Nutraceutical Potential of Fermented Foods: A Perspective on Health and Wellness

Chapter 24 - Lactic Acid Bacteria in Fermented Food

Fermented plant foods, deeply rooted in cultural traditions, are gaining increasing attention for their potential to modulate the gut microbiome and improve host health. This review summarizes current data on the microbial composition, functional metabolites, and health effects of fermented plant foods commonly consumed in Asia, with a focus on fermented soybean foods (e.g., cheonggukjang, natto, and tempeh), and fermented vegetable foods (e.g., kimchi). Several bioactive compounds derived from fermentation modulate gut microbial composition and diversity, gut barrier integrity, and immune and inflammatory responses to help prevent and manage metabolic disorders, inflammatory bowel disease, and other gut-related disorders. Preclinical and animal studies have elucidated the mechanisms underlying these health effects. We highlight the importance of developing personalized dietary interventions, standardizing the production of fermented plant foods, and evaluating health effects using multi-omics approaches. These foods hold promise as microbiome-targeted interventions for maintaining and improving host health.

Indian traditional foods emphasize not only on providing the energy needs of the body but also aim to improve the overall health and prevent diseases in the Indian population. Indian traditional diets which are predominantly vegetarian majorly comprise of whole grains, pulses, nuts, vegetables, fruits, spices, herbs, dairy products, and fermented foods which themselves can be considered as ‘functional’ being high in a variety of phytochemicals with nutraceutical potential. India, being a diverse country with various cultures, languages, climates, religion, and communities, exemplifies great variety in cuisines and their preparation methods. Along with their intrinsic nutritive nature, the traditional foods also enrich the diet with different bioactive compounds. Many factors have resulted in transition in the dietary habits of the Indian population especially in metropolitan cities going away from traditional dietary practices with direct impact on the health of the people. Therefore, a revival in the eating of traditional diets based on appreciation of their health beneficial properties backed by scientific studies is necessary. Indian tradition also considers foods with functional ingredients to be consumed during various stages of life depending on the physiological needs. The major classes of bioactives/phytochemicals present in the Indian traditional foods along with their health benefits have been included and examples of traditional Indian foods with potential as functional foods have been specified. This awareness of traditional wisdom behind healthful properties of traditional foods has opened up many new avenues for scientific investigations which can lead to validation and proper documentation of the claims made.

Chapter 5 - Fermented foods and probiotic beverages in Korea

Traditional fermented foods in India represent one of the oldest biotechnological practices, deeply rooted in diverse cultural and regional culinary traditions. These foods, enriched with probiotic microorganisms, notably lactic acid bacteria (LAB), have gained increasing scientific interest for their multidimensional health advantages including anti-hypertensive, anti-diabetic, anti-obesity, antioxidant, and antimicrobial effects. This bibliometric review reflects the scientific landscape of Indian probiotic traditional foods over the past decade (2015–2024) using data from the Web of Science database. The study analyses 370 publications to identify research trends, prominent authors, core journals, and thematic clusters. Co-occurrence network analyses reveal strong research focus on LAB strains, gut microbiota modulation, bioactive compounds, and microencapsulation technologies. Mechanistic insights highlight the metabolic pathways through which fermented foods exert health-promoting effects, such as modulation of lipid and glucose metabolism, antioxidative enzyme activities, and inhibition of pathogenic microbes. Despite significant advancements, gaps remain in clinical validation, strain characterization, and translational applications of the products. This review emphasizes the strategic importance of integrating traditional knowledge with modern omics and biotechnological approaches to harness the full functional potential of Indian fermented foods while contributing to sustainable food systems and public health objectives.

Chapter 1 - Bioactive compounds modulating inflammation and oxidative stress in some traditional functional foods and beverages

Most fermented foods are based on the cultural preferences of different geographical areas and the heterogeneity of traditions from where they are produced. For instance, many consumers in Asian countries prefer fermented seafood, while consumers in Europe prefer fermented cereal and dairy food products. Even though the food industry has developed various novel techniques in order to produce novel foods (genetic modification, nanotechnology and other processing techniques), traditional foods still represent a significant proportion of the food industry, which has recently appeared to develop further. In addition, the progress in various developed analytical techniques has revealed new knowledge that documents and corroborates certain benefits of traditional foods, mostly regarding their nutritional and health benefits. In this context, the main target of this Special Issue is to deliver new data on how traditional foods exhibit their health-promoting properties and ameliorate the nutritional value of fermented food systems. In addition, the involvement of wild starter culture in the production of traditional foods is a subject area that must be highlighted.

