Impact of oral administration of four Lactobacillus strains on Nugent score - systematic review and meta-analysis.

We aimed at assessing the evidence for an effect on vaginal dysbiosis by oral administration of a mixture of Lactobacillus strains isolated from vaginal microbiota. For this purpose, we systematically reviewed the literature for randomised clinical trials (RCTs) in which the effect of oral administration of a mixture of four Lactobacillus strains (Lactobacillus crispatus LbV 88 (DSM 22566), Lactobacillus gasseri LbV 150N (DSM 22583), Lactobacillus jensenii LbV 116 (DSM 22567) and Lactobacillus rhamnosus LbV96 (DSM 22560)) on vaginal dysbiosis was examined based on Nugent score. Four RCTs were identified: a double-blind (DB)-RCT in 60 male-to-female transsexual women with neovagina; an open label RCT in 60 pregnant women with herpes virus infection; a DB-RCT in 36 women with bacterial vaginosis; a DB-RCT in 22 postmenopausal breast cancer patients receiving chemotherapy. Only in the three DB-RCTs Nugent score was assessed. The meta-analysis of these trials showed a significant reduction of Nugent score by probiotics compared to placebo in the fixed (standardised mean differences (SMD) -0.561; confidence interval (CI) -0.935 to -0.186; P=0.004 and random effect models (SMD -0.561; CI -0.935 to -0.186; P=0.004). The odds ratio (OR) of the cases presenting with improved Nugent score after probiotics compared to placebo treatment showed a significant effect in the fixed (OR=3.936; CI 1.702 to 9.100; P=0.001) and random effect model (OR=3.902; CI 1.681 to 9.059; P=0.001) Cochran's Q and I2 statistics showed no heterogeneity. This meta-analysis indicates that the oral intake of the pertinent Lactobacillus strains improves the microbial pattern in vaginal dysbiosis.

Screening for proteolytically active lactic acid bacteria and bioactivity of peptide hydrolysates obtained with selected strains.

In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and ß-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and ß-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of ß-casein. Peptide length was between 9 (ß-CN(f 59-67)) and 22 amino acids (ß-CN(f 117-138)).

Effects of different fractions of whey protein on postprandial lipid and hormone responses in type 2 diabetes.

BACKGROUND/OBJECTIVES: Exacerbated postprandial lipid responses are associated with an increased cardiovascular risk. Dietary proteins influence postprandial lipemia differently, and whey protein has a preferential lipid-lowering effect. We compared the effects of different whey protein fractions on postprandial lipid and hormone responses added to a high-fat meal in type 2 diabetic subjects. SUBJECTS/METHODS: A total of 12 type 2 diabetic subjects ingested four isocaloric test meals in randomized order. The test meals contained 100 g of butter and 45 g of carbohydrate in combination with 45 g of whey isolate (iso-meal), whey hydrolysate (hydro-meal), α-lactalbumin enhanced whey (lac-meal) or caseinoglycomacropeptide enhanced whey (CGMP-meal). Plasma concentrations of triglyceride, retinyl palmitate, free fatty acid, insulin, glucose, glucagon, glucagon-like peptide 1 and glucose-dependent insulinotropic peptide were measured before and at regular intervals until 8-h postprandially. RESULTS: We found no statistical significant differences between meals on our primary variable triglyceride. The retinyl palmitate response was higher after the hydro-meal than after the iso- and lac-meal in the chylomicron-rich fraction (P=0.008) while no significant differences were found in the chylomicron-poor fraction. The hydro- and iso-meal produced a higher insulin response compared with the lac- and CGMP-meal (P<0.001). Otherwise no significant differences in the hormone responses were found in the incremental area under the curve over the 480-min period. CONCLUSIONS: A supplement of four different whey protein fractions to a fat-rich meal had similar effects on postprandial triglyceride responses in type 2 diabetic subjects. Whey isolate and whey hydrolysate caused a higher insulin response.

Acute differential effects of milk-derived dietary proteins on postprandial lipaemia in obese non-diabetic subjects.

