Resistant starch modifies gut microflora and microbial metabolism in human flora‐associated rats inoculated with faeces from Italian and UK donors

• Published in: Journal of applied microbiology Vol. 86; no. 3; pp. 521 - 530
• Main Authors: Silvi, S., Rumney, C. J., Cresci, A., Rowland, I. R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science, Ltd 01.03.1999; Blackwell Science; Oxford University Press
• Subjects: Ammonia - analysis; Amylose - pharmacology; Animal, plant and microbial ecology; Animals; Bacteria - drug effects; Bacteria - growth & development; Bacteriological Techniques; Biological and medical sciences; Body Weight; Butyric Acid - analysis; Cecum - enzymology; Cecum - microbiology; Cell Division - drug effects; Colon - enzymology; Colon - microbiology; Fatty Acids, Volatile - analysis; Feces - microbiology; Female; Flora; Fundamental and applied biological sciences. Psychology; Glucuronidase - metabolism; Humans; Hydrogen-Ion Concentration; Intestinal Mucosa - enzymology; Intestinal Mucosa - microbiology; Italy; Male; Microbial ecology; Normal microflora of man and animals. Rumen; Rats; Rats, Inbred F344; Sucrose - pharmacology; United Kingdom; England; United Kingdom; Italy; Great Britain; Europe; Human; Short chain; Rat; Sucrose; Rodentia; Resistant starch; Fatty acids; Vertebrata; Mammalia; Enzymatic activity; Nutrient source; Carbohydrate; Associated microflora; Feces; Digestive tract; Comparative study
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.1999.00696.x

The effect of sucrose and resistant starch (‘CrystaLean’– a retrograded, amylose starch) on human gut microflora and associated parameters was studied in human flora‐associated (HFA) rats, colonized with microfloras from UK or Italian subjects, to determine whether such floras were affected differently by dietary carbohydrates. Consumption of the resistant starch diet resulted in significant changes in four of the seven main groups of bacteria enumerated. In both the UK and Italian flora‐associated rats, numbers of lactobacilli and bifidobacteria were increased 10–100‐fold, and there was a concomitant decrease in enterobacteria when compared with sucrose‐fed rats. The induced changes in caecal microflora of both HFA rat groups were reflected in changes in bacterial enzyme activities and caecal ammonia concentration. Although it had little effect on caecal short‐chain fatty acid concentration, CrystaLean markedly increased the proportion of n‐butyric acid in both rat groups and was associated with a significant increase in cell proliferation in the proximal colon of the Italian flora‐associated rats. CrystaLean appeared to play a protective role in the colon environment, lowering caecal ammonia concentration, caecal pH and β‐glucuronidase activity.