Fermented foods hold a significant place in global culinary traditions, particularly in ethnic and traditional diets. These foods are widely consumed in different regions due to their unique flavours, textures, and potential health benefits. Despite the abundance of literature on fermented foods, a comprehensive review of their nutraceutical potential remains scarce. This review article discussed on the key fermented products available and commonly consumed both in the north-eastern region of India and various parts of the world such as natto, chongkukjang, miso, kefir, tempeh, kimchi, kombucha, sauerkraut, and others. These fermented foods are found to be contained beneficial probiotic microorganisms and bioactive compounds alongside essential nutrients and vitamins. In addition to this, antioxidants, phenolic compounds and metabolites present in these fermented foods contributed to the health benefits of fermented foods. Research indicates that consistently consuming these foods may help to prevent and manage a range of health conditions including diabetes, cardiovascular diseases, obesity, gastrointestinal issues, and neurodegenerative disorders. Despite these benefits, gaps in research remain, particularly in understanding the precise mechanisms of action of bioactive compounds and probiotics in these foods. This review focuses on the therapeutic potential of fermented foods and encourages future research to develop health-promoting formulations and support their inclusion in daily diets for disease prevention and overall well-being.

Background/Objectives: Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is a prevalent condition defined by hepatic fat accumulation, inflammation, and metabolic dysregulation. Current evidence demonstrates that gut microbiota and their metabolites are associated with MASLD pathogenesis. Fermented foods, rich in live microbes and bioactive compounds, actively modulate the gut-liver axis and influence disease progression. This narrative review provides a comprehensive summary of current evidence on the impact of fermented foods on gut microbiota, intestinal barrier function, and gut-liver interactions, and demonstrates their potential role in preventing or mitigating MASLD. Methods: A comprehensive literature search of preclinical and clinical studies was conducted. Specifically, the review focused on fermented-food interventions, modulation of gut microbiota, metabolite production, and effects on hepatic metabolism and inflammation. Results: This review found that fermented foods provide probiotics, prebiotics, short-chain fatty acid (SCFAs), and bioactive compounds that enhance microbial diversity, improve intestinal barrier integrity, reduce endotoxemia, and modulate bile acid and lipid metabolism. Evidence from animal and human studies indicates that fermented food consumption can attenuate hepatic steatosis, inflammation, and metabolic dysregulation, with variability depending on individual microbiome composition. Conclusions: Altogether, these findings suggest that fermented foods represent a promising adjunctive dietary strategy for MASLD by modulating the gut-liver axis and supporting metabolic and hepatic health. Personalized approaches and further long-term clinical trials are required to optimize interventions and establish evidence-based recommendations.