BACKGROUND/OBJECTIVES: Postprandial lipaemia is an established risk factor for atherosclerosis. To investigate the acute effect of four milk-derived dietary proteins (alpha-lactalbumin, whey isolate, caseinoglycomacropeptide and whey hydrolysate) on postprandial lipaemia, we have conducted a randomized, acute, single-blinded clinical intervention study with crossover design. SUBJECTS/METHODS: A total of 11 obese non-diabetic subjects (age: 44-74, BMI: 30-41.4 kg m(-2)) were included. On 4 different days the subjects ingested a high-fat meal with the following energy distribution: 66% energy from fat (100 g of butter), 15% of energy from carbohydrate (90 g of white wheat bread) and 19% of energy from protein (45 g of pure protein). Our primary variable was plasma triglyceride measured in the 8-h postprandial period. Secondarily, retinyl palmitate, non-esterified free fatty acids, glucose, insulin, glucagon, GLP-1 and GIP, active and total grehlin and cholecystokinin were measured. RESULTS: We observed no statistically significant (P=0.8) differences between meals on our primary variable that is, triglycerides. Whey hydrolysate was associated with a significantly (P=0.02) smaller postprandial suppression of non-esterified free fatty acids compared with the other dietary proteins. CONCLUSION: We did not observe significant differences in postprandial lipaemia to the four milk-derived dietary proteins. Whey hydrolysate caused less postprandial suppression of free fatty acids.

Identification and characterisation of lactobacilli isolated from Kimere, a spontaneously fermented pearl millet dough from Mbeere, Kenya (East Africa).

The objective of the study was to isolate potential probiotic lactobacilli from Kimere, a pearl millet dough prepared in the Mbeere community of Kenya, East Africa, by fermentation for 18-24 hours. Kimere samples, collected from 11 different homesteads in Mbeere, showed average pH values of 3.63±0.29. Counts of presumptive lactobacilli were 8.52±0.02 log10 colony forming units per gram, respectively. 48 presumptive Lactobacillus isolates were characterised and identified by biochemical and molecular methods. Lactobacillus fermentum (46 isolates) was the dominant Lactobacillus species detected. Analysis of strain diversity with pulsed-field gel electrophoresis indicated relatively large biodiversity among L. fermentum isolates. All L. fermentum isolates were able to grow in MRS medium containing 0.3% ox gall. Twelve of them were able to grow in the presence of 3% ox gall, and of these 60% survived incubation at pH 3 in the presence of 2 mg pepsin per ml for three hours.

Acute effects of casein on postprandial lipemia and incretin responses in type 2 diabetic subjects.

BACKGROUND AND AIMS: Exaggerated and prolonged postprandial lipemia is potentially atherogenic and associated with type 2 diabetes. Limited data exist regarding the influence of dietary protein on postprandial lipemia in type 2 diabetes. We investigated, over 8-h, the acute effects of casein alone or in combination with carbohydrate on postprandial lipid and incretin responses to a fat-rich meal in type 2 diabetes. METHODS AND RESULTS: Eleven type 2 diabetic subjects ingested four test meals in random order: an energy-free soup plus 80 g of fat (control-meal); control-meal plus 45 g carbohydrates (CHO-meal); control-meal plus 45 g of casein (PRO-meal); and PRO-meal plus 45 g carbohydrates (CHO+PRO-meal). Triglyceride and retinyl palmitate responses were measured in plasma and in a chylomicron-rich and chylomicron-poor fraction. We found no significant differences in triglyceride responses to PRO- and CHO+PRO-meal compared to the control-meal. However, the addition of casein to the CHO-meal reduced the raised triglyceride response in the chylomicron-rich fraction. Retinyl palmitate responses did not differ significantly between meals in the chylomicron-rich fraction, whereas the PRO-meal increased retinyl palmitate in the chylomicron-poor fraction. PRO- and PRO+CHO-meal increased insulin and glucagon compared to the control-meal. PRO+CHO-meal increased the glucose-dependent insulinotropic peptide response while no change in glucagon-like peptide-1 responses was detected. CONCLUSIONS: The data presented suggest that casein per se did not modulate the postprandial triglyceride response in type 2 diabetes. When added to carbohydrate, casein suppressed the triglyceride response in the chylomicron-rich fraction, increased insulin and glucagon but did not affect the incretin responses.

Effect of a dietary supplement containing probiotic bacteria plus vitamins and minerals on common cold infections and cellular immune parameters.

