**3. Fermented Foods, Probiotics, Body and Mind**

of a product's storage tim The use of fermentation in conserving food and beverage as a means to provide better taste, improve nutrition and food safety, organically preserve foodstuffs, and promote health properties, is a well-known ancient practice. The reasons for fermenting foods and beverages include improvements of a product's storage time, safety, functionality, organoleptic quality, and nutritional quality properties [54]. Not only is this process beneficial for extending shelf-life, but also, fermentation can enhance nutritional properties in a safe and effective manner [55].

Many types of food groups, including dairy, vegetables, legumes, cereals, starchy roots, and fruits, as well as meat and fish, can be fermented [56]. Fermented foods and beverages can comprise anywhere from 5–40% of the human diet in some populations [57]. –

Phytochemicals, defined as the non-nutritive, naturally-occurring chemicals found in fruits, vegetables, wholegrains, legumes, beans, herbs, spices, nuts, and seeds, are responsible for producing physiological properties, as well as protecting against various environmental stressors of the plant crops. There are more than one thousand known phytochemicals (e.g., lycopene in tomatoes, isoflavones in soy, and flavanoids in fruits). The microbiota comes into contact with a wide variety of dietary components that escape gut digestion and may be affected by phytochemicals [58].

Substantial confusion exists between fermented foods and beverages and the probiotic concept. It is important to address the common misconception that fermented foods are the same thing as probiotics [59]. They are not probiotics, although they may contain them, as their live microbial content is undefined. The term "probiotic" was first coined [60] in 1974, and many authors have described the history and the progress of probiotics and their different applications. Ilya Ilyich Metchnikoff, the Nobel Prize winner in Medicine in 1908, was the first who observed the effect of what is called now "probiotic" [61]. FAO/WHO redefined the term "probiotics", which is now widely accepted as constituting "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host" [62]. Different types of bacteria (e.g., *Lactobacillus*, *Bifidobacterium*, *Streptococcus*, *Bacillus*) and yeast or mold (e.g., *Saccharomyces*, *Aspergillus*, *Candida*) are used as probiotics. Probably, the first real use of food containing probiotics was fermented milk, but today we have to differentiate between probiotics and probiotic-containing foods (e.g., fermented foods) [63]. The scope and appropriate use of the term "probiotic" has been well clarified (Figure 3) [64]. is undefined. The term "probiotic" was first coined [60] in 1974 what is called now "probiotic" FAO/WHO redefined the term "probiotics" "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host" [62]. Different types of bacteria (e.g. " "

**Figure 3.** Overall framework for probiotic products [64].

Probiotics are able to renew, restore, and grow affected tissues lining the digestive tract with beneficial microorganisms neutralizing the harmful ones. Useful live microorganisms will regenerate our microflora fermenting our food correctly and improving our health [65,66].

Despite the impact of fermented foods and beverages on gastro-intestinal well-being and diseases, their health benefits or recommended consumption have not been widely translated to global inclusion in world food guidelines [67]. When fermented foods and beverages are supplemented with probiotic bacteria, they provide numerous extra nutritional and health characteristics [68].

Fermented foods and beverages are more popular than ever before, while research into the health benefits of fermented foods is relatively new. Not all fermented foods contain live organisms; beer and wine, for example, undergo steps that remove the organisms, and other fermented foods like bread are heat-treated and the organisms are inactivated. The strain composition and stability of the microbes in fermented foods is not well understood [69].

Fermentation generates adjustments in yeast and live microorganisms cultures in the absence of air, but retains the enzymes, vitamins, and minerals in foods and beverages, which are usually destroyed by processing [70]. The fermenting microorganism, bacteria or yeast, plays a precious role in

the functional property of fermented foods and beverages [71]. One the biggest benefits of fermented foods comes from the probiotics they might contain [72]. There are currently no authorized European health claims for probiotics, and the application of probiotics is controversial, since the European Food Safety Authority (EFSA) rejected all submitted health claims related to the term "probiotic", while accepting the term "live microorganism cultures" in yoghurt [73].

