Title
Application of direct-fed microbial bacteria and fructooligosaccharides for salmonella control in broilers during feed withdrawal.
Author
Oyarzabal OA; Conner DE
Source
Poult Sci, 1996 Feb, 75:2, 186-90
Abstract
Providing direct-fed-microbial (DFM) bacteria and fructooligosaccharides (FOS) for the control of potential escalation of Salmonella colonization during simulated feed withdrawal and confinement was assessed. Eight hundred and eighty broilers (16 pens; 55 chicks per pen) were reared to 6 wk of age. Chicks were sprayed with a solution containing 10(6) nalidixic-acid resistant Salmonella typhimuriumNR cells per milliliter on the 2nd d after hatching. Because this first challenge did not yield a high infection rate, chickens were rechallenged per Os at Day 18 by providing water containing 10(7) cells of S. typhimuriumNR per milliliter. At 3 and 5 wk of age, 10 birds per pen were euthanatized and cecal Salmonella were quantified (log colony-forming units per gram). Feed was removed from all pens at 6 wk, and pens were randomly assigned to be either the treatment group or the control group. The treatment groups were provided a DFM (mixture of nine bacteria) and FOS 50 (R) (10%) in the drinking water. The control groups received drinking water only. After 6 h of feed withdrawal, chickens were cooped (eight per coop) and held 10 h. Immediately after confinement, 10 chickens were used for cecal enumeration of S. typhimuriumNR. Salmonella colonization declined from 99% at 3 wk to 44% at 5 wk. After feed withdrawal, application of the treatment, and confinement, 11 and 14% of the treated and control groups, respectively, yielded S. typhimuriumNR by direct plating from ceca (3.87 and 3.75 log 10 cfu/g, respectively). No difference (P > 0.05) in Salmonella colonization occurred between the treated and the control groups; however, enrichment of ceca (incubation in nutrient broth at 37 C for 24 h) yielded a higher incidence of S. typhimuriumNR in the control groups (32% in the treated vs 51% in the control). Ceca weights were greater in the treated group (P < 0.05). Simulated feed withdrawal and confinement did not escalate Salmonella colonization in the chicken ceca.

Title
Digestion, excretion, and energy value of fructooligosaccharides in healthy humans.
Author
Molis C; Flourié B; Ouarne F; Gailing MF; Lartigue S; Guibert A; Bornet F; Galmiche JP
Source
Am J Clin Nutr, 1996 Sep, 64:3, 324-8
Abstract
The fate of fructooligosaccharides (FOS) in the human gastrointestinal tract was evaluated in six healthy volunteers over an 11-d period. After an equilibration phase, 20.1 g FOS/d was given in three identical postprandial doses. Distal ileal output of FOS and their constituent components were determined by intestinal aspiration after a single meal, and the amounts of FOS excreted in stools and urine were also measured. Most of ingested FOS, 89 +/- 8.3% (mean +/- SEM), was not absorbed in the small intestine, and none was excreted in stools, indicating that the portion reaching the colon was completely fermented by colonic flora. A small fraction of ingested FOS was recovered in urine. The mean estimated energy value of FOS was 9.5 kJ/g. We conclude that in healthy humans, FOS are only slightly digested in the small intestine and then fermented in the colon, resulting in reduced energy production.

