Starch and dietary fibre: their physiological and epidemiological interrelationships

Until the 1980s, starch in the human diet was assumed to be totally degraded and absorbed in the small intestine. Several lines of evidence since then have indicated that this is not the case, including studies of factors controlling stool output, stool bulk on elemental diets, epidemiological studies of starch intakes in developed versus developing nations, and indications using breath hydrogen that fermentation takes place in the large intestine when starch is fed. Of the few direct estimations of starch escaping absorption in the small intestine that have been carried out, one has been conducted using intubation of healthy volunteers, where two different starch meals were fed and samples aspirated from the terminal ileum. This study demonstrated that 8–10% starch escaped absorption on average, with subjects varying from 2 to 20%. Hence a sizeable proportion of starch consumed daily may reach the large intestine, with important physiological consequences. Neither small intestinal transit time nor volume of flow were related to the extent of starch malabsorption in this study. However, many factors may play a role in the extent of malabsorption, and research is continuing to investigate physiological and food characteristics that may influence the digestion and absorption of starch.Key words: starch, dietary fibre, malabsorption, ileum, gastrointestinal function.

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The effects of S(−) and R(+) sulpiride, metoclopramide, cisapride and domperidone on the small intestine suggest DA2-receptors are involved in the control of small intestinal transit time in rats

Pharmacological Research ◽

10.1016/s1043-6618(05)80131-8 ◽

1992 ◽

Vol 26 (2) ◽

pp. 179-185 ◽

Cited By ~ 14

Author(s):

Ettore Zuccato ◽

Cristina Bertolo ◽

Monica Salomoni ◽

Angelo Forgione ◽

Emilio Mussini

Keyword(s):

Small Intestine ◽

Transit Time ◽

Intestinal Transit ◽

Intestinal Transit Time ◽

Small Intestinal Transit ◽

Small Intestinal ◽

Small Intestinal Transit Time

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The influence of a chronic subclinical infection ofTrichostrongylus colubriformison gastrointestinal motility and digesta flow in sheep

Parasitology ◽

10.1017/s0031182000057449 ◽

1985 ◽

Vol 91 (2) ◽

pp. 381-396 ◽

Cited By ~ 26

Author(s):

P. C. Gregory ◽

G. Wenham ◽

D. Poppi ◽

R. L. Coop ◽

J. C. MacRae ◽

...

Keyword(s):

Small Intestine ◽

Food Intake ◽

Transit Time ◽

Gastrointestinal Motility ◽

Subclinical Infection ◽

Intestinal Transit Time ◽

Small Intestinal Transit ◽

Proximal Small Intestine ◽

Small Intestinal ◽

Small Intestinal Transit Time

The influence of a chronic subclinicael infection ofTrichostrongylus colubriformis, 2500 larvae/day for 12 weeks, on gastrointestinal motility and digesta flow was studied in 12 sheep suppliedad libitumwith food and water. Motility was recorded by X-radiography and electromyography from chronically implanted electrodes;abomasal volume and outflow were estimated by dilution of CrEDTA; small intestinal transit time was estimated by passage of Phenol Red. The findings were compared with measurements made prior to infection at restricted food intake and reported separately. The first effects of infection were seen after 3–4 weeks. No animal developed diarrhoea, but food intake was progressively reduced. Small intestinal transit time, abomasal volume and half-time of marker dilution increased while abomasal outflow decreased during infection. These changes occurred both in absolute terms and when compared with values predicted from the observed level of food intake. As the animals became resistant to the parasites abomasal volume and digesta flow returned towards control values (weeks 10–12). The migrating myoelectric complex (MMC) was disrupted in only one sheep, and only transiently. In all sheep the frequency of the MMC was increased during infection and there was a progressive inhibition of abomasal, duodenal and jejunal motility. X-radiography showed there was prolonged pooling of digesta in the proximal small intestine which was cleared only at the phase of regular spiking activity. Two sheep given an anthelmintic drench recovered normal motility and clearance of digesta. It is concluded that subclinical infection of sheep with T.colubriformisalters the normal pattern of gastrointestinal motility in the absence of any diarrhoea, and causes inhibition of abomasal and proximal small intestinal motility and digesta flow. The increased frequency of MMCs helps to maintain digesta flow through the proximal small intestine.

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The relation between food intake and abomasal emptying and small intestinal transit time in sheep

British Journal Of Nutrition ◽

10.1079/bjn19850044 ◽

1985 ◽

Vol 53 (2) ◽

pp. 373-380 ◽

Cited By ~ 32

Author(s):

P. C. Gregory ◽

S. J. Miller ◽

A. C. Brewer

Keyword(s):

Small Intestine ◽

Food Intake ◽

Transit Time ◽

Intestinal Transit ◽

Phenol Red ◽

Intestinal Transit Time ◽

Small Intestinal Transit ◽

Nichrome Wire ◽

Small Intestinal ◽

Small Intestinal Transit Time

1. The relation between the level of food intake and gastrointestinal motility and digesta flow in the abomasum and small intestine was studied in sheep fitted with nichrome-wire electrodes in the gut wall, an abomasal and a duodenal catheter and a terminal ileal cannula.2. Abomasal volume and outflow were calculated from CrEDTA dilution in six sheep and small intestinal transit time by the passage of Phenol Red in ten sheep.3. The frequency of the migrating myoelectric complex of the small intestine was not altered by the level of food intake but the duration of the periods of irregular spiking activity, the amplitude of abomasal activity and the frequency of duodenal rushes were decreased as the level of food intake was decreased.4. There was a linear relation between the level of food intake (FI) and abomasal outflow (mean with SEM: 327 (69) ml/h for each kg FI/d; P < 0.01), and abomasal volume (mean with SEM: 344 (50) ml/kg FI per d; P < 0.001), without any significant change in the half-time of marker dilution in the abomasum. Small intestinal transit time decreased with an increase in food intake (mean with SEM: - 54.9 (5.6) min/kg FI per d; P < 0.001).5.It is concluded that abomasal volume and the rate of digesta flow from the abomasum and along the small intestine are linearly related to the level of food intake.

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