Safety evaluation of an IPP tripeptide-containing milk protein hydrolysate

Tensguard™ is a milk protein hydrolysate containing the lactotripeptide IPP. It is derived from cow’s milk, which is present in the human diet and has a safe history of consumption. The final Tensguard™ product, a supplement or a functional food ingredient, is intended for use by people who want to follow a healthy diet and lifestyle in order to manage their blood pressure. The safety-in-use of commercial lactotripeptide-containing products has been confirmed in several in vitro and in vivo toxicity studies and in studies with humans. To support the safety, Tensguard™ was examined in three in vitro genotoxicity tests (bacterial reverse mutation test, mammalian cell gene mutation test and mammalian chromosomal aberration test) and in a 90-day repeated-dose oral toxicity study in rats. The genotoxicity tests confirm that Tensguard™ is not mutagenic or clastogenic. The NOAEL from the 90-day study was at the highest dose tested, i.e. 4% in the diet. The NOAEL is equivalent to an overall mean intake of 2 g Tensguard™/kg body weight/day and corresponds to 40 mg IPP/kg body weight/day. This is 141-fold higher than the maximal anticipated intake. In conclusion, Tensguard™ is safe under the conditions of intended use.     

Influence of the route of administration on immunomodulatory properties of bovine β-lactoglobulin-producing Lactobacillus casei

Because of their intrinsic immunomodulatory properties, some lactic acid bacteria were reported to modulate allergic immune responses in mice and humans. We recently developed recombinant strains of Lactobacillus casei that produce β-lactoglobulin (BLG), a major cow's milk allergen. Here, we investigated immunomodulatory potency of intranasal and oral administrations of recombinant lactobacilli on a subsequent sensitization of mice to BLG. Intranasal administration of the BLG-producing Lb. casei stimulated serum BLG-specific IgG2a and IgG1 responses, and fecal IgA response as well, but did not inhibit BLG-specific IgE production. In contrast, oral administration led to a significant inhibition of BLG-specific IgE production while IgG1 and IgG2a responses were not stimulated. After both oral and intranasal administrations, production of IL-17 cytokine by BLG-reactivated splenocytes was similarly enhanced, thus confirming the adjuvant effect of the Lb. casei strain. However, a mixed Th1/Th2 cell response was evidenced in BLG-reactivated splenocytes from mice intranasally pretreated, with enhanced secretions of Th1 cytokines (IFN-γ and IL-12) and Th2 cytokines (IL-4 and IL-5) whereas only production of Th1 cytokines, but not Th2 cytokines, was enhanced in BLG-reactivated splenocytes from mice orally pretreated. Our results show that the mode of administration of live bacteria may be critical for their immunomodulatory effects.     

Magnesium treatment of diuretic-induced hyponatremia with a preliminary report of a new aldosterone-antagonist.

Long-term diuretic treatment of patients with congestive heart failure is often complicated by hyponatremia and resistance to diuretic treatment, as well as by hypokalemia. Less widely recognized is the increase in intracellular sodium in the presence of hyponatremia, and loss of magnesium, caused by sustained diuretic therapy. Because the sodium pump, which maintains intracellular sodium and potassium against a concentration gradient, is dependent on optimal magnesium levels, we have investigated the influence of magnesium infusions on serum and skeletal muscle levels of sodium and potassium in congestive heart failure patients with electrolyte disturbances. Because aldosteronism, such as accompanies the disease and diuretic treatment, increases intracellular sodium, we have measured intracellular sodium and potassium in six patients given a new aldosterone antagonist (canrenone). It lowered the muscle sodium and raised the muscle potassium and magnesium, and slightly raised the serum sodium. The magnesium infusions, given to eight patients, significantly increased the serum sodium and lowered the muscle sodium levels, and normalized both serum and subnormal muscle potassium levels.     

