**Abstract**

Probiotics are the beneficial microorganisms, catalase negative which restore microbial balance inside the gut of humans as well as animals. *Lactobacillus* the earliest probiotic that have the beneficial impact on health. These "Good Microorganisms" can be obtained not only from various non-dairy products but also from processed dairy products like. Another economically viable method is microencapsulation for preserving probiotics and the stability is improved by glucose. Even the vitamins manufacturer the probiotic bacterial agents. The health benefits of probiotics include increased immunological responses, relief of lactose intolerance symptoms, therapy for diarrhea, reduction in serum of cholesterol, production of vitamin, anticarcinogenic. Probiotics play a wide range in the host body (e.g., decreasing illnesses and stress, enhancing immunity, modulation of gut microbiota, nutritional assistance, improving quality of water, etc.). So, the positive effects of probiotics help to boost animal feed value and growth and improve aquaculture breeding and hatching rates. Probiotics can lower the prevalence and severity of illnesses, showing their promise to cure or prevent COVID-19. *Lactobacillus casei* also interact with epithelial cells with Toll-like receptors (TLRs) to improve the production of cytokines that are important in the enhancement of cell productivity and prevent apoptosis during restoration, which promote survival and proliferation. The preservation of the human GI or lung microbiota might help prevent COVID-19, as dysbiosis plays an essential role in people's vulnerability to infectious illnesses. Most of the experimental studies proved that bacteria isolated from processed dairy products belonged to lactic acid bacteria and are declared as probiotic bacteria. In present review, various research studies regarding significance of probiotics as well as their extraction from processed dairy products are discussed.

**Keywords:** probiotics, processed dairy products, gastrointestinal diseases, commercial forms, *Lactobacillus*, health benefits

### **1. Introduction**

"Probiotic" is a Greek term which meaning "for life" [1]. Over the years, there have been numerous meanings of the term "probiotic." Probiotic means living microbiota

cultures that enhance the qualities of the indigenous microbiota when supplied to people or animals. These bacteria are extensively spread in nature and are suitable for usage in food industries. Some foods are considered a good source of probiotics, including milk products, e.g., yogurt. Milk and milk products are often linked with microorganisms that replenish the digestive tract with helpful maintenance [2]. Different generations of lactic acid bacteria like *Enterococcus species, Lactococcus species*, different strains of *Lactococcus* and *Streptococcus* are also present in processed products of milk.

Lactic acid bacteria are a type of gram-positive bacteria that cannot produces spores and catalase negative, so they characterized in the absence of cytochrome system. Different sources of food like yogurt, milk, cheese that are dairy in nature are the good source of probiotics [2]. Most processed milk products contain the *Lactobacillus,* and other strains of it.

Increased taste of food and better shelf life are among the most evident benefits of LAB fermentation. The fact that LABs can produce the bacteriocins and provide health benefits, including controlling intestinal infections, improving lactose uses, reducing the ammonia level of the blood, and providing effective resistance to gastric acid and bile, makes it generally considered safe for bacteria to be used. Impacts the immunological system and decreases serum cholesterol levels. Probiotics are live, health-effecting micro-organisms when eaten. Different LAB strains, particularly *Lactobacilli* and *Bifidobacterium* which reside in the adult bacteria in the gut of humans with good therapeutic functions have been used increasingly as probiotics.

#### **1.1 History**

In 1908, Metchnikoff gave the first probiotic definition, which suggested that use of fermented dairy produce extended the life of the product. In 1956 Lilly and Stillwell decided that some growth stimulators for another microbe were secreted by a microbe. The usage of the word probiotic may lead to this beneficial impact on such micro-organisms.

Parker [1] coined the word probiotic to define the chemicals and organisms that produce microbial balance in the gastrointestinal system. This meaning has given rise to significance meaning, including antibiotics, of the word substances. Fuller refined the description of Parker and described probiotics as a living micro-organism, which has a beneficial effect on warm-blooded animal health through the restoration of native gut microbiota. The definition by Fuller highlighted the survivability and beneficial effects of the probiotic on animals. In the instance of probiotics host, Haveenar and Veld described them as 'viable micro–organics' in 1992, which are administered to humans or animals as mono- or mixed cultures which have a favorable effect on the health of host, by enhancing the intestinal characteristics of the micro-flora. A probiotic is a live bacterium injected in milk products based on the Salminen criteria and enhance host health and diet.

