Fecal Ammonia Research Articles

Colonic protein fermentation and promotion of colon carcinogenesis by thermolyzed casein.

Thermolyzed casein is known to promote the growth of aberrant crypt foci (ACF) and colon cancer when it is fed to rats that have been initiated with azoxymethane. We speculated that the promotion was a consequence of increased colonic protein fermentation (i.e., that the thermolysis of the casein decreases its digestibility, increases the amount of protein reaching the colon, and increases colonic protein fermentation and that the potentially toxic products of this fermentation promote colon carcinogenesis). We found that the thermolysis of casein reduces its digestibility and increases colonic protein fermentation, as assessed by fecal ammonium and urinary phenol, cresol, and indol-3-ol. Thermolysis of two other proteins, soy and egg white protein, also increases colonic protein fermentation with increased fecal ammonia and urinary phenols, and thermolysis of all three proteins increases the levels of ammonia and butyric, valeric, and i-valeric acids in the cecal contents. We found, however, that the increased protein fermentation observed with thermolysis is not associated with promotion of colon carcinogenesis. With casein, the kinetics of protein fermentation with increasing thermolysis time are clearly different from the kinetics of promotion of ACF growth. The formation of the fermentation products was highest when the protein was thermolyzed for one hour, whereas promotion was highest for protein that had been thermolyzed for two or more hours. With soy and egg white, thermolysis increased colonic protein fermentation but did not promote colon carcinogenesis. Thus, although thermolysis of dietary casein increases colonic protein fermentation, products of this fermentation do not appear to be responsible for the promotion of colon carcinogenesis. Indeed, the results suggest that protein fermentation products do not play an important role in colon cancer promotion.

Influence of Yucca schidigera preparations on the activity of urease from Bacillus pasteurii

AbstractExtracts and preparations of the desert plant Yucca schidigera Roezl ex Ortgies (Mohave yucca), family Lillaceae, have a variety of beneficial effects when included in the diet of humans and domestic animals. Such effects include reduced gastrointestinal and faecal ammonia levels. A proposed mode of action is inhibition of microfloral urease (urea amidohydrolase; EC 3.5.1.5). We describe a rigorous method of in vitro urcase assay, in the presence of potential effectors such as Y schidigera preparations, using the phenolindophenol reaction to measure the ammonia product. The urease of Bacillus pasteurii was characterised in order to determine its suitability as a model bacterial urease. K‐phosphate, but not K‐HEPES or K‐citrate, was found to inhibit this bacterial urease, particularly at low pH, as previously reported for other plant and bacterial ureases. B pasteurii urease was found to have a Michaelis‐Menten constant, Km, of 10.5 ± 3.2 mM in 150 mM K‐HEPES, pH 65 and 0.89 M KCl, total ionic strength = 0.90 M at 30°C. It was therefore concluded that B pasteuriiurease is indeed a typical bacterial urease, suitable for studying the influence of Y schidigera preparations. For comparison, the effects of Y schidigera preparations on the activity of β‐galactosidase (β‐D‐galactoside galactohydrolase; EC 3.2.1.23) from Aspergillus or yzae, an unrelated hydrolase, were also determined. Urease and β‐galactosidase were both weakly and non‐specifically inhibited, in a fashion linearly related to the concentration of γ schidigera preparation. Linear regression of the relationship between γ schidigera preparation and enzyme activity yielded inhibition ratios of 3.2 ± 0.4 and 5.4 ± 1.6 nkat ml−1 preparation for urease and β‐galactosidase respectively. By comparing with reported in vivo rates of urea degradation in mammals it was concluded that the observed inhibitory properties of Y schidigera preparations are much too low to account for their in vivo effects at feed inclusion levels of as little as 100 g tonne−1.

ふなずし中乳酸菌のラット腸内細菌叢に及ぼす影響

The effects of Lactobacillus isolated from funazushi (salted and fermented crusian carp) on the fecal microflora and metabolic products were studied in rats.Mixed cultures containing the following viable cell levels per day of Lactobacillus were administered in rats: L. alimentarius, 108; L. plantarum, 1010; L. sake, 1010; L. sanfrancisco, 1010; and L. kefir, 1010. On days 7 and 14 of lactobacilli administration, the number of fecal Lactobacillus tended to increase, while Enterobacteriaceae and Staphylococcus significantly decreased (p<0.05). The concentration of fecal ammonia and short-chain fatty acids, and the fecal pH values did not change markedly during lactobacilli administration. The amount of daily fecal evacuation significantly increased (p<0.05) during the test period.