Title
Chronic consumption of short-chain fructooligosaccharides by healthy subjects decreased basal hepatic glucose production but had no effect on insulin-stimulated glucose metabolism.
Author
Luo J; Rizkalla SW; Alamowitch C; Boussairi A; Blayo A; Barry JL; Laffitte A; Guyon F; Bornet FR; Slama G
Source
Am J Clin Nutr, 1996 Jun, 63:6, 939-45
Abstract
We aimed to study the effects of chronic ingestion of short-chain fructooligosaccharides (FOS), an indigestible carbohydrate, on hepatic glucose production, insulin-mediated glucose metabolism, erythrocyte insulin binding, and blood lipids in healthy subjects. Twelve healthy volunteers received either 20 g FOS/d or sucrose for 4 wk in a double-blind crossover design. FOS did not modify fasting plasma glucose and insulin concentrations. Mean (+/- SEM) basal hepatic glucose production was lower after FOS than after sucrose consumption (2.18 +/- 0.10 compared with 2.32 +/- 0.09 mg.kg-1, min-1, respectively; P < 0.02, paired Student's t test). However, neither insulin suppression of hepatic glucose production nor insulin stimulation of glucose uptake measured by hyperinsulinemic clamp was significantly different between the two dietary periods. Erythrocyte insulin binding was also comparable. Serum triacylglycerols, total and high-density- lipoprotein cholesterol, apolipoproteins A-I and B, and lipoprotein(a) were not modified by FOS. To try to understand why FOS did not increase serum lipids, the in vitro production of short-chain fatty acids from FOS was evaluated by using human fecal inoculum and compared with that from lactulose, which was found to increase serum lipids. FOS produced an acetate-propionate ratio two times lower than that of lactulose. We conclude that 4 wk of 20 g FOS/d decreased basal hepatic glucose production but had no detectable effect on insulin-stimulated glucose metabolism in healthy subjects. The colonic fermentation pattern of undigestible carbohydrates may be relevant to predicting their metabolic effects.

Title
Effects of fructooligosaccharides on the absorption of iron, calcium and magnesium in iron-deficient anemic rats.
Author
Ohta A; Ohtsuki M; Baba S; Takizawa T; Adachi T; Kimura S
Source
J Nutr Sci Vitaminol (Tokyo), 1995 Jun, 41:3, 281-91
Abstract
We investigated the effects of fructooligosaccharides (FO)-feeding on the absorption of iron (Fe), calcium (Ca) and magnesium (Mg) and on the biochemical parameters in Fe-deficient anemic rats. Fe-deficient anemic rats were made by feeding an Fe-deficient diet for 3 weeks. Then these Fe-deficient rats were fed an experimental diet that contained one of two levels of Fe (15 or 30 mg/kg diet), in the form of ferric pyrophosphate, and one of two levels of FO (0 or 50 g/kg diet) for 2 weeks. After the rats were fed these experimental diets, FO-feeding increased the hematocrit ratio, the concentration of hemoglobin and the hemoglobin regeneration efficiency during the first week. Also, the apparent absorption of Fe was increased by FO-feeding. The levels of Fe in the diet did not affect the absorption of Ca and Mg. However, FO-feeding increased the absorption of Ca and Mg. FO-feeding lowered the pH and raised the solubility of Fe, Ca and Mg in the cecal contents, suggesting that those increasing effects of FO-feeding on absorption of these minerals is correlated with fermentation of FO in the large intestine, namely, the cecum and colon. We concluded that FO-feeding improved recovery from anemia and increased the absorption of Fe, Ca and Mg in Fe-deficient anemic rats.

Title
Effects of fructooligosaccharides on the absorption of magnesium in the magnesium-deficient rat model.
Author
Ohta A; Baba S; Takizawa T; Adachi T
Source
J Nutr Sci Vitaminol (Tokyo), 1994 Apr, 40:2, 171-80
Abstract
Magnesium (Mg) is an essential dietary element that plays important roles, acting as a cofactor of many enzymes. Rats fed a Mg-deficient diet have been reported to exhibit auricular and facial peripheral hyperemia and hemorrhage. Moreover, increased intake of calcium (Ca) or phosphorus (P) has been reported to impair apparent absorption of Mg. We tried to induce such typical inflammation in Mg-deficient rats by feeding low-Mg, high-Ca, and high-P diets. Increasing concentrations of Ca or P in the experimental diets significantly decreased the apparent absorption of Mg. And all rats fed the low-Mg (0.25 mg/g diet), high-Ca (10.4 mg/g diet), and high-P (12.0 mg/g diet) diet exhibited auricular and facial peripheral-hyperemia and hemorrhage. Then, we used the low-Mg, high-Ca, and high-P diet to investigate the effects of the fructooligosaccharides (FO) on absorption of Mg and skin inflammation. In the rats fed FO-containing (1 or 5%) diet, apparent absorption of Mg was significantly increased as compared with that of the control (FO 0%) group. In the rats fed a 5% FO-containing diet and sufficient Mg (0.50 mg/g), auricular and facial peripheral hyperemia and hemorrhage were significantly reduced. We concluded that FO increased the Mg absorption in rats fed a low-Mg, high-Ca, and high-P diet. Moreover, FO reduced inflammation in Mg-deficient rats, such as peripheral hyperemia and hemorrhage.

