Effects of bran on serum cholesterol, faecal mass, fat, bile acids and neutral sterols, and biliary lipids in patients with diverticular disease of the colon

Quantification of diacylglycerol and triacylglycerol species in human fecal samples by flow injection Fourier transform mass spectrometry

The intestinal microbiome plays an important role in human health and disease and fecal materials reflect the microbial activity. Thus, analysis of fecal metabolites provides insight in metabolic interactions between gut microbiota and host organism. In this work, we applied flow injection analysis coupled to Fourier transform mass spectrometry (FIA-FTMS) to identify and quantify lipid species in human fecal samples. Fecal homogenates were subjected to lipid extraction and analyzed by FIA-FTMS. The analysis of different subjects revealed a vast heterogeneity of lipid species abundance. The majority of samples displayed prominent signals of triacylglycerol (TG) and diacylglycerol (DG) species that could be verified by MS2 spectra. Therefore, we focused on the quantification of TG and DG. Method validation included limit of quantification, linearity, evaluation of matrix effects, recovery, and reproducibility. The validation experiments demonstrated the suitability of the method, with exception for approximately 10% of samples, where we observed coefficients of variation higher than 15%. Impaired reproducibility was related to sample inhomogeneity and could not be improved by additional sample preparation steps. Additionally, these experiments demonstrated that compared with aqueous samples, samples containing isopropanol showed higher amounts of DG, presumably due to lysis of bacteria and increased TG lipolysis. These effects were sample-specific and substantiate the high heterogeneity of fecal materials as well as the need for further evaluation of pre-analytic conditions. In summary, FIA-FTMS offers a fast and accurate tool to quantify DG and TG species and is suitable to provide insight into the fecal lipidome and its role in health and disease.

Data supporting the production of dietary fibers from sugarcane bagasse and sugarcane tops using microwave - assisted alkaline treatments

The treatment of agroindustrial residues is an alternative to waste management and obtain products with added value. In this article, we describe the confocal microscopy images, the microbiological data, policosanol content and color measurement linked to the paper "production of dietary fibers from sugarcane bagasse and sugarcane tops using microwave - assisted alkaline treatments". The data contain photographs after elaboration of noodles-type pasta and chapatti-type fermented bread; the confocal laser scanning micrographs, before and after including sugarcane bagasse and sugarcane tops fibers in foods. Microbiological analyses of total coliforms, molds and yeasts, and aerobic mesophiles were also presented according to Mexican Standard NOM- 247-SSA1-2008 which confirmed that the food is safe for human consumption. The data provided in this article have not been previously published and are available to enable critical or extended analyses.

The Characterization of Feces and Urine: A Review of the Literature to Inform Advanced Treatment Technology

The safe disposal of human excreta is of paramount importance for the health and welfare of populations living in low income countries as well as the prevention of pollution to the surrounding environment. On-site sanitation (OSS) systems are the most numerous means of treating excreta in low income countries, these facilities aim at treating human waste at source and can provide a hygienic and affordable method of waste disposal. However, current OSS systems need improvement and require further research and development. Development of OSS facilities that treat excreta at, or close to, its source require knowledge of the waste stream entering the system. Data regarding the generation rate and the chemical and physical composition of fresh feces and urine was collected from the medical literature as well as the treatability sector. The data were summarized and statistical analysis was used to quantify the major factors that were a significant cause of variability. The impact of this data on biological processes, thermal processes, physical separators, and chemical processes was then assessed. Results showed that the median fecal wet mass production was 128 g/cap/day, with a median dry mass of 29 g/cap/day. Fecal output in healthy individuals was 1.20 defecations per 24 hr period and the main factor affecting fecal mass was the fiber intake of the population. Fecal wet mass values were increased by a factor of 2 in low income countries (high fiber intakes) in comparison to values found in high income countries (low fiber intakes). Feces had a median pH of 6.64 and were composed of 74.6% water. Bacterial biomass is the major component (25-54% of dry solids) of the organic fraction of the feces. Undigested carbohydrate, fiber, protein, and fat comprise the remainder and the amounts depend on diet and diarrhea prevalence in the population. The inorganic component of the feces is primarily undigested dietary elements that also depend on dietary supply. Median urine generation rates were 1.42 L/cap/day with a dry solids content of 59 g/cap/day. Variation in the volume and composition of urine is caused by differences in physical exertion, environmental conditions, as well as water, salt, and high protein intakes. Urine has a pH 6.2 and contains the largest fractions of nitrogen, phosphorus, and potassium released from the body. The urinary excretion of nitrogen was significant (10.98 g/cap/day) with urea the most predominant constituent making up over 50% of total organic solids. The dietary intake of food and fluid is the major cause of variation in both the fecal and urine composition and these variables should always be considered if the generation rate, physical, and chemical composition of feces and urine is to be accurately predicted.

