and improved well-being (p < 0.05). ...
Beta-glucans are a heterogeneous group of natural polysaccharides mostly investigated for their immunological effects. Due to the low systemic availability of oral preparations, it has been thought that only parenterally applied beta-glucans can modulate the immune system. However, several in vivo and in vitro investigations have revealed that orally applied beta-glucans also exert such effects. Various receptor interactions, explaining possible mode of actions, have been detected. The effects mainly depend on the source and structure of the beta-glucans. In the meantime, several human clinical trials with dietary insoluble yeast beta-glucans have been performed. The results confirm the previous findings of in vivo studies. The results of all studies taken together clearly indicate that oral intake of insoluble yeast beta-glucans is safe and has an immune strengthening effect.
... Six of the studies are addressed to effects on upper respiratory tract infections (URTI) [29][30][31][32][33][34]. Following heavy exercise, athletes are susceptible to URTI due to a weakened immune system. ...
... After 2 weeks, five subjects in the 250 mg treated group (n = 50) and four in the 500 mg group (n = 50) reported symptoms of URTI compared to 16 in the placebo group (n = 50). After 4 weeks, four subjects in both treated groups, and 14 in the placebo group reported symptoms [30]. The differences were reported as statistically significant. ...
Yeast-derived beta-glucans (Y-BG) are considered immunomodulatory compounds suggested to enhance the defense against infections and exert anticarcinogenic effects. Specific preparations have received Generally Recognized as Safe status and acceptance as novel food ingredients by European Food Safety Authority. In human trials, orally administered Y-BG significantly reduced the incidence of upper respiratory tract infections in individuals susceptible to upper respiratory tract infections, whereas significant differences were not seen in healthy individuals. Increased salivary IgA in healthy individuals, increased IL-10 levels in obese subjects, beneficial changes in immunological parameters in allergic patients, and activated monocytes in cancer patients have been reported following Y-BG intake. The studies were conducted with different doses (7.5-1500 mg/day), using different preparations that vary in their primary structure, molecular weight, and solubility. In animal models, oral Y-BG have reduced the incidence of bacterial infections and levels of stress-induced cytokines and enhanced antineoplastic effects of cytotoxic agents. Protective effects toward drug intoxication and ischemia/reperfusion injury have also been reported. In conclusion, additional studies following good clinical practice principles are needed in which well-defined Y-BG preparations are used and immune markers and disease endpoints are assessed. Since optimal dosing may depend on preparation characteristics, dose-response curves might be assessed to find the optimal dose for a specific preparation.
... The control diet contained 0% yeast b-glucan blend (0X) while the 0.5X and 1X treatments contained either 0.012% or 0.023% yeast b-glucan blend, respectively. The target dose (1X) was intended to evaluate about one-third of the predetermined dosage for adult humans (250 mg/day) based on previous studies (Feldman et al., 2009;Talbott and Talbott, 2009;Talbott and Talbott, 2010;Fuller et al., 2012). This inclusion level was then decreased (0.5X) in order to evaluate if half of the target dose would elicit a response in dogs. ...
Oral supplementation of β-glucans may be able to improve the health of companion animals. However, little is understood regarding the effects of yeast β-glucan on diet processing and intestinal function. Therefore, the objectives of this research were to determine the carry through of yeast β-glucan during extruded diet production and its impact on diet utilization by dogs. Three diets were formulated to contain increasing levels of a yeast β-glucan blend at 0, 0.012 and 0.023% inclusion. Processing inputs were held constant during extrusion to allow for evaluation of output parameters and physical characteristics of kibble. Yeast β-glucan concentration was analyzed in extruded diets using the glucan enzymatic method, resulting in >100% recovery. Twenty-four Labrador Retrievers were assigned to one of three dietary groups of 8 dogs each with an equal distribution of sex and age. Dogs were fed dietary treatments for 24-d adaption followed by 4-d total fecal collection. Feces were scored on a 1-5 scale, with 1 representing liquid diarrhea and 5 hard pellet-like with a fecal score of 3.5-4 considered ideal. Fresh fecal samples were collected for analysis of short chain fatty acid concentrations. Apparent total tract digestibility was calculated by total fecal collection (TFC) and titanium (TI) marker methods. Data were analyzed using a mixed model procedure in software (version 9.4, SAS Institute, Inc., Cary, NC). Dry bulk density, kibble diameter, and kibble length did not differ among dietary treatments. Intake was similar among dietary treatments (P > 0.05). Dogs required about 26% more food than estimated [130*BWkg 0.75] to maintain body weight among all treatments. Fecal score was not different (P > 0.05) among dietary treatments but was lower than ideal at an average of 2.6. Nutrient digestibility was not affected (P > 0.05) by inclusion of the yeast β-glucan. By method, the TFC procedure resulted in higher (P< 0.05) digestibility values when compared to the TI procedure. In addition, yeast β-glucan did not alter short or branched chain fatty acid proportions. Overall, processing parameters, physical characteristics of kibble, stool quality, nutrient digestibility, and intestinal health in dogs were not affected by the yeast β-glucan blend.
... Talbott and Talbott investigated the effects of yeast β-glucan (Wellmure, WGP) supplement on mood state and upper-respiratory tract infection (URTI) symptoms in 18-53-year-old marathon runners [161]. The Talbott group later studied the effects of the same β-glucan (WGP) in 18-65-yearold moderate to highly-stressed men and women [162]. In another study, they reported the effects of β-glucans (WGP) on URTI symptoms and psychological well-being in women with moderate levels of psychological stress [163]. ...