Title
Biochemical basis of oligofructose-induced hypolipidemia in animal models.
Author
Delzenne NM; Kok NN
Source
J Nutr, 1999 Jul, 129:7 Suppl, 1467S-70S
Abstract
Oligofructose (OFS), a mixture of nondigestible/fermentable fructooligosaccharides, decreases serum triacylglycerol (TAG) when it is included in the standard, fiber-free or high fat diet of rats. This paper summarizes in vivo and in vitro data to establish a biochemical mechanism underlying the hypolipidemic effect of OFS. When OFS is added to the standard (carbohydrate-rich) diet of rats at the dose of 10 g/100 g, a TAG-lowering action occurs as a consequence of a reduction of de novo liver fatty acid synthesis. The depression in the activity of all lipogenic enzymes and fatty acid synthase mRNA suggests that OFS modifies the gene expression of lipogenic enzymes. Through its modulation of de novo lipogenesis, OFS can protect against liver lipid accumulation induced by providing 10% fructose-enriched water for 48 h. OFS also significantly decreases serum insulin and glucose, which are both known to participate in the nutritional regulation of lipogenesis. It also increases the intestinal production of incretins, namely, glucose-dependent insulinotropic peptide and glucagon-like peptide 1. This latter phenomenon results mainly from promotion of intestinal tissue proliferation by oligofructose fermentation end-products. Collectively, a link likely exists between the modulation of hormone and incretin production by OFS, and its antilipogenic effect.

Title
In vitro fructooligosaccharide utilization and inhibition of Salmonella spp. by selected bacteria.
Author
Oyarzabal OA; Conner DE
Source
Poult Sci, 1995 Sep, 74:9, 1418-25
Abstract
In vitro experiments were conducted to determine: 1) inhibitory capacities of potential direct-fed microbial bacteria against Salmonella serotypes; and 2) the ability of Bifidobacterium bifidum, Enterococcus faecium, Lactobacillus casei, Lactococcus lactis, Pediococcus sp., and Salmonella spp. to grow in media containing fructooligosaccharides (FOS-50 or FOS pure formulation) as the only carbohydrate Source. Thirteen bacteria (two strains of Bacillus coagulans, Bacillus licheniformis, Bacillus subtilis, B. bifidum, E. faecium, two strains of Lactobacillus acidophilus, L. casei, Pediococcus sp., Propionibacterium acidopropionici, P. jensenii, and Propionibacterium sp.) were tested for inhibition of six Salmonella serotypes (S. california, S. enteritidis, S. heidelberg, S. mission, S. senftenberg, and S. typhimurium) using a spot-the-lawn technique. Bifidobacterium bifidum, E. faecium, all lactobacilli, and Pediococcus sp. clearly inhibited growth of all Salmonella serotypes. In the growth experiments, E. faecium, L. lactis, and Pediococcus sp. grew in media with either FOS-50 or the pure formulation of FOS as the sole carbohydrate Source. All tested Salmonella serotypes utilized FOS-50 for growth; however growth varied among the serotypes. In contrast, none of the Salmonella serotypes grew in media containing the pure formulation of FOS as the only carbohydrate Source.

Title
Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics.
Author
Gibson GR; Roberfroid MB
Source
J Nutr, 1995 Jun, 125:6, 1401-12
Abstract
Because the human gut microbiota can play a major role in host health, there is currently some interest in the manipulation of the composition of the gut flora towards a potentially more remedial community. Attempts have been made to increase bacterial groups such as Bifidobacterium and Lactobacillus that are perceived as exerting health-promoting properties. Probiotics, defined as microbial food supplements that beneficially affect the host by improving its intestinal microbial balance, have been used to change the composition of colonic microbiota. However, such changes may be transient, and the implantation of exogenous bacteria therefore becomes limited. In contrast, prebiotics are nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacterial species already resident in the colon, and thus attempt to improve host health. Intake of prebiotics can significantly modulate the colonic microbiota by increasing the number of specific bacteria and thus changing the composition of the microbiota. Nondigestible oligosaccharides in general, and fructooligosaccharides in particular, are prebiotics. They have been shown to stimulate the growth of endogenous bifidobacteria, which, after a short feeding period, become predominant in human feces. Moreover, these prebiotics modulate lipid metabolism, most likely via fermentation products. By combining the rationale of pro- and prebiotics, the concept of synbiotics is proposed to characterize some colonic foods with interesting nutritional properties that make these compounds candidates for classification as health-enhancing functional food ingredients.

