scholarly journals Bifidobacterium pseudolongum in the Ceca of Rats Fed Hi-Maize Starch Has Characteristics of a Keystone Species in Bifidobacterial Blooms

2018 ◽  
Vol 84 (15) ◽  
Author(s):  
Manuela Centanni ◽  
Blair Lawley ◽  
Christine A. Butts ◽  
Nicole C. Roy ◽  
Julian Lee ◽  
...  
Keyword(s):  
Large Bowel ◽  
Resistant Starch ◽  
Keystone Species ◽  
Natural Ecosystem ◽  
Maize Starch ◽  
Critical Function ◽  
Content Type ◽  
Bifidobacterium Animalis ◽  
Rat Gut

ABSTRACT Starches resistant to mammalian digestion are present in foods and pass to the large bowel, where they may be degraded and fermented by the microbiota. Increases in relative abundances of bifidobacteria (blooms) have been reported in rats whose diet was supplemented with Hi-Maize resistant starch. We determined that the bifidobacterial species present in the rat cecum under these circumstances mostly belonged to Bifidobacterium animalis. However, cultures of B. animalis isolated from the rats failed to degrade Hi-Maize starch to any extent. In contrast, Bifidobacterium pseudolongum also detected in the rat microbiota had high starch-degrading ability. Transcriptional comparisons showed increased expression of a type 1 pullulanase, alpha-amylase, and glycogen debranching enzyme by B. pseudolongum when cultured in medium containing Hi-Maize starch. Maltose was released into the culture medium, and B. animalis cultures had shorter doubling times in maltose medium than did B. pseudolongum. Thus, B. pseudolongum, which was present at a consistently low abundance in the microbiota, but which has extensive enzymatic capacity to degrade resistant starch, showed the attributes of a keystone species associated with the bifidobacterial bloom. IMPORTANCE This study addresses the microbiology and function of a natural ecosystem (the rat gut) using DNA-based observations and in vitro experimentation. The microbial community of the large bowel of animals, including humans, has been studied extensively through the use of high-throughput DNA sequencing methods and advanced bioinformatics analysis. These studies reveal the compositions and genetic capacities of microbiotas but not the intricacies of how microbial communities function. Our work, combining DNA sequence analysis and laboratory experiments with cultured strains of bacteria, revealed that the increased abundance of bifidobacteria in the rat gut, induced by feeding indigestible starch, involved a species that cannot itself degrade the starch (Bifidobacterium animalis) but cohabits with a species that can (Bifidobacterium pseudolongum). B. pseudolongum has the characteristics of a keystone species in the community because it had low abundance but high ability to perform a critical function, the hydrolysis of resistant starch.

scholarly journals Butyrylated starch is less susceptible to enzymic hydrolysis and increases large-bowel butyrate more than high-amylose maize starch in the rat

2006 ◽  
Vol 96 (2) ◽  
pp. 276-282 ◽  
Author(s):  
Balázs H. Bajka ◽  
David L. Topping ◽  
Lynne Cobiac ◽  
Julie M. Clarke
Keyword(s):  
Large Bowel ◽  
Resistant Starch ◽  
Effective Means ◽  
Animal Experiments ◽  
Proximal Colon ◽  
Maize Starch ◽  
Rat Growth ◽  
Food Applications ◽  
High Amylose

Large-bowel fermentation of resistant starch produces SCFA that are believed to be important in maintaining visceral function. High-amylose maize starch (HAMS) and acylated starches are sources of resistant starch and are an effective means of increasing colonic SCFA. Cooking increases digestibility of starches but its effects on the capacity of these starches to raise large-bowel SCFA are unknown. We have examined the effects of cooking of HAMS and butyrylated HAMS (HAMSB) on amylolysis in vitro and their capacity to raise caeco-colonic SCFA in rats. The starches were boiled in excess water and microwaved, followed by drying at 100°C. Cooking increased in vitro glucose release for both starches but significantly less from HAMSB. Rat growth rates were unaffected when fed cooked resistant starch. Digesta pH was increased in the caecum and proximal colon of rats fed cooked HAMS. Distal colonic pH was highest in rats fed cooked HAMSB. Factorial analyses (2×2) of caecal SCFA pools showed significant differences between HAMS and HAMSB, and that cooking significantly lowered caecal butyrate pools. Portal venous butyrate concentrations were higher in both HAMSB groups than those fed HAMS. The data suggest that HAMSB is less susceptible to in vitro amylolysis than HAMS following cooking and delivers more butyrate to rat caecum than HAMS. This attribute may be useful in food applications for specific delivery of SCFA to the colon. Preparation of carbohydrates to simulate human food in animal experiments may be important to assess nutritional and physiological effects accurately.