β-Glucans are a group of biologically-active fibers or polysaccharides from natural sources with proven medical significance. β-Glucans are known to have antitumor, anti-inflammatory, anti-obesity, anti-allergic, anti-osteoporotic, and immunomodulating activities. β-Glucans are natural bioactive compounds and can be taken orally, as a food supplement, or as part of a daily diet, and are considered safe to use. The medical significance and efficiency of β-glucans are confirmed in vitro, as well as using animal- and human-based clinical studies. However, systematic study on the clinical and physiological significance of β-glucans is scarce. In this review, we not only discuss the clinical and physiological importance of β-glucans, we also compare their biological activities through the existing in vitro and animal-based in vivo studies. This review provides extensive data on the clinical study of β-glucans.
... Two dosing regimens decreased upper respiratory tract infection symptoms (p < 0.05) and improved overall health and vigor (p < 0.05) with decreased tension and fatigue (p < 0.05) compared to placebo. There were no statistically significant differences between two dosing schedules of β-glucan [24]. ...
Respiratory tract infections (RTIs) are the most common form of infections in every age category. Recurrent respiratory tract infections (RRTIs), a specific form of RTIs, represent a typical and common problem associated with early childhood, causing high indirect and direct costs on the healthcare system. They are usually the consequence of immature immunity in children and high exposure to various respiratory pathogens. Their rational management should aim at excluding other severe chronic diseases associated with increased morbidity (e.g., primary immunodeficiency syndromes, cystic fibrosis, and ciliary dyskinesia) and at supporting maturity of the mucosal immune system. However, RRTIs can also be observed in adults (e.g., during exhausting and stressful periods, chronic inflammatory diseases, secondary immunodeficiencies, or in elite athletes) and require greater attention. Biologically active polysaccharides (e.g., β-glucans) are one of the most studied natural immunomodulators with a pluripotent mode of action and biological activity. According to many studies, they possess immunomodulatory, anti-inflammatory, and anti-infectious activities and therefore could be suggested as an effective part of treating and preventing RTIs. Based on published studies, the application of β-glucans was proven as a possible therapeutic and preventive approach in managing and preventing recurrent respiratory tract infections in children (especially β-glucans from Pleurotus ostreatus), adults (mostly the studies with yeast-derived β-glucans), and in elite athletes (studies with β-glucans from Pleurotus ostreatus or yeast).
... β-glucans (BG) are naturally occurring cell wall polysaccharides in yeast, mushrooms, some cereals, seaweeds and bacteria. In recent years, certain BG's, such as those from yeast, have received much attention due to their immune-modulating properties, and an increasing number of clinical trials have been conducted to address biological effects following oral administration of BG preparations (Aarsaether, Rydningen, Engstad, & Busund, 2006; Feldman, Schwartz, Kalman, & Mayers, 2009; Talbott & Taklbott, 2010; Auinger, Riede, Bothe, Busch, & Gruenwald, 2013). BG from different sources share some common structures, as they are all composed of β-linked D-Glc monomers, however, solubility, molecular mass, degree of branching and tertiary structure may differ, depending on the source and isolation procedure, all of which in turn can affect their immune modulating effects (Bohn & BeMiller, 1995; Eccles, 2005 ). ...
Particulate yeast β-glucan is internalized by RAW 264.7 macrophages and reduces the activity of the tumor-associated protease legumain Legumain Protease RAW 264.7 cells Tumor a b s t r a c t Yeast-derived β-glucans (Y-BG) are potential immune-modulating compounds able to activate macro-phages. We investigated whether Y-BG affects the activity of a proteolytic enzyme, legumain, which is expressed in macrophages and involved in inflammatory conditions as well as in cancer development. RAW 264.7 macrophages were stimulated with either particulate (BG-P), water soluble (BG-S) or partly water soluble (BG-PS) Y-BG for 48 h, and cellular legumain activity was determined using a fluorogenic peptide substrate. BG-P inhibited legumain activity in a dose-dependent manner, while BG-S and BG-PS did not. Immunoblotting indicated that the observed inhibition of legumain activity was caused by reduced prolegumain synthesis within the cells, rather than inhibition of legumain proform activation. Blocking of the C-type lectin dectin-1 receptor with antibodies abolished the effect, revealing that this receptor was involved, and it was further demonstrated by confocal microscopy that fluorescently labeled BG-P was internalized into macrophages. RAW 264.7 macrophages stimulated with Y-BG for 6 h were shown to secrete TNF-α, and BG-P was more potent than BG-PS and BG-S in this respect. Y-BG is shown to inhibit legumain activity after internalization into macrophages, providing new insight into the mode of action of β-glucans.
... Mushroom-derived β-glucan was found to reduce restrain stress in mice [6], and oat β-glucan managed to lower the effects of exercise stress [7]. Positive findings were also found in highly-stressed subjects [8]. When several different types of β-glucans were directly compared as anti-stress molecules, the level of activity was found to widely differ among individual β-glucans [9]. ...
Stress has repeatedly been found to reduce the abilities of the immune system to fight against individual attacks. The current dissatisfaction with classical medications has led to more attention being focused on natural molecules. As recent studies have suggested that some bioactive molecules can have synergistic effects in stimulation of immune system and reduction of stress, we have evaluated the stress-reducing effects of the resveratrol-β-glucan-vitamin C combination. We found that compared to its individual components, this combination was the strongest reducer of stress-related symptoms, including corticosterone levels and IL-6, IL-12 and IFN-γ production.
