Biomarkers of human colonic cell growth are influenced differently by a history of colonic neoplasia and the consumption of acarbose.

The nutritional effects of butyrate on the colonic mucosa and studies of transformed cells suggest that butyrate has anti-colon cancer effects. If butyrate has antineoplastic effects, mucosal growth contrasts between normal subjects and those with a history of colonic neoplasia would parallel changes in growth characteristics caused by butyrate in a colon neoplasia population. To test this hypothesis, rectal biopsies from a survey of colonoscopy patients (n = 50) with and without a history of colonic neoplasia (controls) were compared. Similarly, rectal biopsies were compared from subjects (n = 44) with a colon neoplasia history in an acarbose-placebo crossover trial. Control subjects in the colonoscopy survey had higher bromodeoxyuridine (BrdU) uptake than subjects with a history of neoplasia (P = 0.05). The control subjects also had a higher correlation of BrdU and Ki-67 labeling (P = 0.003). Both findings were paralleled by acarbose use. Acarbose augmented BrdU uptake (P = 0.0001) and improved the correlation of BrdU and Ki-67 labeling (P = 0.013). Acarbose also augmented fecal butyrate (P = 0.0001), which was positively correlated with Ki-67 labeling (P = 0.003). p52 antigen had an earlier pattern of crypt distribution in subjects with a history of colon neoplasia but was not affected by acarbose use. Lewis-Y antigen was expressed earlier in the crypt with acarbose but had similar expression in the colonoscopy survey groups. The use of acarbose to enhance fecal butyrate concentration produced mucosal changes paralleling the findings in control subjects as opposed to those with neoplasia, supporting the concept of an antineoplastic role for butyrate.

Changes of fermentation pathways of fecal microbial communities associated with a drug treatment that increases dietary starch in the human colon.

Acarbose inhibits starch digestion in the human small intestine. This increases the amount of starch available for microbial fermentation to acetate, propionate, and butyrate in the colon. Relatively large amounts of butyrate are produced from starch by colonic microbes. Colonic epithelial cells use butyrate as an energy source, and butyrate causes the differentiation of colon cancer cells. In this study we investigated whether colonic fermentation pathways changed during treatment with acarbose. We examined fermentations by fecal suspensions obtained from subjects who participated in an acarbose-placebo crossover trial. After incubation with [1-13C]glucose and 12CO2 or with unlabeled glucose and 13CO2, the distribution of 13C in product C atoms was determined by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. Regardless of the treatment, acetate, propionate, and butyrate were produced from pyruvate formed by the Embden-Meyerhof-Parnas pathway. Considerable amounts of acetate were also formed by the reduction of CO2. Butyrate formation from glucose increased and propionate formation decreased with acarbose treatment. Concomitantly, the amounts of CO2 reduced to acetate were 30% of the total acetate in untreated subjects and 17% of the total acetate in the treated subjects. The acetate, propionate, and butyrate concentrations were 57, 20, and 23% of the total final concentrations, respectively, for the untreated subjects and 57, 13, and 30% of the total final concentrations, respectively, for the treated subjects.

Acarbose enhances human colonic butyrate production.

Earlier studies suggest that butyrate has colonic differentiating and nutritional effects and that acarbose increases butyrate production. To determine the effects of acarbose on colonic fermentation, subjects were given 50-200 mg acarbose or placebo (cornstarch), three times per day, with meals in a double-blind crossover study. Fecal concentrations of starch and starch-fermenting bacteria were measured and fecal fermentation products determined after incubation of fecal suspensions with and without added substrate for 6 and 24 h. Substrate additions were cornstarch, cornstarch plus acarbose and potato starch. Dietary starch consumption was similar during acarbose and placebo treatment periods, but fecal starch concentrations were found to be significantly greater with acarbose treatment. Ratios of starch-fermenting to total anaerobic bacteria were also significantly greater with acarbose treatment. Butyrate in feces, measured either as concentration or as percentage of total short-chain fatty acids, was significantly greater with acarbose treatment than with placebo treatment. Butyrate ranged from 22.3 to 27.5 mol/100 mol for the 50-200 mg, three times per day doses of acarbose compared with 18.3-19.3 mol/100 mol for the comparable placebo periods. The propionate in fecal total short-chain fatty acids was significantly less with acarbose treatment (10.7-12.1 mol/100 mol) than with placebo treatment (13.7-14.2 mol/100 mol). Butyrate production was significantly greater in fermentations in samples collected during acarbose treatment, whereas production of acetate and propionate was significantly less. Fermentation decreased when acarbose was added directly to cornstarch fermentations. Acarbose effectively augmented colonic butyrate production by several mechanisms; it reduced starch absorption, expanded concentrations of starch-fermenting and butyrate-producing bacteria and inhibited starch use by acetate- and propionate-producing bacteria.

Dietary guar gum alters colonic microbial fermentation in azoxymethane-treated rats.