Schaafsma extends the concept and according to its definition probiotics are live bacteria which, if swallowed and absorbed in a more than intrinsic basic nutritional way, have health benefits on the host. Salminen noted that the probiotic in milk products is a microbial culture. Accordingly, the food matrix is a big indicator for the microbe and food being regarded as probiotics. However, because non-dairy food includes viable probiotic products, it was not justifiable to take milk products

## *Probiotics in Processed Dairy Products and Their Role in Gut Microbiota Health DOI: http://dx.doi.org/10.5772/intechopen.104482*

only as a probiotic matrix. In 2001, Probiotics were seen by Schrezenmeir and by De Vrese as live micro-organisms which have independent health effects of the place of activity.

In 2001, probiotics are known as "live micro-organisms by the WHO (WORLD HEALTH ORGANNIZATION) and FAO (FOOD AND AGRICULTURE ORGANIXATION OF THE UNITED STATES) that provide the host with a health advantage by being given adequately." Finally, in 2014, the ISAPP changed the latter definition of probiotics to somewhat and described it as 'live micro-organisms, which provide a health benefit on a host when administering in appropriate quantities.' This concept has been extensively adopted by the scientific community since then and is a criterion in most government agencies to evaluate medicines, food, and supplements as probiotics. The viability of a microbe and of the related product as 'probiotic' is one of the essential criteria in this definition.

### **1.2 Lactobacilli**

*Lactobacillus* is regarded as the earliest probiotic reported. This genus is made up of LAB group gram-positive bacteria. These bacteria in rod shape include over 183 recognized species and are frequently used in diverse commercial food processes [3]. *L. acidophilus* is a bacterium that has a positive impact on the host. Recent investigations have investigated the finding of normal vaginal flora of certain species producing hydrogen peroxide. The beneficial products have thus been examined in urine and vaginal tract infections among women, so it helps in the treatment of it. It was also used to treat Candida infections in the mouth (**Figure 1**).

Reticence of harmful organisms like *Salmonella, Shigella* and different *Helicobacter* comprise valuable effects mediated by Lactobacilli. Lactobacilli was also related with

**Figure 1.** *Types of probiotic strain.*

several additional health advantages, e.g., improved immunological response and lessening of lactose intolerance. A good function was also revealed in colon cancer for Lactobacilli. Lactobacilli strengthen the immune system and cure cancer, pancreas, fever blisters, hives. In infants who are born preterm, necrotizing enters colitis (NEC). Cheese is a milk product that may be delivered in the intestine of people by probiotic bacteria. Italian, Argentinean, and Bulgarian cheese have isolated the strains of *L. plantarum*.

#### **1.3 Source of probiotics**

Cheese is a milk product that may be delivered in the intestine of people by probiotic bacteria. Italian, Argentinean, and Bulgarian cheese have isolated the strains of *L. plantarum* [4].

#### *1.3.1 Lactic acid bacteria in ice cream*

It is referred as a frozen dairy product that is produced by freezing a sterilized mixture to incorporate air to maintain homogeneity. Milk products, sugar, dextrose, water, eggs or egg products, and different non-harmful aromas are used to form a mix that is utilized to make ice cream. Its nutritional content and their energy value are generally determined by their food value [5]. Irrespective of the mix, ice creams usually constitute great sources of dietary energy and are an appropriate substratum for probiotic proliferation.

Ice cream is considered as favorable for the probiotics as it helps in survivability and metabolic activity of probiotics and its different strains shows more benefit for transferring probiotic organisms to the body [6]. Ice creams are more advantageous than other fermented dairy products. But freezing and thawing have detrimental consequences on probiotics, including disruption of metabolic activity and cell death. There have been reports of studies designed to reduce these negative consequences.