Analysis of intestinal flora of a patient with congenital absence of the portal vein

A 14-year-old female patient, admitted for a closer examination of liver tumour (hepatocellular adenoma), was diagnosed as having a congenital absence of the portal vein. The blood ammonia level (approximately 120 μg dl −1) in the superior mesenteric vein was markedly low compared to the normal value of 300–350 μg dl −1 in the portal vein. The decreased ammonia concentration and urease activity of the patient's faeces were demonstrated. The dominant intestinal flora in the faeces of the patient, before operation, was Bifidobacterium sp., Bifidobacterium breve, Bifidobacterium lonqum, Lactobacillus plantarum, and after the operation Bacteroides vulgatus, Veillonella parvula, Peptococcus magnus Bifidobacterium longum. In contrast, Bifidobacterium bifidum, Bacteroides ureolyticus, Bacteroides ovatus and Bacteroides distasonis, B. ovatus, Bifidobacterium adolescentis were dominant flora in the faeces of two healthy volunteers, respectively. Among microorganisms isolated from the patient, Morganella morganii, Candida sp., Eubacterium aerofacience and Eubacterium rectale were strongly positive in urease activity in vitro; Streptococcus mitior, Staphylococcus intermedius, Micrococcus kristinae, Selenomonas ruminantum, Bacteroides ureolyticus and Lactobacillus casei ss. pseudoplantarum from the healthy volunteers. These results imply the homeostatic regulation system of faecal ammonia concentration by urease-producing microorganisms in the patient.

Effects of transgalactosylated disaccharides on the human intestinal microflora and their metabolism.

The effects of transgalactosylated disaccharide (TD) intake on human fecal microflora and their metabolism were investigated in 12 Japanese males. TD is a mixture of sugars, galactosyl galactose, and galactosyl glucose, synthesized from lactose through the transgalactosylation reaction of Streptococcus thermophilus beta-galactosidase. Volunteers took 15 g of the test sugar daily for 6 days. The TD ingestion increased the number of bifidobacteria and lactobacilli, but decreased the number of Bacteroidaceae and Candida spp. in the feces. The ratio of bifidobacteria to total bacteria increased from 0.28 to 0.51. TD decreased the fecal concentrations of propionic acid, isobutyric acid, isovaleric acid, and valeric acid. This sugar also lowered the fecal pH, and the concentrations of fecal ammonia, p-cresol, and indole. Moreover, a positive correlation was found between the concentration of ammonia, and that of branched-chain fatty acids (isobutyric acid and isovaleric acid), p-cresol, and indole. All of these compounds are produced from amino acids through deamination by the intestinal bacteria. The depression of amino acid fermentation by intestinal bacteria may be involved in the reduction of fecal ammonia. These results suggest that a part of the transgalactosylated disaccharides passes into the colon, inducing changes in the colonic microflora composition, hastening carbohydrate fermentation, and depressing amino acid fermentation in the human gut.

Impact of Bifidobacterium longum on human fecal microflora.

The effects of Bifidobacterium longum feedings for five weeks on the fecal microflora, water contents, pH values, ammonia concentration, and beta-glucuronidase activity were investigated in five healthy human volunteers. Although numbers of major bacterial groups of the fecal microflora were not changed by the bifidobacteria feedings, a remarkably decreasing number of lecithinase-negative clostridia was observed. The percentage of lecithinase-negative clostridia and bacteroides to the total bacterial numbers isolated were decreased during the feedings and numbers of C. paraputrificum and C. innocuum were reduced. A significant reduction of fecal pH values for the last week of the feeding was observed. Ammonia concentration and beta-glucuronidase activity in the feces during the feedings were significantly lower than those before or after the feedings. The oral supplement of B. longum may be introduced to improve the fecal properties such as fecal ammonia concentration and beta-glucuronidase activity, but not the composition of fecal flora.