PROBIOTICS

The term “probiotic” was first used in 1965, by Lilly and Stillwell, to describe substances secreted by one organism which stimulate the growth of another. The use of antibiotics, immunosuppressive therapy and irradiation, amongst other means of treatment, may cause alterations in the composition and have an effect on the GIT flora. Therefore, the introduction of beneficial bacterial species to GI tract may be a very attractive option to re-establish the microbial equilibrium and prevent disease. Prebiotic is a non-digestible food ingredient that confers benefits on the host by selectively stimulating one bacterium or a group of bacteria in the colon with probiotic properties. Both probiotics and prebiotics are together called as Synbiotics. Various bacterial genera most commonly used in probiotic preparations are Lactobacillus, Bifidobacterium, Escherichia, Enterococcus, Bacillus and Streptococcus. Some fungal strains belonging to Saccharomyces have also been used. Probiotics have been shown to be effective in varied clinical conditions-ranging from infantile diarrhoea, necrotizing enterocolitis, antibiotic-associated diarrhoea, relapsing Clostridium difficle colitis, Helicobacter pylori infections, inflammatory bowel disease to cancer, female uro-genital infection and surgical infections. Lactobacillus rhamnosus strain GG has proven beneficial affects on intestinal immunity. It increases the number of IgA and other immunoglobulins secreting cells in the intestinal mucosa. It also stimulates local release of interferons. It facilitates antigen transport to underlying lymphoid cells, which serves to increase antigen uptake in Peyer’s patches. Probiotics are live microorganisms, so it is possible that they may result in infection in the host. The risk and morbidity of sepsis due to probiotic bacteria should be weighed against the potential for sepsis due to more pathological bacteria and the morbidity of diseases for which probiotic bacteria are being used as therapeutic agents. Also, future, well-designed placebo controlled studies with validated results are required for ascertaining the true health benefits of probiotics The important point in this regard is careful selection of the probiotic agent, its dose standardization and a thorough knowledge of its beneficial effects.     

Designer probiotics: Development and applications in gastrointestinal health

Given the increasing commercial and clinical relevance of probiotics, improving their stress tolerance profile and ability to overcome the physiochemical defences of the host is an important biological goal. Herein, I review the current state of the art in the design of engineered probiotic cultures, with a specific focus on their utility as therapeutics for the developing world; from the treatment of chronic and acute enteric infections, andtheir associated diarrhoeal complexes, to targeting HIV and application as novel mucosal vaccine delivery vehicles.     

The current place of probiotics and prebiotics in the treatment of pouchitis

Pouchitis is a common complication in patients undergoing restorative proctocolectomy for ulcerative colitis. Therapeutic attempts include manipulations of pouch flora composition. In this review, we bring together the evidence supporting the use of probiotics and prebiotics in pouchitis patients, to clarify the place of these treatments in current therapeutic regimens.     

低聚糖对人阴道产H_2O_2的乳酸杆菌体外增殖的影响

目的:通过观察低聚糖对人阴道产H2O2的乳酸杆菌体外增殖的影响,为将低聚糖和乳酸杆菌制成能更有效地防治生殖道感染的复方乳杆菌制剂提供实验室依据。方法:从健康妇女阴道分离出1株产H2O2的优势乳酸杆菌,对其进行生化鉴定;通过测定培养液OD值的变化来观察3种不同种类和浓度的低聚糖对该株乳杆菌体外增殖的影响。结果:从健康妇女阴道分离出的1株产H2O2的优势乳酸杆菌经鉴定为卷曲乳酸杆菌,其生长的最佳pH为pH=7,在体外拮抗试验中可抑制大肠杆菌和金黄色葡萄球菌的生长。该株产H2O2的乳酸杆菌培养液的OD值随着3种低聚糖浓度的增大逐渐升高,其在含有3种不同浓度的低聚异麦芽糖的培养液中的净增OD值最大。结论:低聚糖能有效促进人阴道卷曲乳酸杆菌的增殖;将低聚异麦芽糖与该株乳酸杆菌制成复方制剂将比与水苏糖和低聚果糖制成复方制剂或单一乳杆菌制剂能更有效地防治生殖道感染。