RESUMEN

AIM: To develop a novel validated method for the isolation of Bifidobacterium animalis ssp. lactis BB-12 (BB-12) from faecal specimens and apply it to studies of BB-12 and Lactobacillus rhamnosus GG (LGG) recovered from the healthy human gastrointestinal (GI) tract. METHODS AND RESULTS: A novel method for isolating and enumerating BB-12 was developed based on its morphologic features of growth on tetracycline-containing agar. The method identified BB-12 correctly from spiked stool close to 100% of the time as validated by PCR confirmation of identity, and resulted in 97-104% recovery of BB-12. The method was then applied in a study of the recovery of BB-12 and LGG from the GI tract of healthy humans consuming ProNutrients® Probiotic powder sachet containing BB-12 and LGG. Viable BB-12 and LGG were recovered from stool after 21 days of probiotic ingestion compared to baseline. In contrast, no organisms were recovered 21 days after baseline in the nonsupplemented control group. CONCLUSIONS: We demonstrated recovery of viable BB-12, using a validated novel method specific for the isolation of BB-12, and LGG from the GI tract of healthy humans who consumed the probiotic supplement. SIGNIFICANCE AND IMPACT OF THE STUDY: This method will enable more detailed and specific studies of BB-12 in probiotic supplements, including when in combination with LGG.

Asunto(s)

RESUMEN

Probiotic bacteria are used to treat or prevent a broad range of human diseases, conditions, and syndromes. In addition, there are areas of medical use that have been proposed for future probiotic applications. Randomized double-blind studies have provided evidence of probiotic effectiveness for the treatment and prevention of acute diarrhea and antibiotic-induced diarrhea, as well as for the prevention of cow milk-induced food allergy in infants and young children. Research studies have also provided evidence of effectiveness for the prevention of traveler's diarrhea, relapsing Clostridium difficile-induced colitis, and urinary tract infections. There are also studies indicating that probiotics may be useful for prevention of respiratory infections in children, dental caries, irritable bowel syndrome, and inflammatory bowel disease. Areas of future interest for the application of probiotics include colon and bladder cancers, diabetes, and rheumatoid arthritis. The probiotics with the greatest number of proven benefits are Lactobacillus rhamnosus strain GG and Saccharomyces boulardii.

Asunto(s)

RESUMEN

Evidence suggests that oxidative modification of low density lipoprotein (LDL) occurs in vivo, increasing the atherogenecity of the particle. A total of 13 subjects (age range 46-78 years) with an LDL cholesterol concentration >3.36 mmol/l consumed each of four diets for 32-day periods. The diets contained 30% energy as fat of which 2/3 was either corn oil or beef tallow with and without 115 mg/4.2 MJ of supplemental cholesterol in the form of cooked egg yolk. The susceptibility of LDL to oxidation was assessed during a challenge with hemin and hydrogen peroxide, and results are expressed as lag time to oxidation in minutes. Addition of moderate amounts of cholesterol to either the corn oil or beef tallow enriched diet resulted in increased susceptibility of LDL to oxidation (decreased lag time): 69+/-22 min versus 96+/-24 min in the corn oil diet with versus without supplemental cholesterol, respectively, P = 0.006; 82+/-20 min versus 96+/-26 min in the beef tallow diet with versus without supplemental cholesterol, respectively, P = 0.025. A stepwise equation indicated that as plasma oleic acid concentrations increased and/or linoleic acid concentrations decreased, lag time increased (decreased susceptibility to oxidation), whereas as dietary cholesterol concentrations increased, lag time decreased (increased susceptibility to oxidation). In conclusion, these data suggest that addition of a moderate amount of dietary cholesterol to a reduced fat diet rich in polyunsaturated or saturated fatty acids increased the in vitro susceptibility of LDL to oxidation.