Traditional and modern dietary practices utilize fermented foods and beverages, contributing significantly to the food chain value and belonging to a category of foods called "functional foods" (e.g., probiotics, prebiotics, stanols and sterols) by having an additional characteristic, i.e., health-promotion or disease prevention effect [74].

Fermentation converts sugars, in the absence of oxygen, into organic acids, gases, alcohols, and carbon dioxide, and provides several benefits such as new and desirable tastes and textures, enhancement of nutrients (e.g., linoleic acid; bioactive peptides), removal of toxic or undesirable food constituents (e.g., phytic acid; bitter-tasting phenolic compounds), delivery of probiotic bacteria (e.g., *Lactobacillus delbrueckii* subsp. *bulgaricus*; *Streptococcus thermophilus*), and inhibition of foodborne pathogens [75,76].

Fermented foods and beverages are useful because they help provide a spectrum of probiotics to foster a vigorous microbiome. Fermented foods with unidentified microbial content cannot be considered probiotic suppliers. The two main effects of the daily consumption of fermented foods are upon the immune system and upon metabolic function [77].

Dealing with fermented foods has parallels with One Health, since it involves the links between human, animal, environment, foods and microbiota that impacts the organoleptic and physicochemical characteristics of foods as well as human health [78].

There are well documented effects of how adverse early life influences on the gut-brain axis and the use of fermented foods and beverages, mainly with probiotic bacteria, can restore a disturbance of the normal luminal habitat, and so change the effects of the central nervous system on the microbiota [79].

Our guts control and deal with every aspect of our health. How we digest our food, and even the food sensitivities we have are linked to our mood, behavior, energy, weight, food cravings, hormone balance, and immunity [80]. The interaction of nutrients with the microbiota is essentially what determines overall health. Eating and drinking fermented foods and beverages, especially organic unpeeled and unpasteurized fruits and vegetables, improves the bioaccessibility and bioavailability of food bioactive components, supplying dietary fibers and essential micronutrients such as trace-elements and phytochemicals, together with enzymes, lactic acid bacteria, and organic acids, all of which are crucial for good health [81].

Changes in the human colonic microbiota fingerprint are associated with the major causes of morbidity and mortality worldwide, diabetes and cardiovascular diseases, due to imbalances between beneficial and pathogenic bacteria [82].

Physiologically-active peptides with different functionalities are produced from food proteins during fermentation and food digestion by lactic acid bacteria. In some fermented products, bioactive peptides (e.g., immunoglobulins, antibacterial peptides, antimicrobial proteins, oligosaccharides, lipids, and other "minor" components) have the potential to be used in the formulation of health-enhancing nutraceuticals [83], and include short amino acid sequences that, upon release from the parent protein, may play different physiological roles, including antioxidant, antihypertensive, antimicrobial, and other bioactivities [84,85].

Fermentation may enhance the benefits of a wide variety of foods, dairy products, herbs, and beverages, acting upon the absorption and activity of their secondary metabolites and chemical elements [86]. However, it is not always possible to clearly distinguish the potential contribution of the microbial content from that of the food matrix. There is recent evidence and consumer perception of the health benefits of fermented foods and beverages [87], beyond the popular recognized effects on the impairment of gastrointestinal function, namely, their relevance on gut microbiota, correlated

to human health and to several infectious [88], inflammatory, and neoplastic disease processes [89], as well as to brain functionality [90].

Despite disagreement among mental health practitioners and researchers pertaining to the aetiology, categorization, and medical care of several mental disorders [91], current research regarding fermented foods, the microbiome, and their effect on human health, particularly the global epidemic of mental health [92], describes problems associated with the modern lifestyle, and with the western diet being high in sugar and saturated fat [93].

The degradation of the intestinal mucous membrane, weakening the tight barrier against the ingress of harmful substances, and the protection against a reaction to omnipresent harmless compounds, is a primary cause of several disturbances [94].