Humans are colonized from birth by bacteria, which form a complex and dynamic consortium of microorganisms known as microbiota. Overall, this complex microbial community outnumbers the somatic and germ cells of the host and collectively contains significantly higher genetic variability than that of the host genome (Backhed et al. 2005). Health-promoting indigenous bacteria, known as probiotic bacteria, represent a significant proportion of the human gut microbiota, whose composition is modulated by several factors including diet (Muegge et al. 2011). Probiotic bacteria are often introduced as live dietary supplements, but they are also present as live microflora in fermented foodstuffs for human consumption. The molecular mechanisms by which probiotics beneficially affect human health include strengthening of the intestinal barrier, modulation of the immune response and antagonism of pathogens through production of antimicrobial compounds or competition for mucosal binding sites (Marco et al. 2006). A significant proportion of the commercialized probiotic bacterial species was originally selected on the basis of their technological stability (e.g., resistance and viability during food processing and storage) or by a variety of easily measurable phenotypes, such as the ability to tolerate bile salts or to survive passage through the gastro-intestinal tract. These features do not necessarily associate with capabilities to provide human health benefits. Regulatory requirements concerning probiotic products are currently undergoing a profound transformation that will require elucidation of the mechanisms by which probiotic microorganisms beneficially influence human health. In order to achieve such fine characterization, the so-called “omics” approaches involving genomics and functional analysis represent an essential tool. In particular, probiogenomics, a recently proposed genomic discipline (Ventura et al. 2009), provides insights into the diversity and the evolution of probiotic microorganisms, thus allowing to clarify the molecular basis of their health-promoting activities. Probiogenomics also includes functional genomics, as well as investigation of microbe–microbe and host-microbe interactions that represent crucial aspects to expand our understanding of the roles of probiotics. The study of probiotic bacteria must necessarily take into account recent advances on the microbial ecology of the human gut. Elucidation of the bacterial biodiversity encompassing such a complex ecosystem is essential to highlight the presence or absence of specific groups of microorganisms (microbial biomarkers) and their association with health/disease conditions. In-depth knowledge of the composition and functionality of the human gut microbiota can also provide molecular criteria to predict individual susceptibility to specific probiotic supplements and could be utilized as a priori criteria for successful probiotic therapy. For all these reasons, we believe that a special issue of Genes & Nutrition devoted to probiotic bacteria and human gut microbiota is extremely appropriate. Two reviews within this special issue deal with the genomics of lactobacilli (Alterman et al.) and bifidobacteria (Pokusaeva et al.), which are considered the golden stars among probiotic bacteria. Probiotics are subject to several stressful conditions during industrial processing as well as in nature, where a fast stress-response is essential for survival (Ventura et al. 2006). Genetic characterization of the molecular players that enable probiotic bacteria to cope with such stressful stimuli are discussed by Ruiz et al. Microbial diversity within the human intestinal community is reported by Gerritsen et al., with special focus on the contribution of the gut microbiota to the health/disease balance. The impact of bacteriophages in modulating gut microbiota, as well as on bacterial survival and thus on the efficacy of probiotic treatments is described by Ventura et al. Prebiotic approaches represent new avenues for manipulating gut microbial composition and host responses to achieve health benefits. Conterno et al. explore the possible relationships between prebiotics and modulation of bifidobacterial and lactobacilli populations in the human gut, as a potential tool for obesity prevention and treatment. The effects of probiotics on human health are further discussed by Taverniti and Guglielmetti, who review the current knowledge on interactions of gut bacteria with the mammalian immune system. Safety is a crucial pre-requisite that probiotic bacteria must possess, and safety validation of probiotics includes exclusion of pathogenic potential. A key food safety issue reviewed by Devirgiliis et al. is the potential presence of horizontally transferable antibiotic resistance genes in probiotic strains naturally present in fermented foods, which can interact with the gut microbiota through the food chain. We wish to thank all authors who provided their manuscripts for this special issue, as well as all reviewers involved in processing the submitted articles. Overall, such a collective effort has provided a clear picture of the rapid progress occurring in the field of biology of probiotic bacteria, with special focus on the health benefits resulting from their interactions with the human host.

Fermented foods have been a part of human diet for almost 10,000 years, and their level of diversity in the 21st century is substantial. The health benefits of fermented foods have been intensively investigated; identification of bioactive peptides and microbial metabolites in fermented foods that can positively affect human health has consolidated this interest. Each fermented food typically hosts a distinct population of microorganisms. Once ingested, nutrients and microorganisms from fermented foods may survive to interact with the gut microbiome, which can now be resolved at the species and strain level by metagenomics. Transient or long-term colonization of the gut by fermented food strains or impacts of fermented foods on indigenous gut microbes can therefore be determined. This review considers the primary food fermentation pathways and microorganisms involved, the potential health benefits, and the ability of these foodstuffs to impact the gut microbiome once ingested either through compounds produced during the fermentation process or through interactions with microorganisms from the fermented food that are capable of surviving in the gastro-intestinal transit. This review clearly shows that fermented foods can affect the gut microbiome in both the short and long term, and should be considered an important element of the human diet.