Asunto(s)

RESUMEN

We report on the clinical, cytogenetic, and molecular cytogenetic findings in a 4-year-old girl who was evaluated for developmental delay and a catlike cry from birth. No other findings of cri-du-chat syndrome were present. Karyotype analysis demonstrated a de novo deletion and inverted duplication of the 5p region. The abnormality was confirmed and further defined by detailed FISH analysis using cosmid and lambda phage clones previously mapped to distinct regions of 5p. The analyses documented deletion of 5p15.3-->pter and an inverted duplication of 5p14-->5p15.3. The deleted segment on 5p contains the region implicated in the isolated catlike cry feature of the cri-du-chat syndrome, confirming that the genes involved in the catlike cry map to the distal end of 5p. Except for the catlike cry and possibly the developmental delay that may be due to the deletion of 5p, the duplication of 5p14-->5p15.3 in this patient did not present with additional anomalies. This study further demonstrates the usefulness of the molecular cytogenetic approach for characterizing complex chromosome rearrangements. Such analyses of patients with an isolated catlike cry can avoid an incorrect diagnosis of the cri-du-chat syndrome, which is associated with a more severe prognosis.

Asunto(s)

RESUMEN

BACKGROUND: Lactose intolerance is the most common disorder of intestinal carbohydrate digestion. Lactobacillus acidophilus BG2FO4 is a strain of lactobacilli with properties of marked intestinal adherence and high beta-galactosidase activity. OBJECTIVE: This study was designed to determine whether oral feeding of Lactobacillus acidophilus BG2FO4 leads to a lactose-tolerant state. DESIGN: We studied 42 subjects with self-reported lactose intolerance and performed breath-hydrogen tests to determine whether they were lactose maldigesters. Subjects with established lactose maldigestion (n = 24) were invited to be randomly assigned to an omeprazole-treated (hypochlorhydric) group or a non-omeprazole-treated group, but 6 subjects chose not to participate. All randomly assigned subjects (n = 18) ingested Lactobacillus acidophilus BG2FO4 twice per day for 7 d and stool samples were collected. Breath-hydrogen tests were performed and symptom scores were recorded at baseline and after lactobacilli ingestion. RESULTS: Lactose maldigestion was established in 24 of 42 subjects (57%) with self-reported lactose intolerance. In 18 lactose-maldigesting subjects, overall hydrogen production and symptom scores after ingestion of Lactobacillus acidophilus BG2FO4 were not significantly different from baseline values. Live Lactobacillus acidophilus BG2FO4 was recovered in stool samples from 7 subjects. CONCLUSIONS: Lactose intolerance is overreported in subjects with gastrointestinal symptoms after lactose ingestion. Treatment of lactose-maldigesting subjects with and without hypochlorhydria with Lactobacillus acidophilus BG2FO4 for 7 d failed to change breath-hydrogen excretion significantly after lactose ingestion.

Asunto(s)

RESUMEN

Many environmental chemicals and pesticides have been found to be estrogenic and have been shown to stimulate the growth of estrogen receptor-positive (ER-positive) human breast cancer cells. Since it is difficult to avoid human exposure to environmental estrogens, a potentially important area of research is the development of dietary strategies to prevent the stimulated growth of breast tumors by environmental estrogens. In this context, the inhibitory action of curcumin and a combination of curcumin and isoflavonoids were studied in ER-positive human breast cancer cells (MCF-7 and T47D) and ER-negative MDA-MB-231 cells induced by the pesticide o,p'-DDT and the environmental pollutants 4-nonylphenol and 4-octylphenol. The median inhibitory concentration (IC50) for curcumin in T47D cells was 10 microM when measured at either a 48-hr or a 6-day incubation time. The IC50 value for curcumin was within the 8-10 microM range for inhibiting the growth of T47D cells induced by a 10- microM concentration each of 4-nonylphenol, 4-octylphenol, and o, p'-DDT. The IC50 for curcumin in MCF-7 cells induced by 10 microM of either o,p'-DDT, 4-octylphenol, or 4-nonylphenol were 9, 39, and >50 microM, respectively. A combination of curcumin and isoflavonoids was able to inhibit the induced growth of ER-positive cells up to 95%. For MDA-MB-231 cells, the IC50 for curcumin was 17 microM, which was reduced to 11 microM in the presence of 25 microM genistein. Curcumin and genistein induce drastic changes in the morphological shape of both ER-positive and ER-negative cells. Data presented here indicate that a mixture of curcumin and isoflavonoids is the most potent inhibitor against the growth of human breast tumor cells. These data suggest that combinations of natural plant compounds may have preventive and therapeutic applications against the growth of breast tumors induced by environmental estrogens.

