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Administration of charcoal, Yucca schidigera, and zinc acetate to reduce malodorous flatulence in dogs
Abstract
To determine whether feeding activated charcoal, Yucca schidigera, and zinc acetate would ameliorate the frequency and odor characteristics of flatulence in dogs.
In vitro screening of active agents followed by a randomized controlled trial.
8 adult dogs.
A fecal fermentation system was used to assess the effects of activated charcoal, Yucca schidigera, and zinc acetate alone and in combination on total gas production and production of hydrogen sulfide, the primary determinant of flatus malodor in dogs. All 3 agents were subsequently incorporated into edible treats that were fed 30 minutes after the dogs ate their daily rations, and the number, frequency, and odor characteristics of flatulence were measured for 5 hours, using a device that sampled rectal gases and monitored hydrogen sulfide concentrations.
Total gas production and number and frequency of flatulence episodes were unaffected by any of the agents. Production of hydrogen sulfide in vitro was significantly reduced by charcoal, Yucca schidigera, and zinc acetate by 71, 38, and 58%, respectively, and was reduced by 86% by the combination of the 3 agents. Consumption of the 3 agents was associated with a significant decrease (86%) in the percentage of flatulence episodes with bad or unbearable odor and a proportional increase in the percentage of episodes of no or only slightly noticeable odor.
Results suggest that activated charcoal, Yucca schidigera, and zinc acetate reduce malodor of flatus in dogs by altering the production or availability of hydrogen sulfide in the large intestine.
... In a crossover study (18), dogs fed a commercial dry food received placebo and test treats (1 treat/5 kg body weight). Test treats contained three carminatives: activated charcoal (320 mg/treat), Yucca schidigera (2.5 mg) and zinc acetate dihydrate (57 mg). ...
... In 7 dog studies, yucca ingestion (280 mg preparation/kg diet) lowered overall offensiveness scores for feces by 31% (21,22,Notes 2,3). Incubation of dog feces with yucca lowered hydrogen sulfide formation (18), but the mechanism of action remains open. ...
... Dogs were fed their daily ration at 8:30 am, and treats were offered 30 minutes later. Hydrogen sulfide in rectal gas was measured continuously at 20-second intervals between 10:30 am and 3:30 pm on each of the five days of the two treatment periods of the crossover study (18). The number of flatulence episodes (NOE), i.e. the number of hydrogen sulfide readings > 1 ppm during the sampling period, was 12 for the control treat and 8 for the test treat. ...
... Tannins extracted from chestnut (Castanea sativa Miller) wood are characterised by the presence of hydrolysable tannins, which are known to act as effective microbiota modulatory agents in poultry (Jamroz et al. 2009), swine (Biagi et al. 2010) and ruminants (Hassanat and Benchaar 2013). While the administration of Y. schidigera to dogs and cats resulted in lower faecal odour Giffard et al. 2001), to the best of our knowledge, there are no studies on the influence of tannins on the canine and feline intestinal ecosystems. ...
... In the feline experiment, an increase of carbon sulphide and hydrogen sulphide was observed at 6 h in the vessels containing CT, while hydrogen sulphide was decreased at 24 h by addition of CT + YSE. In a previous in vitro study with dog faecal inoculum, the addition of Y. schidigera (0.17 g/l) resulted in lower (−38%) hydrogen sulphide but did not affect total gas production (Giffard et al. 2001). In the study by Swanson et al. (2002), feeding dogs with a Lactobacillus acidophilus supplemented diet tended to increase dimethyl sulphide, methanethiol and hydrogen sulphide faecal concentrations. ...
The in vitro effect of a Yucca schidigera extract (YSE) and tannins from chestnut wood on composition and metabolic activity of canine and feline faecal microbiota was evaluated. Four treatments were carried out: control diet, chestnut tannins (CT), YSE and CT + YSE. The YSE was added to canine and feline faecal cultures at 0.1 g/l, while CT were added at 0.3 g/l for a 24-h incubation. A total of 130 volatile compounds were detected by means of headspace-solid phase microextraction gas-chromatography/mass spectrometry analyses. Several changes in the metabolite profiles of fermentation fluids were found, including a decrease of alcohols (−19%) and esters (−42%) in feline and canine inoculum, respectively, which was due to the antibacterial properties of tannins. In canine inoculum, after 6 h, YSE + CT caused lower cadaverine concentrations (−37%), while ammonia (−4%) and quinolone (−27%) were reduced by addition of CT. After 24 h, the presence of CT resulted in a decrease of sulphur compounds, such as dimethyl sulphide (−69%) and dimethyl disulphide (−20%). In feline faecal cultures, after 6 h, CT lowered the amount of indole (−48%), whereas YSE tended to decrease trimethylamine levels (−16%). Both in canine and feline inoculum, addition of CT and, to a minor extent, YSE affected volatile fatty acids patterns. In canine faecal cultures, CT exerted a marginal inhibitory effect on Escherichia coli population (−0.45 log 10 numbers of DNA copies/ml), while enterococci were increased (+2.06 log 10 numbers of DNA copies/ml) by YSE. The results from the present study show that YSE and tannins from chestnut wood exert different effects on the composition and metabolism of canine and feline faecal microbiota. In particular, the supplementation of YSE and tannins to diets for dogs and cats may be beneficial due to the reduction of the presence of some potentially toxic volatile metabolites in the animals’ intestine.
... Feeding animals with charcoal was common in the late 19th and early 20th centuries. Horses can suffer from colic (Edmunds et al. 2016), dogs can experience flatulence (Giffard et al. 2001), and horses can absorb toxins (Kaye et al. 2012). Claw and foot disease causes substantial economic loss due to decreased body weight, milk output, dry matter intake, herd lifespan, and reproductive efficiency in chickens. ...
In the last decade, both biochar production and use have seen a surge in popularity. Biochar is comparable to charcoal and activated charcoal in that it is a pyrogenic carbonaceous matter made by pyrolyzing organic carbon-rich materials. There is a lack of research into the effects of adding biochar to animal feed. Based on the reviewed literature, including its effects on adsorption of toxins, blood biochemistry, feed conversion rate, digestion, meat quality, and greenhouse gas emissions, adding biochar to the diet of farm animals is a good idea. This study compiles the most important research on biochar's potential as a supplement to the diets of ruminants (including cows and goats), swine, poultry, and aquatic organisms like fish. Biochar supplementation improves animal growth, haematological profiles, meat, milk and egg yield, resistance to illnesses (especially gut pathogenic bacteria), and decrease in methane emission by ruminants. Biochar's strong sorption capacity also helps efficiently remove contaminants and poisons from both the bodies of animals and the farm surroundings in which they are raised. Animal farmers are predicted to make greater use of biochar in the future. Biochar could potentially be of value in the healthcare and human health fields; hence research into this area is encouraged. The present review highlights the potential benefits of biochar as an additive to animal feed and demonstrates how, when combined with other environmentally friendly practices, biochar feeding has the potential to extend the longevity of animal husbandry.
... Based on our calculated medians, it appears that these products are found in higher concentrations in medium than in small dogs. Lastly, to our knowledge there is no data on gas production in dogs and the two studies on gas composition focused on malodorous compounds such as hydrogen sulphide [125,126]. ...