... There have been a number of health benefits attributed to the consumption of β-glucans, including immunomodulatory effects (6). Published research has shown that certain β-glucans may enhance the ability of white blood cells to attack tumor cells through a defined mechanism of action (7), reduce the symptoms of respiratory tract infections (8)(9)(10), and protect mammals against infectious disease (11). The influence of the source and structure on biological activity was demonstrated in a study that compared the therapeutic efficacy of various sources of β-glucans (12). ...
An enzymatic method to measure β-glucan content (GEM assay) is applicable in a variety of matrices. The method is composed of swelling the sample with KOH and initial digestion with a lyticase, which is followed by treatment with a mixture of exo-1,3-β-d-glucanase and β-glucosidase that converts the β-glucan to glucose. The glucose generated by the enzymatic hydrolysis is measured by another enzymatic method. The method is shown to be accurate and precise. The method is selective and applicable to both highly branched and unbranched β-1,3-glucans.
Introduction: Viral respiratory tract infections (RTIs) have been recognized as a global public health burden. Despite current theories about their effectiveness, the true benefits of dietary supplements on the prevention and treatment of viral RTIs remain elusive, due to contradictory reports. Hence, we aimed to evaluate the effectiveness of dietary supplements on the prevention and treatment of viral RTIs.
Areas covered: We systematically searched databases of PubMed, Web of Science, Scopus, and Google Scholar through March 04, 2020, to identify randomized controlled trials that evaluated the effects of consuming select dietary supplements on the prevention or treatment of viral RTIs.
Expert opinion: Thirty-nine randomized controlled trials (n=16797 participants) were eligible and included. Namely, vitamin D supplementation appeared to improve viral RTIs across cohorts particulate in those with vitamin D deficiency. Among the evaluated dietary supplements, specific lactobacillus strains were used most commonly with select prebiotics that showed potentially positive effects on the prevention and treatment of viral RTIs. Further, ginseng extract supplementation may effectively prevent viral RTIs as adjuvant therapy. However, longitudinal research is required to confirm these observations and address the optimal dose, duration, and safety of dietary supplements being publicly recommended.
ABSTRACT
A number of pre-clinical and clinical studies indicate that nutritional yeasts as well as Saccharomyces boulardii are important products for prophylactic and/or therapeutic purposes. Nutritional yeasts are a rich source of amino acids, single cell proteins, several bioavailable minerals (e.g. chromium, selenium, zinc, iron, magnesium, cooper, manganese), and B vitamins. The properties of these non-infectious yeasts may be of particular importance for human and animal health. Amongst them, Saccharomyces cerevisiae is the best-known species used as a source of B vitamins and nutrients, especially chromium and selenium incorporated as organic compounds. Chromium is necessary for the maintenance of normal blood glucose levels, while selenium promotes a normal function of immune system. Another less-known species is Yarrowia lipolytica, which contributes to the production of a number of important nutritional elements, including bioavailable proteins, essential amino acids, minerals, organic acids, polyalcohols, carotenoids, aroma compounds, single cell oil, and microbial surfactants. Nutritional yeasts are beneficial for vegans, vegetarians, athletes, reconvalescents, as well as young people during the puberty period. Furthermore, some yeast species possess properties required for a microorganism to be considered as probiotic. One of them is S. boulardii, particularly recommended in antibiotic-associated diarrhoea and recurrent Clostridium difficile intestinal infections.
Keywords: nutritional yeasts, Saccharomyces cerevisiae, Saccharomyces boulardii, Yarrowia lipolytica, probiotics
In elite level athletes it is commonly believed that there is a link between high-intensity exercise and increased incidence of upper respiratory tract infections (URTI). Physiological changes associated with exercise are well documented on various components of the immune system, including: changes in number of circulating immune cells and their responsiveness, changes in cytokines and chemokines, and changes in mucosal IgA levels. This chapter uses the example of long-distance running to review what is known about the link between intense exercise and URTI incidence, and changes in various immune system parameters after intense exercise. Finally, the ability of nutritional interventions to rebalance the immune system parameters affected by strenuous exercise are reviewed with an emphasis on the ability of yeast beta glucan to mitigate the negative impact of exercise on the immune system.
Vitamin C and zinc play important roles in nutrition, immune defence and maintenance of health. Intake of both is often inadequate, even in affluent populations. The common cold continues to place a great burden on society in terms of suffering and economic loss. After an overview of the literature on the effects of the separate administration of either vitamin C or zinc against the common cold, this article presents data from two preliminary, double-blind, randomized, placebo-controlled trials, conducted with a combination of 1000 mg vitamin C plus 10 mg zinc in patients with the common cold. In both studies, a nonsignificant reduction of rhinorrhoea duration (range 9-27%) was seen. In pooled analyses of both studies (n=94), vitamin C plus zinc was significantly more efficient than placebo at reducing rhinorrhoea over 5 days of treatment. Furthermore, symptom relief was quicker and the product was well tolerated. In view of the burden associated with the common cold, supplementation with vitamin C plus zinc may represent an efficacious measure, with a good safety profile, against this infectious viral disease.
It is not known whether psychological stress suppresses host resistance to infection. To investigate this issue, we prospectively studied the relation between psychological stress and the frequency of documented clinical colds among subjects intentionally exposed to respiratory viruses.