Incident diverticular disease is inversely related to vigorous physical activity

PURPOSE

In 1995, the Health Professionals Follow-up Study published an isolated report of lower diverticular disease risk in physically active men, particularly among those who ran. The purpose of this article was to assess whether this finding can be verified among older men and women of the National Runners' Health Study.

METHODS

Survival analyses were applied to incident disease occurring during 7.7 yr of follow-up in 9072 men and 1664 women, representing 84% follow-up of the original >or=50-yr-old cohort. In addition to the usual running distance (km x d(-1)), 80% of the baseline respondents included 10-km footrace performance times (a measure of cardiorespiratory fitness). Results were adjusted for age, sex, and reported intakes of meat, fish, fruit, and alcohol.

RESULTS

A total of 127 men and 21 women reported clinically diagnosed diverticular disease since baseline. The risk for incident diverticular disease decreased 6.2% per km x d(-1) run (P = 0.04). Relative to men and women who ran 8 km x d(-1) had 48% lower risk (P = 0.05). Each meter-per-second increment in the 10-km performance was associated with a 68% risk reduction (P = 0.04). Men and women who ran >4 m x s(-1) had 70% lower risk for diverticular disease than those who ran

CONCLUSION

These results demonstrate an inverse association between vigorous physical activity and incident diverticular disease among older men and women but are limited by their reliance on self-reported physician diagnosis.

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Key Words Collapse

MESH Headings

• Adult
• Aging
• Diverticulitis/epidemiology
• Diverticulitis/etiology
• Diverticulitis/prevention & control
• Female
• Humans
• Male
• Middle Aged
• Risk Assessment
• Running/physiology
• Surveys and Questionnaires
• United States/epidemiology

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Grants

• HL72110 NHLBI NIH HHS
• DK066738 NIDDK NIH HHS
• R03 AG032004 NIA NIH HHS
• R01 DK066738 NIDDK NIH HHS
• AG032004 NIA NIH HHS
• R01 HL072110 NHLBI NIH HHS

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Affiliation(s)

Paul T Williams Life Sciences Division, Lawrence Berkeley Laboratory, Donner Laboratory, Berkeley, CA 94720, USA.

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Collaborators Collapse

Influence of a psyllium-based fibre preparation on faecal and serum parameters

A fibre made of psyllium husk was given to 12 elderly patients for 4 months in order to investigate their faecal output and selected serum parameters. The fibre significantly improved bowel function and faecal output confirming its value as a non-irritant, harmless bulk-forming laxative. Serum cholesterol was decreased by 20% while triglycerides remained unchanged. There was a significant reduction in serum calcium after withdrawal of the fibre supplement. There were no significant changes in serum iron, total iron binding capacity, fibrinogen, or in the haematological parameters (ESR, haemoglobin, leucocyte count) attributable to the fibre. The high phytate content of the fibre does not appear to have any clinically significant effect on mineral absorption. It is suggested that dietary fibre (at least psyllium-based fibre preparations) may have significant cholesterol lowering capacity due to the binding of bile-acids in the intestine.

Origin of symptoms in diverticular disease

BACKGROUND

A significant number of patients with colonic diverticula experience unexplained, recurrent, short-lived but often debilitating abdominal pain and alteration in bowel habit. Such patients account for many medical consultations every year but, as our understanding of the cause of their symptoms remains imperfect, treatment options are limited. This article reviews the possible mechanisms that may be responsible for the symptoms of diverticular disease.

METHODS

Medline and Science Citation Index searches were performed to locate English language articles relating to colonic diverticula and symptoms published between January 1966 and July 2002. Manual cross-referencing was also performed and some historical articles were included.

RESULTS AND CONCLUSION

Several theories now exist about the mechanisms underlying the symptoms of diverticular disease. Initial studies suggested that they may be due to alterations in the intracolonic pressure, extrapolating earlier thoughts on the likely pathogenesis of diverticula. It seems more likely, however, that several inter-related processes, such as muscular dysfunction, visceral hypersensitivity and inflammation, are involved in symptom generation.

