Effects of Queso Blanco cheese containing Bifidobacterium longum KACC 91563 on fecal microbiota, metabolite and serum cytokine in healthy beagle dogs

Highlights

• B. longum was used to evaluate effects of microbiota and immune response in beagle.

• B. longum decrease abundance of Enterobacteriaceae and C. perfringens in dogs.

• B. longum decrease Fusobacterium, Blautia and Collinesella on fecal microbiota.

• B. longum KACC 91563 increase the serum TNF-α and IL-6 of health beagle dogs.

Abstract

The study describes the effects of administration of Queso Blanco cheese containing Bifidobacterium longum on the fecal microbiota, metabolite and serum cytokine in healthy beagle dogs. Twelve healthy beagle dogs were randomly divided in three groups of four dogs each:a control group, not fed with any cheese, and groups fed with Queso Blanco cheese with B. longum KACC 91563 (QCB) or without B. longum (QC) for 8 weeks. Fecal microbiota was analyzed using a culture-based method and 16s rRNA gene sequencing. Serum cytokine levels, activation of natural killer cells, and proliferation of peripheral blood mononuclear cells were determined. SPME-GC-MS method was used to determine the concentrations of short chain fatty acids and indole in dog feces. Administration of QCB for 4 weeks significantly increased the Bifidobacterium. QCB supplementation for 8 weeks reduceds Enterobacteriaceae and Clostridium perfringens (p < 0.05). The abundance of Fusobacterium, Blautia and Collinesella in QCB group were reduced as compared with the control group. Serum TNF-α and IL-6 levels at 8 weeks significantly increased in QCB group as compared with QC group. There was no change in the concentrations of total short chain fatty acids by B. longum at 0 and 4 weeks. At week 8, the acetic acid, propionic acid and butyric acid of the QCB and QC groups were significantly decreased compared to the control group. In conclusion, our results demonstrate that administration of QCB had positive effects on fecal microbiota and immune response in beagle dogs. We suggest that Queso Blanco cheese containing B. longum KACC 91563 could be used as a functional food for companion animals.

Introduction

Gastrointestinal microbiota plays an essential role in the health of the host, both humans and animals [1]. The intestinal microbes provide nutrient substrates, regulate host physiology, such as immune system and carbohydrate metabolism, and protect the host by limiting the multiplication of intestinal pathogens [2]. The composition of fecal microbiota has attracted considerable scientific and commercial attention because of increasing interest in the intestinal health of animals.

Probiotics are generally defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host” [3]. Probiotics are widely used to improve intestinal health by various mechanisms [4]. Increasing the number of probiotics in the intestinal tract is important for the successful health promotion of probiotics [5]. A number of studies investigating the survival and colonization characteristics of probiotics in the intestine after ingestion [6].

Bifidobacterium longum is a symbiotic species that resides in the human gastrointestinal tract; B. longum has been recognized as a health functional material by the Korea Ministry of Food and Drug Safety (MFDS, 2011). B. longum KACC 91563 was isolated from fecal sample of a healthy Korean infant [7]. In a previous study, B. longum KACC 91563 has been reported to improve allergen-induced food allergies by reducing the accumulation of mast cell in small intestinal lamina propria and decreasing mast cell proteases in the serum [7].

Probiotics produce various metabolites that can modulate microbiota composition [8]. The composition and metabolic activity of intestinal microbiota affects intestinal short chain fatty acids (SCFAs), which are an important component of gut health and are associated with several health conditions [9]. SCFAs serve as an energy source, accelerate intestinal motility, improve the risk of metabolic syndrome, modulate host immune cells, and decrease plasma cholesterol levels [10]. In this study, changes in intestinal lactic acid bacteria and SCFA levels were analyzed.

The gut microbiota also contributes to host immune system by competing with pathogenic microbes for available nutrients in the intestine, interrupting colonization sites, producing antimicrobial substance, modulating gut microbiota, activating immune cells, and regulating cytokine production [11,12]. Intestinal Bifidobacterium species have been reported to induce various pro-inflammatory cytokines [13].

Cheese is a good source of protein, calcium, and vitamins for companion animals. Although consumption of cheese may affect health owing to its high energy and salt content, consumption of small amounts of cheese should not be a problem in healthy dogs. Queso Blanco cheese is one of the easiest cheeses to make and does not require careful handling. Also, addition of B. longum to Queso Blanco cheese is technically not difficult. Currently, snack for companion animals include jerky, functional gum, sausage, dried-fruit, cheese and so on. However, Queso Blanco cheese has not been used as a snack for pet until now. The research of cheese having the function of improving intestinal health and immunity for companion animals has not been widely carried out. Effects of probiotics on the overall intestinal health have been extensively studied in humans [14]; however, such effects are investigated in only a limited number of animal species [15]. In a previous study, we demonstrated the effects of Queso Blanco cheese containing B. longum KACC 91563 on the intestinal microbiota in companion dogs [16]. The purpose of this study was to confirm the positive effects of Queso Blanco cheese containing B. longum KACC 91563 in beagle dogs by analyzing the fecal microbiota, immunomodulatory effects such as serum cytokines and fecal metabolites.