After completing questionnaires assessing degrees of psychological stress, 394 healthy subjects were given nasal drops containing one of five respiratory viruses (rhinovirus type 2, 9, or 14, respiratory syncytial virus, or coronavirus type 229E), and an additional 26 were given saline nasal drops. The subjects were then quarantined and monitored for the development of evidence of infection and symptoms. Clinical colds were defined as clinical symptoms in the presence of an infection verified by the isolation of virus or by an increase in the virus-specific antibody titer.
The rates of both respiratory infection (P less than 0.005) and clinical colds (P less than 0.02) increased in a dose-response manner with increases in the degree of psychological stress. Infection rates ranged from approximately 74 percent to approximately 90 percent, according to levels of psychological stress, and the incidence of clinical colds ranged from approximately 27 percent to 47 percent. These effects were not altered when we controlled for age, sex, education, allergic status, weight, the season, the number of subjects housed together, the infectious status of subjects sharing the same housing, and virus-specific antibody status at base line (before challenge). Moreover, the associations observed were similar for all five challenge viruses. Several potential stress-illness mediators, including smoking, alcohol consumption, exercise, diet, quality of sleep, white-cell counts, and total immunoglobulin levels, did not explain the association between stress and illness. Similarly, controls for personality variables (self-esteem, personal control, and introversion-extraversion) failed to alter our findings.
Psychological stress was associated in a dose-response manner with an increased risk of acute infectious respiratory illness, and this risk was attributable to increased rates of infection rather than to an increased frequency of symptoms after infection.
Beta-glucan from oats and barley may decrease cardiovascular risk factors. Beta-glucan from some kinds of mush- rooms may have as similar effect while modulating the immune system. This pilot trial examined whether beta-glucan derived from Saccharomyces cerevisiae can favorably decrease the risk of or symptomology associated with upper respiratory illness. Forty healthy adult subjects (18 to 65 years of age) were enrolled in a 12-week, randomized, dou- ble-blind, placebo-controlled, parallel- group trial conducted during the cold/flu season. The treatment arm compared
Two-hundred seventy-six volunteers completed a life stressor interview and psychological questionnaires and provided blood and urine samples. They were then inoculated with common cold viruses and monitored for the onset of disease. Although severe acute stressful life events (less than 1 month long) were not associated with developing colds, severe chronic stressors (1 month or longer) were associated with a substantial increase in risk of disease. This relation was attributable primarily to under- or unemployment and to enduring interpersonal difficulties with family or friends. The association between chronic stressors and susceptibility to colds could not be fully explained by differences among stressed and nonstressed persons in social network characteristics, personality, health practices, or prechallenge endocrine or immune measures.
One hundred sixty-eight volunteers were randomized to receive a placebo or a vitamin C supplement, two tablets daily, over a 60-day period between November and February. They used a five-point scale to assess their health and recorded any common cold infections and symptoms in a daily diary. Compared with the placebo group, the active-treatment group had significantly fewer colds (37 vs 50, P<.05), fewer days challenged virally (85 vs 178), and a significantly shorter duration of severe symptoms (1.8 vs 3.1 days, P<.03). Consequently, volunteers in the active group were less likely to get a cold and recovered faster if infected. Few side effects occurred with the active treatment, and volunteers reported greatly increased satisfaction with the study supplement compared with any previous form of vitamin C. This well-tolerated vitamin C supplement may prevent the common cold and shorten the duration of symptoms. Volunteers were generally impressed by the protection afforded them during the winter months and the general acceptability of the study medication.
Respiratory tract infections are prevalent in elderly individuals, resulting in increased morbidity, mortality, and use of health care services. Vitamin E supplementation has been shown to improve immune response in elderly persons. However, the clinical importance of these findings has not been determined.
To determine the effect of 1 year of vitamin E supplementation on respiratory tract infections in elderly nursing home residents.
A randomized, double-blind, placebo-controlled trial was conducted from April 1998 to August 2001 at 33 long-term care facilities in the Boston, Mass, area. A total of 617 persons aged at least 65 years and who met the study's eligibility criteria were enrolled; 451 (73%) completed the study.
Vitamin E (200 IU) or placebo capsule administered daily; all participants received a capsule containing half the recommended daily allowance of essential vitamins and minerals.
Incidence of respiratory tract infections, number of persons and number of days with respiratory tract infections (upper and lower), and number of new antibiotic prescriptions for respiratory tract infections among all participants randomized and those who completed the study.
Vitamin E had no significant effect on incidence or number of days with infection for all, upper, or lower respiratory tract infections. However, fewer participants receiving vitamin E acquired 1 or more respiratory tract infections (60% vs 68%; risk ratio [RR], 0.88; 95% confidence interval [CI], 0.76-1.00; P =.048 for all participants; and 65% vs 74%; RR, 0.88; 95% CI, 0.75-0.99; P =.04 for completing participants), or upper respiratory tract infections (44% vs 52%; RR, 0.84; 95% CI, 0.69-1.00; P =.05 for all participants; and 50% vs 62%; RR, 0.81; 95% CI, 0.66-0.96; P =.01 for completing participants). When common colds were analyzed in a post hoc subgroup analysis, the vitamin E group had a lower incidence of common cold (0.67 vs 0.81 per person-year; RR, 0.83; 95% CI, 0.68-1.01; P =.06 for all participants; and 0.66 vs 0.83 per person-year; RR, 0.80; 95% CI, 0.64-0.98; P =.04 for completing participants) and fewer participants in the vitamin E group acquired 1 or more colds (40% vs 48%; RR, 0.83; 95% CI, 0.67-1.00; P =.05 for all participants; and 46% vs 57%; RR, 0.80; 95% CI, 0.64-0.96; P =.02 for completing participants). Vitamin E had no significant effect on antibiotic use.
