scholarly journals Contribution of the digestive tract microflora to amylomaize starch degradation in the rat

1992 ◽  
Vol 67 (3) ◽  
pp. 489-499 ◽  
Author(s):  
Claude Andrieux ◽  
Emperatriz Delahaye Pacheco ◽  
Brigitte Bouchet ◽  
Daniel Gallant ◽  
Odette Szylit
Keyword(s):  
Small Intestine ◽  
Starch Granule ◽  
Bacterial Flora ◽  
Short Chain Fatty Acids ◽  
Starch Degradation ◽  
Maize Starch ◽  
Germ Free ◽  
Transmission Electron ◽  
Normal Maize

To study in vivo the contribution of the bacterial flora to amylomaize starch degradation in the rat, germ-free and conventional rats were fed on a diet containing either a normal maize starch or an amylomaize starch. In germ-free rats maize starch was almost totally digested in the small intestine, whereas 40% of the ingested amylomaize starch reached the caecum and 30% was excreted, despite the very high endogenous amylase activity. Study by transmission electron microscopy of germ-free caecal contents showed an endocorrosion of the starch granule. In conventional rats, as in germ-free rats, digestibility of maize starch reached 98% in the small intestine, whereas that of amylomaize starch was only 60%. In the caecum of these rats amylomaize starch was fermented, and this led to a decrease in caecal pH and to formation of short-chain fatty acids (SCFA), especially propionate. Comparison between conventional rats fed on maize starch or amylomaize starch showed that caecal SCFA concentrations during a circadian cycle varied in the same way whereas total SCFA and lactic acid concentrations were much higher in rats fed on amylomaize starch. Amylase (EC 3.2.1.1) activity was similar in the caecal contents of conventional rats whatever the ingested starch. It was lower in conventional than in germ-free rats, but no starch granule remained in the caecum of conventional rats. These results showed that bacterial amylase was more efficient at degrading resistant amylomaize starch than endogenous amylase.

scholarly journals Potato and high-amylose maize starches are not equivalent producers of butyrate for the colonic mucosa

2000 ◽  
Vol 84 (5) ◽  
pp. 689-696 ◽  
Author(s):  
Lucile J. M. Martin ◽  
Henri J. W. Dumon ◽  
Gérard Lecannu ◽  
Martine M. J. Champ
Keyword(s):  
Colonic Mucosa ◽  
Potato Starch ◽  
Portal Blood Flow ◽  
Short Chain Fatty Acids ◽  
Portal Blood ◽  
Maize Starch ◽  
Catheterization Technique ◽  
High Amylose

Portal appearance of short-chain fatty acids (SCFA) produced from fermentation of three different resistant starch (RS) sources (raw potato starch, high-amylose maize starch and retrograded high-amylose maize starch) was investigated in pigs. The catheterization technique coupled with determination of portal blood flow was used to estimate SCFA uptake by the colonic mucosa. Our hypothesis was that these three RS were not equivalent butyrate providers for the colonic mucosa and that butyrate uptake would therefore be different after in vivo fermentation of each starch. The starches induced different patterns of appearance of SCFA in the portal blood; raw potato starch was the only RS source to show a significant appearance of butyrate in the portal blood. Thus, uptake of butyrate by the colonic mucosa apparently differed between starches. This finding suggests that butyrate uptake does not only depend on the flow of butyrate appearing in the lumen. Indeed, for unexplained reasons, utilization of butyrate by the colonic mucosa appeared to be less efficient when the butyrate was produced from fermentation of potato starch than when it was produced from fermentation of the other RS sources.

scholarly journals In Vivo Autophagy Up-Regulation of Small Intestine Enterocytes in Chinese Soft-Shelled Turtles during Hibernation

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 682 ◽  
Author(s):  
Waseem Ali Vistro ◽  
Yue Zhang ◽  
Xuebing Bai ◽  
Ping Yang ◽  
Yufei Huang ◽  
...  
Keyword(s):  
Small Intestine ◽  
Adenosine Monophosphate ◽  
Mucosal Surface ◽  
Multivesicular Bodies ◽  
Sequestosome 1 ◽  
Main Challenge ◽  
Transmission Electron ◽  
Late Endosomes ◽  
Positive Immunoreactivity

