PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “FECES, IMPACTED”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

GnRH agonist Lupron (leuprolide acetate) pre-treatments prevent ovulation in response to gonadotropin stimulation in the clouded leopard (Neofelis nebulosa).

In many species, controlling the ovary prior to induction of ovulation improves the success of ovarian response and artificial insemination (AI). We assessed the impact of suppression of estrus with the GnRH agonist, Lupron, on ovarian sensitivity to equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) in the clouded leopard. Seven female clouded leopards were given two injections of Lupron (3.75 mg IM) 23 d apart, followed 44 d later by eCG and hCG. Daily fecal samples were collected from 60 d before Lupron to 60 d after hCG. Fecal metabolites of estrogen (E) and progesterone (P) were measured by radioimmunoassay. Lupron decreased (P < 0.05) the number of E peaks during Lupron treatment compared to pre-Lupron. All females had baseline E and six of seven (86%) had nadir P on day of eCG. Exogenous gonadotropins induced E elevations in all females. However, mean E in the gonadotropin-provoked estrus was decreased (P < 0.05) compared to pre-Lupron estrous periods. Only one of seven (14%) females ovulated after eCG/hCG. In conclusion, estrous cycle control with Lupron resulted in predictable ovarian suppression prior to gonadotropin stimulation but altered ovarian sensitivity by an as yet unknown mechanism so that ovulation was inhibited, even when using a proven exogenous gonadotropin protocol.

Animals↗

Impact of cefotaxime on the fecal flora in children.

A differential quantitative analysis was used to study the effect of cefotaxime on the fecal flora in 26 hospitalized children ranging from two days to four years of age. Fecal specimens were obtained before, during and after therapy. This study was evaluated in comparison to 41 patients of the same age and from the same environment without antibiotic treatment or signs of infection. The fecal flora of the control group showed qualitative and quantitative stability. Two groups of species were distinguished: a group in which the upper limit was less than or equal to 10(7) bacteria/g of stool (Klebsiella, Enterobacter, other enterobacteria, Staphylococcus, Pseudomonas) and a group with less than or equal to 10(10) bacteria/g of stool (anaerobes, Escherichia coli, Streptococcus D). This stability of the control group of subjects allowed us to interpret the variations of microbial concentrations during and after cefotaxime treatment. In previous studies, we showed in the newborn a substantial risk of septicemia of intestinal origin when overgrowth occurred, especially with Klebsiella. With cefotaxime there was a decrease or a disappearance in 65% of E. coli and a slight decrease of Klebsiella and Enterobacter. This fact was of great interest in the treatment of endogenous secondary septicemia. We observed an appearance of Pseudomonas (nine Pseudomonas aeruginosa, two Pseudomonas putida, one Pseudomonas fluorescens) in 12 cases among the 26 children treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗

Pancreatin therapy in patients with insulin-treated diabetes mellitus and exocrine pancreatic insufficiency according to low fecal elastase 1 concentrations. Results of a prospective multi-centre trial.

BACKGROUND: Recently, high prevalence of exocrine dysfunction in diabetic populations has been reported. Patients with fecal elastase 1 concentration (FEC) <100 microg/g have also been demonstrated to suffer from steatorrhea in about 60% of cases, indicating the need of pancreatic enzyme replacement therapy. Until now, there have only been a few reports on the use of enzyme replacement therapy in diabetic patients with exocrine pancreatic insufficiency. This investigation was designed to evaluate the impact of enzyme-replacement therapy on glucose metabolism and diabetes treatment in a prospective study of insulin-treated patients with diabetes mellitus. METHODS: A total of 546 patients with diabetes mellitus requiring insulin treatment were screened for exocrine dysfunction by FEC measurements. One hundred and fifteen patients (21.1%) had FEC <100 microg/g (normal >200 microg/g). Of these, 95 patients entered the study and 80 patients were randomized to receive either pancreatin (Creon) (39 patients) or placebo (41 patients) in a double-blind manner. Parameters of glucose metabolism, diabetes therapy and clinical symptoms were recorded in standardized protocols for 16 weeks. RESULTS: During the observation phase of 16 weeks, there were no significant differences between both groups concerning HbA(1c), fasting glucose levels, 2-h pp glucose levels, clinical parameters and safety parameters. A reduction in mild and moderate hypoglycemia was observed in the pancreatin group at the end of the study. CONCLUSIONS: Pancreatin therapy can be used safely in patients with diabetes mellitus and exocrine dysfunction. Parameters of glucose metabolism were not improved by enzyme replacement therapy.