Supplementation with 200 IU per day of vitamin E did not have a statistically significant effect on lower respiratory tract infections in elderly nursing home residents. However, we observed a protective effect of vitamin E supplementation on upper respiratory tract infections, particularly the common cold, that merits further investigation.
Zinc gluconate and zinc acetate lozenges have been reported to shorten the duration of common colds in a dose-response manner when the amount of the active ingredient, positively charged zinc ions, is sufficient.
To improve results using a zinc gluconate nasal spray with zinc orotate lozenges.
Double-blind, placebo-controlled clinical trial.
Private physician's clinic in Austin, Texas.
Seventy-seven volunteers, all of whom had 2 or more signs and symptoms of common colds (with at least 1 nasal symptom) on enrollment in the study.
Zinc gluconate nasal spray (10 mmol) or placebo was used every 15 to 30 minutes, and lozenges were used each several hours to reduce duration and severity of common colds. An intention of treatment was to keep the nasal tissues wet with zinc gluconate solution during wakeful hours.
After 7 days of treatment, 10 of 16 (63%) zinc-treated patients were asymptomatic compared to 9 of 17 (53%) placebo-treated patients (P = .57). This treatment caused olfactory region pain in some patients and did not reduce the duration or severity of common colds. Treatment did not produce anosmia, which has been reported in other studies following olfactory region administration of ionic zinc in many species and in humans from zinc nasal sprays and gels.
We contend that it is unethical to introduce any potentially permanent anosmia-inducing agent such as zinc or other heavy metals into the interior of the nose in a manner that could result in contact with the olfactory region to treat a temporary discomfort such as a common cold or allergy. We found no reason to recommend intranasal zinc gluconate or zinc orotate lozenges in treating common colds.
Sepsis is one of the most important risk factors in acute respiratory distress syndrome (ARDS). beta-Glucan is a potent reticuloendothelial modulating agent, the immunobiological activity of which is mediated in part by an increase in the number and function of macrophages. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced lung injury. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. The control group received saline, and the treatment groups received beta-glucan or beta-glucan + beta-1,3-D-glucanase. Five hours thereafter, plasma tumor necrosis factor (TNF) alpha, interleukin (IL) 1beta, and IL-6 levels were determined. Presence of lung injury was determined via lung tissue myeloperoxidase (MPO) activity, intercellular adhesion molecule (ICAM) 1 levels, and histopathological examination at 18 h after CLP. In a separate set of experiments, survival was monitored for 7 days after CLP. beta-Glucan treatment led to a significant increase in survival rate (63% in glucan-treated rats vs 38% in saline-treated rats). Administration of the beta-glucan inhibitor abrogated beta-glucan's survival benefit (50%). After CLP, plasma TNF-alpha, IL-1beta, and IL-6 concentrations were increased in control animals. When beta-glucan was administered, it completely blocked the elevation of TNF-alpha, IL-1beta, and IL-6. Administration of beta-1,3-D-glucanase suppressed glucan-induced decrease in cytokines. Animals treated with beta-glucan showed a significant reduction in lung injury score, a marked decrease in ICAM-1 expression, and a significant decrease in MPO levels. In contrast, beta-1,3-D-glucanase caused a significantly increased MPO and ICAM-1 levels in the lung. These data reveal that beta-glucan treatment improved the course of CLP-induced peritonitis and attenuated the lung injury. Administration of beta-glucanase inhibited the beta-glucan activity and resulted in enhanced lung injury.
Despite widespread public belief that psychological stress leads to disease, the biomedical community remains skeptical of this conclusion. In this Commentary, we discuss the plausibility of the belief that stress contributes to a variety of disease processes and summarize the role of stress in 4 major diseases: clinical depression, cardiovascular disease (CVD), human immunodeficiency virus (HIV)/AIDS, and cancer.Corresponding Author: Sheldon Cohen, PhD, Department of Psychology, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (scohen@cmu.edu).Financial Disclosures: Dr Cohen reported consulting for Johnson & Johnson Consumer Companies Inc on issues of stress measurement. None of the other authors reported any financial disclosures.Role of the Sponsor: This article is based on a paper commissioned by the Institute of Medicine Committee on Psychosocial Services to Cancer Patients and Families in Community Settings. The Institute of Medicine suggested the topic but played no role in structuring the paper; in the collection, management, and interpretation of the data; or the preparation, review, or approval of the manuscript.Additional Contributions: We thank David Krantz, PhD (Uniformed Services University of the Health Sciences), Margaret Kemeny, PhD (School of Medicine, University of California at San Francisco), Stephen Manuck, PhD, and Karen Matthews, PhD (University of Pittsburgh), and Scott Monroe, PhD (Notre Dame University), for their comments on an earlier draft; the John D. and Catherine T. MacArthur Foundation Network on Socioeconomic Status and Health and members of the Pittsburgh Mind-Body Center (HL65111, HL65112) for their intellectual support; and Ellen Conser, MA, Ashleigh Molz, and Wesley Barnhart, BS (Carnegie Mellon University), for assistance in preparing the manuscript. None of these individuals received any extra compensation for their contributions.