Diverticular disease of the colon: New perspectives in symptom development and treatment

Diverticular disease of the colon is a common disease worldwide. Although the disease is asymptomatic in about 70%-80% of patients, it represents, at least in Western countries, one of the most important gastrointestinal diseases in terms of direct and indirect health costs. Pathogenesis of the disease is still unknown. However, it is the result of complex interactions between colonic structure, intestinal motility, diet and genetic factors. Whilst efficacious preventive strategies remain to be identified, fibre supplementation in the diet is recommended. Why symptoms develop is still unclear. Results of recent experimental studies on irritable bowel syndrome speculated that low grade inflammation of colonic mucosa, induced by changes in bacterial microflora, could affect the enteric nervous system, which is crucial for normal gut function, thus favouring symptom development. This hypothesis could be extrapolated also for diverticular disease, since bacterial overgrowth is present, at least in a subgroup of patients. These perspectives on symptom development are reviewed and new therapeutic approaches are hypothesized.

Preventing diverticular disease. Review of recent evidence on high-fibre diets

OBJECTIVE

To review recent evidence on dietary factors associated with diverticular disease (DD) with special emphasis on dietary fibre.

QUALITY OF EVIDENCE

MEDLINE was searched from January 1966 to December 2001 for articles on the relationship between dietary and other lifestyle factors and DD. Most articles either focused on dietary intervention in treating symptomatic DD or were case-control studies with inherent limitations for studying diet-disease associations. Only one large prospective study of male health professionals in the United States assessed diet at baseline and before initial diagnosis of DD.

MAIN MESSAGE

A diet high in fibre mainly from fruits and vegetables and low in total fat and red meat decreases risk of DD. Evidence indicates that the insoluble component of fibre is strongly associated with lower risk of DD; this association was particularly strong for cellulose. Caffeine and alcohol do not substantially increase risk of DD, nor does obesity, but higher levels of physical activity seem to reduce risk of DD.

CONCLUSION

A diet high in fibre and low in total fat and red meat and a lifestyle with more physical activity might help prevent DD.

Diverticular disease. Epidemiology and pharmacological treatment

Diverticular disease is worldwide in distribution, but the incidence is highest in industrialised countries. It is associated with aging and low intake of dietary fibre. There is a broad range of clinical manifestations--from asymptomatic diverticula to life-threatening complications. Elderly patients often present with complicated diverticular disease, and may lack typical symptoms and signs. Treatment includes fibre supplementation, drugs or antibiotics for complications, and surgery for refractory disease. Proper diagnosis and treatment requires knowledge of the full range of presentations and careful selection and timing of medical versus surgical intervention.

In vivo studies with fibre components

There are few studies in man examining the in vivo effects of dietary fibre on bile acid metabolism but divergent results have been recorded depending on the amount and type of fibre eaten. Studies in which the fibre components pectin, cellulose, and lignin were fed to normal volunteers for four weeks have been reported. The highly fermentable component pectin is associated with increased secondary bile acid formation in contrast to the partially fermentable component cellulose in which the opposite occurs. Lignin has no effect on bile acid metabolism. No component significantly alters biliary lipids. Since ordinary diets contain a mixture of different fibres the net effect will depend on the relative amounts of each. Significant changes in bile acid metabolism and biliary lipids in the longer term (greater than 4 weeks) however, are not precluded by the results of these short term studies.

Effects of the fibre components pectin, cellulose, and lignin on bile salt metabolism and biliary lipid composition in man

Randomised crossover studies in three separate groups of 10 healthy volunteers were undertaken to determine the effects of biliary lipid composition and bile salt metabolism of daily dietary supplementation for four weeks with the purified fibre components pectin (12 g/day), cellulose (15 g/day) and lignin (12 g/day). The subjects' biles were initially unsaturated with cholesterol and no significant changes in the lithogenic indices or mean percentages of cholesterol, phospholipid, or total bile acids after any of the supplements were observed. After pectin, the mean (+/- SD) percentage of cholic acid decreased significantly from 42.8 (+/- 10.8) to 39.0 (+/- 11.2), the mean (+/- SD) percentage of deoxycholic acid increased significantly from 18.2 (+/- 13.7) to 25.4 (+/- 13.5) and C14-deoxycholate metabolites were raised significantly by 65%. After cellulose, the mean (+/- SD) percentage of chenodeoxycholic acid was increased significantly from 33.6 (+/- 6.3) to 35.4 (+/- 7.0), the mean (+/- SD) percentage of deoxycholic acid decreased significantly from 18.6 (+/- 9.6) to 14.2 (+/- 8.3) and C14-deoxycholate metabolites halved. Lignin did not exert any significant effects. Though these results show that individual fibre components are associated with quite different effects on bile acid metabolism, in the short term no significant effect on biliary cholesterol saturation was observed in bile initially unsaturated with cholesterol. The bile acid changes most likely result from the different effects on colonic metabolism induced by the individual fibre components.