Diabetes Mellitus, Type 1↗

Sweat nitrogen losses by and nitrogen balance of preadolescent girls consuming three levels of dietary protein.

A nitrogen balance study was undertaken to determine the effects of three levels of nitrogen intake on the loss of nitrogen through sweat and to assess the impact of sweat nitrogen on the protein needs of preadolescent girls. Values were determined through the collection of 24-hour, total body sweat samples from 15 healthy girls with a mean age of 8 years, 7 months. Mean height and weight of the subjects were 132 cm and 28.9 kg, respectively. Mean sweat nitrogen losses, collected under uncontrolled environmental conditions, were 201 mg, 263 mg and 319 mg/day on 34 g, 57 g and 88 g of protein intake. The environmental conditions throughout the study remained fairly constant. Mean nitrogen balances per day were 0.04 g, 0.55 g and 1.42 g on the respective levels of nitrogen intake, with the inclusion of sweat nitrogen loss, however, a negative nitrogen balance per day was found in 8 and 2 subjects on 34 g and 57 g protein intake. After considering nitrogen retention of 0.3 g which has been recommended by NRC for the minimum nitrogen allowance for growth of preadolescent children, protein intakes higher than that recommended by the NRC-RDA for preadolescent girls may be required for support of normal growth.

Body Surface Area↗

[Distribution and genetic characterization of porcine Campylobacter coli isolates].

The aim of this study was to evaluate the impact of the slaughter process on the Campylobacter (C.) coli prevalence on pig carcasses and finally pork. To detect C. spp., faecal samples, organ samples and surfaces of slaughter pigs were sampled. Additionally, various abattoir surfaces (n=208) and 227 pork and minced meat samples were included in our study. Whereas a high C. spp. prevalence (64.0%) was detectable in the faeces of slaughter pigs (all isolates were identified as C. coli), low detection rates were observed on pig carcasses after the slaughter process before the chilling period (21.1%). The impact of chilling reduced the detection rate of C spp. on pig carcasses even further to 0.8%. Only C. jejuni strains were isolated after the chilling process. Chilling and the associated drying of the skin are responsible for that massive reduction of C. spp prevalence. Significantly more C. spp. were isolated from livers compared to the corresponding carcasses. Only 5 out of 208 swab samples from different surfaces of the abattoir were C. coli positive. Bacteriological investigation could not detect any C. spp. strains from pork and minced pork meat. The low detection rates at the end of the slaughter and processing line indicate that pork may only play a minor role in the transmission of C. coli infections to humans. By genotyping C. coli-isolates from selected animals we were able to demonstrate three possible ways of contamination of the slaughter carcass surface. Genetically highly related strains were detectable on carcass surfaces of consecutively slaughtered animals. Faecal isolates and isolates from the carcass surface showed occasional high similarities. C. coli-genotypes from tonsils and genotypes from the corresponding slaughter carcasses formed a close cluster.

Abattoirs↗

Plasmid profile analysis of salmonellae in a large-animal hospital.

The plasmid profiles of salmonellae isolated from the patients and environment of the Purdue Large Animal Hospital were used as markers to identify strains and to assess the impact of improvements in hospital operation on nosocomial salmonellosis. Plasmid profile analysis proved to be more sensitive than either serotyping or antimicrobial susceptibility testing in identifying Salmonella isolates. During June and July 1983, 29 of 34 salmonellae isolated were one of three strains with distinct plasmid profiles: one S. typhimurium var. Copenhagen, and two S. muenchen. Each of these strains was isolated from at least one patient and two environmental sites, suggesting the possibility that infections were hospital-acquired. Patient and environmental sampling was repeated in June and July 1984, after improvements had been made in hospital traffic flow and sanitation. In contrast to 1983, only seven isolates, representing six strains not seen previously, were obtained in 1984. None of these strains was isolated from both patient and environmental sources. The results indicate that the high incidence of clinical salmonellosis in 1983 was largely due to nosocomial infections. The decrease in the incidence of salmonellosis and the absence of the 1983 strains from samples taken in 1984 were presumed to be due to improvements made in hospital operation. This study demonstrates the value of plasmid analysis in monitoring nosocomial salmonellosis in a veterinary hospital.

Animals↗

Mass treatment with albendazole reduces the prevalence and severity of Oesophagostomum-induced nodular pathology in northern Ghana.

