Oral Kefir Grains Supplementation Improves Metabolism and Liver Antioxidant Enzymes Expression in Malnourished Mice

Research Article

Austin J Nutri Food Sci. 2020; 8(3): 1148.

Oral Kefir Grains Supplementation Improves Metabolism and Liver Antioxidant Enzymes Expression in Malnourished Mice

Fabio Ribeiro SANTOS¹, Amanda Souto MACHADO², Deborah Farias LELIS², André Luiz Sena GUIMARÃES², Alfredo Mauricio B. DE PAULA², Renato Sobral MONTEIROJUNIOR ²,Theles de Oliveira COSTA¹, Igor Viana BRANDI¹, Junio COTA¹, Sergio Henrique Sousa SANTOS¹,²*

1Institute of Agricultural Science, Food Engineering, Universidade Federal de Minas Gerais (UFMG), Brazil

2Laboratory of Health Science, Postgraduate Program in Health Sciences, Universidade Estadual de Montes Claros (Unimontes), Montes Claros, MG, Brazil

*Corresponding author: Sergio H S Santos. Institute of Agricultural Sciences. Food Engineering, Universidade Federal de Minas Gerais (UFMG); Avenida Universitaria, Brazil

Received: November 12, 2020; Accepted: November 17, 2020; Published: November 24, 2020


Scope: This study has a novel approach to investigate the effects of oral supplementation of kefir grains on metabolic improvement and the expression of the antioxidant enzymes Glutathione Peroxidase (GPx) and Catalase (CAT) of the liver in malnourished mice.

Method and Results: Swiss mice were divided into four groups and subjected to two treatment phases: the food restriction phase of 20% in relation to the control group was maintained until animals reached a weight deficit of about 20% in relation to their original weight and the renutrition phase, the animals received diets every day for 30 days. Diets (chow powder plus kefir grains) were administered orally. Thereafter, during throughout the experiment measurements of body weight and energy consumption were obtained. After the end of treatment, fasting glucose tolerance tests were performed at night and insulin sensitivity with fed mice. Soon in then, the mice were euthanized by beheading in guillotine and the blood and liver were collected for evaluation of biochemical parameters, Histopathological assessments and Reverse transcriptase (RT-PCR).

Conclusion: The present study demonstrated the kefir grains ability to modulate inflammation and hepatic oxidative-stress under malnourished-state.

Keywords: Food Restriction; Malnutrition; Hepatic; Oxidative Stress; Nutrition


Malnutrition is characterized by proteins and/or other nutrients intake deficiency or imbalance. In this sense, this disorder can manifest itself in several ways: due to a primary factor, resulting from insufficient food intake; or secondary factors, resulting from its complications or disease [1,2]. It is a prevalent condition that affects one in three people worldwide [3]. Malnutrition alters body composition and is associated with a systemic inflammatory state [4]. Besides, malnutrition that can lead to an increase in genes related to oxidative stress [5] and affects the expression of enzymes with antioxidant activity, such as Glutathione Peroxidase (GPx) and catalase in several organs including the liver [6].

The liver plays an important role in malnutrition. This organ is responsible for a plethora of biochemical pathways in the production, modification, and use of nutrients and other metabolically important substances. It is also one of the vital organs of our body as it is important in the detoxification of toxic chemical substances and drugs [7,8]. Hepatic function may be modulated by several nutrients and/or food supplementation, including kefir.

Kefir grains are described as a symbiotic association of yeasts, lactic acid bacteria, and acetic acid bacteria surrounded by a matrix of polysaccharides referred to as kefiran. Kefir is rich in lactic, acetic and gluconic acid, ethyl alcohol, carbon dioxide, vitamin B12 and polysaccharides that give the product unique sensory characteristics. The lactic acid formed from lactose fermentation acts as a natural preservative, making kefir a biologically safe product, combining it with nutrients, calcium and iron, facilitating their absorption. The product also has high digestibility, which is attributed to the nature of the curd, whose proteins undergo, during fermentation, denaturation in various degrees, thus obtaining a curd of finely divided particles, easily penetrated by gastric juice [9,10]. Hence, this work aimed to evaluate the effect of kefir grains supplementation on the metabolism and liver inflammatory and antioxidant markers in malnourished mice.

Materials and Methods

Animals and Diet

The experiment was carried out with 32 male Swiss mice, aged 6 weeks, divided into 4 groups (n = 8 each). The animals were kept in an initial adaptation phase (10 days), with free access to water and the standard chow (Presence) for rats and mice containing 67.5% carbohydrates, 22.5% proteins, and 10% lipids. All procedures performed involving animals were in accordance with the institution’s ethical standards (CEEBEA - State University of Montes Claros - Annex 1). The animals were kept under controlled conditions of light and temperature. (Protocol number 189/2019).

Kefir Preparation

Kefir grains were donated from the biotechnology laboratory of the Institute of Agricultural Sciences of UFMG, at the Montes Claros Campus, and rehydrated three weeks before the experiments. The grains were inoculated (5%, weight/volume) and propagated in sterilized milk at 20 °C for 20 h for activation. After the filtration of the grains, the fermented milk was discarded and the grains were separated and refrigerated at 20 °C [11]. Regarding the nutritional composition, kefir can vary widely and is influenced by the composition of milk, the origin and composition of grains, time, temperature of fermentation, and storage conditions. However, the nutritional composition of kefir is still not well described in the literature. Thus, the nutritional composition of kefir is described in Table 1 [12].