Effects of Yucca Shidigera extract on feed utilization by equine weanlings

Summary Reports in the literature suggest that dietary supplementation with water soluble extract of Yucca shidigera can reduce biological ammonia emissions from livestock in confinement. Because a reduction in environmental ammonia in equine housing facilities would benefit both human and animal health, the effects of Y. shidigera extract(YSE) on equine nitrogen metabolism were examined in this experiment. The addition of 100 ppm Y. shidigera extract to a 75% hay, 25% grain, lysine-deficient feed resulted in a significant increase in fecal nitrogen excretion by weanling Thoroughbreds and therefore a decrease in the apparent digestibility of dietary nitrogen. The proportion of fecal nitrogen that was water soluble increased (p A reduction in ambient ammonia in equine housing facilities may be desirable from several health perspectives. Environmental ammonia is noxious to both animals and man, and may provoke respiratory irritation and compromise. 6. , 29. Soluble compounds extracted from Yucca shidigera have recently been reported to reduce airborne ammonia concentrations in livestock production facilities when added directly to manure or incorporated into livestock feeds. 3. , 29. Althohgh free ammonia production may increase in the presence of a water soluble extract of Y. shidigera, ammonia in digesta and fecal materials apparently binds to the steroid saponins (sarsapogenin, smilagenin, hecogenin) found in the extract. 19 The most convenient method for introducing saponins into equine waste would be via the feed. Dietary saponins are apparently neither absorbed nor metabolized by ruminants or nonruminants, 7. , 10. , 27. although their ingestion may be associated with improved feed utilization and rates of growth. 18. , 27. However, it is not clear whether increased production efficiency resulted from metabolic effects attributable to saponins or from a reduction in animal stress accompanying a reduction in ambient ammonia concentrations. In the equine, growth efficiency is dependent on effective reutilization of a portion of the cecal and colonic ammonia derived from the hydrolysis of urea secreted into the intestine 11 Significant binding of ammonia to saponins within the cecum and colon could impair nitrogen economy and be detrimental to growing horses. On the other hand, increased urease hydrolysis of recycled urea could compensate for a saponin-induced reduction in the free ammonia content ofdigesta. Live yeast culture preparations may stimulate urease activity in young horses; 13. , 14. combined supplementation with both saponins and yeast culture might maintain efficient utilization of dietary nitrogen and tissue growth while reducing ammonia emissions. This experiment was undertaken to determine whether supplementation with Y. shidigera extract (YSE) affects the digestibility of dietary nutrients, the production of fecal ammonia, the efficiency of utilization of dietary nitrogen or growth in young horses. In order to ease the detection of any responses, particularly in the absence of any dose-response data, nitrogen-replete but lysine-deficient diets were used. The possibility that supplemental live yeast culture (YC) added with the saponins-emiched extract might beneficially interact with any effects of the saponins was also examined.

Fecal ammonia in patients with adenomatous polyps and cancer of the colon.

The correlation between high intakes of protein and high incidence of human colonic cancer is unexplained. Appreciable amounts of ammonia are generated in the large bowel through bacterial degradation of proteins and peptides, and experimental studies indicate that ammonia may select for neoplastic growth. Fecal concentrations of ammonia did not differ among 17 patients with former colonic adenomas [40.6 +/- 4.5 (SE) mM], 17 patients with former colonic cancer (51.4 +/- 3.9 mM), and 16 healthy controls (46.4 +/- 6.1 mM). By use of an in vitro fecal incubation system, possible alterations in bacterial fermentation and formation of ammonia were investigated. Fecal suspensions were incubated for 6 and 24 hours with and without addition of fermentable substrates (ispaghula husk, wheat bran, albumin, and glucose; 10 mg/ml). The in vitro production of ammonia in unsupplemented fecal homogenates from both groups of patients was comparable with the production found in homogenates from healthy controls, and the response to fermentable substrates was similar in all three groups. Addition of albumin caused a marked increase in the production of ammonia, and addition of glucose increased bacterial assimilation of ammonia considerably. These well-known characteristics of bacterial metabolism of ammonia apparently did not differ between healthy individuals and patients investigated more than three months after colonoscopic polypectomy or colonic cancer resection.