Previous surveys conducted in northern Ghana where Oesophagostomum bifurcum is endemic showed that O. bifurcum-induced nodular pathology could be detected in up to 50% of the inhabitants. The impact of albendazole-based mass treatment to control both infection and morbidity is assessed and compared with the situation in a control area where no mass treatment has taken place. A significant reduction in the prevalence of infection based on stool cultures was achieved following two rounds of mass treatment in one year: from 52.6% (361/686) pre treatment to 5.2% (22/421) 1 year later (chi(1)(2)=210.1; P<0.001). At the same time, the morbidity marker of ultrasound-detectable nodules declined from 38.2% to 6.2% (chi(1)(2)=138.1; P<0.001). There was a shift from multinodular pathology, often seen in heavy infections, to uninodular lesions. In the control villages where no treatment took place, O. bifurcum infection increased from 17.8% (43/242) to 32.2% (39/121) (chi(1)(2)=9.6; P<0.001). Nodular pathology decreased slightly from 21.5% to 19.0%, but a higher proportion of these subjects developed multinodular pathology compared with baseline (chi(1)(2)=5.5; P=0.019). It is concluded that repeated albendazole treatment significantly reduces O. bifurcum-induced morbidity.

Adolescent↗

A rational approach to the stool ova and parasite examination.

BACKGROUND: Examination of multiple stool specimens per patient to rule out parasitic infection continues to be recommended in the literature. Attractive alternatives have been proposed, such as examination of a single specimen, but data to support their use have been inconclusive. METHODS: We reviewed the results of comprehensive stool ova and parasite examinations performed during a 1-year period to determine the incremental value of examining >1 specimen. Next, we implemented rejection criteria, allowing analysis of only a single specimen in most cases, and studied the impact of the change by reviewing data from a subsequent year. RESULTS: Prior to implementation of rejection criteria, 91% of parasites were detected in the first specimen submitted, although many clinical evaluations (72%) involved the submission of only 1 stool specimen. When at least 3 specimens were submitted, the sensitivity of examining the first in the series was 72%. Even the latter sensitivity provides negative predictive values of approximately 98%, approximately 97%, approximately 95%, or approximately 93% when the prevalence of parasites among those tested is 5%, 10%, 15%, or 20%, respectively. Examination of additional specimens after examination of the first specimen that yielded a positive finding revealed previously undetected parasites in only 10% of cases. After the application of rejection criteria, the parasite detection rate did not change significantly. CONCLUSIONS: Comprehensive examination of a single stool specimen is sufficient for most patients, when the prevalence of infection among the tested population is up to 20%. Rational use of the stool ova and parasite examination relies on communication between clinician and laboratory, and retention of deferred specimens in case examination of additional specimens is clinically warranted.

Animals↗

Distance-dependence in two Amazonian palms: effects of spatial and temporal variation in seed predator communities.

Animals aid population growth and fitness in tropical forest communities through dispersal and negatively impact populations through seed predation. The interaction between dispersal and seed predation can produce distance- or density-dependence; powerful mechanisms for maintaining species diversity incorporated in the Janzen-Connell model. Large mammals, the highest biomass seed predators of intact Amazonian communities and at risk due to human disturbance, are potentially central to these interactions. This study tests the Janzen-Connell model and investigates the impact of mammalian seed predators on seedling recruitment and maintenance of tree diversity. Patterns of both vertebrate and invertebrate seed predation and seedling recruitment were studied in the two most abundant canopy tree species in western Amazonia (Arecaceae: Astrocaryum murumuru and Iriartea deltoidea). We specifically examined effects of both spatial and temporal variation of the highest biomass seed predator in southwest Amazonian forests, the white-lipped peccary ( Tayassu pecari), on recruitment through disturbed and undisturbed sites and through a fortuitous 12 year natural extinction and recolonization event of T. pecari. Distance-dependent seedling recruitment was found in Astrocaryum and Iriartea at both sites. However, the median distance of seedlings was approximately 1.5x farther from reproductive adults in both palms at the undisturbed site. The number of Iriartea seeds escaping predation increased 6,000% in both space and time due to the decline of T. pecari abundance. The results demonstrate that Janzen-Connell effects are stronger in intact ecosystems and tie these mechanistically to changes in seed predator abundance. This study shows that anthropogenic changes in mammal communities decrease the magnitude of Janzen-Connell effects in Amazonian forests and may result in decreases in tree diversity.

Animals↗

Metagenomic insights into the global wild boar faecal microbiome reveal novel taxa and carbohydrate degraders distinguishing wild and domesticated Sus.