scholarly journals In Vitro and In Vivo Digestibility of Native Maize Starch Granules Varying in Amylose Contents

2007 ◽  
Vol 90 (6) ◽  
pp. 1628-1634 ◽  
Author(s):  
Tatsuya Morita ◽  
Yusuke Ito ◽  
Ian Lewis Brown ◽  
Ryuichi Ando ◽  
Shuhachi Kiriyama
Keyword(s):  
Surface Area ◽  
Linear Correlation ◽  
Resistant Starch ◽  
Amylose Content ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
Maize Starch ◽  
Positive Linear Correlation

Abstract Digestibility of maize starch granules with different amylose content (AL-0, 22, 54, 68, 80, or 90) was investigated. Measurement of the in vivo resistant starch (RS) content of the starches was performed using surgically prepared ileorectostomized rats. The rats were fed a purified diet containing one of the starches at 652.5 g/kg diet. The in vivo RS content was determined based on the fecal starch excretion. The dietary fiber (DF) value increased as a function of the amylose content in the starch and showed a positive linear correlation with the gelatinization temperature of the granules. In contrast, the in vitro RS content was likely to depend on both the surface area and amylose contents of the starch granules. The maximum in vitro RS content was obtained with AL-68 (54.4). In vivo RS content showed a significant correlation with the amount of in vitro RS but not in respect to the DF detected. The in vivo RS content of AL-68 (43.4) was higher than that found in AL-90 (37.8). A profound gap was observed for AL-54 between the amount of DF (6.4) and RS (in vitro = 46.6 and in vivo = 40.9) present. The results suggest that both in vitro and in vivo digestibility of maize starch is affected by the amylose content and surface area of the granules. The current evaluation suggests that the physiological occurrence of RS from maize starch might be predictable by reference to the in vitro RS value.

In vitro digestibility and pasting properties of epichlorohydrin modified cassava starch

2016 ◽  
Vol 46 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Marta Aurelia Horianski ◽  
Juan Manuel Peralta ◽  
Luis Alberto Brumovsky
Keyword(s):  
Reaction Time ◽  
Resistant Starch ◽  
Reaction Times ◽  
Cassava Starch ◽  
Pasting Properties ◽  
Cross Linking ◽  
In Vitro Digestibility ◽  
Total Dietary Fiber ◽  
Content Type

Purpose The purpose of this study was to analyze the influence of epichlorohydrin (ECH) concentration and reaction time on the food-grade resistant starch production and its pasting properties by using native cassava starch of Misiones-Argentina origin. Design/methodology/approach Cassava starch was modified using ECH (0.30 and 0.15 per cent) during 4 or 8 h. Digestibility was evaluated by determining resistant starch as total dietary fiber. Pasting properties and the cross-linking degree were studied using a micro-viscoamylograph (Brabender). Findings Resistant starch content was not influenced by ECH concentration and reaction time. Cross-linking was detected at higher reaction times (8 h) and ECH concentrations (0.30 per cent), where a decrease in viscosity peaks by more than 80 per cent was observed. Both pasting temperature and breakdown were increased, whereas a decrease in retrogradation was detected. Practical implications Starches can be suitable for different food applications. This is because of the ability to modify its pasting properties and the invariability of the in vitro digestibility of cassava starch as a result of using ECH (at concentrations approved by local and regional legislation) and reaction times of 4 and 8 h. Originality/value Information related to the modification of cassava starch using ECH is scarce or not available nowadays in literature.

scholarly journals Two high-amylose maize starches with different amounts of resistant starch vary in their effects on fermentation, tissue and digesta mass accretion, and bacterial populations in the large bowel of pigs

2007 ◽  
Vol 97 (1) ◽  
pp. 134-144 ◽  
Author(s):  
Anthony R. Bird ◽  
Michelle Vuaran ◽  
Ian Brown ◽  
David L. Topping
Keyword(s):  
Large Bowel ◽  
Resistant Starch ◽  
Live Weight ◽  
Distal Region ◽  
Maize Starch ◽  
Bacterial Populations ◽  
Young Pigs ◽  
Waxy Starch ◽  
High Amylose ◽  
The Three Rs