Health and well-being of dogs are of paramount importance to their owners. Digestion plays a key role in dog health, involving physicochemical, mechanical and microbial actors. However, decades of breeding selection led to various dog sizes associated with different digestive physiology and disease sensitivity. Developing new products requires the consideration of all the multi-faceted aspects of canine digestion, the evaluation of food digestibility, drug release and absorption in the gut. This review paper provides an exhaustive literature survey on canine digestive physiology, focusing on size effect on anatomy and digestive parameters, with graphical representation of data classified as "small", "medium" and "large" dogs. Despite the huge variability between protocols and animals, interesting size effects on gastrointestinal physiology were highlighted, mainly related to the colonic compartment. Colonic measurements, transit time permeability, fibre degradation, faecal short-chain fatty acid concentration and faecal water content increase while faecal bile acid concentration decreases with body size. A negative correlation between body weight and Proteobacteria relative abundance was observed suggesting an effect of dog body size on faecal microbiota. This paper gathers helpful in vivo data for academics and industrials and supports the development of new food and pharma products to move towards canine personalized nutrition and health.
... Five studies have compared fecal microbiota composition of obese and lean dogs (Fig. 3). Using 16S rRNA gene pyrosequencing in companion and laboratory dogs, dominance of Firmicutes (> 90%) was observed dogs, and the two available studies on gas composition focused on malodorous compounds such as hydrogen sulfide Giffard et al., 2001). ...
Dogs occupy a full place in the family and their well-being is of paramount importance to their owners. Digestion, a complex process involving physicochemical, mechanical, and microbial parameters, plays a central in maintaining animals healthy. As in vivo studies in dogs are more and more restricted by ethical, regulatory, societal, and cost reasons, an alternative option resides in the use of in vitro models simulating the different parts of the canine gastrointestinal tract. This review paper first introduces digestion and gut microbiota as key factors in dog nutrition and health, under both healthy and diseased conditions (obesity and inflammatory bowel disease), by highlighting when relevant similarities or differences between human and canine digestion process. Then, we provide for the first time an in-depth description of currently available models of the canine digestive tract, discuss technical and scientific challenges that need to be addressed and introduce potential applications of in vitro gut models in food and veterinary fields. Even if the development of some in vitro models remains limited by a lack of in vivo data in dogs necessary for a relevant configuration and validation, translation of long-term expertise on human in vitro gut models to dog's ecosystem opens avenues for canine in vitro gut model development and their adaptation to specific digestive conditions associated to various ages, sizes, breeds and/or diets, under both physiological and diseased states.
... The Zn source has been suggested to differently impact the number and intensity of flatulence episodes due to different production and release of H2S in the large intestine. Giffard et al. reported a reduction of 58% in H2S production with oral administration of Zn acetate, suggesting that the free Zn cations not absorbed in the small intestine bind sulfhydryl compounds such as H2S and methanethiol to form insoluble salts [57]. From these results, it was anticipated that inorganic Zn would reduce the number and intensity of flatulence episodes, but the values among diets were similar. ...
... The Zn source has been suggested to differently impact the number and intensity of flatulence episodes due to different production and release of H2S in the large intestine. Giffard et al. reported a reduction of 58% in H2S production with oral administration of Zn acetate, suggesting that the free Zn cations not absorbed in the small intestine bind sulfhydryl compounds such as H2S and methanethiol to form insoluble salts [57]. From these results, it was anticipated that inorganic Zn would reduce the number and intensity of flatulence episodes, but the values among diets were similar. ...
Zinc is an essential element, a cofactor of many enzymes, and performs catalytic, structural and regulatory functions. Once in the gastrointestinal tract, zinc can interact with food constituents. Phytic acid, the major phosphorus storage in plants, limits zinc availability from animal feeds due to the formation of insoluble complexes with phytates. This study tested the effect of supplemental zinc source (zinc sulfate and a chelate zinc proteinate) and the addition of exogenous enzymes from a solid-state fermentation product of Aspergillus niger to a high phytate diet. The study was designed according to three Latin Squares 4 × 4 with a 2 × 2 factorial arrangement of treatments, with four periods, four diets, and 12 young adult Beagles. Periods lasted 5 weeks each. Diets were supplemented with 75 mg/kg of zinc sulfate (IZ) or zinc proteinate (OZ), and without or with 200 mg/kg of exogenous enzymes (IZ+, OZ+). Results showed that zinc proteinate increased the bioavailability of phosphorus, yet the zinc biomarkers remained unaffected by the zinc source, with the exception of lymphocyte subsets that benefit from zinc proteinate. The use of exogenous enzymes did not affect zinc availability nor nutrient and energy digestibility.
... From the end of 19th to the early 20th century, feeding a regular dosage of charcoal was widely used to improve animal health and growth performance. Activated charcoal has been administered to relieve a range of different digestive problems in various animals including colic in horses (Edmunds et al., 2016), flatulence in dogs (Giffard, Collins, Stoodley, Butterwick, & Batt, 2001) and ingested toxins in horses (Kaye, Elliott, & Jalim, 2012). It is regarded as a universal poison antidote and has been used in time-restricted medications against bacterial toxins such as those produced by Clostridium botulinum, Clostridium tetani and Campylobacter jejuni in chickens (Prasai et al., 2016), as well as against viral animal diseases such as bovine rotavirus and bovine coronavirus in vitro (Toth & Dou, 2016). ...
The production and application of biochar has become increasingly popular in the past 10 years. Biochar has similar characteristics to charcoal and activated charcoal: they are all pyrogenic carbonaceous matter derived from organic carbon-rich materials and produced by pyrolysis. Studies related to the incorporation of biochar in animal feed are limited. This review summarizes major studies related to the use of biochar as a feed additive for ruminants (cattle and goats), pigs, poultry (chickens and ducks) and fish. Documented positive responses to biochar supplementation include improved growth performance, blood profiles, egg yield, ability to resist pathogens including gut pathogenic bacteria and a reduction of methane production by ruminant animals. In addition, the high sorption capacity of biochar efficiently aids the removal of pollutants and toxins from animals’ bodies as well as from farm environments. It is expected that there will be increasing use of biochar in animal farming. The potential use of biochar in the medical and human health sectors should also be explored.
... SENSI diet has been supplemented with Sepiolite (0.8% of the formula) which acts as clay: thanks to its high capacity to absorb excessive water and gas in the intestinal lumen, Sepiolite is aimed to normalize faeces consistency and flatulence [21,22]. Because of its demonstrated effectiveness in reducing faecal odour in a high protein diet as well as faecal ammonia and production of intestinal gases independently of protein content in the diet, Yucca schidigera extract has been incorporated to SENSI (representing 42 ppm of saponins in the diet) [23][24][25]. ...
... Only 18% of the placebo group reported reductions of flatulence [682]. Although administration of charcoal, yucca and zinc acetate reduced the percentage of episodes of malodorous gas [683], there are inconsistent findings about reductions in flatulence from ingesting activated charcoal in humans [165] [684]. Two clinical trials involving small sample sizes (19 and eight persons, respectively ) showed that the over-the-counter product, Beano, which contains α-galactosidase, reduced flatus frequency in normal persons following the ingestion of beans [685] [686]. ...