Effect of corn fiber residue supplementation on fecal properties, flora, ammonia, and bacterial enzyme activities in healthy humans.

Effects of corn fiber residue (5 g/day for 10 days) on fecal weight, moisture, pH, fecal flora, ammonia content, and on the activities of beta-glucuronidase and beta-glucosidase were investigated in six healthy subjects. Corn fiber residue was remnant of hemicellulose extraction from corn fiber by calcium hydroxide. Fecal weight showed a tendency to increase, and fecal pH did not change during corn fiber residue supplementation. No remarkable changes in the fecal flora at the bacterial group level were observed. Fecal ammonia content and beta-glucuronidase activity per gram of wet feces decreased slightly but the daily output did not change. Fecal beta-glucosidase activities per gram of wet feces increased significantly (p less than 0.05) and the daily output also tended to increase during corn fiber residue supplementation.

Effect of the dietary supplementation of corn hemicellulose on fecal flora and bacterial enzyme activities in human adults.

The effect of a dietary supplementation of corn hemicellulose (10g/day for 10 days) extracted from corn hull on fecal weight, moisture, pH, microflora, ammonia content, and on the activities of β-glucuronidase, β-glucosidase and nitroreductase were studied in nine healthy volunteers. Corn hemicellulose increased the fecal weight, lowered the fecal pH, decreased the fecal ammonia content, and decreased the β-glucuronidase and nitroreductase activities (per gram of wet feces and daily output) significantly (p < 0.05). β-Glucosidase activity per gram of wet feces was decreased, but its daily output did not change. No remarkable changes in the fecal flora were observed at the bacterial group level. The results demonstrate that corn hemicellulose significantly influenced the fecal bulk and harmful bacterial products.

Effect of dietary copper sulfate, Aureo SP250, or clinoptilolite on ureolytic bacteria found in the pig large intestine.

The predominant ureolytic bacteria in the pig large intestine were determined while growing pigs were fed a basal diet or basal diet plus copper sulfate, Aureo SP250, or clinoptilolite. Fecal samples were collected from four pigs fed each diet at 3, 9, and 14 weeks and analyzed for total colony counts and percent ureolytic bacteria. Fecal urease activity, ammonia nitrogen, and identity of the ureolytic bacteria were determined at 14 weeks. Copper sulfate and Aureo SP250 reduced the number of ureolytic organisms, with a marked decrease occurring in the Streptococcus spp., which made up 74% of the ureolytic isolates from the pigs on the basal diet. Other ureolytic species detected at lower concentrations were Staphylococcus spp., Selenomonas ruminantium, Bacteroides multiacidus, and Eubacterium limosum. Copper sulfate also reduced fecal urease activity (P less than 0.10). Fecal ammonia concentrations were not different between pigs fed the various diets. These data suggest that the streptococci are the most numerous ureolytic species in the pig intestinal tract and are significantly reduced by copper sulfate and Aureo SP250; however, only copper sulfate reduced intestinal urease activity.

The contribution of endogenous urea to faecal ammonia in man, determined by 15N labelling of plasma urea.

To establish the role of endogenous urea as a source of faecal ammonia, the plasma urea of two healthy men was labelled with 15N at a constant level for several days and its 15N enrichment was compared with that of faecal ammonia and total nitrogen. Faeces collected after one complete gastrointestinal transit from the onset of plasma labelling had ammonia 15N enrichments which were only 8.5 +/- 1.2% and total nitrogen enrichments which were 6.8 +/- 0.7% of the plasma urea 15N enrichment. These results show that endogenous urea is not the main precursor of faecal ammonia, which is probably derived by bacterial deamination from the protein of dietary residues, intestinal secretions and shed epithelial cells. The minor contribution of endogenous urea to faecal ammonia suggests that the lumen of the large bowel is not the main site of endogenous urea hydrolysis. The similar labelling of faecal total nitrogen and ammonia nitrogen supports other evidence that these faecal nitrogen fractions are in a constant state of exchange.

