Microbial foods for improving human and planetary health.

The current food production system is negatively impacting planetary and human health. A transition to a sustainable and fair food system is urgently needed. Microorganisms are likely enablers of this process, as they can produce delicious and healthy microbial foods with low environmental footprints. We review traditional and current approaches to microbial foods, such as fermented foods, microbial biomass, and food ingredients derived from microbial fermentations. We discuss how future advances in science-driven fermentation, synthetic biology, and sustainable feedstocks enable a new generation of microbial foods, potentially impacting the sustainability, resilience, and health effects of our food system.

Gut-microbiota-targeted diets modulate human immune status.

Diet modulates the gut microbiome, which in turn can impact the immune system. Here, we determined how two microbiota-targeted dietary interventions, plant-based fiber and fermented foods, influence the human microbiome and immune system in healthy adults. Using a 17-week randomized, prospective study (n = 18/arm) combined with -omics measurements of microbiome and host, including extensive immune profiling, we found diet-specific effects. The high-fiber diet increased microbiome-encoded glycan-degrading carbohydrate active enzymes (CAZymes) despite stable microbial community diversity. Although cytokine response score (primary outcome) was unchanged, three distinct immunological trajectories in high-fiber consumers corresponded to baseline microbiota diversity. Alternatively, the high-fermented-food diet steadily increased microbiota diversity and decreased inflammatory markers. The data highlight how coupling dietary interventions to deep and longitudinal immune and microbiome profiling can provide individualized and population-wide insight. Fermented foods may be valuable in countering the decreased microbiome diversity and increased inflammation pervasive in industrialized society.

Microbiome Assembly in Fermented Foods.

For thousands of years, humans have enjoyed the novel flavors, increased shelf-life, and nutritional benefits that microbes provide in fermented foods and beverages. Recent sequencing surveys of ferments have mapped patterns of microbial diversity across space, time, and production practices. But a mechanistic understanding of how fermented food microbiomes assemble has only recently begun to emerge. Using three foods as case studies (surface-ripened cheese, sourdough starters, and fermented vegetables), we use an ecological and evolutionary framework to identify how microbial communities assemble in ferments. By combining in situ sequencing surveys with in vitro models, we are beginning to understand how dispersal, selection, diversification, and drift generate the diversity of fermented food communities. Most food producers are unaware of the ecological processes occurring in their production environments, but the theory and models of ecology and evolution can provide new approaches for managing fermented food microbiomes, from farm to ferment.

Isolation and characterization of lactic acid bacteria producing a potent anti-listerial bacteriocin-like inhibitory substance (BLIS) from chhurpi, a fermented milk product.

Nowadays, the bacteriocin industries have seen significant growth, supplanting chemical preservatives in its ability to improve the shelf-life and safety of food. The increasing customer desire to use natural preservatives has fueled advancing bacteriocin research. The objective of this study was to identify lactic acid bacteria (LAB) that produce bacteriocin-like inhibitory substance (BLIS) and have strong anti-listerial activity. We have identified and analyzed a LAB obtained from chhurpi samples, a popular milk-derived product in the Himalayan regions of India and Nepal. The strain was studied and identified based on its morphological, biochemical, and physiological characteristics. Furthermore, the molecular 16s-rDNA analysis suggests that the strain was Lactococcus sp. RGUAM1 (98.2% similar to Lactococcus lactis subsp. hordniae NBRC 100931T). The isolated strain can produce a potent BLIS, which has shown efficacy against three gram-positive bacteria responsible for food spoilage, such as Listeria monocytogenes (MTCC 657), Staphylococcus aureus subsp. aureus (MTCC 87), Lactobacillus plantarum (MTCC 1407), Lactobacillus paraplantarum (MTCC 12904). The scanning electron microscope (SEM) image illustrates that the crude cell-free supernatant (CFS) disrupts the cell envelope, leading to the release of cellular contents and the clustering of cells. In addition, this BLIS can easily withstand a wide range of pH (2-12), temperature (up to 100 °C for 15 min), bile salt (0.3% W/V), salinity (4% W/V), and enzyme activity of 1600 AU/ml against Listeria monocytogenes. Our research offers a robust framework and valuable insights into bio-preservation and its potential applications in diverse food products.

Odor and taste characteristics, transduction mechanism, and perceptual interaction in fermented foods: a review.

Fermentation is a critical technological process for flavor development in fermented foods. The combination of odor and taste, known as flavor, is crucial in enhancing people's perception and psychology toward fermented foods, thereby increasing their acceptance among consumers. This review summarized the determination and key flavor compound screening methods in fermented foods and analyzed the flavor perception, perceptual interactions, and evaluation methods. The flavor compounds in fermented foods could be separated, purified, and identified by instrument techniques, and a molecular sensory science approach could identify the key flavor compounds. How flavor compounds bind to their respective receptors determines flavor perception, which is influenced by their perceptual interactions, including odor-odor, taste-taste, and odor-taste. Evaluation methods of flavor perception mainly include human sensory evaluation, electronic sensors and biosensors, and neuroimaging techniques. Among them, the biosensor-based evaluation methods could facilitate the investigation of the flavor transduction mechanism and the neuroimaging technique could explain the brain's signals that relate to the perception of flavor and how they compare to signals from other senses. This review aims to elucidate the flavor profile of fermented foods and highlight the significance of comprehending the interactions between various flavor compounds, thus improving the healthiness and sensory attributes.

Live dietary microbes and reduced prevalence of periodontitis: A cross-sectional study.