BACKGROUND: The inclusion of fibre in domestic pig diets is favourable from a digestive health, environmental, and socio-economic perspective. Unlike the highly optimized formulated diets of domestic pigs, wild boars feed opportunistically, consuming a broad range of foods that consist predominantly of plant materials. Consequently, the intestinal microbiota of wild boars is thought to be adapted to a versatile, fibre-rich diet and may represent a valuable source of probiotics for enhancing fibre degradation. However, comprehensive studies characterizing the wild boar gut microbiome, particularly its community structure and carbohydrate utilization potential, and comparison to that of domestic pigs are still lacking. RESULTS: We collected 89 faecal samples from wild boars across four countries and analysed them primarily using metagenomic sequencing. De novo assembly yielded 3,288 high- and medium-quality metagenome-assembled genomes (MAGs) representing 968 distinct species, of which 538 were previously unknown. Incorporating these MAGs enabled robust microbiome comparisons with 125 previously published samples largely from domestic pigs, which revealed significant structural and functional differences. These differences resolved into two community types, determined not by host species but by diet and lifestyle: C1 comprising 81% of samples from free-ranging, foraging wild boars and C2 consisting of 93% of samples from captive, fed domestic pigs. The lower alpha-diversity observed in C1 likely reflected the impact of highly fluctuating dietary resources and environmental conditions, resulting in dominance of fewer resilient or adaptable taxa. Nevertheless, both community types maintained substantial carbohydrate utilization potential: while C2 exhibited a higher relative abundance of CAZymesub genes associated with a broader range of carbohydrate substrate (CHO) classes, C1 was enriched in individual species that were generally richer in CAZymesub genes and CHO classes. To leverage this potential, we curated a catalogue of carbohydrate degraders from both community types and identified 47 highly versatile species, with several novel species amongst them. CONCLUSIONS: This study uncovered the previously untapped microbial diversity in the wild boar faecal microbiome and demonstrated that the faecal microbiome of Sus is primarily shaped by diet and lifestyle. The two community types identified, which differed both structurally and functionally, represent alternative states of microbiome homeostasis in wild versus domesticated Sus populations. The curated catalogue of carbohydrate degraders provides a valuable resource to guide tailored probiotic supplementation during dietary transitions to novel fibrous feedstocks. Video Abstract.

Animals↗

Clinical and epidemiological aspects of children hospitalized with severe rotavirus-associated gastroenteritis in Salvador, BA, Brazil.

Little is known about the epidemiology of severe rotavirus-associated gastroenteritis in Brazil. Given the morbidity associated with this condition and the importance of having detailed knowledge about the impact of rotavirus infection on the epidemiology of acute diarrhea in children, especially those with the most severe diarrheal conditions, we retrospectively reviewed the medical records of all pediatric patients admitted to a tertiary hospital in Salvador, Brazil, due to rotavirus-associated gastroenteritis during one year. It was observed that rotavirus was responsible for 15.6% of the hospitalizations caused by diarrhea and/or vomiting during the period of the study and that 87 of 218 (39.1%) patients seen at the emergency room with rotavirus-associated gastroenteritis needed to be hospitalized, comprising the population of our study. Most patients presented signs of dehydration, and 41% of them had metabolic acidosis. Most patients (79%) were between six months and four years of age and 72% of the cases occurred in June and July. Gastrointestinal symptoms were rarely present at the beginning of the clinical presentation, and they normally did not last for more than one week.

Acute Disease↗

Effects of Different Feeding Patterns on the Gut Virome of 6-Month-Old Infants.

The gut microbiome is essential for infant health, and in recent years, the impact of enteroviruses on infant health and disease has received increasing attention. The transmission of breast milk phages to the infant gastrointestinal tract contributes to the shaping of the infant gut virome, while breastfeeding regulates the colonization of the infant gut virome. In this study, we collected fecal samples from healthy infants and analyzed the distribution characteristics of infant viral communities by viral metagenomic analysis, and analyzed the differences in infant viral communities under different feeding practices. Our results indicate that the infant intestinal virome consists of phages and eukaryotic viruses. Caudovirales and Microviridae dominated the phage composition, and except for Siphoviridae, which was more predominant in the intestines of formula-fed infants, there were no significant differences in the overall abundance of other Caudovirales and Microviridae in the intestines of infants with different feeding patterns. Breastfeeding can lead to a higher diversity of infant gut viruses through vertical transmission, and a highly diverse gut virome helps maintain the maturation of the gut microbiome. This study informs the shaping of gut virome in healthy infants by breastfeeding and contributes to further research on infant gut virome characteristics and formation processes.