Asunto(s)

RESUMEN

The effect of the fatty acid composition of reduced-fat diets on the in vitro oxidation of LDL was examined in 14 moderately hypercholesterolemic [low density lipoprotein (LDL) > 3.36 mmol/L] postmenopausal female and male subjects (age 44-78 y). Each subject consumed each of five reduced-fat diets [30 energy percent (E%) fat, 17 E% protein and 53 E% carbohydrate] enriched in beef tallow, canola oil, corn oil, olive oil or rice bran oil (20 E%) for 32-d periods. In vitro oxidation of LDL was assessed by incubating LDL with hemin and hydrogen peroxide, and measuring the time required for the reaction to reach maximum velocity (lag time). LDL lag times were 93.2 +/- 25.8, 95.9 +/- 26.4, 104.2 +/- 32.7, 108.0 +/- 26.6 and 113.1 +/- 24.0 min for corn oil, beef tallow, rice bran oil, canola oil and olive oil periods, respectively. When the data from all dietary phases were pooled, LDL alpha-tocopherol level (r = 0.30, P = 0.01) and plasma 18:1/18:2 ratio (r = 0.22, P = 0.08) were positively related to resistance of LDL to oxidation. Differences induced by the dietary perturbations in LDL content of beta-cryptoxanthin, lutein/zeaxanthin, lycopene, alpha-carotene or beta-carotene, and LDL particle size were not related to resistance of LDL to oxidation. In conclusion, in middle-aged and elderly moderately hypercholesterolemic subjects, the consumption of reduced-fat diets enriched in animal fat or vegetable oils with a relatively wide range of fatty acid profiles did not alter the in vitro susceptibility of LDL to oxidation. The advantages of reducing the saturated fat content of the diet were reflected in lower total and LDL cholesterol levels.

Asunto(s)

RESUMEN

Isoflavonoids are natural plant compounds and possess antitumorigenic properties. Many environmental chemicals have been found to be estrogenic and can enhance tumor growth in estrogen receptor-positive cells. In the present study, the effects of genistein, daidzein, biochanin A, formononetin, and equol on the proliferation of estrogen receptor-positive MCF-7 cells induced by synthetic chemicals 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2,2-trichloroethane (o,p'-DDT), 4-nonylphenol (4-NP), and 5-octylphenol (5-OP) found in the environment were investigated. Genistein, biochanin A, equol, and to some extent daidzein, but not formononetin, at < 10 microM can enhance the growth of MCF-7 cells in the absence of environmental chemicals. Formononetin was toxic to MCF-7 cells at the tested concentrations. The environmental chemicals 4-NP, 5-OP, and o,p'-DDT and the natural estrogen 17 beta-estradiol at 5, 5, and 10 microM and 5 nM, respectively, induced proliferation of MCF-7 cells. In the presence of isoflavonoids (> 25 microM), the environmental chemical-induced cell proliferation was inhibited. Individually, genistein (IC50 = 25-33 microM) was the most potent inhibitor against the induced proliferation of MCF-7 cells of the isoflavonoids needed for a 50% suppression of growth induced by 4-NP, 5-OP, and o,p'-DDT. A mixture of isoflavonoids was the most potent inhibitor against the induced proliferation. Estrogen receptor-dependent and -independent pathways could be involved in the inhibitory actions of isoflavonids. Because it is impossible to have a chemical-free environment, the in vitro data presented here are of practical importance to develop evolving dietary strategies and tactics against the adverse health effects of environmental chemicals.