... In many species, including the horse, charcoal has been administered to relieve a range of different digestive problems including: endotoxemia [22], colic [19], flatulence [8] and ingested toxins [12]. In addition, some companies suggest that it may be useful in treating colitis and/or laminitis, although there appears to be no scientific publication to support these suggestions. ...
The present study uses in vitro analytical techniques to investigate the effect of activated charcoal on the microbial community of the equine hindgut and the metabolites they produce. Incubations were performed in Wheaton bottles using a 50 ml incubation of a high-energy feed or a low-energy feed, plus bottles with no added food source, together with five levels of activated charcoal (0, 10, 25, 50 or 100 mg per bottle) and fecal samples as a bacterial inoculum. Using this method the rate of gas production, volatile fatty acid and ammonia concentrations, and pH values were analyzed and found to vary depending on the addition of feed, but the activated charcoal had no effect (P>0.05) on any of these. It is already believed that the effect of activated charcoal as a control for toxic substances is at its highest in the foregut or midgut of animals, and therefore should have little impact on the hindgut. The data presented here suggest that if any of the activated charcoal does reach the hindgut, then it has no significant impact on the microbial community present, nor on the major metabolites produced, and so should not have a detrimental effect on the principal site of fermentation in the horse.
... Cet effet découlerait de la modification du profil des fermentations microbiennes (inhibition des germes sulfitoréducteurs), avec réduction de la production des métabolites aromatiques impliqués dans la perception d'odeurs désagréables, mais aussi de leur fixation sur le support végétal . L'efficacité de cette plante dans la réduction de la production d'H2S dans le gros intestin du chien, le principal composant responsable du caractère malodorant des épisodes de flatulence, aurait été confirmée ultérieurement (Giffard et al., 2001). ...
... As for the quantity of gas, this may be considered a reflection of intestinal function. In another study evaluating the effect of YSE on flatulence in dogs, it was observed that the additive did not affect the total production of gas and the number and frequency of episodes of flatulence; however, it reduced the production of hydrogen sulphide by 38% (Giffard et al. 2001). Although the program and the method used to measure the intestinal gas field are recent, there is still a need for improvement to match the pictures taken and the mechanism for measuring the gas area. ...
This study evaluated the effects of inclusion of Yucca schidigera extract (YSE) in two diets with different levels of crude protein (CP) for dogs on facal odour, nutrient digestibility, ammonia concentration in feces and hematological and serum biochemical profiles. Twenty adults Beagles were used, distributed in a randomized block design in a 2 × 4 factorial design (two diets, 25% and 34% CP, and four YSE levels: 0, 250, 500 and 750 mg/kg) with five replicates, obtained during two experimental periods. The fecal odour reduced (P < 0.05) when 500 mg/kg of YSE was used in diets with higher CP. The inclusion of YSE reduced (P < 0.05) fecal ammonia, and the inclusion of 250 and 500 mg/kg YSE reduced intestinal gas. The inclusion of 750 mg/kg YSE increased the mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT) activity and tended to increase the serum cholesterol concentration, regardless of the protein level of the diets. There was no effect on the digestibility of nutrients, fecal consistency, nitrogen balance and thickness of the intestinal wall. The inclusion of 500 mg/kg YSE is effective in reducing fecal odour in dogs receiving diets with 34% of CP. Regardless of the protein content, YSE reduces fecal ammonia, but may cause adverse effects if included at higher doses.
... However, another investigation showed no reductions from charcoal after eating baked beans. [49][50][51] The benefits of charcoal on flatus odor are unproved. The combination of charcoal, Yucca schidigera, and zinc acetate reduced malodorous flatulence by 86% in one study, but charcoal had no effect in another investigation. ...
Gaseous symptoms including eructation, flatulence, and bloating occur as a consequence of excess gas production, altered gas transit, or abnormal perception of normal amounts of gas within the gastrointestinal tract. There are many causes of gas and bloating including aerophagia, luminal obstructive processes, carbohydrate intolerance syndromes, small intestinal bacterial overgrowth, diseases of gut motor activity, and functional bowel disorders including irritable bowel syndrome (IBS). Because of the prominence of gaseous complaints in IBS, recent investigations have focused on new insights into pathogenesis and novel therapies of bloating. The evaluation of the patient with unexplained gas and bloating relies on careful exclusion of organic disease with further characterization of the underlying condition with directed functional testing. Treatment of gaseous symptomatology should be targeted to pathophysiologic defects whenever possible. Available therapies include lifestyle alterations, dietary modifications, enzyme preparations, adsorbents and agents which reduce surface tension, treatments that alter gut flora, and drugs that modulate gut transit.
Köpeklerin sağlıklı beslenmesine önem veren insanların sayısı gün geçtikçe artmaktadır. Bundan dolayı fonksiyonel faydaları olduğu bilinen gıdalar ve katkılar köpek sahipleri arasında popülerlik kazanmaktadır. Artan bu ilgi ile birlikte evcil hayvanların sağlığını optimize etmek için fonksiyonel katkıların rolü önem kazanmaya başlamıştır. Biyoaktif fonksiyonel özellikleri nedeniyle sık kullanılan bitkilerden biri de Yucca schidigera’dır. Yucca ekstraktı insan, at, çiftlik hayvanları ve kedi-köpek diyetlerinde uzun süredir yem katkı maddesi olarak kullanılmaktadır. Yucca tozunun veya ekstraktının ana bileşenleri, antioksidan, antienflamatuar, antiviral, antiprotozoal, antimutajenik, antikanser ve kolesterol azaltımına sahip steroidal saponinler, polisakkaritler ve polifenollerdir. Yucca sağlık ve performansa olumlu etkileri, besin madde yararlanımı artırma, dışkı kokusunu azaltma, amonyak ve hidrojen sülfit gibi bazı zararlı uçucu bileşiklerin giderilmesi amacıyla köpeklerde diyet katkı maddesi olarak değerlendirilir. Fakat, dışkı kokusunu azaltıcı etkileri dışında köpekler üzerindeki etkileri bilinmemektedir. Bu derlemede Yucca schidigera’nın köpeklerde sağlık, sindirilebilirlik, dışkı kokusu, bağırsak gazı oluşumu, kan parametreleri, oksidasyon ve dışkı mikrobiyotasına olan etkileri açıklanmıştır.
One of the raw forms of graphite is activated charcoal which has an extensive surface area allowing for the adsorption of a wide range of chemicals. It possesses the strongest physical adsorption forces of the available materials, as well as the largest volume of adsorbing porosity. Activated charcoal acts as an adsorbent, collecting and storing substances in the gastrointestinal tract, reducing or blocking absorption in the bloodstream. The ingested toxins interact with charcoal by recycling toxins in the intestinal cavity. In cases where the drug has not been absorbed from the abdominal system, it is recirculated through the liver and intestines or by means of passive diffusion or active secretion. The article aims to review the most recent advances in the use of the activated charcoal, including the dose, how charcoal acts in the body, the mechanism of action, administration, contraindications, as well as the impact of various factors on the adsorption process. In addition, we also discussed numerous medical applications of activated charcoal.