Humans↗

Epidemiological evidence for a differential effect of hookworm species, Ancylostoma duodenale or Necator americanus, on iron status of children.

BACKGROUND: The hookworms, Ancylostoma duodenale and Necator americanus, cause significant gastrointestinal blood loss. In clinical studies, greater blood losses have been reported with A. duodenale. However, there has been no evidence that endemic A. duodenale infection has greater impact than N. americanus infection on the iron status of populations. METHODS: In a sample of 525 school children in Pemba Island, Tanzania, we compared the degree of anaemia and iron deficiency associated with the two hookworm species at the individual and community (i.e. school) levels. Multiple regression was used to control for infection intensities and other child characteristics. RESULTS: In the 492 children with hookworm positive faecal cultures, haemoglobin and ferritin concentrations decreased with increasing proportions of A. duodenale. Among children with only N. americanus larvae, the prevalence of anaemia was 60.5 % and the prevalence of ferritin <12 microg/l was 33.1%, while in children with > or =50% A. duodenale larvae, the respective prevalences were 80.6% and 58.9%. When children were grouped by the prevalence of A. duodenale at the school level, children from high prevalence (> or =20%) schools had significantly worse iron deficiency and anaemia than children from low prevalence schools. CONCLUSIONS: The species of hookworm being transmitted in a community influences the burden of iron deficiency anaemia in the community, and should be considered in prioritizing and planning programmes for hookworm and anaemia control.

Ancylostomiasis↗

The effects of sweat nitrogen losses in evaluating protein utilization by preadolescent children.

A nitrogen balance study was conducted to determine the effects of three levels of nitrogen intake on the loss of nitrogen through sweat and to assess further the impact of sweat nitrogen on protein needs of preadolescent children. Values were determined through the collection of 24-hr, total body sweat samples from twelve healthy boys having a mean age of 8 years, 8 months. Mean height and weight of the subjects were 131.4 cm and 31.0 kg, respectively. Environmental conditions were relatively constant during the study. Mean sweat nitrogen losses were 208, 287, and 368 mg/day on daily protein intakes of 29, 54, and 84 g, respectively. Mean nitrogen balances per day were 0.39, 0.09, and 1.95 g when sweat nitrogen losses were included in the calculations. At the lower and moderate levels of protein intake, nine and six subjects were in negative nitrogen balance when sweat losses were considered. Sweat nitrogen losses in the boys were similar to a previous study with preadolescent girls. Based upon published basal metabolic rates and mean sweat nitrogen losses of 261 and 288 mg/day for girls and boys, the nitrogen lost through sweat was 0.25 mg/basal kcal for both sexes. An estimation of 0.5 mg/basal kcal for integumental nitrogen loss appears realistic for this age group.

Body Surface Area↗

Impact of quinupristin/dalfopristin (RP59500) on the faecal microflora in healthy volunteers.

The effect of 5 days' administration of quinupristin/dalfopristin (RP59500) on the faecal microflora was evaluated in healthy volunteers. Twenty healthy volunteers received 7.5 mg/kg of quinupristin/dalfopristin infused over 1 h twice daily for 5 days and four received a matched placebo. Faecal samples were collected before, during and after treatment (days -1/-2, 6, 8, 14/15, 35 +/- 2, 60 +/- 4, 90 +/- 4). In the treated volunteers, anaerobes, including sporulating and Gram-negative bacteria, decreased slightly during treatment, whereas numbers of enterococci and Enterobacteriaceae increased significantly (P < 0.01). Counts of anaerobes and enterococci resistant to erythromycin or to quinupristin/dalfopristin increased significantly (P < 0.01) during treatment and returned slowly to their baseline levels after the end of treatment. Mean faecal antibiotic concentrations reached 291 +/- 184 and 42 +/- 22 microg/g of faeces for quinupristin and dalfopristin, respectively, by the fifth day of treatment. Counts of yeasts were not influenced significantly by the treatment. No emergence of glycopeptide-resistant enterococci, Staphylococcus aureus, Pseudomonas aeruginosa or Clostridium difficile was observed. No episode of diarrhoea was reported. In conclusion, quinupristin/dalfopristin administration was associated with a temporary shift towards resistance of the endogenous flora and a temporary increase in counts of enterobacteria and enterococci. However, no decrease in colonization resistance towards exogenous potentially pathogenic bacteria was observed and the observed modifications disappeared within 12 weeks after the end of quinupristin/dalfopristin administration.