*Lactobacillus delbrueckii* sub specie was investigated by Leandro [7]. Bulgaricus UFV H2b20 is kept at −16°C for 40 days in three formulations of ice cream (it contains less fat, free of fat and high-fat). Although in the three formulations (*P* > 0.05), LABs may be integrated into ice-cream formation and different processing parameters for different consumer groups may be handled (**Table 1**).

#### *1.3.2 Agitated milk products*

It is an old method that is used for the preservation of food by the development and activity of microorganisms. Moreover, the additional benefit of fermentation is the formation of metabolites such as bacteriocins, helps in improved nutritional status and for the sensory properties of foodstuffs, and helps in reduced toxic and anti-nutritional components [13]. Due to these positive impacts, these food stuffs are important to human diets since ancient times.

In 2001 regarded probiotics are known to be "living microorganisms by the WHO and FAO that offer health benefits to the host if properly supplied". In 2014, the definition of probiotics changed by the department of International Scientific Association for Probiotics and Prebiotics (ISAPP) as a "lived micro-organism that, when supplied adequately, conveys a health advantage to the host." In 2014, Yerlikaya described that, *Lactobacillus* and varieties of *Bifidobacterium* are the most frequent probiotics in fermented food items. In 2012, Mishra find out that dairy-based matrix is appropriate


*Probiotics in Processed Dairy Products and Their Role in Gut Microbiota Health DOI: http://dx.doi.org/10.5772/intechopen.104482*

#### **Table 1.**

*Use of different strains of probiotics in ice cream [8].*

to proliferate probiotics by providing a high carbon and necessary amino acid source owing to the hydrolyzing of lactose and the usage of casein in the proteolytic system.

Traditional white cheese is widely referred to as Lighvan cheese in Tabriz marketplaces. It was originally prepared of raw ewe's milk, raw goats' milk, and raw cow's milk and/or mixed with them from time to time. This sort of cheese is popular and often consumed across Iran and has significant economic and nutritional benefits because of its attractive organoleptic qualities. In the manufacturing and maturation of cheese, lactic acid bacteria (LAB) are involved. Many genera are involved in LAB, such as *Lactobacillus, Streptococcus, Enterococcus and Leucon Stoc.*

#### **1.4 Mechanism of action of probiotic**

In 2012, Bermudez studied that the principal mechanisms of probiotics action include to enhance the epithelial barriers, increases in the adherence to gut mucosa and microbial adhesion, generation of antimicrobial compounds and regulation of immune systems. This process is shown in **Figure 2**: that illustrates how these processes appear in the intestinal mucosa, as a schematic illustration. Lactic acid from various carbohydrates (e.g., carbon sources are produced in the micro-organisms of the LAB Group [15]. Pereira [16] conducted a study in which various antibacterial processes of probiotic activity are connected to these components.

#### **1.5 Development of probiotics**

As we know that during human development microbiota changes in the gut of human. The newborns' gut is completely sterile yet colonization of several types of

**Figure 2.** *Probiotics as an alternative antimicrobial therapy: current reality and future directions [14].*

bacteria starts shortly after delivery. The first- and second days following delivery have been demonstrated to be present in newborn feces, including coliforms, enterococci, clostridia, and lactobacilli. Bifidobacterial start colonization in three to 4 days and prevail about the fifth day. Coliform numbers drop at the same time. In feces, 1 log count of bifidobacterial is more prevalent in infants than those fed by bottle. Bottle-fed babies show greater levels of strains of Enterobacteriaceae, and other putrefactive bacteria, indicating that babies that are given breast are resistant to gastrointestinal diseases than infants fed by bottles. To ensure a person's diet and health, the gastrointestinal system also modify in addition to the changes in the microbiome that happen throughout human aging. Using antibiotics, for example, might disrupt the balance of gut microbiota, reduce bifidobacterial and lactobacilli count and increase clostridium. This imbalance may result in diarrhea in senior citizens and in those who are immunocompromised.