The judicious use of perioperative antibiotic prophylaxis reduces the infectious complications of surgery. However, increased bacterial resistance within hospitals may make antibiotic prophylaxis less effective in the future and alternative strategies are needed. New immunomodulatory agents might prevent wound infections by stimulation of the host immune system. To test this hypothesis, we administered poly-[1-6]-beta-D-glucopyranosyl- [1-3] -beta-D-glucopyranose glucan (PGG glucan), which enhances neutrophil microbicidal activity, intravenously to guinea pigs in doses ranging from 0.015 to 4 mg/kg of body weight on the day before, on the day of, and on the day after intermuscular inoculation with methicillin-resistant strains of Staphylococcus aureus and Staphylococcus epidermidis. Abscesses were identified at 72 h, and median infective doses (ID50) and statistical significance were determined by logistic regression. Guinea pigs receiving PGG glucan and inoculated with methicillin-resistant S. aureus and S. epidermidis exhibited ID50 of as much as 2.5- and 60-fold higher, respectively, than those of control guinea pigs not receiving PGG glucan. Maximal protection was observed with a dose of 1 mg of PGG glucan per kg, and efficacy was reduced at higher as well as at lower PGG glucan doses. Furthermore, a single dose of PGG glucan given 24 h following bacterial inoculation was found to be effective in preventing infection. We conclude that PGG glucan reduces the risk of staphylococcal abscess formation. Neutrophil-activating agents are a novel means of prophylaxis against surgical infection and may be less likely than antibiotics to be affected adversely by the increasing antibiotic resistance of nosocomial pathogens.
To examine the relationship between stress and upper respiratory tract infection, 235 adults aged 14-57 years, from 94 families affiliated with three suburban family physicians in Adelaide, South Australia, participated in a six-month prospective study. High and low stress groups were identified by median splits of data collected from the Life Events Inventory, the Daily Hassles Scale, and the General Health Questionnaire, which were administered both before and during the six months or respiratory diary data collection. Using intra-study stress data, the high stress group experienced significantly more episodes (mean of 2.71 vs. 1.56, p < 0.0005) and symptom days (mean of 29.43 vs. 15.42, p = 0.005) of respiratory illness. The two groups were almost identical with respect to age, sex, occupational status, smoking, passive smoking, exposure to air pollution, family size, and proneness to acute respiratory infection in childhood. In a multivariate model with total respiratory episodes as the dependent variable, 21% of the variance was explained, and two stress variables accounted for 9% of the explained variance. Significant, but less strong relationships were also identified between intra-study stress variables and clinically 'definite' episodes and symptom days in both clinically definite and total respiratory episodes. Pre-study measures of stress emphasized chronic stresses and were less strongly related to measures of respiratory illness than those collected during the study. However, significantly more episodes (mean of 2.50 vs. 1.75, p < 0.02) and symptom days (mean of 28.00 vs. 17.06, p < 0.03) were experienced in the high stress group. In the multivariate analyses, pre-study stress remained significantly associated with total respiratory episodes and symptom days in total and 'definite' respiratory episodes. In all of the multivariate analyses performed, sex (female) and age also appeared as important correlates of respiratory illness.
PGG-Glucan [Betafectin], a highly purified soluble beta-(1-6)-branched beta-(1 3)-linked glucan isolated from Saccharomyces cerevisiae, has broad in vitro and in vivo anti-infective activities unrelated to cytokine induction. Here we present in vivo results on the anti-infective activity of PGG-Glucan against a multiple antibiotic resistant Staphylococcus aureus. PGG-Glucan (0.25-4 mg/kg) was administered intramuscularly to male Wistar rats 48 h, 24 h, and 4 h before and 4 h after intraperitoneal implantation of a gelatin capsule containing 10(8)S. aureus colony forming units (CFU). Blood samples were collected at various times after challenge to determine CFU levels, leukocyte counts and neutrophil oxidative burst activity; serum TNF-alpha, and IL-1beta levels were also evaluated. The 0.25 mg/kg PGG-Glucan dose had no effect on reducing blood CFU levels; however, PGG-Glucan doses of 0.5 mg/kg, 1 mg/kg, 2 mg/kg or 4 mg/kg significantly reduced blood CFU levels by 48 h after challenge. Reduced CFU levels correlated with significantly elevated absolute monocyte counts, absolute neutrophil counts, and neutrophil oxidative burst activity in the absence of any effect on TNF-alpha or on IL-1beta levels. In additional studies, effects on mortality and blood CFU levels were evaluated in rats treated with ampicillin (an antibiotic to which the S. aureus was resistant), PGG-Glucan, or both agents. Mortality and blood CFU levels were reduced most in combination-treated rats compared to saline control rats or rats treated with either ampicillin alone or PGG-Glucan alone. We conclude that in vivo (1) PGG-Glucan can enhance clearance of an antibiotic resistant S. aureus, (2) that this clearance is accompanied by an increase in monocytes and neutrophils as well as a potentiation of neutrophil oxidative microbiocidal activity without alteration of the proinflammatory cytokine response, and (3) PGG-Glucan can enhance the effectiveness of traditional antibiotic treatment.
Several recent studies have shown that stress markedly delays wound healing. This study assessed the relationship between psychological stress and the secretion of proinflammatory cytokines at an actual wound site, providing in vivo data on the development of local immune responses that are central in the early stages of wound repair.
To study the dynamics of inflammation, skin blisters were induced on the forearm of 36 women (mean age, 57 years) by suction. After the blister roofs were removed, a plastic template was taped to the arm, and wells were filled with 70% autologous serum in buffer. Specimens were aspirated from blister chamber wells 5 and 24 hours after wounding.