To assess the effects of guar gum on colonic microbial fermentation and cancer development, azoxymethane-treated rats were fed a partially hydrolyzed guar or control diet. Anaerobic fecal incubations were conducted at 8-wk intervals, either without added substrate or with cornstarch or hydrolyzed guar as substrates. Short-chain fatty acids in colonic contents and colonic carcinoma areas were measured at 27 wk. Fecal in vitro fermentation rates were higher for guar-fed rats than for control rats [three-way ANOVA (diet, time, in vitro substrates), P = 0.002]. Fecal in vitro butyrate production was greater for guar-fed rats than for control rats after 3-11 weeks of diet treatment (three-way ANOVA, P = 0.027). Butyrate concentrations of colonic contents at 27 wk were higher in guar-fed than in control rats and higher in the cecum than in the post-cecal colon (two-way ANOVA, P = 0.0001). A regression equation predicting colonic carcinoma area (r2 = 0.279) using propionate and butyrate concentrations of the contents of the post-cecal colon showed propionate as a positive predictor (P < 0.001) and butyrate as a negative predictor (P = 0.033). Our results show that patterns of short-chain fatty acid production may affect the results of fiber-carcinogenesis experiments. Dietary addition of hydrolyzed guar is associated with fecal fermentation low in propionate and high in butyrate; short-chain fatty acid concentrations are greater proximally than distally. These results suggest that butyrate protects against colonic neoplasia, whereas propionate enhances it, and demonstrate that colonic microbiota adapt to produce more butyrate if given time and the proper substrate.

Nonsteroidal antiinflammatory drugs are associated with gastric outlet obstruction.

Nonsteroidal antiinflammatory drug associated gastric ulcerations are often prepyloric and painless; when recurrent, such ulcers may lead to pyloric scarring and gastric outlet obstruction. We performed a retrospective case control study to seek an association between gastric outlet obstruction and nonsteroidal antiinflammatory drug use. The use of nonsteroidal antiinflammatory drugs in cases with gastric outlet obstruction was compared to an age- and sex-matched outpatient control group undergoing endoscopy. The proportion of drug use by patients with gastric outlet obstruction, seven of nine, was significantly higher than the proportion in controls, 29 of 90. The duration of nonsteroidal antiinflammatory drug use was also significantly longer in patients with gastric outlet obstruction than in control patients. Chronic nonsteroidal antiinflammatory drug use is associated with gastric outlet obstruction.

Cornstarch fermentation by the colonic microbial community yields more butyrate than does cabbage fiber fermentation; cornstarch fermentation rates correlate negatively with methanogenesis.

Fermentations of cornstarch and a cabbage-fiber preparation by human fecal suspensions were studied. The molar percent of butyrate of total short-chain fatty acid products was significantly higher when cornstarch was the substrate. Higher molar percents of butyrate were also produced from cornstarch as compared with endogenous substrate when rat fecal suspensions were used. A range of cornstarch fermentation rates was found with suspensions from 20 human subjects. Rapid fermentaion was associated with the absence of methane production. Methane-negative rat fecal suspensions also fermented cornstarch more rapidly than did methane-positive suspensions. High butyrate production may be important because butyrate provides energy to colonocytes and it regulates differentiation of cultured cells.

Increased iron absorption in uroporphyrin-treated rats.

Rats were given 59Fe (28 micrograms) together with doses of 0, 2 and 200 micrograms of uroporphyrin III in paired observations. Absorption of 59Fe was determined by comparing whole body counts of the rats 30 min and 7 days after dosing. Prior treatment with 200 micrograms of uroporphyrin twice daily for 3 days was associated with significantly increased 59Fe absorption of 6.2% compared to the absorption of 4.6% without uroporphyrin (control) and 4.6% with a 2-micrograms dose (p less than 0.05).

Constancy of glucose and starch fermentations by two different human faecal microbial communities.

The fermentation of glucose and corn starch by faecal suspensions from two subjects was examined over a three and a half year period. The substrate specificity and products of the faecal fermentations of each subject were relatively stable during this period and were significantly different between subjects. The major soluble end products of fermentation of glucose or starch were acetate, propionate, and butyrate. Hydrogen temporarily accumulated and was subsequently used in fermentations by both subjects. Hydrogen was used without methane production in fermentations of subject 1, but was used for methane formation in fermentations of subject 2. Although the rates of glucose fermentation were similar between both subjects; subject 1 produced a significantly greater molar ratio of propionate than did subject 2. The rate of fermentation of starch by faecal suspensions from subject 1 was faster than that of subject 2. The molar ratio of butyrate was greater for starch fermentations by subject 2, while the molar ratio of propionate was greater with subject 1. Significant differences were found between subjects in molar ratios and concentration of acetate and propionate and concentrations of butyrate in faeces.

Short chain fatty acid distributions of enema samples from a sigmoidoscopy population: an association of high acetate and low butyrate ratios with adenomatous polyps and colon cancer.