OBJECTIVE: A randomized, double-blind, placebo-controlled intervention study was carried out in order to investigate whether consumption of a dietary supplement containing probiotic bacteria plus vitamins and minerals over a period of at least three months in winter/spring affects the duration, frequency, and severity of symptoms of naturally acquired common cold infections as well as cellular immune parameters. METHODS: 477 healthy men and women (aged 36 +/- 13, mean +/- SD) who had not been vaccinated against influenza were randomly assigned to a group who received daily the probiotic multivitamin and mineral supplement (verum) or a placebo, for three (n = 239) or for 5.5 months (n = 238). Cellular immune response was determined in 60 participants per study group by flow cytometry before and after 14 days of supplementation. RESULTS: The incidence of respiratory tract infections regarded as being virally induced was 13.6% lower in the verum group compared to the placebo group (p = 0.07). During respiratory tract infection episodes, the subjects recorded common cold and influenza-like symptoms daily. All symptoms were reduced in the verum group. We found a relative reduction of 19% in the total symptom score (p = 0.12), 25% in influenza symptoms (p = 0.09), and 54% in the number of days with fever (p = 0.03). The duration of these infections was not affected. Leukocytes, lymphocytes, in particular T-lymphocytes including CD4+ and CD8+ cells, as well as monocytes were significantly higher increased in the verum group, during the first 14 days of supplementation compared to placebo. CONCLUSION: These data indicate that the intake of a dietary supplement containing probiotic bacteria plus vitamins and minerals during a period of at least three months in winter/spring may reduce the incidence and the severity of symptoms in common cold infections in otherwise healthy adults. This may be due to stimulated cellular immunity.

Influence of salivary pellicle formation time on enamel demineralization--an in situ pilot study.

This study assessed the protective potential of salivary pellicles formed in situ over periods ranging from 2 to 24 h. Pellicles were produced on enamel slabs mounted on the palatal aspect of removable acrylic splints and exposed to the oral environment in three subjects for 2, 6, 12 and 24 h. Enamel specimens with and without pellicles were immersed in citric acid (1%) for 60 s, and the amount of dissolved calcium was measured by atomic absorption spectroscopy. In addition, specimens were processed for transmission electron microscopy (TEM). Mean values (standard deviations) for calcium release (mg/l related to the specimen's surface area of 5 x 5 mm(2)) were: 2-h pellicle 6.94 (1.55); 6-h pellicle 6.69 (2.05); 12-h pellicle 6.57 (2.31); 24-h pellicle 5.71 (2.46); enamel without pellicle 8.95 (1.66). There were no significant differences in calcium release that were dependent on pellicle formation time, but in comparison to enamel specimens without pellicle, significantly less (p <0.05) demineralization of the enamel was observed in pellicle-covered specimens. TEM showed that the pellicle was partly, but not completely dissolved following acid exposure. It is concluded that even a 2-h in-situ-formed pellicle layer protects the enamel surface to a certain extent against demineralization.

Probiotics and non-intestinal infectious conditions.

Orally ingested probiotic micro-organisms do not exert health effects exclusively in the intestine. Some strains can alleviate or prevent bacterial, fungal or viral infections in other organs by stimulation of the immune system. By preservation or improvement of the barrier function of the intestinal mucosa, they may inhibit translocation of potential pathogens and thus prevent infections of the blood stream and other tissues and organs. Modulation of the intestinal microflora can affect the local microflora of the urogenital tract and possibly of the oral cavity. Finally, some strains of orally ingested bacteria reach target organs like the urogenital tract in a viable state; alternatively they can be applied locally. Despite the infection-preventing properties of probiotic bacteria, lactic acid bacteria have rarely been identified in infections of the blood stream, heart valves and other organs, usually only in patients with severe disease. It is the general opinion that in most cases the source of infection was the commensal microflora of the intestine or the oral cavity. Until now only one case of infection associated with administration of a probiotic strain has been published. The most promising health-promoting effects have been seen in vaginosis, urinary tract infections, Helicobacter pylori gastritis and infections of the respiratory tract in children. More controlled clinical trials with sufficient numbers of participants are needed to determine the scientific basis for the use of probiotic bacteria in infections in locations of the body other than the intestine.

Probiotics, prebiotics, and synbiotics--approaching a definition.

Definitions of different pro-, pre-, and synbiotics suggested by different investigators are critically discussed. On the basis of this analysis, the probiotic concept is confined to effects exerted by viable microorganisms but is applicable independent of the site of action and route of administration. It therefore may include sites such as the oral cavity, the intestine, the vagina, and the skin.

Probiotics--compensation for lactase insufficiency.

Yogurt and other conventional starter cultures and probiotic bacteria in fermented and unfermented milk products improve lactose digestion and eliminate symptoms of intolerance in lactose maldigesters. These beneficial effects are due to microbial beta-galactosidase in the (fermented) milk product, delayed gastrointestinal transit, positive effects on intestinal functions and colonic microflora, and reduced sensitivity to symptoms. Intact bacterial cell walls, which act as a mechanical protection of lactase during gastric transit, and the release of the enzyme into the small intestine are determinants of efficiency. There is a poor correlation between lactose maldigestion and intolerance; in some studies, low hydrogen exhalation without significant improvement of clinical symptoms was observed. Probiotic bacteria, which by definition target the colon, normally promote lactose digestion in the small intestine less efficiently than do yogurt cultures. They may, however, alleviate clinical symptoms brought about by undigested lactose or other reasons.