Many studies have focused on how autophagy plays an important role in intestinal homeostasis under pathological conditions. However, its role in the intestine during hibernation remains unclear. In the current study, we characterized in vivo up-regulation of autophagy in enterocytes of the small intestine of Chinese soft-shelled turtles during hibernation. Autophagy-specific markers were used to confirm the existence of autophagy in enterocytes through immunohistochemistry (IHC), immunofluorescence (IF), and immunoblotting. IHC staining indicated strong, positive immunoreactivity of the autophagy-related gene (ATG7), microtubule-associated protein light chain (LC3), and lysosomal-associated membrane protein 1 (LAMP1) within the mucosal surface during hibernation and poor expression during nonhibernation. IF staining results showed the opposite tendency for ATG7, LC3, and sequestosome 1 (p62). During hibernation ATG7 and LC3 showed strong, positive immunosignaling within the mucosal surface, while p62 showed strong, positive immunosignaling during nonhibernation. Similar findings were confirmed by immunoblotting. Moreover, the ultrastructural components of autophagy in enterocytes were revealed by transmission electron microscopy (TEM). During hibernation, the cumulative formation of phagophores and autophagosomes were closely associated with well-developed rough endoplasmic reticulum in enterocytes. These autophagosomes overlapped with lysosomes, multivesicular bodies, and degraded mitochondria to facilitate the formation of autophagolysosome, amphisomes, and mitophagy in enterocytes. Immunoblotting showed the expression level of PTEN-induced kinase 1 (PINK1), and adenosine monophosphate-activated protein kinase (AMPK) was enhanced during hibernation. Furthermore, the exosome secretion pathway of early–late endosomes and multivesicular bodies were closely linked with autophagosomes in enterocytes during hibernation. These findings suggest that the entrance into hibernation is a main challenge for reptiles to maintain homeostasis and cellular quality control in the intestine.

Oral intake of slowly digestible α-glucan, isomaltodextrin, stimulates glucagon-like peptide-1 secretion in the small intestine of rats

2019 ◽  
Vol 123 (6) ◽  
pp. 619-626
Author(s):  
Yoshihiko Komuro ◽  
Takashi Kondo ◽  
Shingo Hino ◽  
Tatsuya Morita ◽  
Naomichi Nishimura
Keyword(s):  
Small Intestine ◽  
Oral Delivery ◽  
Oral Intake ◽  
Membrane Vesicles ◽  
Rat Small Intestine ◽  
Maize Starch ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

AbstractTo investigate whether oral intake of highly branched α-glucan isomaltodextrin (IMD) could stimulate ileal glucagon-like peptide-1 (GLP-1) secretion, we examined (1) the digestibility of IMD, (2) the digestion and absorption rates of IMD, in rat small intestine and (3) portal GLP-1 concentration in rats given IMD. In Expt 1, ileorectostomised rats were given a 3 % IMD diet for 10 d. Separately, a 16-h in vitro digestion of IMD, using porcine pancreatic α-amylase and brush-border membrane vesicles from rat small intestine, was conducted. In Expt 2, upon 24-h fasting, rats were given any of glucose, IMD and high-amylose maize starch (HAMS) (1 g/kg of body weight). In Expt 3, caecectomised rats were given 0·2 % neomycin sulphate and a 5 % IMD diet for 10 d. The in vivo and in vitro digestibility of IMD was 70–80 %. The fraction of IMD digested in vitro for the first 120 min was 67 % of that in maize starch. The AUC for 0–120 min of plasma glucose concentration was significantly lower in HAMS group and tended to be lower in IMD group than in the glucose group. Finally, we also observed that, when compared with control rats, glucose of IMD significantly stimulated and improved the concentration of portal active GLP-1 in antibiotic-administered, caecectomised rats. We concluded that IMD was slowly digested and the resulting glucose stimulated GLP-1 secretion in rat small intestine. Oral delivery of slowly released IMD glucose to the small intestine probably exerts important, yet unknown, physiological effects on the recipient.

SCFA increase intestinal Na absorption by induction of NHE3 in rat colon and human intestinal C2/bbe cells

2001 ◽  
Vol 280 (4) ◽  
pp. G687-G693 ◽  
Author(s):  
Mark W. Musch ◽  
Cres Bookstein ◽  
Yue Xie ◽  
Joseph H. Sellin ◽  
Eugene B. Chang
Keyword(s):  
Brush Border ◽  
Apical Membrane ◽  
Bacterial Flora ◽  
Short Chain Fatty Acids ◽  
Rat Colon ◽  
Dependent Manner ◽  
Soluble Fiber ◽  
Concentration Dependent Manner

Short-chain fatty acids (SCFA), produced by colonic bacterial flora fermentation of dietary carbohydrates, promote colonic Na absorption through mechanisms not well understood. We hypothesized that SCFA promote increased expression of apical membrane Na/H exchange (NHE), serving as luminal physiological cues for regulating colonic Na absorptive capacity. Studies were performed in human colonic C2/bbe (C2) monolayers and in vivo. In C2 cells exposed to butyrate, acetate, proprionate, or the poorly metabolized SCFA isobutyrate, apical membrane NHE3 activity and protein expression increased in a time- and concentration-dependent manner, whereas no changes were observed for NHE2. In contrast, no significant changes in brush-border hydrolase or villin expression were noted. Analogous to the in vitro findings, rats fed the soluble fiber pectin exhibited a time-dependent increase in colonic NHE3, but not NHE2, protein, mRNA, and brush-border activity. These changes were region-specific, as no changes were observed in the ileum. We conclude that luminal SCFA are important physiological cues for regulating colonic Na absorptive function, allowing the colon to adapt to chronic changes in dietary carbohydrate and Na loads.

