**5. Conclusion**

Probiotics mean live organisms that have positive effects on the health of host. The aim of current study was to isolate probiotic bacteria from different non-dairy products. The total of 1 l samples was collected from different areas and from these samples 10 bacterial strains were isolated. All of these were characterized based on morphological, biochemical tests and 16S rRNA ribotyping. Probiotics are helpful bacteria that are catalase negative and help to restore microbial equilibrium in both people and animals' guts. Lactobacillus was the first probiotic to show a positive influence on health. These "Good Microorganisms" can be gotten not only from non-dairy products, but also from processed dairy products such as. They improve epithelial barriers, increase adherence to gut mucosa and microbial adhesion, produce antimicrobial compounds, and regulate immune systems, and can be used as food supplements to treat various gastrointestinal tract diseases, as well as in research studies to develop commercial probiotic foods. Probiotics have health advantages such as improved immune responses, easing of lactose intolerance symptoms, diarrhea treatment, cholesterol decrease in serum, vitamin generation, and anticarcinogenic properties. Probiotics serve a variety of roles in the host body (e.g., decreasing illnesses and stress, enhancing immunity, modulation of gut microbiota, nutritional assistance, improving quality of water, etc.). As a result, the beneficial effects of probiotics contribute to increased animal feed value and growth, as well as improved aquaculture breeding and hatching rates. Probiotics have the potential to treat or prevent COVID-19 by lowering the occurrence and severity of diseases. *Lactobacillus casei* also interacts with epithelial cells via Toll-like receptors (TLRs) to boost the production of cytokines, which are vital in increasing cell productivity and preventing apoptosis during restoration, promoting survival and proliferation. The preservation of the human GI or lung microbiota may aid in the prevention of COVID-19, since dysbiosis plays an important role in people's susceptibility to infectious diseases. Most experimental experiments demonstrated that bacteria extracted from processed dairy products belonged to lactic acid bacteria, which are classified as probiotic bacteria. Appropriate sample dilutions were made, and a concentration of just 50 PI-J was dispersed on MRS-agar plates. For 48 h, each plate was kept at 37°C in a static incubator and all the steps were done for performing the tests. Then electrophoresis and pcr is done to confirm the antimicrobial activity.

Various research findings on the importance of probiotics as well as their extraction from processed dairy products are reviewed in this review.

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