Protection from gastrointestinal diseases with the use of probiotics.

Probiotics are nonpathogenic microorganisms that, when ingested, exert a positive influence on the health or physiology of the host. They can influence intestinal physiology either directly or indirectly through modulation of the endogenous ecosystem or immune system. The results that have been shown with a sufficient level of proof to enable probiotics to be used as treatments for gastrointestinal disturbances are 1) the good tolerance of yogurt compared with milk in subjects with primary or secondary lactose maldigestion, 2) the use of Saccharomyces boulardii and Enterococcus faecium SF 68 to prevent or shorten the duration of antibiotic-associated diarrhea, 3) the use of S. boulardii to prevent further recurrence of Clostridium difficile-associated diarrhea, and 4) the use of fermented milks containing Lactobacillus rhamnosus GG to shorten the duration of diarrhea in infants with rotavirus enteritis (and probably also in gastroenteritis of other causes). Effects that are otherwise suggested for diverse probiotics include alleviation of diarrhea of miscellaneous causes; prophylaxis of gastrointestinal infections, which includes traveler's diarrhea; and immunomodulation. Trials of gastrointestinal diseases that involve the ecosystem are currently being performed, eg, Helicobacter pylori infections, inflammatory bowel disease, and colon cancer.

Protein-bound D-amino acids, and to a lesser extent lysinoalanine, decrease true ileal protein digestibility in minipigs as determined with (15)N-labeling.

Heat and alkali treatment of food may increase the concentrations of protein-bound D-amino acids and cross-links such as lysinoalanine (LAL). To examine how protein treatment affects digestibility, purified test meals [total protein 150 g/kg dry matter (DM), 0.44 MJ/(kg BW(0.75). d)] were prepared, containing (g/kg DM) casein, 75; beta-lactoglobulin, 50; or wheat protein, 40. Each was (15)N-labeled. Test proteins were used either in their native form or after treatment for 6 or 24 h at 65 degrees C, pH 10.5-11.5. Each meal was fed to nine adult miniature pigs (twofold complete cross-classification). Chyme was collected continuously over 33 h postprandially via T-fistulas in the terminal ileum, and digestibilities of test proteins and individual L- and D-amino acids were calculated on the basis of recovery of (15)N and the respective amino acids in the chyme. Treatment of casein, beta-lactoglobulin or wheat protein for 24 h increased levels of D-amino acid residues. L-Asparagine and aspartate (L-Asx) were particularly susceptible; 14. 7 +/- 0.4, 11.7 +/- 0.2 and 11.0 +/- 0.9%, respectively, underwent racemization. LAL levels increased in parallel; 11.7 +/- 0.3, 13.6 +/- 0 and 14.8 +/- 0.0%, respectively, of total lysine was converted to LAL. At the same time, prececal protein digestibility was decreased by 13.4 +/- 2.3, 15.3 +/- 1.4 and 17.8 +/- 1.2% units, respectively (P < 0.05; mean +/- SEM, n = 9). Digestibility of individual L-amino acids decreased by 10-15%, but L-amino acids prone to peptic cleavage, such as L-phenylalanine and L-tyrosine, were not affected. Digestibilities of D-amino acids and LAL were approximately 35%. It seems that mainly D-amino acids, and to a lesser extent LAL, were responsible for lower digestibility by interfering with peptic cleavage.

[Lactose in human nutrition]. / Laktose in der menschlichen Ernährung.

The disaccharide lactose is naturally present as a component of foods in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. In most people lactase activity decreases at the age of approximately 2 years of age. After this lactose intake can cause symptoms of bloating, flatulence, abdominal pain and diarrhoea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended that these people abandon the consumption of milk and dairy products. However, most lactose-intolerant people are able to digest small amounts of milk (approximately 200 ml). They can also consume cheese without (hard and semi-hard cheese) or only low lactose content (only present in 10% of soft cheese). These products are a very important source of calcium.

[Lactose intolerance and consumption of milk and milk products]. / Laktoseintoleranz und Verzehr von Milch und Milchprodukten.

The disaccharide lactose is present as a natural component of foods only in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. With the exception of the caucasian race, the lactase activity decreases in most people at an age of 4 to 6 years. Lactose intake can cause symptoms of bloating, flatulence, abdominal pain, and diarrhea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended to those persons that they refrain from the consumption of milk and dairy products. However, most lactose intolerant people are able to digest small amounts of milk. They can also consume cheese that contains no (hard and semi-hard) or only small amounts of lactose (present in only 10% of soft cheeses). These products are very important sources of calcium. Compared to milk, the lactose content of yogurt is usually lower by about one third. Studies during the last 10 years have shown that in spite of its lactose content yogurt is very well tolerated by lactose intolerant persons. This advantage is ascribed to the presence of living lactic acid bacteria in fermented dairy products which survive passage through the stomach and also to the lactase present in these products.