This in vitro study aimed to evaluate the effects of Yucca schidigera powder (YSP) and inulin (IN) on protein fermentation metabolites (short-chain fatty acids [SCFA] and branched-chain fatty acids, phenolic and indolic compounds, biogenic amines, ammonia and pH) by using faecal inocula from dogs fed either a low (L) or a high (H) protein diet (crude protein 201 or 377 g/kg as fed). Four treatments for each diet were evaluated in an in vitro batch culture system over 24 h: (1) control with no addition of substrates; (2) 4 g YSP/l; (3) 5 g IN/l; (4) 4 g YSP/l in combination with 5 g IN/l of faecal culture of dogs fed Diet L or H. Several changes in fermentation metabolites were analysed. Samples incubated with the faecal inocula of dogs fed Diet L produced higher concentrations of total SCFA, propionate (p = 0.001), acetate (p ≤ 0.001), d-lactate (p = 0.041) and indole (p = 0.003), whereas pH (p = 0.004) was decreased. Supplementation of IN increased the content of putrescine, d- and l-lactate, total SCFA, acetate, propionate, n-butyrate (p ≤ 0.001) and n-valerate (p = 0.003), while i-valerate, indole and pH (p ≤ 0.001) were reduced. Ammonia was lower (p = 0.013) in samples with faecal inocula from dogs fed Diet H and further reduced by the addition of IN (p ≤ 0.001). Samples with faecal inocula from dogs fed Diet L had a fewer quotient of ammonia and total SCFA (p = 0.040). Supplementation of YSP (p = 0.021), IN (p ≤ 0.001) and YSP in combination with IN (p = 0.047) led to a higher reduction of the quotient of ammonia and total SCFA. In conclusion, dietary protein concentration and the supplementation of IN resulted in a stimulation of fermentation while YSP appeared to have only minor effects.
Background:
The pathogenesis and treatment of cutaneous malodour in dogs have not been investigated previously. Staphylococcus and Corynebacterium spp. are associated with human axillary malodour.
Hypothesis:
Staphylococcus and Corynebacterium spp. are associated with cutaneous malodour in dogs, and treatment with a topical essential oil-based product will improve malodour and reduce the abundance of odour-causing bacteria.
Animals:
Twenty seven bloodhound dogs from a south Texas boarding facility were enrolled in this study.
Methods and materials:
Skin swabs were taken from the axilla and dorsum of 27 dogs at initiation of the study. Mean malodour scores were used to assign dogs to control or malodour groups. The malodourous dogs were randomly assigned to a treatment or placebo group, received four weekly topical applications of the spot-on or placebo, and samples were recollected. Next-generation sequencing (NGS) and real-time quantitative PCR (qPCR) were performed on all swabs.
Results:
Psychrobacter and Pseudomonas spp. were significantly more abundant (P < 0.001, P = 0.006; respectively), and overall bacterial diversity was reduced (P = 0.0384) on the skin of malodourous dogs. Staphylococcus and Corynebacterium spp. were not associated with malodour. The topical essential oil-based product significantly (P = 0.0078) improved malodour in the treatment group and shifted their bacterial community structure.
Conclusions and clinical importance:
A novel association of bacterial genera with malodour in bloodhound dogs, identified by NGS, highlights future targets for odour control. The topical treatment significantly reduced malodour. The interaction between the topical treatment and cutaneous microbiota should be further investigated and may be useful in other dermatological conditions involving microbiota.
Flatulence is defined as excessive formation of gases in the stomach or intestine. It is usually associated with noticeable flatus, belching, borborygmus, abdominal distention, or a combination of these signs. Excessive aerophagia is a risk factor for flatulence and is noted commonly in brachycephalic, working, and sporting breeds as well as in dogs with aggressive or competitive eating behaviors. The primary goal of dietary management of flatulence is to reduce the gas formation that results from bacterial fermentation of intestinal substrates.
Different masking materials were evaluated for their ability to ameliorate odor of model poultry manure solution by assessing their effects oil sensory pleasantness and odor intensity Results indicated extracts from Eastern red cedar leaves, Loblolly pine needless, and commercial masking agents such as pine extract and odor neutralizer were effective (p < 0.05) for masking odor of model poultry manure solution by increasing (p < 0.05) pleasantness (82 and 86% increases in pleasantness using red cedar and pine needle extracts, respectively) and decreasing (p < 0.05) odor intensity (odor intensity reduction by 66 and 76% using red cedar pine needle extract). The most odor-active compound in Loblolly pine needle extract was alpha-terpineol (1,573.8 ug/g) which is responsible for aroma of pine trees (piney) and effective for ameliorating agricultural odors.
In a completely randomized block design experiment, 16 ruminally cannulated sheep (40±2.1 kg) fed a 50% concentrate: 50% forage diet (DM basis) were given intraruminal doses of powdered Yucca schidigera extract (YSE). Doses of 0 (control), 100, 200, or 300 mg kg−1 diet were given at 8 p.m. and 4 a.m. On 15, 16, and 17 d of the experimental period, ruminal contents were sampled 0, 2, 4, 6, and 8 h after dosing, and blood samples were collected at the end of the experiment (18th and 19th d). Acidity was not affected (P > 0.05) by the addition of YSE. Compared with the control, ruminal propionate concentration was increased by 29.4 and 29.8% (P > 0.05) and the acetic acid concentration was decreased by 15.1 and 19.8% (P > 0.05) at 4 and 6 h after YSE (300 mg kg−1) dosing, respectively. Ruminal ammonia concentration in the first 2 h after feeding was higher (P < 0.05) in the sheep that did not receive YSE (increased by 17.57 mg 100 mL−1) than in those that received 200 mg kg−1 (increased by 6.77 mg 100 mL−1) or 300 mg kg−1 (increased by 6.50 mg 100 mL−1) YSE. Protozoan populations in the rumen were lower (P < 0.05) in the animals that received 300 mg kg−1 of YSE compared with the control. All serum parameters of the four groups were in the normal range and were similar among the treatment groups (P > 0.05), after being fed for 19 d with different doses of YSE. The effect of YSE on ruminal ammonia concentration likely resulted from a decreased concentration of protozoan populations and, presumably, from ammonia binding by YSE.
This review covers methods that have been applied to study the nutrient value or quality of specific ingredients fed to dogs, cats and comparable species (i.e. foxes, minks, rats, etc.). Typically, the nutritional value or utilization of a specific ingredient is measured by total tract digestibility and has been expanded through the measurement of total nutrient balance (i.e. nitrogen or energy). However, to better understand digestion it is necessary to obtain a more accurate measurement of nutrients entering and leaving the small intestine. Accurate measurement of small intestinal digestion is crucial in dogs and cats because nutrient digestion and absorption occurs primarily in the small intestine. Measuring small intestinal digestibility requires access to digesta leaving the small intestine and can be obtained by placing a cannula at the terminal ileum. This approach also necessitates the use of markers (e.g. chromic oxide) to monitor flow of digesta. Specifically, this approach has been used for the direct measurement of intestinal digestion of carbohydrates and amino acids. It also permits a separate measurement of large intestinal digestion which is particularly useful for the study of fiber fermentation. Passage of foods through the gastrointestinal tract is also an important component of utilization and these methods are reviewed.