Comparison of biliary lipid secretion in non-obese cholesterol gallstone patients with normal, young, male volunteers

Measurements of biliary lipid secretion rates were performed in 14 non-obese patients with radiolucent gallstones (9 females, 5 males; mean age 48 years; mean body weight 65 kg) and in 14 healthy male volunteers (mean age 26 years, mean body weight 74 kg). The results in the gallstone patients differ in several respect from those obtained in the volunteers. Molar percentage of cholesterol was higher (5.8 versus 5.0 mol%; P less than 0.05) and molar percentage of bile acids lower (73.8 versus 76.9 mol%; P less than 0.05) in the gallstone patients. However, these changes were not followed by notable differences in cholesterol saturation of bile (94% vs 88%). Generally, hepatic secretion rates of cholesterol were significantly elevated in the gallstone patients (55 vs 46 mg/h; P less than 0.05) whereas outputs of bile acids and phospholipids did not differ between the two groups. Although patients with cholesterol gallstones tended to have a lower percentage of chenodeoxycholic acid (38 versus 42 mol%) and increased deoxycholic acid (23 versus 16 mol%) in their bile, these differences were not significant. Nevertheless, in patients with cholesterol gallstones a significant positive correlation between deoxycholic acid secretion and cholesterol output was observed. For the whole group of patients and volunteers a positive correlation between age and cholesterol secretion could be demonstrated. The higher hepatic cholesterol secretion in gallstone patients seems not be due to differences in body weight, but rather to the older age of the patients. These results suggest that age itself or age-related changes in deoxycholic acid metabolism contributes to biliary cholesterol output in non-obese patients with cholesterol gallstones.

Cholesterol absorption and sterol balance in normal subjects receiving dietary fiber or ursodeoxycholic acid

Twelve normal subjects were placed on a constant diet and evaluated during three treatment periods, each lasting four weeks. Patients received regular diet alone during period A, regular diet plus 60 g/day wheat bran during period B, and regular diet plus 15 mg/kg/day ursodeoxycholic acid during period C. Cholesterol absorption, plasma lipid concentration, daily fecal excretion of neutral and acidic sterols, and sterol balance were determined following each treatment. No changes in serum lipid levels are observed in the three study periods. Bran administration increases fecal neutral sterol excretion and decreases cholesterol absorption (from 50.1 to 42.0%) with respect to period C. Ursodeoxycholic acid administration has no effect on fecal neutral sterol excretion, whereas bile acid excretion is markedly increased. Sterol balance (evaluated as neutral and acidic fecal sterols excreted per day minus dietary cholesterol plus ursodeoxycholic acid given per day) is lower during ursodeoxycholic acid feeding (360 +/- 145 mg/day) than during bran feeding (593 +/- 174 mg/day). In conclusion, ursodeoxycholic acid decreases sterol balance values; bran-rich diet increases sterol balance and reduces cholesterol absorption.

Treatment of chronic constipation by a bulk-forming laxative (Fibrolax)

Seventy-five patients affected by chronic constipation were treated for 4 weeks with an Ispaghula Husk preparation (Fibrolax), a bulk-forming laxative. Frequency, stool consistency, abdominal pain and signs of venous stasis improved after treatment. No important side-effect was recorded. Cholesterol, HDL-cholesterol and triglycerides did not show significant changes.

[Effect of bulk materials on the upper intestinal tract]

Dietary fibers comprise a very heterogenous group of indigestible plant compounds. Whereas they exert only little effects on the recovery of the digestible parts of a meal they can modify various digestive processes. Most important seems to be the ability to inhibit digestion and absorption of carbohydrates, which enables better treatment of diabetics. The observation that serum cholesterol can be decreased by certain dietary fibers finds special interest also because of the possible reduction of risk for developing atherosclerosis. The various effects depend upon the physicochemical properties of the different fibers: they comprise the ability to bind water and organic substances, viscosity and cationic-exchange.