Title
Continuous culture selection of bifidobacteria and lactobacilli from human faecal samples using fructooligosaccharide as selective substrate.
Author
Sghir A; Chow JM; Mackie RI
Source
J Appl Microbiol, 1998 Oct, 85:4, 769-77
Abstract
The human large intestine contains a large and diverse population of bacteria. Certain genera, namely Bifidobacterium and Lactobacillus, are thought to exert health-promoting effects. Prebiotics such as fructooligosaccharides (FOS) have been shown to stimulate the growth of endogenous bifidobacteria. In this study, changes of lactic acid producing bacteria in continuous culture fermentors (semi-defined, anaerobic medium containing 5 g 1(-1) FOS, dilution rate of 0.1 h-1, pH 5.5) were followed over a 21 d period after inoculation with blended human faeces from four healthy adults. Samples were also taken every 3 d for influent/effluent FOS, short chain fatty acid (SCFA), lactate and microbiological analyses. Results showed that SCFA concentrations decreased abruptly 1 d after inoculation while lactate concentrations increased. Classical methods of enumeration using selective media showed that the proportion of total culturable count represented by bifidobacteria and lactobacilli increased from 11.9% on day 1 to 98.1% on day 21. However, molecular methods using genus-specific 16S rRNA oligonucleotide probes indicated that the bifidobacterial population maintained a level between 10 and 20% of total 16S rRNA during the first 6 d and disappeared rapidly when the maximum concentration of lactate was reached. Lactobacilli, which were initially present in low numbers, increased until day 9 and remained at high levels (20-42% of total 16S rRNA) to day 21, with the exception of day 18. Although FOS has usually been regarded as a selective substrate for bifidobacteria, these observations suggest that: (1) lactobacilli are also able to use FOS, (2) lactobacilli can out-compete bifidobacteria in continuous culture at pH 5.2-5.4 when FOS is the primary carbon and energy Source, and (3) bifidobacteria can grow faster on FOS than lactobacilli under controlled conditions.

Title
True calcium absorption in the intestine is enhanced by fructooligosaccharide feeding in rats. Author
Morohashi T; Sano T; Ohta A; Yamada S
Source
J Nutr, 1998 Oct, 128:10, 1815-8
Abstract
Fructooligosaccharides (FOS) have been shown to stimulate apparent calcium absorption in the intestine. In this study, we examined the effect of FOS on true calcium absorption using the calcium balance in combination with the 45Ca kinetics method. Sixteen 45-d-old male Wistar rats were randomly divided into two groups, a control group (n = 8) and a FOS group (n = 8). The diet fed to the FOS group contained 5% FOS, at the expense of half of the sucrose in the control diet. After an adaptation period (3 d) and a free-access period (3 d) that were used to estimate the amount of food required for pair-feeding on the basis of calcium, all of the rats were pair-fed throughout the experiment from the age of 51 d. A constant amount of calcium was fed to the rats in each group (95 mg /d). At age 60 d, a 3-d metabolic study was started by the intravenous injection of 45Ca. Several variables were calculated on the bases of measurements of calcium intake, calcium in feces and serum, and 45Ca in feces, urine and serum. Both true and apparent calcium absorption in the intestine (Vad and Vna) and urinary calcium were significantly greater in rats that had been fed FOS. There were no differences between the groups in endogenous net calcium excretion into feces (Vf; Vad - Vna). The calcium balance was also enhanced by FOS. Calcium balance in the FOS group was significantly correlated with the absorbed calcium (r2 = 0.936, P < 0.01), as was that in the control group (r2 = 0.994, P < 0.01). These results suggest that the increased true calcium absorption and balance produced by FOS feeding might improve bone calcification.