Estimation of Nitrogen Digestibility in Poultry: Content and Distribution of Major Urinary Nitrogen Compounds in Excreta

The investigation concerned the digestibility of nitrogen and the content of uric acid, ammonia, and urea in urine and feces in White Leghorn layers. Eight colostomized hens were given a commercial cage-layer diet. Feces and urine were collected separately for 4 weeks on 3 consecutive days each week. Urine from four of the hens was collected under acid conditions. Acidified urine contained more ammonia than untreated urine. For quantitative determination of ammonia, urine collection ought to be done under acid conditions. Of urinary nitrogen uric acid represented 88%, ammonia 7%, urea 3%, and 2% unidentified . Urinary ammonia constituted 90% of ammonia in total excreta and urinary urea 86% of the urea in excreta. By means of these distribution factors and content of nitrogen compounds in total excreta, good estimates of the nitrogen digestibility were obtained. Our method appears to be applicable to chickens of other ages, sex, breeds, and environmental conditions.

Studies with Clinoptilolite in Poultry: I. Effect of Feeding Varying Levels of Clinoptilolite (Zeolite) to Dwarf Single Comb White Leghorn Pullets and Ammonia Production

An experiment involving 240 10-month-old dwarf Single Comb White Leghorn layers was carried out to study the effect of feeding clinoptilolite on layer performance and to exploit the ion exchange ability of clinoptilolite for ammonium ion. The layers were housed in individual cages in a naturally-ventilated cage house and fed rations containing 0, 2.5, 5, and 10% clinoptilolite for six 28-day periods. No significant differences in mortality, egg weight, body weight gains, shell quality, or interior egg quality were noticed between the treatments. Significant treatment effects were found in percent egg production, daily feed consumed per layer, feed conversion, and fecal moisture level. Layers fed the 10% clinoptilolite ration produced more daily wet manure per layer than layers fed no clinoptilolite. There were also more tota l dried feces and nonvolatile solids from layers fed rations containing 10% clinoptilolite than layers fed rations without clinoptilolite. However, volatile solids in the dried feces from 10% clinoptilolite-fed layers were less than in dried feces from feeding no clinoptilolite. Fecal pH unit changes after 7 days storage of fecal samples were slightly more in feces from the 10% clinoptilolite-fed layers than in feces from layers fed no clinoptilolite. No consistent lowering trend of fecal ammonia evolution rate was noticed between the fecal samples from layers fed 0 and 10% clinoptilolite. A fishy odor from fecal samples from the 10% clinoptilolite-fed layers was detected.

The effect of meat protein and dietary fiber on colonic function and metabolism II. Bacterial metabolites in feces and urine

The association of high meat protein intakes with a high incidence of large bowel cancer cannot be explained on the basis of current hypotheses for the cause of this cancer. A variety of protein metabolites including the volatile phenols, tryptophan, and ammonia have been implicated in the etiology of cancer. We have, therefore, investigated by using controlled diet studies in four subjects the effect of increasing meat protein intake on bacterial metabolism in the gut as indicated by urinary volatile phenol excretion and fecal ammonia and short-chain fatty acid concentration and tryptophan excretion. The possible protective role of dietary fiber from wheat has also been assessed in relation to these products. Increasing protein intake from 62.7 to 136 g/day increased urinary volatile phenol excretion from 74 ± 14.5 to 108 ± 14.6 mg/day and fecal ammonia concentration from 14.8 ± 1.3 to 30.4 ± 1.1 mmole/liter but did not significantly alter fecal nitrogen excretion. Adding 29.8 g dietary fiber per day to the high protein diet did not alter fecal ammonia concentration despite a large increase in stool output. Urinary total volatile phenol excretion fell (81 ± 4.8 mg/day) and fecal nitrogen excretion almost doubled. The dietary changes did not alter fecal short-chain fatty acid concentrations. Increasing meat intake, therefore, increases the concentration in the feces and excretion in the urine of certain protein metabolites some of which may be carcinogenic. The role of dietary fiber in protecting against large bowel cancer cannot be related to any one single effect on colonic metabolism and may be due to a combination of dilution of colonic contents, shortened transit time, altered bacterial metabolism, or possibly other properties such as adsorption of potentially harmful materials.