Women with higher perceived stress scores demonstrated significantly lower levels of 2 key cytokines--interleukin 1alpha and interleukin 8--at wound sites. In addition, subjects who had low levels of both cytokines after 24 hours reported more stress and negative affect, and they had higher levels of salivary cortisol than those who had high cytokine levels.
Consistent with the evidence that stress delays wound healing, these data suggest a possible mechanism: psychological stress has measurable effects on proinflammatory cytokine production in the local wound environment.
Immune response in elderly individuals has been reported to improve after micronutrient supplementation. However, efficacy trials evaluating infectious diseases as outcomes are scarce and inconclusive.
To investigate the effect of daily multivitamin-mineral and vitamin E supplementation on incidence and severity of acute respiratory tract infections in elderly individuals.
A randomized, double blind, placebo-controlled, 2 x 2 factorial trial.
A total of 652 noninstitutionalized individuals aged 60 years or older enrolled from 2 community-based sampling strategies in the Wageningen area of the Netherlands, conducted from 1998 to 2000. At baseline, 6% of participants had suboptimal ascorbic acid and 1.3% had suboptimal alpha-tocopherol plasma concentration.
Physiological doses of multivitamin-minerals, 200 mg of vitamin E, both, or placebo.
Incidence and severity of self-reported acute respiratory tract infections at 15 months, as assessed by a nurse (telephone contact), home visits, and microbiological and serological testing in subsets of patients.
During a median observation period of 441 days, 443 (68%) of 652 participants recorded 1024 respiratory tract infection episodes. The incidence rate ratio of acute respiratory tract infection for multivitamin-mineral supplementation was 0.95 (95% confidence interval, 0.75-1.15; P =.58) and for vitamin E supplementation, 1.12 (95% confidence interval, 0.88-1.25; P =.21). Severity of infections was not influenced by multivitamin-mineral supplementation. For vitamin E vs no vitamin E, severity was worse: median (interquartile range) for illness-duration was 19 (9-37) vs 14 (6-29) days, P =.02; number of symptoms, 6 (3-8) vs 4 (3-8), P =.03; presence of fever, 36.7% vs 25.2%, P =.009; and restriction of activity, 52.3% vs 41.1%, P =.02.
Neither daily multivitamin-mineral supplementation at physiological dose nor 200 mg of vitamin E showed a favorable effect on incidence and severity of acute respiratory tract infections in well-nourished noninstitutionalized elderly individuals. Instead we observed adverse effects of vitamin E on illness severity.
This study attempted to determine whether stress of moderate intensity could modulate the antibody response to an influenza vaccination in healthy young adults, identify critical periods during which stress could influence antibody response, and delineate behavioral and biological pathways that might explain relations between stress and antibody.
A cohort of 83 healthy young adults underwent 13 days of ambulatory monitoring before, during, and after vaccination. Four times daily, subjects reported the extent to which they felt stressed and overwhelmed and collected a saliva sample that was later used to measure cortisol. A battery of health practices (cigarette smoking, alcohol use, physical activity, sleep hygiene) was assessed daily. Antibody titers to the vaccine components were measured at baseline and at 1-month and 4-month follow-up assessments.
To the extent that they reported higher levels of stress across the monitoring period, subjects exhibited poorer antibody responses to the New Caledonia strain of the vaccine. Stress ratings on the 2 days before the vaccine and the day it was given were not associated with antibody response. However, the 10 days afterward appeared to be a window of opportunity during which stress could shape the long-term antibody response to varying degrees. With respect to potential mediating pathways, little evidence emerged in favor of cortisol secretion, alcohol consumption, physical activity, or cigarette smoking. However, analyses were consistent with a pattern in which feelings of stress and loss of sleep become locked into a feed-forward circuit that ultimately diminishes the humoral immune response. These findings may shed light on the mechanisms through which stress increase vulnerability to infectious disease.
Echinacea has been widely used as an herbal remedy for the common cold, but efficacy studies have produced conflicting results, and there are a variety of echinacea products on the market with different phytochemical compositions. We evaluated the effect of chemically defined extracts from Echinacea angustifolia roots on rhinovirus infection.
Three preparations of echinacea, with distinct phytochemical profiles, were produced by extraction from E. angustifolia roots with supercritical carbon dioxide, 60 percent ethanol, or 20 percent ethanol. A total of 437 volunteers were randomly assigned to receive either prophylaxis (beginning seven days before the virus challenge) or treatment (beginning at the time of the challenge) either with one of these preparations or with placebo. The results for 399 volunteers who were challenged with rhinovirus type 39 and observed in a sequestered setting for five days were included in the data analysis.
There were no statistically significant effects of the three echinacea extracts on rates of infection or severity of symptoms. Similarly, there were no significant effects of treatment on the volume of nasal secretions, on polymorphonuclear leukocyte or interleukin-8 concentrations in nasal-lavage specimens, or on quantitative-virus titer.
The results of this study indicate that extracts of E. angustifolia root, either alone or in combination, do not have clinically significant effects on infection with a rhinovirus or on the clinical illness that results from it.
To investigate the relationship between the common cold and vitamin C supplementation.
A double-blind, 5-year randomized controlled trial.
A village in Akita prefecture, one of the regions in Japan with the highest mortality from gastric cancer.