Effects of dietary fibre on serum lipid levels and fecal bile acid excretion

Epidemiologic studies have suggested that dietary fibre protects humans against coronary heart disease, but interpretation of the data is confounded by coexisting differences in both dietary and environmental variables. The hypocholesterolemic action of dietary fibre varies: in general mucilaginous fibres such as pectin and oat bran are more effective than particulate fibres such as wheat bran. Although the mechanism of action of mucilaginous fibres is not completely understood, there is evidence that they induce small increases in the fecal excretion of bile acids and neutral steroids that are not fully compensated for by de novo cholesterol synthesis.

Serum lipids, biliary lipid composition, and bile acid metabolism in vegetarians as compared to normal controls

Since dietary factors have been implicated in various diseases, such as coronary heart disease, gallstone formation and colonic cancer, possibly by affecting cholesterol and bile acid metabolism, we studied serum lipid levels, biliary lipid composition, cholic acid and deoxycholic acid kinetics in a group of young healthy male vegetarians and in age, sex and weight matched control subjects. Daily intake of nutrients was higher with respect to polyunsaturated fatty acids, carbohydrates and dietary fibre in the vegetarian group. Although mean serum lipid levels in the vegetarian were 8-28% lower than in the control subjects, differences were not statistically significant. Biliary lipid and biliary bile acid composition were similar in both groups. Bile acid kinetics, measured after simultaneous injection of [3H]cholic acid and [14C]deoxycholic acid, showed a slightly lower output of cholic acid and a slightly higher input of deoxycholic acid in the vegetarians, this causing a significantly (P less than 0.025) higher 7 alpha-dehydroxylation fraction (input deoxycholic acid divided by synthesis of cholic acid) in the vegetarians. Our results in young males suggest that bile acid conservation is associated with a vegetarian diet, but do not support the supposition that a vegetarian diet reduces deoxycholate formation.

Effects of a standardized wheat bran preparation on biliary lipid composition and bile acid metabolism in young healthy males

The effects of adding bran to the normal diet on biliary lipid composition and bile acid metabolism in a group of young healthy males was studied. A chemically standardized coarse wheat bran product, with serum lipid lowering properties, in a dose of 0.5 kg-1 body weight per day was used. Bran feeding for 4 or 8 weeks did not change biliary lipid and biliary bile acid composition. Faecal bile acid and neutral sterol composition was similar before and after 8 weeks of bran. Bile acid kinetics, measured by double isotope dilution after simultaneous injection of [3H]cholic acid and [14C]deoxycholic acid, showed only minor differences before and during bran ingestion. The most surprising finding was an increase in 7 alpha-dehydroxylation fraction (input of deoxycholic acid divided by synthesis of cholic acid) in six out of seven subjects after 4 weeks of brain and in all four subjects after 8 weeks of bran. In conclusion, the bran product we used is not effective in lowering the biliary cholesterol saturation in healthy young males. Nor does it reduce deoxycholate input in our subjects even after 8 weeks of bran.

Faecal bile acid excretion in diverticular disease

Faecal bile acid excretion and sigmoid myoelectrical activity were measured on three separate occasions over a 12-month period in 21 patients with diverticular disease and the result were compared with those of 17 age-matched normal subjects. Statistically significantly lower faecal concentrations of both deoxycholic and lithocholic acid were found in patients with diverticular disease (96.7 +/- 11.3 mg/100 g, 59.6 +/- 6.0 mg/100 g respectively) when compared with normal subjects (219 +/- 32.0 mg/100 g and 117.6 +/- 14.6 mg/100 g respectively, P < 0.001). These values persisted throughout the period of study. Patients with diverticular disease were found to have an abnormally rapid myoelectrical rhythm (frequency 0.2-0.3 Hz [12-18 c/min] which returned towards normal after 1 year's bran treatment. Significant correlations were found between lithocholic acid concentrations and activity of 0.2-0.3 Hz (r = 0.67) and deoxycholic acid concentrations and activity of 0.1-015 Hz (6-9 c/min) (r = 0.62). It is suggested that increased colonic absorption of bile acids may occur in diverticular disease which may influence the myoelectrical activity.

Fecal beta-sitosterol in patients with diverticular disease of the colon and in vegetarians

Fecal sterol analysis showed that excretion of beta-sitosterol, a major component of poorly absorbable dietary vegetable sterols, is subnormal in patients with diverticular disease of the colon. Thus, the patients had evidently consumed a diet low in plant materials. The finding agrees with the current opinion that diverticular disease of the colon is associated with dietary fibre deficiency and suggests that fecal beta-sitosterol provides a rough measure of the vegetable intake. In vegetarians the beta-sitosterol excretion was actually high.