Asunto(s)

Asunto(s)

RESUMEN

This paper reviews the evidence for the claims of health benefits derived from the use of probiotics. A brief history of probiotics and the types of probiotics currently used and the criteria for the selection of probiotics is discussed. The ability of probiotics to enhance the nutritional content and bioavailability of nutrients and the scientific evidence for the usefulness of probiotics in alleviating the symptoms of lactose intolerance and in enhancing growth development is examined. The remainder of the review focuses on studies of a specific probiotic, Lactobacillus GG which has been extensively investigated for its health benefits in humans and animals. These studies severe as a model for the potential benefits of probiotics. The ability of Lactobacillus GG to treat or prevent diarrhoeal disease, to serve as an adjuvant for vaccines, to prevent rotavirus-induced diarrhoea, to prevent milk-based allergic reactions, alcohol-induced liver disease and colon cancer are presented. The review concludes with a discussion of the data supporting the safety of probiotics.

Asunto(s)

RESUMEN

A high correlation between national per capita disappearance of fat and national rates of colon cancer led to the hypothesis that consumption of fat, especially from animal sources, increases risk for colon cancer. Over the past two decades, this hypothesis has been tested in numerous case-control and cohort studies. In general, neither case-control nor cohort studies find that the total fat composition of the diet increases risk of colon cancer. Case-control studies frequently find that total energy consumption is related to a higher risk of colon cancer, but this result is difficult to interpret because physical activity appears to be protective whereas obesity increases risk. In contrast with the results for total fat, epidemiologic data regarding the role of specific fatty acids are sparse. Nonetheless, useful information regarding major fatty acids may be inferred from the numerous studies that have examined major source of various fats in relation to colon cancer. Intake of red meat or beef has been related to colon cancer risk in most case-control and cohort studies, whereas dietary fat from sources other than red meat, including dairy, poultry, and vegetable oils, does not increase risk of colon cancer. The apparent influence of red meat does not appear to be mediated through its total lipid content, suggesting that other factors such as heterocyclic amines formed during cooking may be critical. Mechanisms whereby fat or red meat may influence colon carcinogenesis are discussed, although none appear compelling.

Asunto(s)

RESUMEN

Curcumin and genistein are two natural products of plants obtained from Curcuma longa Linn (turmeric) and soybeans, respectively. Both compounds when present at micromolar concentrations are able to inhibit the growth of estrogen-positive human breast MCF-7 cells induced individually or by a mixture of the pesticides endosulfane, DDT and chlordane or 17-beta estradiol. When curcumin and genistein were added together to MCF-7 cells, a synergistic effect resulting in a total inhibition of the induction of MCF-7 cells by the highly estrogenic activity of endosulfane/chlordane/DDT mixtures was noted. These data suggest that the combination of curcumin and genistein in the diet have the potential to reduce the proliferation of estrogen-positive cells by mixtures of pesticides or 17-beta estradiol. Since it is difficult to remove pesticides completely from the environment or the diet and since both turmeric and soybeans are not toxic to humans, their inclusion in the diet in order to prevent hormone related cancers deserves consideration.