Four groups of young pigs (n6) were fed a diet containing 50 % maize starch as either a highly digestible waxy starch (control; 0 % amylose) or one of three resistant starch (RS) diets, namely a high-amylose maize starch (HAMS; 85 % amylose), this starch subjected to hydrothermal treatment (HTHAMS; 85 % amylose), or a blend of HAMS and HTHAMS included in equal amounts, for 21 d. Food intake and live weight at the end of the study were similar among the four groups. Ileal starch digestibility was lower in pigs fed the three RS diets but was greater for HAMS (88 %) than for HTHAMS (70 %;P < 0·05). Faecal output and large bowel digesta mass, and concentrations and pools of individual and total SCFA were higher (by about two- to threefold; allP < 0·05) and digesta pH lower (by about 1 unit, allP < 0·001) in pigs fed either HAMS or HTHAMS compared to the controls. These differences in biomarkers were seen along the length of the large bowel. Colon length was 0·5–0·9 m longer (19–35 %) in pigs fed the high-RS diets relative to those fed the highly digestible starch diet (P < 0·05). Faecal and proximal colonic lactobacilli and bifidobacteria numbers were higher (by 1 and 3 log units;P < 0·05) in pigs fed the HAMS or HTHAMS diets. Although both high-amylose starches promoted fermentation throughout the large bowel, the data suggest that the effects of HTHAMS may be more pronounced in the distal region compared to those of HAMS.

scholarly journals Relevance of Bifidobacterium animalis subsp. lactis Plasminogen Binding Activity in the Human Gastrointestinal Microenvironment

2011 ◽  
Vol 77 (19) ◽  
pp. 7072-7076 ◽  
Author(s):  
Marco Candela ◽  
Silvia Turroni ◽  
Manuela Centanni ◽  
Jessica Fiori ◽  
Simone Bergmann ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Cross Talk ◽  
Probiotic Strain ◽  
Binding Activity ◽  
Human Gastrointestinal Tract ◽  
Human Feces ◽  
Content Type ◽  
Human Host ◽  
Bifidobacterium Animalis

ABSTRACTHuman plasmin(ogen) is regarded as a component of the molecular cross talk between the probiotic speciesBifidobacterium animalissubsp.lactisand the human host. However, up to now, onlyin vitrostudies have been reported. Here, we demonstrate that the probiotic strainB. animalissubsp.lactisBI07 is capable of recruiting plasmin(ogen) present at physiological concentrations in crude extracts from human feces. Our results provide evidence that supports the significance of theB. lactis-plasmin(ogen) interaction in the human gastrointestinal tract.

PREPARATION AND CHARACTERISATION OF ACETYLATED WHEAT STARCH SUPPORTING FOR DIABETES TREATMENT

2018 ◽  
Vol 8 (5) ◽  
pp. 78-84
Author(s):  
Uyen Tran Thi Ngoc ◽  
Nam Nguyen Khac ◽  
Dung Tran Huu
Keyword(s):  
Physicochemical Properties ◽  
Resistant Starch ◽  
Starch Content ◽  
Degree Of Substitution ◽  
Wheat Starch ◽  
Diabetes Treatment ◽  
Glucose Response ◽  
Swelling Capacity ◽  
Wheat Starches

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase

scholarly journals Mutations in fbiD (Rv2983) as a Novel Determinant of Resistance to Pretomanid and Delamanid in Mycobacterium tuberculosis

2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Evidence ◽  
Clinical Samples ◽  
Loss Of Function ◽  
Wild Type ◽  
Content Type ◽  
Solid Media ◽  
High Level ◽  
Level Resistance

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.

scholarly journals In VitroActivities of Hexaazatrinaphthylenes against Leishmania spp.

2015 ◽  
Vol 59 (5) ◽  
pp. 2867-2874 ◽  
Author(s):  
Atteneri López-Arencibia ◽  
Daniel García-Velázquez ◽  
Carmen M. Martín-Navarro ◽  
Ines Sifaoui ◽  
María Reyes-Batlle ◽  
...  
Keyword(s):  
Therapeutic Agents ◽  
Content Type ◽  
Inhibition Effect ◽  
Intracellular Amastigotes ◽  
Dependent Inhibition ◽  
Leishmania Spp ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Potential Use

ABSTRACTThein vitroactivity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species ofLeishmaniais described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC50s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives againstLeishmaniaspecies, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

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