Ukrainian Journal of Veterinary Sciences

Effect of a prebiotic from the Saccharomyces cerevisiae yeast cell wall on the clinical condition of laboratory rats

Svitlana Tkachuk*, Vladyslav Hromyk

ohdin@ukr.net

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Abstract

The cell wall of Saccharomyces cerevisiae yeast cells, which forms the basis of the commercial preparation Actigen, is one of the most effective natural prebiotics and immunomodulators. However, preliminary studies in laboratory animals are necessary for the effective use of the prebiotic in production animals. In this regard, the purpose of the study was to examine the effect of different doses of the prebiotic on laboratory rats. The study used 40 laboratory rats aged 2 months, which were divided into group 1 (control) and experimental groups 2, 3, and 4, depending on the dose of the prebiotic administered with feed. The clinical condition of the rats was assessed through behavioural reactions, body weight, and the weight of internal organs during the 28-day experiment. It was established that prebiotic doses of 1 kg/t of feed for rats in experimental group 2 and 5 kg/t for rats in experimental group 3 were safe and did not cause toxic effects. However, increasing the dose to 10 kg/t of feed for rats in experimental group 4 caused marked somatic and behavioural changes. Body temperature increased within the normal range by 2.70% compared with animals in group 1 (control), which was associated with the development of an immunogenic and stress reaction accompanied by decreases in horizontal (by 1.77%), vertical (by 4.54%), and integral (by 2.78%) motor activity. The calculated correlation coefficient (R=-0.996) confirmed a strong inverse linear relationship between the prebiotic dose and behavioural activity in the animals. Body weight and absolute organ weight in rats of all groups remained within normal limits. However, spleen weight increased in rats of all experimental groups by 24.7-40.0%, indicating a stimulatory effect of the preparation on immunopoietic organs. The increase in relative stomach weight in animals of groups 3 (by 15.9%) and 4 (by 29.5%) reflected an adaptive-trophic response of the gastrointestinal tract to polysaccharide administration. A statistically significant increase in relative liver weight in rats of group 4 by 23.2%, exceeding the normal range, suggests the development of compensatory organ hypertrophy at the maximum dose

Keywords

behavioural activity; body weight; absolute and relative weight of internal organs; linear and parabolic approximation

Suggested citation
Tkachuk, S., & Hromyk, V. (2026). Effect of a prebiotic from the Saccharomyces cerevisiae yeast cell wall on the clinical condition of laboratory rats. Ukrainian Journal of Veterinary Sciences, 17(3), 27-46. https://doi.org/10.31548/veterinary3.2026.27
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