Adult↗

Sources and growth dynamics of fecal indicator bacteria in a coastal wetland system and potential impacts to adjacent waters.

Coastal wetlands are receiving increased attention as a putative source of fecal indicator bacteria (FIB) in Southern California coastal waters. We examined temporal trends of water and sediment-associated FIB after rain events along with spatial sediment characteristics at two sites within the Santa Ana River wetlands and made comparisons to FIB levels observed in adjacent surf zone waters. During the first two rain events, total coliforms (TC), Escherichia coli (EC) and enterococci (ENT) in wetland water and sediment samples peaked either on the same day or within several days of the rain event, while the third resulted in elevated wetlands sediment TC levels only. TC in adjacent coastal waters consistently peaked on the same day as the rain event and decreased quickly thereafter (within 1 day). The TC/EC ratios of surf zone samples consistently fell below 10, indicating an increased probability of human fecal contamination whereas wetland TC/EC ratios were higher, averaging approximately 60 and 14 at each site. These results suggest sediment-associated FIB populations may be distinct from those found in the water samples, or at least have internal dynamics independent of water-borne populations. Increases in sediment-associated FIB may be due to in situ population growth and/or increased survival due to changes in environmental parameters (salinity, moisture and nutrient input) resulting from the rain events. Spatial differences in between the two sites may be due to sediment differences such as organic content and finer grain size and/or discrete sources of FIB.

Ecosystem↗

Betalactam therapy and intestinal flora.

Betalactams, mainly when orally administered, may lead to intestinal flora modifications related to their spectrum of activity, rate of absorption and degradation. therefore it is important to investigate the possible influence of recently developed oral cephem derivatives on normal human microflora. We have investigated the impact on normal human intestinal flora in a 10-day course with cefetamet-pivoxil (CET, 500 mg BID) in comparison to cefixime (CFX, 400 mg qD) or cefuroxime axetil (CA, 250 mg BID) in 24 patients suffering from acute exacerbation of chronic bronchitis. Stool specimens were taken before (day 0), at the end (day 10) and 14 days after treatment (day 24) and quali-quantitative microflora composition was determined with a detection limit of 10 CFU/g dry weight. Treatment with CET caused slight and non-significant modifications of normal intestinal flora. On the contrary CFX and CA significantly affect Enterobacteriaceae and clostridia with a concomitant increase in enterococci for CFX. With both CFX and CA there was a new appearance of Salmonella spp. as well as Clostridium difficile in 4 and 2 cases, respectively. Therefore CET seems to affect normal bowel flora minimally in comparison to other oral cephalosporins. This aspect might contribute to the low incidence of GI related side effects in patients treated with CEt for longer than 1 week.

Administration, Oral↗

Prevention of heterocyclic amine-induced DNA damage in colon and liver of rats by different lactobacillus strains.

The aim of the present study was to investigate the impact of four different lactobacillus (LB) strains, namely Lactobacillus bulgaricus 291, Streptococcus thermophilus F4, S.thermophilus V3 and Bifidobacterium longum BB536, which are used for the production of yogurt, on the DNA-damaging effects of heterocyclic aromatic amines (HCAs). Male F344 rats were treated orally with HCA mixtures containing 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline, 2-amino-9H-pyrido[2,3-b]indole and 2-amino-3-methyl-3H- imidazo[4,5-f]quinoline, which were representative of the HCA contents found in fried beef ('beef mix') and chicken ('chicken mix'). Suspensions of LB were given by gavage to the animals simultaneously with and at different time periods before administration of the HCAs. Subsequently, the extent of DNA migration was measured in colon and liver cells in single cell gel electrophoresis (SCGE) assays. All four strains caused complete inhibition of DNA damage induced with beef mix after administration of 1 x 1010 LB cells/animal, whereas with chicken mix only marginal (non-significant) effects were seen. The inhibition of beef-induced DNA damage was dose dependent and was still significant when 1 x 107 cells/animal were administered. Kinetics studies showed that the protective effects were still significant when LB was given 12 h before the beef mix. A comparison of the present results with chemical analytical data from in vitro experiments suggests that the strong reduction in DNA migration seen in the animals can be only partly explained by direct binding effects. The results of the present study show that LB are highly protective against the genotoxic effects of HCAs under conditions which are relevant for humans and provide a possible explanation for the reduced colon cancer rates observed in some studies in individuals with either high LB counts in their feces or with a high consumption of LB-containing foods.

Amines↗