Ingestion of vibrant probiotics, especially in fermented foods, is found to cause significant positive improvements in balancing intestinal permeability and barrier function [95], with direct effects on metabolic syndrome, atherosclerosis, inflammatory bowel diseases, and colon cancer [96] and indirect effects on depression, anger, anxiety, and levels of stress hormones [97].

Young individuals with autism often have a reduced number of microorganisms in the gut [98], and atypical digestive health conditions may occur, like chronic gastrointestinal and functional bowel disorder, causing discomfort, diarrhea and bloating, abdominal pain and cramping, collectively described as irritable bowel syndrome [99]. Children with autism spectrum, besides having a genetic predisposition, show a disruption of the indigenous gut flora and an elevated number of potentially pathogenic (toxin-producing) *Clostridia* in the gut [100,101]. The effectiveness of fermented foods, mushroom biomass, and probiotics in relieving gut symptoms in autistic children has been studied [102–104].

The involvement of the microbiota in inflammatory diseases may contribute to altered mood via intestinal permeability, systemic and local lipopolysaccharide burden, and even direct-to-brain microbial communication [105]. In future, insights based upon omics techniques will increase our knowledge between pathogens and healthy strains, thereby explaining food ecosystems and their dynamics [106,107].

## **4. Fermented Foods in Developing Settings**

Around the world, each culture has its own distinctiveness in terms of food culture and heritage, where fermented foods are included. In the developing world, for people living in poverty, the main priority is not food hygiene, safety, and nutritive factors, as they consume less nutritious foods in which chemical, microbiological, zoonotic, and other hazards may pose a health risk [108].

African traditional fermented foods and beverages have been used since ancient times. Throughout the continent, there is great variety of fermented foods and beverages, mainly sour porridges and drinks. Of the various types of fermentations used to obtain fermented foods and beverages, lactic acid and alcoholic fermentations are the most popular in developing settings, where some 80% of the population still seek care from traditional healers who prescribe indigenous products.

In Africa, a continent which consumes high levels of lactic acid fermented products, estimates for mental disorders and depression vary widely, but seemingly, such diseases are not less common than in developed societies [109], although factors other than diet exist which may exacerbate conditions such as socio-economic changes, urbanicity, alterations in dietary habits, and, more recently, sedentary behavior among youth [110].

People from Sub-Saharan Africa, often plagued by civil conflicts, drought, floods, famine, and disease, but with huge biodiversity of plants and herbs, tend to rely on traditional healers who often interpret mental illness in terms of possession or curses, and tackle mental health by rituals, but also by recommending traditional plants, herbs, fermented foods, and beverages [111,112]. Many rural communities in Africa are totally reliant on traditional fermented foods as the primary source of nutrition for nourishment, as well as for cultural traditional practices [113].

In Mozambique and Zimbabwe, traditional fermented foods are used for weaning from the age of four months. The commonest fermented food is known are *mahewu*, a traditional, fermented, malted, sour, non-alcoholic maize or cassava thin porridge, sour milk and sour porridge [114,115]. The Tanzanian fermented gruel, *togwa*, has been found to protect against foodborne illnesses in regions that have poor sanitation [116].

However, each person is unique in their needs and sensitivities. Most of us only think of histamine when thinking of allergies. Indigenous fermented foods and beverages, as potential sources of probiotics, may be very therapeutic for some, while others may have an intolerance to histamine since there is no histamine free diet, and this amine, with many functions in the body, occurs naturally, and is a neurotransmitter in the central nervous system [117].

Fruits and vegetables are easily perishable commodities in Africa due to their high water activity and nutritive values. This phenomenon is more critical in tropical and subtropical countries, whose climates favor the growth of spoilage causing microorganisms. It is in developing settings in Africa, Asia [118], and Latin America [119,120] that perhaps the greatest need for probiotics and fermented foods exist; however, for many reasons, this is not the case [121].