Participants in annual screening programs for circulatory diseases conducted under the National Health and Welfare Services Law for the Aged, and diagnosed as having atrophic gastritis. Of the 439 eligible subjects, 144 and 161 were assigned to receive 50 or 500 mg of vitamin C, respectively, after protocol amendment. During the supplementation phase, 61 dropped out, and 244 completed the trial. Intervention: Daily vitamin C supplementation of 50 mg (low-dose group) or 500 mg (high-dose group).
Total number of common colds (per 1000 person-months) was 21.3 and 17.1 for the low- and high-dose groups, respectively. After adjustment for several factors, the relative risks (95% confidence interval (CI)) of suffering from a common cold three or more times during the survey period was 0.34 (0.12-0.97) for the high-dose group. No apparent reduction was seen for the severity and duration of the common cold.
A randomized, controlled 5-year trial suggests that vitamin C supplementation significantly reduces the frequency of the common cold but had no apparent effect on the duration or severity of the common cold. However, considering several limitations due to protocol amendment, the findings should be interpreted with caution.
We examined the immunological actions of Sophy beta-glucan(Ikewaki N., et al. United States Patent 6956120 and Japan Patent 2004-329077), a type of beta-1,3-1,6 glucan produced by the black yeast Aureobasidium pullulans (A. pullulans) strain AFO-202, currently available commercially as a health food supplement, using different human in vitro experimental systems. Sophy beta-glucan significantly (P<0.01) stimulated the (3)H-thymidine incorporation rates (marker of DNA synthesis) in human peripheral blood mononuclear cells (PBMCs) obtained from normal adult donors, in vitro. Enzyme-linked immunoassays (EIAs) revealed that Sophy beta-glucan stimulated the production of interleukin-8 (IL-8) or soluble Fas (sFas), but not that of IL-1beta, IL-2, IL-6, IL-12 (p70+40), interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) or soluble Fas ligand (sFasL), in either cultured PBMCs or cells of the human monocyte-like cell line, U937. The induction by Sophy beta-glucan of DNA synthesis in PBMCs was completely blocked by the addition of monoclonal antibodies (mAbs) to CD11a, CD54, human leukocyte antigen-class II (HLA-class II), Toll-like receptor-2 (TLR-2), and Toll-like receptor-4 (TLR-4). In these blocking experiments using the mAbs, the main differences in the results between PBMCs and U937 cells were that the mAbs against TLR-2 and TLR-4 did not block the Sophy beta-glucan-induced production of IL-8 in the U937 cells. Furthermore, a mAb to the beta-glucan receptor, Dectin-1, significantly (P<0.05) blocked the Sophy beta-glucan induced DNA synthesis in the PBMCs, and Sophy beta-glucan-induced production of IL-8 in the U937 cells. The Sophy beta-glucan-induced production of IL-8 in the U937 cells was significantly (P<0.01) blocked by the conventional protein kinase C (PKC) inhibitor Go6976, the novel PKC inhibitor Rottlerin, the protein kinase A (PKA) inhibitor H-89, and the protein tyrosine kinase (PTK) inhibitor herbimycin A. Among these, the blocking effect of the novel PKC (PKC delta isoenzyme) inhibitor Rottlerin was the most pronounced. Studies employing reverse transcriptase-polymerase chain reaction (RT-PCR) showed that Sophy beta-glucan stimulated the expression of IL-8 mRNA in the U937 cells, and that this induction was inhibited by Rottlerin. Sophy beta-glucan also blocked the stimulator cell induction of DNA synthesis and IFN-gamma production in the responder cells in a one-way mixed lymphocyte reaction (MLR) using allogenic PBMCs. Interestingly, immunoglobulin G (IgG), but not IgM to Sophy beta-glucan was detected in the sera derived from normal adult donors and from the umbilical cord blood of neonates. Taken together, these findings strongly suggest that the Sophy beta-glucan may have unique immune regulatory or enhancing properties that could be exploited by the health food, medical and pharmaceutical industries.
This study investigated the effects of oat beta-glucan (BG) supplementation on chronic resting immunity, exercise-induced changes in immune function, and self-reported upper respiratory tract infection (URTI) incidence in human endurance athletes.
Trained male cyclists were randomized to BG (N = 19) or placebo (P; N = 17) groups and under double-blind procedures received BG (5.6 g x d(-1)) or P beverage supplements for 2 wk before, during, and 1 d after a 3-d period in which subjects cycled for 3 h x d(-1) at approximately 57% maximal watts. URTI symptoms were monitored during BG supplementation and for 2 wk afterward. Blood samples were collected before and after 2 wk of supplementation (both samples, 8:00 a.m.), immediately after the 3-h exercise bout on day 3 (6:00 p.m.), and 14 h after exercise (8:00 a.m.) and were assayed for natural killer cell activity (NKCA), polymorphonuclear respiratory burst activity (PMN-RBA), phytohemagglutinin-stimulated lymphocyte proliferation (PHA-LP), plasma interleukin 6 (IL-6), IL-10, IL-1 receptor agonist (IL-1ra), and IL-8, and blood leukocyte IL-10, IL-8, and IL-1ra mRNA expression.
Chronic resting levels and exercise-induced changes in NKCA, PMN-RBA, PHA-LP, plasma cytokines, and blood leukocyte cytokine mRNA did not differ significantly between BG and P groups. URTI incidence during the 2-wk postexercise period did not differ significantly between groups.
An 18-d period of BG versus P ingestion did not alter chronic resting or exercise-induced changes in immune function or URTI incidence in cyclists during the 2-wk period after an intensified exercise.