We investigated the distribution of short chain fatty acids (SCFA) in enema samples taken from subjects before sigmoidoscopy as an indicator of possible microbial community differences between subjects subsequently diagnosed as normal or having colonic disorders. The major SCFA in all groups were acetic, propionic, and butyric acids. A significantly higher ratio of acetate to total SCFA and lower ratio of butyrate to total SCFA was found for polyp-colon cancer subjects than for normal subjects. There were no significant differences in the ratios of acetate, propionate, or butyrate between the diverticulosis or inflammatory bowel groups and the normal group. There were no significant sex differences nor were there correlations with the ratios of acetate, propionate or butyrate and age, subject weight, or dry weights of samples. Significant differences in concentrations of individual acids were found between normal and certain diagnostic groups. The difference in proportions of individual SCFA between groups suggest differences in fermentation patterns of the colonic microflora.

Albumin Cooperstown: a serum albumin variant with the same (313 Lys----Asn) mutation found in albumins in Italy and New Zealand.

Albumin Cooperstown is an electrophoretically fast genetic variant (alloalbumin) inherited in a family in New York State. To determine the structural change, we separated the alloalbumin from normal albumin A by "high-performance" liquid chromatography, reduced and carboxymethylated it, and cleaved it with CNBr. Isoelectric focusing showed that the substitution was in fragment CB4 (residues 299 to 329). The variant CNBr fragment from the albumin of two siblings was purified by liquid chromatography. Automated sequence analysis established the substitution of lysine-313 by asparagine (313 Lys----Asn), which corresponds to mutation of a single nucleotide base. The same substitution has recently been reported in albumin variants in Italy and New Zealand. This provides the first evidence for independent mutations at a single site within the structure of the mature albumin molecule. Because of the significance of albumin for study of protein evolution, clinical chemists are asked to be on the alert for cases of bisalbuminemia.

Effect of zearalenone on dairy cows.

Doses of 99% pure zearalenone (0.0, 31.25, 62.5, 125.0, 250.0, or 500.0 mg) in gelatin capsules were given once a day per os to 18 nonpregnant, nonlactating, multiparous dairy cows for 2 consecutive estrous cycles. There was no effect (P less than 0.10) on serum progesterone concentrations, RBC, WBC, PCV, hemoglobin, and estrous cycle length. Differential cell counts, clinical health, and sexual behavior were not affected by the zearalenone. One cow from each of the groups given zearalenone and a control were euthanatized at the end of the study. The zearalenone had no effect on the terminal bone marrow smears and did not induce any gross lesions discernible at necropsy or any microscopic lesions in representative samples of 30 tissues/cow. Rectal palpation of the reproductive tracts once a week indicated that the corpora lutea were small in cows given zearalenone. There was a general trend to increased hemoglobin concentrations in cows given the larger doses of zearalenone. Zearalenone of and by itself does not seem to be an important factor in dairy cow health.

Incidence of methanogenic bacteria in a sigmoidoscopy population: an association of methanogenic bacteria and diverticulosis.

This study determined the incidence and concentration of methane-producing bacteria in tap water enema samples of 130 individuals taken before sigmoidoscopy. The number of subjects classified in five major colonic groups were as follows: normal colon 36, diverticulosis 57, inflammatory bowel disease 11, colon polyps 34, and colon cancer 11. Some patients were placed in more than one category. Ninety four of the subjects or 72% had methanogenic bacteria ranging in concentration from 6 to about 3 X 10(10)/g dry weight of faeces. The predominant methanogen in all groups was Methanobrevibacter smithii. Chi-square analysis showed that the incidence of methanogens in concentrations of 10(7)/g dry weight of faeces or greater in patients with diverticulosis (58%) was significantly greater than in normal patients (25%). High methanogen concentrations are associated with excretion of methane in the breath.

Effect of zearalenone on the fertility of virgin dairy heifers.

Eighteen cycling, virgin, Holstein heifers daily were given 250 mg of 99% purified zearalenone in a gelatin capsule orally, and 18 controls were given an empty gelatin capsule once a day. The study lasted through 1 non-breeding estrous cycle and the next 2 consecutive estrous cycles during which the 36 heifers were bred, using artificial insemination. Serum concentrations of progesterone and complete blood cell counts were determined throughout the study. The treated and control heifers had conception rates of 62% and 87%, respectively. There was no effect (P less than 0.05) on the serum concentration of progesterone or the complete blood cell counts. Three heifers, bred but not pregnant by the end of the study, were euthanatized and necropsied. The treated heifer did not have any zearalenone-attributable lesions, and there was no effect seen in the bone marrow smears. The remaining 33 heifers were sold as a herd, and the 31 pregnant heifers calved normally. There was no effect (P less than 0.05) on the sex ratio of the offspring, which were all clinically healthy. Zearalenone did lower the conception rate of the treated heifers (P less than 0.065).

Management of bleeding angiodysplasia of the upper small intestine.

Five patients thought to have bleeding angiodysplasia in the distal duodenum and proximal jejunum were treated surgically after conservative measures failed to control hemorrhage. Aspiration through a long oral tube preoperatively and intraoperative endoscopy were most helpful in locating the site of bleeding.