Fermented food products are widely consumed for their nutritional and health-promoting properties, earning them a central place in diets around the globe. However, these foods can present a paradox, as they have the potential to harbor not only beneficial probiotics but also antibiotic-resistant (AR) microbes and genes. The impact of AR microbes and genes in fermented foods has far-reaching implications, such as potential effects on human health, repercussions in the food industry, and environmental consequences. An in-depth analysis of AR microbes and genes in fermented foods, including dairy products, fermented fruits and vegetables, meat products, and beverages, would provide insights into the extent and ramifications of the issue with these foods. Therefore, this review systematically presents the status of AR in fermented foods, with a particular focus on AR bacteria and genes within this category of food products. The review also highlights the complexities of AR in fermented foods, emphasizing the role of bacterial adaptation during the fermentation process and the dynamics of bacterial gene transfer. Various factors contributing to AR microbes and genes are brought into focus, including intrinsic resistance among bacteria in fermented foods and the potential risk of contamination with pathogenic bacteria. Moreover, this review presents a range of mitigation strategies, from the development of novel antimicrobials to advances in fermentation technology and regulatory control. This comprehensive perspective on the intricate interplay between AR and fermented food will potentially pave the way for more targeted research and mitigation strategies in this critical area.

Chapter4 - Indigenous probiotic microorganisms in fermented foods

Recently, demand for fermented foods has increased due to their improved nutritional value, taste, and health-promoting properties. Worldwide consumption of these products is increasing. Fermented foods are generally safe for human consumption. However, some toxins, primarily biogenic amines (putrescine, phenylethylamine, histamine, tyramine, and cadaverine), mycotoxins (fumonisins, aflatoxins, ochratoxin A, zearalenone, and trichothecenes), and bacterial toxins (endotoxins, enterotoxins, and emetic toxins) can be produced as a result of using an inappropriate starter culture, processing conditions, and improper storage. These toxins can cause a multitude of foodborne illnesses and can lead to cardiovascular aberration and adverse gastrointestinal symptoms. Analytical techniques are in use for the detection of toxins in fermented foods for monitoring and control purposes. These include culture, chromatographic, immunoassays, and nano sensor-based techniques. These detection techniques can be used during the production process and along the food chain. On an industrial scale, HPLC is widely used for sensitive quantification of toxins in fermented foods. Recently, biosensor and nano sensor-based techniques have gained popularity due to accuracy, time efficiency, and simultaneous detection of multiple toxins. Other strategic methods being investigated for the removal of toxins from fermented foods include the use of specific starter cultures for bio-preservation, aflatoxin-binding, and biogenic amine-degradation agents that may help to appropriately manage the food safety concerns associated with fermented foods.

Kefir is a fermented milk product obtained through gelatinous grains containing probiotic microorganisms, known for millennia worldwide due to its numerous benefits. Fermented foods, such as kefir, have been widely recognized for their health-promoting properties, including anti-inflammatory, antioxidant, and antimicrobial activities, as well as their ability to modulate the gut microbiota—factors that contribute to the prevention of chronic diseases and the promotion of overall well-being. The aim of this study was to develop a butter with probiotic properties by fermenting cream with kefir and to evaluate its acceptance. After cream fermentation with kefir, butter was obtained through the churning process. Yield, moisture content, titratable acidity, lactic acid bacteria (LAB) count, and yeast count were assessed. Product acceptance was evaluated by sensory analysis using a 9-point hedonic scale and a 5-point purchase intent scale, and results were compared to a commercial butter brand considered as the standard. Sensory analysis was carried out for each butter sample (kefir and standard) on different days. The kefir butter showed higher moisture and acidity levels compared to the standard. The LAB and yeast counts were approximately 10⁷ and 10³ CFU/g, respectively. The kefir butter had good acceptance, achieving an overall score of 7.6 and a purchase intent score of 4.4. The butter obtained from cream fermented with kefir demonstrated good acceptance and a high LAB count, indicating functional and probiotic properties. However, improvements are needed to reduce moisture and acidity, which could enhance both shelf life and consumer acceptance. The use of kefir as a fermenting culture in dairy products, such as butter, represents a promising innovation, allowing the incorporation of viable probiotic microorganisms into diverse food matrices and expanding probiotic consumption options beyond traditional yogurts and fermented beverages.