Prevention of amino acid racemization during guanidination--a prerequisite for measurement of protein digestibility by homoarginine labeling.

Homoarginine labeling (guanidination) is used to calculate true prececal protein digestibility. A particular worry is that guanidination of proteins at alkaline pH might cause formation of D-amino acids. If D-amino acids show decreased protein digestibility in vivo, as seen in vitro, then the homoarginine method would underestimate protein digestibility. Therefore, the degree of protein racemization was measured during guanidination of casein at pH values between pH 9 and 11 and temperatures between 4 degrees and 65 degrees C. Optimal conditions for the guanidination reaction were 4 degrees C and pH 10.5-11 or 22 degrees C and pH 10. A higher pH value at 22 degrees C or temperatures above 22 degrees C at each pH leads to the formation of appreciable amounts of D-amino acids.

Enhancement of intestinal hydrolysis of lactose by microbial beta-galactosidase (EC 3.2.1.23) of kefir.

The effect of microbial beta-galactosidase (EC 3.2.1.23) activity on intestinal lactose digestion was estimated directly by following post-prandial venous plasma galactose concentrations. To avoid superimposing effects of free galactose, as with yogurt, fresh or heat-treated suspensions of mechanically disintegrated kefir grains in kefir, containing lactose but no free galactose, were fed to ten Göttingen minipigs. Each meal contained 101.1 (SEM 0.1) mmol lactose in kefir supplemented by either native or heat-treated kefir grains corresponding to a mean beta-galactosidase activity of either 72 (SEM 8) U or zero. Feeding kefir with beta-galactosidase activity resulted in a 30% enhancement of the mean post-prandial plasma galactose peak concentration from 33 (SEM 7) to 43 (SEM 12) mumol/l (n 10), as well as in 23% greater mean areas under the galactose-response curves (8.1 (SEM 1.5) v. 6.6 (SEM 1.2) mmol/min per l) if compared with kefir with heat-treated grains. Both differences were significant (P less than 0.05; paired Wilcoxon test by ranks). There was no induction of intestinal beta-galactosidase (EC 3.2.1.108) activity or intestinal lactose-hydrolysing bacteria by lactose feeding. These results give direct evidence of an enhanced lactose digestion and absorption in native fermented milk products due to the microbial beta-galactosidase activity.

Postprandial plasma D-lactate concentrations after yogurt ingestion.

The risk of D-lactic acidosis after consumption of yogurt was investigated in seven healthy volunteers. After ingestion of yogurt containing 1.06 mmol/kg body weight, D-lactic acid postprandial plasma D-lactate concentrations increased from 0.070 +/- 0.020 to a maximum of 0.200 +/- 0.010 mmol/l within 60 min. That was half the maximum concentration after the equivalent amount of D-lactate in the form of an aqueous solution of DL-lactate. The shape of the postprandial plasma D-lactate peak was flatter, but much broader after yogurt than after the aqueous solution, the peak areas being equal. When 0.64 mmol/kg body weight D-lactate were consumed as yogurt, plasma concentrations amounted to 0.086 +/- 0.030 mmol/l. Signs of a mild, transient, compensated metabolic acidosis, which was apparent in case of the aqueous lactic acid solution did not occur in case of yogurt. It is concluded that the consumption of foods containing D-lactic acid gives no reason for concern in healthy adults.

Difference of plasma amino acids following casein or soy protein intake: significance for differences of serum lipid concentrations.

There were significant differences of postprandial plasma concentrations for 8 amino acids (Cys, Val, Met, Leu, Tyr, Lys, Trp, and Arg) depending on whether pigs consumed a meal containing casein or isolated soy protein. The postprandial plasma amino acid pattern conformed with the amino acid composition of the dietary protein (except for Ser). The data, however, do not allow to conclude unambiguously, whether specific amino acids are responsible for the difference of serum cholesterol following casein or soy protein intake. Significant differences between casein- and soy-fed rats were observed regarding total and free plasma thyroxine and triiodothyronine concentrations. This observation can explain the accompanying different serum cholesterol concentrations. The different thyroid hormone concentrations were not paralleled by differences in TSH levels suggesting that dietary proteins affect thyroid function at the thyroid gland.