In a completely randomized block design experiment, 16 ruminally cannulated male sheep(40±2.1 kg)fed a 50% Concentrate:50% Forage diet(DM basis)were given intraruminal doses of powdered Yucca schidigera extract(YSE). Doses of 0 (control), 100, 200or 300 mg/kg diet were fed twice at 8:00 and 16:00 daily. On 15th,16th,and 17th d of experimental period, ruminal content was sampled 0,2,4,6 and 8 h after dosing (8:00), and blood samples were collected at the end of experiment (18th, 19th d).Results showed that acidity was not affected (P=0.13)by YSE. Relative to control, ruminal propionate concentration was increased by YSE addition in a dose-dependent manner by up to 29.8%(P
In a completely randomized block design experiment, 16 ruminally cannulated male sheep with body weights of (40 ± 2.1) kg
were fed twice daily (8:00 and 16:00) with concentrate and forage (50:50 on dry matter (DM) basis). Dietary treatments were
supplemented with intraruminal doses of powdered Yucca schidigera extract (YSE) at the levels of 0 (control), 100, 200 and 300 mg · kg−1. On days of 15, 16 and 17 after feeding, ruminal content was sampled at 0, 2, 4, 6 and 8 h after dosing (8:00), and blood
samples were collected at the end of experiment (the days 18 and 19 after feeding). Results showed that the treatment groups’
acidity was not affected (P = 0.13) by YSE. Comparing to the control, the ruminal propionate concentration was increased by YSE addition in a dose-dependent
manner by up to 29.8% (P < 0.05), and the acetic concentration was decreased by up to 17.5% (P < 0.05). The ruminal ammonia concentration 2 hours after feeding was higher (P < 0.05) in sheep fed without YSE (increased by 17.57 mg· 100 mL−1) than those fed with YSE at 200 mg · kg−1 (6.77 mg · 100 mL−1 increase in NH3) and at 300 mg · kg−1 (6.50 mg· 100 mL−1 increase in NH3). Protozoal populations in the rumen were lower (P < 0.05) with the YSE feeding dose at 300 mg · kg−1 than the control. The serum chemistries were not different among treatments (P > 0.05) and were within the normal physiological ranges for sheep 19 days after feeding. The study indicated that 200 mg·
kg−1 and 300 mg· kg−1 YSE groups had particular suppressing effects on ruminal ammonia concentration, ammonia-N concentrations and protozoal populations.
The effect of YSE on ruminal fermentation could be attributed to the selective inhibitory effect on rumen microbial species.
High level (300 mg · kg−1) YSE as feed additives resulted no negative impact on sheep in our tests.
To develop a noninvasive method for the in vivo assessment of flatulence in dogs.
8 adult dogs.
Rectal gases were collected via a perforated tube held close to each dog's anus and attached to a monitoring pump fitted with a sensor that recorded hydrogen sulfide concentrations every 20 seconds. Patterns of flatulence were monitored for 14 hours after feeding on 4 days, and within- and between-dog variation was assessed over 4 hours on 4 consecutive days. Rate of hydrogen sulfide production (flatulence index) and frequency and number of emissions were evaluated as potential indicators of flatus characteristics. An odor judge assigned an odor rating to each flatulence episode, and the relationship between that rating and hydrogen sulfide concentration was determined.
Flatulence patterns varied within and between dogs. Variation was most pronounced for flatulence index; mean coefficients of variance within dogs over time and between dogs on each day were 75 and 103%, respectively. Flatus with hydrogen sulfide concentrations > 1 parts per million could be detected by the odor judge, and severity of malodor was highly correlated with hydrogen sulfide concentration. Odor ratings were accurately predicted by use of the equation 1.51 X hydrogen sulfide concentration(0.28).
The technique described in this report appears to provide sensitive, reliable, and relevant data and will enable further studies of the factors that influence flatulence in dogs. Use of this technique also has the potential to aid in investigations of colonic physiology and pathology.
A mixed culture of human fecal bacteria was grown for 120 days in a three-stage continuous culture system. To reproduce some of the nutritional and pH characteristics of the large gut, each vessel had a different operating volume (0.3, 0.5, and 0.8 liter) and pH (6.0, 6.5, and 7.0). A mixture of polysaccharides and proteins was used as carbon and nitrogen sources. Measurements of H2, CH4, S2-, sulfate reduction rates, sulfate-reducing bacteria (SRB), and volatile fatty acids were made throughout the experiment. After 48 days of running, porcine gastric mucin (5.8 g/day) was independently fed to vessel 1 of the multichamber system. The mucin was extensively degraded as evidenced by the stimulation of volatile fatty acid production. In the absence of mucin, sulfate-reducing activity was comparatively insignificant and methanogenesis was the major route for the disposal of electrons. The reverse occurred upon the addition of mucin; sulfate reduction predominated and methanogenesis was completely inhibited. This was attributed to release of sulfate from the mucin which enabled SRB to outcompete methanogenic bacteria for H2. SRB stimulated by mucin were acetate-utilizing Desulfobacter spp., lactate- and H2-utilizing Desulfovibrio spp., and propionate-utilizing Desulfobulbus spp. When the mucin pump was switched off, the multichamber system reverted to a state close to its original equilibrium. These data provide further evidence that sulfated polysaccharides such as mucin may be a source of sulfate for SRB in the human large gut.
It has been proposed that the reduction in n-butyrate oxidation by colonic epithelial cells observed in ulcerative colitis may be related to exposure to reduced forms of sulfur derived from dissimilatory sulfate reduction by luminal microflora. This study aims to compare stool sulfide concentrations in control and colitic subjects. Control subjects had significant colorectal disease excluded by virtue of their selection. Patients with ulcerative colitis were stratified by disease extent and activity, and by salicylate drug use. Stool sulfide was measured using a direct spectrophotometric method on NaOH (free sulfide) and zinc acetate (total sulfide) stool slurries. Fifteen control and 19 colitic subjects were studied. There was no significant difference in stool sulfide between control and colitic patients (free sulfide, control = 0.52 (0.17), colitic = 0.45 (0.10), t = 0.36, P = 0.71, total sulfide, control = 1.33 (0.21), colitic = 0.96 (0.15), t = 1.44, P = 0.16). Disease extent or activity did not significantly influence stool sulfide. These results do not support a primary etiologic role for luminal sulfide in ulcerative colitis.
This paper describes a simple yet sensitive laboratory procedure that was developed to provide detailed information on the fermentation kinetics of ruminant feeds. In principle, the technique is similar to other in vitro digestibility procedures using ground particulate substrates, anaerobic media and a rumen fluid inoculum. It differs, however, in that incubations are conducted in gas-tight culture bottles, thus enabling gases to accumulate in the head-space as the fermentation proceeds. A pressure transducer connected to a digital readout voltmeter and gas-tight syringe assembly is then used to measure and release the accumulated gas pressures from the incubating culture bottles. By repeating this gas-measurement, gas-release procedure at regular intervals during the fermentation, it is possible to construct gas accumulation profiles for feeds by summation of regression-corrected gas volumes. These profiles are then described using a recently derived growth function developed to characterise gas production profiles. Results obtained establish the pressure transducer as a suitable tool for determining the fermentation kinetics of ruminant feeds and ranking them with respect to their in vitro fermentability.
