SummaryFermented foods such as yogurt, kefir, and sauerkraut have been part of the human diet throughout history and have gained attention in recent years due to their immense health and nutritional benefits. As a result, fermented foods are considered biofuel for the human microbiome which helps to boost the immune system. Fermented foods are those foods and beverages that are produced by employing specific microbial‐based fermentation aids such as yeasts and bacteria, particularly lactic acid bacteria (LAB). Through controlled enzymatic reactions, these microbial cultures transform food components as substrates into value‐added products promoting various healthy fermentative activities these microbes in fermented foods also produce compounds that can inhibit food spoilage and pathogenic microorganisms, thereby extending the product shelf of fermented products. Probiotics are live microbiota with beneficial health properties, prevent gastrointestinal diseases, and modulate the human microbiome. Thus, foods that are fermented by certain strains of probiotic bacteria that exhibit evidence of health benefits are referred to as probiotic fermented foods. This review describes fermented and functional foods, probiotics, and their relationship to human health. In addition, we offer our perspective on the distinct differences between probiotic and fermented foods to promote awareness for consumers and key stakeholders regarding these highly functional and nutritionally fermented food products.

Lactic acid bacteria are gram-positive microorganisms that are characterized by the production of lactic acid as a key fermentation product. LAB, specifically Lactobacillus delbrueckii subsp. bulgaricus, are essential dairy starter cultures for the manufacture of several fermented dairy products such as yogurt. Some LAB are useful microorganisms and are well known to have probiotic effects to provide foods with unique sensory qualities such as aroma and taste. Probiotic strains help to strengthen the human immune system, increasing the body’s resistance to diseases. Additionally, probiotics and postbiotics improve gut microbiome balance and prevent health issues. Postbiotics are substances that are produced by microbes’ metabolic activities and have a positive impact on diseases, either directly or indirectly. Extensive research has shown that postbiotics possess immunomodulatory and significant clinical effects. Their use has been found to enhance general health and alleviate symptoms of various disorders in healthy individuals. Furthermore, postbiotics exhibit anti-inflammatory, antioxidant, and anticancer properties. Therefore, this chapter presents an overview and the importance of LAB as a probiotic and its importance to human health, metabolic fermentation, and antioxidant potential. The review also discusses different biotechnological methods that improve the survival rate of probiotics during processing and GIT transit like microbial encapsulation.

This study intended to examine the growth and stability of Saccharomyces boulardii and Lactobacillus acidophilus in amla drink with the aim of formulation of probiotic drink and to analyze the nutritive value, sensory qualities and shelf life of the product. S. boulardii CNCM 1-745 and L. acidophilus MCC10307 were capable of growing in 15 per cent amla drink at natural pH, 30°C with 22°Brix and 5 per cent honey. Optimum fermentation time at which the highest population was observed (8-10 log CFU/ml), for S. boulardii CNCM 1-745 was 35 hr while L. acidophilus MCC10307, it was 64 hr. The sensory scores for fermented drinks were significantly (P≤0.05) lesser than the unfermented drink. In order to enhance the sensory qualities by reducing fermentation time while maintaining the highest population, initial pH and total soluble solids were adjusted and L. acidophilus (nu-trish LA-5) was used to replace L. acidophilus MCC 10307. With these modifications, amla drink with 3 hr of fermentation provided better sensory qualities with required cell population and 97-108 µg/ml of ascorbic acid and 937.5 µg/ml of antioxidant potential. With the consideration to both population and sensory qualities, amla drink with S. boulardii CNCM 1-745 could be stored at refrigerated conditions (4°C) for 30 days while L. acidophilus (nu-trish LA-5) could be stored for 12 days.