Gas supersaturation in the cecal wall of mice due to bacterial CO2production

1999 ◽  
Vol 86 (4) ◽  
pp. 1311-1318 ◽  
Author(s):  
Henrik Rasmussen ◽  
Gunnvald Kvarstein ◽  
Helge Johnsen ◽  
Hubert Dirven ◽  
Tore Midtvedt ◽  
...  
Keyword(s):  
Bacterial Flora ◽  
Intestinal Bacteria ◽  
Bacterial Activity ◽  
Germ Free ◽  
Cecal Wall ◽  
Mixture Formula ◽  
Intestinal Segments ◽  
Normal Bacterial Flora

Pco2in the lumen and serosa of cecum and jejunum was measured in mice. The anesthetic used was a fentanyl-fluanisone-midazolam mixture.[Formula: see text] was recorded in vivo and postmortem. [Formula: see text] was 409 ± 32 Torr (55 ± 4 kPa) in the cecal lumen and 199 ± 22 Torr (27 ± 3 kPa) on the serosa in normal mice. Irrigation of the cecum resulted in serosal and luminal [Formula: see text]levels of 65–75 Torr. Cecal [Formula: see text]was significantly lower in germ-free mice (65 ± 5 Torr). Cecal[Formula: see text] increased significantly after introduction of normal bacterial flora into germ-free mice. Introduction of bacterial monocultures into germ-free mice had no effect. After the deaths of the mice, cecal[Formula: see text] increased rapidly in normal mice. The intestinal bacteria produced the majority of the cecal[Formula: see text], and the use of tonometry in intestinal segments with a high bacterial activity should be interpreted with caution. We propose that serosal[Formula: see text] levels >150–190 Torr (20–25 kPa) in the cecum of mice with a normal circulation may represent a state of gas supersaturation in the cecal wall.

scholarly journals Physiological Aspects of Resistant Starch and in vivo Measurements

2004 ◽  
Vol 87 (3) ◽  
pp. 749-755 ◽  
Author(s):  
Martine M-J Champ
Keyword(s):  
Resistant Starch ◽  
Short Chain Fatty Acids ◽  
Glucose Absorption ◽  
Starch Degradation ◽  
Physiological Properties ◽  
Fermentation Pattern ◽  
Colonic Health ◽  
Available Information ◽  
Different Characteristics

Abstract Resistant starch (RS) is the sum of starch and products of starch degradation not absorbed in the small intestine of healthy individuals. There are a number of RS with different characteristics which may have a different fate in the colon. As a consequence, all RS should not be considered equivalent as far as physiological properties are concerned; indeed, they may have a different impact on colonic health. This statement may explain part of the apparent contradictions in the literature on RS and cancer or inflammatory disease prevention. RS is fermented in the large intestine into short-chain fatty acids and, among those, butyrate, which is recognized as the main nutrient of the colonocyte. This fermentation pattern seems to be responsible for most of the effects of RS on colonic health. Another important property is linked to its ability to lower colonic pH, which is usually considered as beneficial for mineral biovailability in the colon or cancer prevention. Due to their fate in the digestive tract, RS materials do not seem to have any significant impact on glucose absorption or metabolism. On the contrary, they may have a hypocholesterolemic effect, but available information is contradictory.

Luminal bacterial flora determines physiological expression of intestinal epithelial cytoprotective heat shock proteins 25 and 72

2005 ◽  
Vol 288 (4) ◽  
pp. G696-G704 ◽  
Author(s):  
Donna L. Arvans ◽  
Stephan R. Vavricka ◽  
Hongyu Ren ◽  
Mark W. Musch ◽  
Lisa Kang ◽  
...  
Keyword(s):  
Small Intestine ◽  
Heat Shock ◽  
Small Bowel ◽  
Heat Shock Proteins ◽  
Ex Vivo ◽  
Short Circuit ◽  
Bacterial Flora ◽  
Short Chain Fatty Acids ◽  
Shock Proteins ◽  
Hsp72 Expression