Adsorption of hydrogen sulfide, methanethiol, methyl sulfide, trimethylamine, and ammonia on thirteen kinds of adsorbents (5 kinds of silicate, 4 kinds of activated carbon, and 4 kinds of zeolite) was measured by gravimetry, at 30 degrees C and 50 Torr, using an adsorption apparatus with a spring balance in order to find the most suitable adsorbent for the removal of these gases by dry process. The relations between the amount of these gases adsorbed (mmol/cm2) on the adsorbent and the surface properties or the porous structure were examined to clarify the mechanism of adsorption of these gases on them through surface pH, pore size distribution, and area of an adsorbed particle of these gases. Among the thirteen adsorbents, the activated carbon Nos. 6 and 7 were the most suitable adsorbent for methanethiol, methyl sulfide, and trimethylamine whose area of an adsobed particle (wrho) was larger than about 17 A2, and zeolite Nos. 12 and 13 were most suitable for removal of hydrogen sulfide and ammonia (wrho less than about 17A2). The amount of these gases adsorbed (mmol/cm2) on these adsorbents was mainly determined by their porous structure rather than by their surface properties.
Flatulence can cause discomfort and distress but there are few published data of normal patterns and volumes. Twenty four hour collections were made using a rectal catheter in 10 normal volunteers taking their normal diet plus 200 g baked beans. Total daily volume ranged from 476 to 1491 ml (median 705 ml). Women and men (both n = 5) expelled equivalent amounts. The median daily flatus hydrogen volume was 361 ml/24 h (range 42-1060) and the carbon dioxide volume 68 ml/24 h (range 25-116), three volunteers produced methane (3, 26, and 120 ml/24 h), and the remaining unidentified gas (presumably nitrogen) or gases contributed a median 213 ml/24 h (range 61-476). Larger volumes of flatus were produced after meals than at other times. Flatus produced at a faster rate tended to contain more fermentation gases. Flatus was produced during the sleeping period, but the rate was significantly lower than the daytime rate (median 16 and 34 ml/h respectively). Ingestion of a 'fibre free' diet (Fortisip) for 48 hours significantly reduced the total volume collected in 24 hours (median 214 ml/24 h), reduced the carbon dioxide volume (median 6 ml/24 h), and practically eradicated hydrogen production. The volume of unidentified gas was not significantly affected (median 207 ml/24 h). Thus fermentation gases make the highest contribution to normal flatus volume. A 'fibre free' diet eliminates these without changing residual gas release of around 200 ml/24 h.
Idiopathic chronic colitis was diagnosed in 13 dogs. Owners sought veterinary care because of semiformed to liquid feces, fresh blood and/or mucus in the feces, tenesmus, increased frequency of defecation, vomiting, weight loss, and flatulence in their dogs. A lymphocytic, plasmacytic infiltration in the colonic lamina propria was found on colonic biopsy specimens. Signs resolved in all 13 dogs after they were fed a low residue, easily assimilated, relatively hypoallergenic diet. In 11 dogs, two commercial diets not previously fed to these dogs were successfully substituted for the initial test diet, without causing recurrence of signs. Only two of these 11 dogs subsequently tolerated a switch to diets that had been fed at the time of onset of signs of colitis. All 13 dogs have been successfully managed from 2 months to 28 months following the initiation of dietary therapy. The results of these dietary challenges strongly suggest a dietary role in the pathogenesis of this disorder, and also illustrate the importance of dietary therapy in the management of idiopathic chronic colitis.
It has been reported that activated charcoal reduces intestinal gas production after ingestion of beans as evidenced by decreased breath hydrogen excretion and decreased passage of flatus. In the present study we assessed the ability of activated charcoal to reduce intestinal gas production by in vitro and in vivo methods. In vitro studies were performed using human fecal homogenates incubated with or without additional carbohydrate. In all studies hydrogen and carbon dioxide production and consumption occurred at similar rates in the charcoal-treated homogenate as compared with the untreated control. The influence of activated charcoal on gas production, in vivo, was studied by double-blind assessment of breath hydrogen excretion and flatus excretion after ingestion of a baked bean meal. No significant difference was observed in breath hydrogen concentration or number of passages of flatus in subjects who ingested 16 capsules of activated charcoal (4 g) as opposed to the placebo. We conclude that activated charcoal does not influence gas formation in vitro or in vivo.
The relationship between the small intestinal and colonic flora and the gas volumes and composition resulting from the introduction of navy bean homogenates into surgically prepared intestinal segments of normal and antibiotically pretreated dogs was investigated. Intestinal gas production was effectively inhibited or greatly reduced in animals pretreated with Neomycin Sulfate and Sulfathalidine, Mexaform, and Vioform, following the administration of navy bean homogenates. Mexaform and Vioform effectively destroyed the anaerobic bacteria of the intestinal tract while the normal aerobic and coliform bacteria increased in total numbers, indicating that the increased gas production from a navy bean homogenate was due to the anaerobic intestinal flora. Contrary to some current belief, it has been shown that bacterial action in the duodenum, jejunum, and ileum of the dog may add significantly to the total intestinal gas volume of animals fed navy bean homogenates.
The volume and composition of intestinal gas of 11 normal subjects was studied by means of a technic in which an intestinal infusion of argon was used to wash out gases present in the bowel. These studies indicated that the bowel normally contains relatively small quantities of gas ranging from 30 ml to 200 ml. The composition of this gas was highly variable although N2 was usually the predominant gas whereas O2 was present in concentrations of less than 2 per cent. Gases produced within the bowel (CO2, H2 and CH4) accounted for most of the gas of three subjects. Intestinal bacteria directly influence the composition of intestinal gas through their production of H2, CH4 and CO2 and utilization of O2 and, by reducing the luminal PN2, indirectly influence the N2 content of the bowel.
The effectiveness of activated charcoal in treating intestinal gas, following a gas producing meal, was compared with a placebo. Both the number of flatus events and breath hydrogen levels were measured. These experiments showed that orally administered activated charcoal was effective in preventing the large increase in the number of flatus events and increased breath hydrogen concentrations that normally occur following a gas-producing meal.
To examine the influence of dietary factors in Italian patients with ulcerative colitis and Crohn's disease.
We studied dietary habits immediately prior to the onset of disease in 104 patients enrolled in a prospective, epidemiological study of the incidence of inflammatory bowel disease in Italy.
Each patient was interviewed using a recall questionnaire to provide information on the daily intake of nutrients. The differences in diet between patients and healthy subjects matched for age, sex and city of residence were determined.
Our data confirm that patients with Crohn's disease and ulcerative colitis have a high intake of total carbohydrate, starch and refined sugar. This resulted in a significantly higher relative risk (P < 0.001) in both ulcerative colitis and Crohn's disease patients. Total protein intake was significantly higher in ulcerative colitis, but not in Crohn's disease patients, than in controls. Fibre consumption did not differ between patients and controls.
Our results confirm that carbohydrate consumption is significantly higher in IBD patients than in healthy controls. Ulcerative colitis patients also consumed more total protein than controls. The pathogenetic significance of these findings, however, remains unclear.
The purpose of the present study was to measure the frequency of flatus emission by 25 healthy subjects and to determine if factors commonly thought to influence flatulence actually correlate with the frequency of gas passage. Over a one-week period on their usual diet, subjects passed gas 10 +/- 1 times/day [upper limit of normal (mean + 2 SD): 20 times/day]. The addition of the nonabsorbable disaccharide lactulose (10 g/day) to the diet significantly (P < 0.01) increased flatus frequency to 19 +/- 2.4 times per day. Gender, age, and the ability of an individual's colonic flora to produce methane had no significant influence on flatus frequency either on the basal or lactulose-supplemented diets. Some subjects consistently passed gas more often than did others. These individual differences appeared to result, in part, from differences in the ability of the flora to produce gas from a given quantity of fermentable material.