Asunto(s)

RESUMEN

The effects of National Cholesterol Education Program (NCEP) Step 2 diets on plasma lipoprotein profiles in 72 men [mean (+/- SD) age: 44 +/- 15 y, range: 19-81 y] and 48 women (mean age: 50 +/- 21 y, range: 21-78 y) participating in five previously published studies were examined. Subjects were placed on a baseline diet similar to an average American diet (35-41% total fat, 13-16% saturated fat, 31-45 mg cholesterol/MJ) and then on an NCEP Step 2 diet (18-29% total fat, 4-7% saturated fat, 11-20 mg cholesterol/MJ) under isoenergetic conditions. All food and drink were provided. Compared with the baseline diet, consumption of the NCEP Step 2 diets was associated with significant decreases in concentrations of low-density-lipoprotein (LDL) cholesterol (-18.9% and -15.6%, respectively) and high-density-lipoprotein (HDL) cholesterol (-17.0% and -11.2%, respectively) in both men and women. Men with the apolipoprotein (apo) E 3,4 phenotype had a significantly greater decrease in LDL cholesterol (-24.2%) with the NCEP Step 2 diets than men with the apo E 3,3 phenotype (-17.7%). Men with the apo A-IV 1,2 phenotype tended to have less LDL cholesterol lowering (-12.8%) than men with the apo A-IV 1,1 phenotype (-19.6%), but this difference was not significant. No differences were seen by apo E and A-IV phenotype in women. A large variability in lipid response to the diet was observed, with changes in LDL cholesterol ranging from +3% to -55% in men and and from +13% to -39% in women. Forty-eight percent of the variability in LDL-cholesterol response (in mmol/L) to the diet could be accounted for by baseline LDL concentrations and age in men, and 13% by age in women.

Asunto(s)

Asunto(s)

RESUMEN

The effects of two National Cholesterol Education Program (NCEP) Step 2 diets (< or = 30% of energy as total fat, < 7% of energy as saturated fat, and < 200 mg cholesterol/d), one relatively high and the other relatively low in fish-derived fatty acids, on plasma lipoprotein concentrations and blood pressure were compared in 22 men and women with a mean (+/- SD) age of 63 +/- 10 y. Subjects were placed on a baseline diet similar to the diet currently consumed in the United States (35% of energy as total fat, 14% of energy as saturated fat, 35 mg cholesterol/MJ) for 6 wk and then on either an NCEP Step 2 diet relatively high in fish (Step 2 high-fish, n = 11) or relatively low in fish (Step 2 low-fish, n = 11) for 24 wk. All food and drinks were provided. Compared with baseline values, consumption of both the Step 2 high-fish and the Step 2 low-fish diets under weight-stable conditions was associated with significant decreases in plasma concentrations of total cholesterol (-14% and -19%, respectively), low-density-lipoprotein (LDL) cholesterol (-15% and -20%, respectively), and high-density-lipoprotein (HDL) cholesterol (-11% and -17%, respectively). Postprandial, but not fasting, triacylglycerol concentrations were significantly reduced during consumption of the Step 2 high-fish diet. There were no significant changes in these indexes after consumption of the Step 2 low-fish diet compared with the baseline diet. LDL particle size decreased significantly (-12%) only in subjects on the Step 2 low-fish diet. Both Step 2 diets caused small but significant reductions in diastolic blood pressure. Our results indicate that NCEP Step 2 diets relatively high or relatively low in fish are both effective in significantly reducing total and LDL-cholesterol concentrations without changes in the ratio of total cholesterol to HDL cholesterol under controlled weight-stable conditions in middle-aged and elderly subjects. A beneficial effect on diastolic blood pressure was also observed.

Asunto(s)

RESUMEN

Male Fischer 344 rats were fed a 20% or a 5% corn oil diet and were injected subcutaneously with dimethylhydrazine (DMH) weekly for 16 weeks. In addition, an approximately equal number of animals challenged with DMH were fed daily, until the end of the study, 2 x 10(10) Lactobacillus casei subsp. rhamnosus strain GG starting three weeks before DMH administration or after the ninth weekly injection. The feeding of the Lactobacillus GG before and during carcinogen treatment resulted in a significant decrease in the incidence of colon tumors and the number of small intestinal and colon tumors per tumor-bearing animal for rats fed a 20% corn oil diet. This decrease in tumor incidence or number of tumors was not seen when animals were fed the Lactobacillus after the ninth week of carcinogen treatment. Animals fed a 5% corn oil diet had a lower tumor incidence and number of tumors resulting from the decrease in dietary fat; in addition the feeding of Lactobacillus GG before the carcinogen challenge resulted in a lower incidence of colon tumors. These studies show that a specific strain of L. casei subsp. rhamnosus designated GG can interfere with the initiation or early promotional stages of DMH-induced intestinal tumorigenesis, and this effect is most pronounced for animals fed a high-fat diet.

