Probiotics can be defined as " [...] live microbial, dietary supplements or food ingredients that have a beneficial effect on the host by influencing the composition and or metabolic activity of the flora of the gastrointestinal tract [...]" (Fuller, 1989, p.366). Probiotics are present in fermented food products and known as lactic acid bacteria (LAB). These bacteria consist of several genera including Lactobacillus, Bifidobacterium, Streptococcus, and Enterococcus which have different beneficial effects on the host and has been used for decades in the food and natural sources to promote good health of human (Shori & Baba, 2013;Shori et al., 2020a, b).
Characteristics of Bifidobacterium spp as probioticsBifidobacteria are probiotic commonly found throughout the colon of both humans and animals which are considered normal residents of the gastrointestinal tract (Nielsen et al., 2003). They are once classified under the genus lactobacillus but they are found phylogenetically distinct from LAB and classified under phylum Actinobacteria. Out of 25 species, only ten are commercially used in conjunction with L. acidophilus as probiotics. For example, B. bifidum, B. infants, and B. lactis. Bifidobacteria usually appear in pairs with a V or Y-like shaped. These microbes are anaerobic, non-pathogenic, gram-positive, non-spore forming,