To better understand the physiology of colonic gas production, each flatus passage of 16 subjects over a 4-h period was analyzed by gas chromatography for N2, O2, H2, CO2, CH4, and for odoriferous sulfur-containing gases. Appreciable intraindividual and enormous interindividual variability was observed, indicating that each gas passage reflected the interaction of highly variable liberation and/or removal mechanisms. The predominant flatus gas was CO2, H2, and N2 in seven, six, and three subjects, respectively. Gases produced intraluminally (H2, CO2, and CH4) comprised approximately 74% of flatus, and rapid CO2 and H2 productions were responsible for high passage rates. A positive correlation between flatus H2 and CO2 suggested that CO2, like H2, mainly was a bacterial product. Whereas methanogens and H2S-producing bacteria usually are mutually exclusive in feces, CH4 and H2S did not negatively correlate, indicating coexistence of both organisms in the colon. We conclude that analysis of flatus composition provides a novel means of assessing colonic physiology, particularly ongoing bacterial metabolism throughout the unperturbed colon.
A role for colonic sulfide in the pathogenesis and treatment of ulcerative colitis (UC) has emerged based on biochemical, microbiological, nutritional, toxicological, epidemiological, and therapeutic evidence. Metabolism of isolated colonic epithelial cells has indicated that the bacterial short-chain fatty acid n-butyrate maintains the epithelial barrier and that sulfides can inhibit oxidation of n-butyrate analogous to that observed in active UC. Sulfur for fermentation in the colon is essential for n-butyrate formation and sulfidogenesis aids disposal of colonic hydrogen produced by bacteria. The numbers of sulfate-reducing bacteria and sulfidogenesis is greater in UC than control cases. Sulfide is mainly detoxified by methylation in colonic epithelial cells and circulating red blood cells. The enzyme activity of sulfide methylation is higher in red blood cells of UC patients than control cases. Patients with UC ingest more protein and thereby sulfur amino acids than control subjects. Removing foods rich in sulfur amino acids (milk, eggs, cheese) has proven therapeutic benefits in UC. 5-Amino salicylic acid reduces fermentative production of hydrogen sulfide by colonic bacteria, and aminoglycosides, which inhibit sulfate-reducing bacteria, are of therapeutic benefit in active UC. Methyl-donating agents are a category of drugs of potential therapeutic use in UC. A correlation between sulfide production and mucosal immune responses in UC needs to be undertaken. Control of sulfidogenesis and sulfide detoxification may be important in the disease process of UC, although whether their roles is in an initiating or promoting capacity has yet to be determined.
Addition of Yucca schidigera extract (YSE) products to canine or feline diets improved faecal aroma as monitored by a human panel. Odour port-gas chromatography (GC) indicated different odour component types in dog faecal volatiles and, in particular, 'faecal'-type odours due to methyl sulfides. GC-mass spectrometry demonstrated several chemical compound classes present in faecal volatiles and quantitation in the cat indicated apparently significant changes in the concentrations of several compounds on YSE treatment, although these were not necessarily aroma components. The potential for direct YSE alteration of aroma perception in a mixture of volatiles, possibly by binding, was demonstrated.
Addition of Yucca schidigera extract (YSE) products to canine or feline diets improved the character and reduced the intensity of faecal aroma as monitored by a human panel. The general condition of the animals was not adversely affected as monitored by faecal pH, food retention time, and blood cell counts. Blood urea increased significantly in YSE-treated cats, possibly due to the saponins of YSE affecting gut wall permeability. This finding contrasts with previously published reports of a reduction in blood urea on the addition of sarsaponin (from YSE) to rat diets and of YSE products to poultry and cattle diets.
Sulfide, a product of sulfate-reducing bacteria, has been proposed to play an etiologic role in ulcerative colitis. Ulcerative colitis feces have increased numbers and activity of sulfate-reducing bacteria, but only modestly increased sulfide. However, fecal sulfide exists largely in the volatile, highly toxic H2S form that moves rapidly from feces to surrounding gas. Our aim was to quantify the fecal release of H2S and other volatiles (CO2, H2, CH4, methanethiol, and dimethylsulfide).
Fecal samples from 25 subjects with ulcerative colitis and 17 controls were incubated in 4-L containers, and gas release was assessed at intervals over 24 h.
H2S release by ulcerative colitis feces was elevated 3-4-fold at every measurement point compared with normal feces (p < 0.003 at 24 h). The only other significant difference was increased CO2 release by ulcerative colitis feces at 1 h. Supplementation of fecal homogenates with sulfur-containing substrates showed that organic compounds (mucin, cysteine, taurocholate) provided more readily utilizable substrate for H2S production than did sulfate.
Increased H2S release is a relatively localized metabolic aberration of ulcerative colitis feces. This increased H2S may reflect abnormalities of the fecal bacteria and/or substrate availability.
Hydrogen sulfide is one of the main malodorous compounds in human flatus. This toxic gas also has been implicated in the pathogenesis of ulcerative colitis. Therefore, a treatment that reduces colonic H2S levels could be clinically useful in the treatment of flatus odor and of ulcerative colitis. In this study the ability of bismuth subsalicylate, a compound that binds H2S, to reduce H2S release in the colon, was tested.
Homogenates made from human and rat feces were incubated with and without bismuth subsalicylate, and gas production was measured. Fecal samples from 10 healthy subjects were analyzed before and after ingestion of bismuth subsalicylate (524 mg four times a day) for 3-7 days.
Fecal homogenates showed a dose-dependent relationship between the concentration of bismuth subsalicylate and H2S release. Treatment of subjects with bismuth subsalicylate produced a >95% reduction in fecal H2S release.
The ability of bismuth subsalicylate to dramatically reduce H2S could provide a clinically useful means of controlling fecal and/or flatus odor and of decreasing the putative injurious effects of H2S on the colonic mucosa.
The disease process of ulcerative colitis (UC) is associated with a block in beta-oxidation of short chain fatty acid in colonic epithelial cells which can be reproduced by exposure of cells to sulfides. The aim of the current work was to assess the level in the beta-oxidation pathway at which sulfides might be inhibitory in human colonocytes. Isolated human colonocytes from cases without colitis (n = 12) were exposed to sulfide (1.5 mM) in the presence or absence of exogenous CoA and ATP. Short chain acyl-CoA esters were measured by a high performance liquid chromatographic assay. 14CO2 generation was measured from [1-14C]butyrate and [6-14C]glucose. 14CO2 from butyrate was significantly reduced (p < 0.001) by sulfide. When colonocytes were incubated with hydrogen sulfide in the presence of CoA and ATP, butyryl-CoA concentration was increased (p < 0.01), while crotonyl-CoA (p < 0.01) and acetyl-CoA (p < 0.01) concentrations were decreased. These results show that sulfides inhibit short chain acyl-CoA dehydrogenase. As oxidation of n-butyrate governs the epithelial barrier function of colonocytes the functional activity of short chain acyl-CoA dehydrogenase may be critical in maintaining colonic mucosal integrity. Maintaining the functional activity of dehydrogenases could be an important determinant in the expression of ulcerative colitis.