Asunto(s)

RESUMEN

We have investigated the effects of a low-fat, high-fiber diet on plasma lipid and lipoprotein levels and serum sex hormone concentrations in 22 normal premenopausal women (mean age, 25.8 +/- 3.8 years). Participants consumed a baseline diet for 4 weeks (40% of calories as fat, 16% as saturated fatty acids, 8% as polyunsaturated fatty acids, 400 mg/d cholesterol, and 12 g/d dietary fiber) and then a low-fat, high-fiber diet for 8 to 10 weeks (16% to 18% of calories as fat, 4% as saturated fatty acids, 4% as polyunsaturated fatty acids, 150 mg/d cholesterol, and 40 g/d fiber). Blood samples for determination of plasma lipids and serum hormones were obtained during the follicular and luteal phases of the menstrual cycle during both diets. Compared with the baseline diet, the low-fat, high-fiber diet resulted in significant decreases in total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations during both the follicular and luteal phases (TC, -14% and -16%; LDL cholesterol, -14% and -17%; and HDL cholesterol, -15% and -18%, respectively). During the follicular phase but not the luteal phase on the low-fat, high-fiber diet, women exhibited significant increases in plasma triglyceride ([TG] 22%) and very-low-density lipoprotein (VLDL)-TG (36%) concentrations. During the follicular phase, serum estrone sulfate concentrations decreased by 25% (P < .0001) when subjects were fed the low-fat, high-fiber diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

Because many Western diseases are hormone-dependent cancers, we have postulated that the Western diet, compared with a vegetarian or semi-vegetarian diet, may alter hormone production, metabolism or action at the cellular level. Recently, our interest has been focused on the cancer-protective role of some hormone-like diphenolic phytoestrogens of dietary origin, the lignans and isoflavonoids. The precursors of the biologically active compounds originate in soybean products (mainly isoflavonoids but also lignans), as well as whole grain cereals, seeds, probably berries and nuts (mainly lignans). The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormone-like compounds with weak estrogenic and antioxidative activity; they have now been shown to influence not only sex hormone metabolism and biological activity but also intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation and angiogenesis, making them strong candidates for a role as natural cancer protective compounds. Epidemiological investigations support this hypothesis, because the highest levels of these compounds are found in countries or regions with low cancer incidence. This report is a review of results that suggest that the diphenolic isoflavonoids and lignans are natural cancer-protective compounds.

Asunto(s)

RESUMEN

The effect of the live bacterial yogurt cultures, namely Streptococcus thermophilus and Lactobacillus bulgaricus, and a mucosal adhering strain of Lactobacillus gasseri (ADH) on small intestinal and fecal bacterial characteristics was examined in 10 elderly subjects with atrophic gastritis and 23 elderly normal volunteers (11 received yogurt and 12 received ADH). Neither S thermophilus nor L bulgaricus was recovered from the stomach or small intestine of subjects fed yogurt or pasteurized yogurt. ADH was recovered from gastric or small intestinal aspirates in three of four subjects and in the stools of four of five subjects diagnosed with atrophic gastritis. In 11 of 12 normal subjects, ADH was isolated from stools. There was a significant reduction in fecal bacterial enzyme activity in both normal volunteers and subjects with atrophic gastritis after being fed with viable ADH. Adherent strains of bacteria such as ADH are likely to survive passage through the gastrointestinal tract and thus have greater metabolic effects.

Asunto(s)

Asunto(s)