Dose-dependent effects of polyphenolic extracts from green tea, blue-berried honeysuckle, and chokeberry on rat caecal fermentation processes.

The physiological status of the colon or ceacum is known to be very important for the host organism. Therefore, the aim of this study was to estimate the influence of high doses of polyphenolic extracts from chokeberry (CH), blue-berried honeysuckle (H), and green tea (GT) on fermentation processes in the caecum and caecal parameters of rats fed casein diets. In a 4-week experiment, 35-day-old rats were fed diets containing 0.4, 0.8, and 1.2 % of pure polyphenols. The greatest weight of digesta was recorded in rats fed 1.2 % of GT extract, and these animals were also characterised by having the lowest content of dry matter. Supplementation of diets with the extracts of interest caused a reduction in pH values and ammonia concentrations in caecal digesta in comparison to control animals. The results of a two-way analysis of variance indicated dose-dependent (except for 0.4 % supplementation) inhibition of enzymatic activity compared to control animals. Introduction of CH and H extracts significantly reduced the activity of β-glucuronidase compared to rats fed tea diets. Two-way analysis of variance showed a significant decrease in volatile fatty acids concentration in rats fed diets supplemented with H and CH extracts in comparison to control and tea-fed rats. The obtained results showed that the extracts tested can distinctly influence caecal parameters and metabolism. © Georg Thieme Verlag KG Stuttgart · New York.