Highly toxic sulfur-containing gases have been pathogenetically implicated in ulcerative colitis. Utilizing a rat model, we studied the production and elimination of sulfur-containing gases within the unperturbed colon. The major sulfur-containing gases were hydrogen sulfide (H2S), methanethiol, and dimethyl sulfide with cecal accumulation rates of 2.6, 0.096, and 0.046 microliter/min, respectively. The dependence of H2S production on dietary components was demonstrated via a sixfold reduction with fasting and a fivefold increase with carrageenan (a nonabsorbable, sulfur compound) feeding. Zinc acetate reduced cecal H2S by fivefold, indicating the importance of H2S binding by divalent cations. During passage from the cecum to the rectum, > 90% of the sulfur gases were absorbed or metabolized. An H2 35S turnover of 97%/min was observed in the isolated cecum. Thus mucosal exposure is > 10 times the measured accumulation rate. Cecal mucosal tissue very rapidly metabolized H2S and methanethiol via a nonmethylating reaction.
While the social significance of flatus derives mainly from its odour, previous studies have focused on the non-odoriferous components of rectal gas. The aims of the present study were to determine the role of sulphur-containing gases in flatus odour and test the efficacy of a device purported to reduce this odour.
Flatus was quantitatively collected via rectal tube from 16 healthy subjects who ingested pinto beans and lactulose to enhance flatus output. The concentrations of sulphur-containing gases in each passage were correlated with odour intensity assessed by two judges. Odour intensity was also determined after treatment of flatus samples with zinc acetate, which binds sulphydryl compounds (hydrogen sulphide and methanethiol), or activated charcoal. Utilising gastight Mylar pantaloons, the ability of a charcoal lined cushion to adsorb sulphur-containing gases instilled at the anus of eight subjects was assessed.
The main sulphur-containing flatus component was hydrogen sulphide (1.06 (0.2) mumol/l), followed by methanethiol (0.21 (0.04) mumol/l) and dimethyl sulphide (0.08 (0.01) mumol/l) (means (SEM)). Malodour significantly correlated with hydrogen sulphide concentration (p < or = 0.001). Zinc acetate reduced sulphur gas content but did not totally eliminate odour, while activated charcoal removed virtually all odour. The cushion absorbed more than 90% of the sulphur gases.
Sulphur-containing gases are the major, but not the only, malodorous components of human flatus. The charcoal lined cushion effectively limits the escape of these sulphur-containing gases into the environment.
Activated charcoal is used to treat excessive volume or malodor of intestinal gas. Our previous studies demonstrated that activated charcoal failed to bind appreciable quantities of the volumetrically important gut gases. However, the odor of feces and flatus derives primarily from trace quantities of sulfur-containing gases, primarily H2S and methanethiol, which should avidly bind to activated charcoal. The goal of this study was to determine if ingestion of activated charcoal reduces the fecal release of sulfur gases.
Five healthy human volunteers ingested 0.52 g of activated charcoal four times daily for 1 wk and the fecal liberation of intestinal gases was measured before and after the activated charcoal treatment. In an effort to explain the in vivo results, additional in vitro studies were performed to compare the binding capacity of charcoal to the sulfur gas released by feces.
Ingestion of activated charcoal produced no significant reduction in the fecal release of any of the sulfur-containing gases, nor was total fecal gas release or abdominal symptoms significantly influenced. In vitro studies suggested that the failure of ingested charcoal to reduce liberation of sulfur gases probably is explained by the saturation of charcoal binding sites during passage through the gut.
Commonly employed doses of activated charcoal do not appreciably influence the liberation of fecal gases.
Colonic bacteria liberate large quantities of the highly toxic gases hydrogen sulfide (H(2)S) and methanethiol (CH(3)SH). The colonic mucosa presumably has an efficient means of detoxifying these compounds, which is thought to occur through methylation of H(2)S to CH(3)SH and CH(3)SH to dimethylsulfide (CH(3)SCH(3)). We investigated this detoxification pathway by incubating rat cecal mucosal homogenates with gas containing H(2)S, CH(3)SH, or CH(3)SCH(3). Neither CH(3)SH nor CH(3)SCH(3) was produced during H(2)S catabolism, whereas catabolism of CH(3)SH liberated H(2)S but not CH(3)SCH(3). Thus, H(2)S and CH(3)SH are not detoxified by methylation to CH(3)SCH(3). Rather, CH(3)SH is demethylated to H(2)S, and H(2)S is converted to nonvolatile metabolites. HPLC analysis of the homogenate showed the metabolite to be primarily thiosulfate. Analysis of cecal venous blood obtained after intracecal instillation of H(2)(35)S revealed that virtually all absorbed H(2)S had been oxidized to thiosulfate. The oxidation rate of H(2)S by colonic mucosa was 10,000 times greater than the reported methylation rate. Conversion to thiosulfate appears to be the mechanism whereby the cecal mucosa protects itself from the injurious effects of H(2)S and CH(3)SH, and defects in this detoxification possibly could play a role in colonic diseases such as ulcerative colitis.
Butyrate oxidation within the colonocyte is selectively inhibited by hydrogen sulphide, reproducing the metabolic lesion observed in active ulcerative colitis.
To study generation of hydrogen sulphide by sulphate reducing bacteria (SRB) and the effects of 5-aminosalicylic acid (5-ASA) in patients with ulcerative colitis in order to identify a role of this noxious agent in pathogenesis.
Fresh faeces were obtained from 37 patients with ulcerative colitis (23 with active disease) and 16 healthy controls.
SRB were enumerated from fresh faecal slurries and measurements made of sulphate reducing activity, and sulphate and hydrogen sulphide concentrations. The effect of 5-ASA on hydrogen sulphide production was studied in vitro.
All controls and patients with active ulcerative colitis carried SRB and total viable counts were significantly related to the clinical severity grade. SRB were of two distinct types: rapidly growing strains (desulfovibrios) which showed high sulphate reduction rates, present in 30% of patients with ulcerative colitis and 44% of controls; and slow growing strains which had little activity. In vitro, 5-ASA inhibited sulphide production in a dose dependent manner; in patients with ulcerative colitis not on these drugs faecal sulphide was significantly higher than in controls (0.55 versus 0.25 mM, p=0.027).
Counts and carriage rates of SRB in faeces of patients with ulcerative colitis are not significantly different from those in controls. SRB metabolism is not uniform between strains and alternative sources of hydrogen sulphide production exist in the colonic lumen which may be similarly inhibited by 5-ASA. The evidence for hydrogen sulphide as a metabolic toxin in ulcerative colitis remains circumstantial.
etalFlatulence measurement in dogs: development of a technique, description of normal variability, and relationship to human organoleptic assessments
- S B Collins
- G Perez-Camargo
- G Gettingby
Collins SB, Perez-Camargo G, Gettingby G, et al. Flatulence measurement in dogs: development of a technique, description of normal variability, and relationship to human organoleptic assess-ments. Am J Vet Res 2001;in press.
Yucca schidigera: definitive mode of action and application in animal feed
- D R Headon
- K Dawson
- R Fallon
Headon DR, Dawson K, Fallon R. Yucca schidigera: defini-tive mode of action and application in animal feed. Feed Compounder 1991;Feb:32–34.
- Kirk E