Heat shock proteins (HSP) 25 and 72 are expressed normally by surface colonocytes but not by small intestinal enterocytes. We hypothesized that luminal commensal microflora maintain the observed colonocyte HSP expression. The ability of the small intestine to respond to bacteria and their products and modulate HSPs has not been determined. The effects of luminal bacterial flora in surgically created midjejunal self-filling (SFL) vs. self-emptying (SEL) small-bowel blind loops on epithelial HSP expression were studied. HSP25 and HSP72 expression were assessed by immunoblot and immunohistochemistry. SFL were chronically colonized, whereas SEL contained levels of bacteria normal for the proximal small intestine. SFL creation significantly increased HSP25 and HSP72 expression relative to corresponding sections from SEL. Metronidazole treatment, which primarily affects anaerobic bacteria as well as a diet lacking fermentable fiber, significantly decreased SFL HSP expression. Small bowel incubation with butyrate ex vivo induced a sustained and significant upregulation of HSP25 and altered HSP72 expression, confirming the role of short-chain fatty acids. To determine whether HSPs induction altered responses to an injury, effects of the oxidant, monochloramine, on epithelial resistance and short-circuit current ( Isc) responses to carbachol and glucose were compared. Increased SFL HSP expression was associated with protection against oxidant-induced decreases in transmural resistance and Iscresponses to glucose, but not secretory responses to carbachol. In conclusion, luminal microflora and their metabolic byproducts direct expression of HSPs in gut epithelial cells, an effect that contributes to preservation of epithelial cell viability under conditions of stress.

The Influence of Amylose and Amylopectin Characteristics on Phase Transition of Cornstarches Observed under Shearless Condition

2012 ◽  
Vol 554-556 ◽  
pp. 1170-1173
Author(s):  
Pei Chen ◽  
Xiao Zhang ◽  
Nan Xiao ◽  
Xue Hui Wu
Keyword(s):  
Phase Transition ◽  
Internal Structure ◽  
Starch Granule ◽  
Central Area ◽  
Starch Granules ◽  
Maize Starch ◽  
Waxy Maize ◽  
Normal Maize ◽  
Increasing Temperature

The influence of amylose and amylopectin characteristics on phase transition of cornstarches under shearless condition was observed by SEM and CLSM. The change of internal structure of starch granules during heating were directly observed online. Brightness of starch granule indicates the degree of gelatinization. The brightness of all the starches decreased with increasing temperature, this change being initiated at the centre of granule. Thus it is clear that the gelatinization process starts at the hilum of the granules. The central area of the granule around the hilum is believed to be the least organized region. The granules of waxy maize and normal maize starch subsequently break through at their cavity and channels, when the granules became swollen during gelatinization, whilst the granules of G50 and G80 remain granular and break down to smaller pieces.

scholarly journals Comparing the Ileal and Hindgut Fermentations in the Pig Model (P08-087-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Carlos Montoya ◽  
Edward de Haas ◽  
Paul Blatchford ◽  
Paul Moughan
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Tertiary Education ◽  
Short Chain Fatty Acids ◽  
Pig Model ◽  
Funding Sources ◽  
Important Amount ◽  
Caecal Fermentation

Abstract Objectives This study aimed to compare ileal and hindgut fermentations in the pig model using a combined in vivo/in vitro methodology. Methods Pigs (23 kg bodyweight, n = 5) were fed a human-type diet for 15 days. On day 15, pigs were euthanased and the small intestine was immediately dissected out and ligated in three equal lengths. Digesta from the last 50 cm of the second (terminal jejunum) and last (terminal ileum) third sections of the small intestine were collected as substrates. Digesta from the remaining last third (i.e., last third minus 50 cm) of the small intestine (ileum) was collected along with caecal digesta for preparing inocula. Terminal jejunal digesta substrates were fermented in vitro with a pooled ileal digesta inoculum for 2 h (ileal fermentation), while terminal ileal digesta substrates were fermented in vitro with a pooled caecal digesta inoculum for 24 h (hindgut fermentation). Results The ileal organic matter (OM) fermentability (28%) was similar than the hindgut counterpart (35%) (P > 0.05). However, the fermentable OM was 63% higher during ileal fermentation than hindgut fermentation (P < 0.05). The production of acetic, isovaleric and succinic acids was higher during ileal fermentation than caecal fermentation (P < 0.05), but the production of propionic, iso-butyric, butyric, valeric and pyruvic acids was lower (P < 0.05). The SCFAs produced in each gastrointestinal tract location was absorbed in their respective gastrointestinal tract location. Conclusions An important amount of OM is fermented in the ileum producing comparable amounts of short-chain fatty acids and organic acids to hindgut fermentation. This challenge the current paradigm concerning gastrointestinal tract fermentation. Funding Sources Centre of Research Excellence Fund from the Tertiary Education.

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