Faecal ammonia and pH during lactulose administration in man: comparison with other cathartics.

The effect of lactulose on faecal pH and ammonia has been studied in three normal subjects with the aid of dialysis of faeces in vivo. Observations were also made with sodium sulphate and the two hexahydric alcohols, mannitol and sorbitol, given in doses sufficient to cause a similar increase in stool weight. All four cathartics rendered the stool more acid, but there was no increase in the concentration of faecal ammonia. Lactulose, despite increasing faecal volume, did not cause an increase in the absolute amount of ammonia lost in the faeces, but the other purgatives did show a modest rise. The results are inconsistent with the theory that lactulose benefits the clinical picture of portosystemic encephalopathy by trapping ammonia in an acid stool. An alternative suggestion is advanced, namely, that any cathartic (including lactulose) reduces ammonia absorption from the colon by decreasing colonic transit time, and so reducing the amount of ammonia generated by autolysis of colonic bacteria.

The relation between faecal pH, ammonia, and bicarbonate in man.

The relation between faecal pH, ammonia, and bicarbonate in man.

A Re-Examination of the Excretion of Nitrogen by Terrestrial Isopods

ABSTRACT In spring and summer specimens of Porcellio scaber feeding on old poplar leaves excrete from 0·46 to 1·12 ng. dissolved ammonia/mg. body weight × hr. via the faeces, and from 2·3 to 3·25 ng. in gaseous form via the body wall. Non-feeding specimens excrete an average of 11 ng. ammonia/mg. × hr. in gaseous form. In the course of a normal cycle in which periods of feeding activity alternate with periods of inactivity (temporary starvation), faecal ammonia thus constitutes only 10% of the total ammonia released by the animals. If the gaseous component is taken into account, the rate of nitrogen excretion in terrestrial isopods is comparable with that of fresh water and marine species. Oniscus asellus and P. scaber excrete approximately five times more ammonia in spring and summer than in autumn and winter. The faeces produced by P. scaber contain an average of 220 μg. total nitrogen/ 10 mg. of dry faeces of which 2−4% consist of ammonia. Following abrupt changes of temperature, from 5 to 20°C. and from 20 to 5°C. the rates of the release of ammonia and of the production of faeces follow similar time courses, increasing with an initial Q10 of 3·7 if the change is from the low to the high temperature, decreasing with an initial Q10 of 4·6 if the change is in the opposite direction. It is suggested that in terrestrial isopods nitrogen output in the form of gaseous ammonia more or less balances nitrogen input from leaf litter (the animals’ main source of food) and that no reduction of protein metabolism takes place in terrestrial species of isopods as compared with aquatic species.

Effects of fermented bamboo vinegar liquid on growth performance, nutrient digestibility, faecal Escherichia coli concentration and ammonia emissions in growing pigs

Fermented bamboo vinegar liquid (FBVL) was prepared through liquid fermentation of bamboo vinegar with multispecies probiotics, and its effect on growing pigs was investigated. A 42-day feeding trial with 84 growing pigs (28.0 ± 0.08 kg) was conducted to evaluate the effects of FBVL on growth performance, nutrient digestibility, faecal Escherichia coli concentration and faecal ammonia emissions. Pigs were randomly distributed to one of four dietary treatments, namely control, CTC (0.003% chlortetracycline), FBVL 0.2%, and FBVL 0.4%. Overall, the final weight and daily weight gain of the pigs in the CTC group were higher than that of pigs in the control group. Dietary supplementation with 0.4% FBVL reduced the feed intake of growing pigs, whereas the feed conversion ratio (FCR) was lower in the CTC supplemented group. The dry matter digestibility was higher in pigs fed CTC and 0.2% FBVL diets, and crude protein digestibility was improved in all treatment groups compared with control. The faecal E. coli numbers were reduced in response to CTC and 0.4% FBVL supplementation. Faecal ammonia emissions were reduced by dietary supplementation with CTC and FBVL at weeks 1, 2 and 3. In conclusion, dietary FBVL supplementation increased nutrient digestibility and reduced faecal E. coli population and ammonia emissions without negative effects on growth performance.Keywords: Chlortetracycline, digestibility, fermentation, probiotics, swine