OBJECTIVE: Investigate the link between live dietary microbe consumption and the prevalence of periodontitis. METHODS AND MATERIALS: National health and nutrition examination survey (2009-2014) data was used to assess the association among adults. Live dietary microbe intake was categorized as low or medium to high. Regression models were employed to assess this association, adjusting for demographic variables and other covariates. Examined dose-response relationship and conducted subgroup analyses by ethnicity, age and gender. Multiplicative interactions were evaluated using likelihood ratio tests. RESULTS: The analysis included 8574 participants. After adjusting for various factors including age, gender, ethnicity, dietary habits, dietary inflammatory index, alcohol consumption, smoking status, hypertension, diabetes mellitus and oral health behaviors, individuals with daily intake of medium to high levels of live dietary microbes showed a significantly reduced risk of periodontitis compared to those who did not consume such microbes with a dose-response trend (p for trend <0.0001, p < 0.01). Significant differences in the impact of live microbe intake on periodontitis were also observed across different age groups in all Models (p for interaction ≤0.05). CONCLUSION: Medium to high live dietary microbe consumption independently correlates with lower periodontitis risk, irrespective of traditional risk factors and demographics.

Staphylococcus aureus in Dairy Industry: Enterotoxin Production, Biofilm Formation, and Use of Lactic Acid Bacteria for Its Biocontrol.

Staphylococcus aureus is a well-known pathogen capable of producing enterotoxins during bacterial growth in contaminated food, and the ingestion of such preformed toxins is one of the major causes of food poisoning around the world. Nowadays 33 staphylococcal enterotoxins (SEs) and SE-like toxins have been described, but nearly 95% of confirmed foodborne outbreaks are attributed to classical enterotoxins SEA, SEB, SEC, SED, and SEE. The natural habitat of S. aureus includes the skin and mucous membranes of both humans and animals, allowing the contamination of milk, its derivatives, and the processing facilities. S. aureus is well known for the ability to form biofilms in food processing environments, which contributes to its persistence and cross-contamination in food. The biocontrol of S. aureus in foods by lactic acid bacteria (LAB) and their bacteriocins has been studied for many years. Recently, LAB and their metabolites have also been explored for controlling S. aureus biofilms. LAB are used in fermented foods since in ancient times and nowadays characterized strains (or their purified bacteriocin) can be intentionally added to prolong food shelf-life and to control the growth of potentially pathogenic bacteria. Regarding the use of these microorganism and their metabolites (such as organic acids and bacteriocins) to prevent biofilm development or for biofilm removal, it is possible to conclude that a complex network behind the antagonistic activity remains poorly understood at the molecular level. The use of approaches that allow the characterization of these interactions is necessary to enhance our understanding of the mechanisms that govern the inhibitory activity of LAB against S. aureus biofilms in food processing environments.

The effects of fermented food consumption in pregnancy on neonatal and infant health: An integrative review.

OBJECTIVE: This study was carried out to determine the effects of fermented food in maternal diet during pregnancy on neonatal and infant health. INTRODUCTION: Fermented food consumption positively affects microbiota development. It is widely acknowledged that maternal microbiota is a crucial component in the microbiota formation of the newborn. However, the short-term and long-term effects of fermented food consumption during pregnancy on newborns/infants have not been fully investigated so far. INCLUSION CRITERIA: The study included studies that were randomized controlled, quasi-experimental, pre-test and post-test controlled, cohort, descriptive and qualitative studies published in English with full-text access and with "moderate" or "strong" scores in quality assessment. METHODS: The researchers conducted research on Pubmed, Google Scholar, Web of Science, Scopus, Clinical Keys, Cochrane and Ebsco-Host databases without any time limitation. RESULTS: As a result, 1419 articles were reviewed and five studies were selected among which two studies demonstrated that fermented food consumption during pregnancy may reduce the risk of atopic dermatitis in the infant, and another study indicated that it may reduce the risk of food protein-induced allergic proctocolitis. One cohort study also reported that fermented food consumption during pregnancy improved sleep duration while another cohort study pointed out that it increased the birth weight of infants. CONCLUSION: Evidence supports the positive effects of including fermented foods in pregnancy nutrition on neonatal and infant health. Fermented products can be added to the daily diet as an alternative to probiotic supplements. By adding these foods to the nutritional guidelines, awareness of pregnant women can be raised.

Production, characterization, and potential applications of lipopeptides in food systems: A comprehensive review.

Lipopeptides are a class of lipid-peptide-conjugated compounds with differing structural features. This structural diversity is responsible for their diverse range of biological properties, including antimicrobial, antioxidant, and anti-inflammatory activities. Lipopeptides have been attracting the attention of food scientists due to their potential as food additives and preservatives. This review provides a comprehensive overview of lipopeptides, their production, structural characteristics, and functional properties. First, the classes, chemical features, structure-activity relationships, and sources of lipopeptides are summarized. Then, the gene expression and biosynthesis of lipopeptides in microbial cell factories and strategies to optimize lipopeptide production are discussed. In addition, the main methods of purification and characterization of lipopeptides have been described. Finally, some biological activities of the lipopeptides, especially those relevant to food systems along with their mechanism of action, are critically examined.

Miso, fermented soybean paste, suppresses high-fat/high-sucrose diet-induced muscle atrophy in mice.

This study investigated the effects of miso, a traditional fermented soybean food in Japan, on muscle mass atrophy. Eight week old male C57BL/6J mice were fed high fat/high sucrose diet with or without miso for 12 weeks. A miso diet increased soleus muscle weights (p<0.05) and reduced intraperitoneal glucose tolerance and insulin tolerance (p<0.05). The miso diet downregulated the Tnfα and Ccl2 expression, related to inflammation, and Trim63 and Fbxo32 expression, related to muscle atrophy, in the soleus muscle (p<0.05). The miso diet increased short-chain fatty acids levels, including acetic, propanoic, and butanoic acids, in the feces, serum, and soleus muscle (p<0.05). According to the LEfSe analysis, the miso diet increased family Prevotellaceae, family Christensenellaceae, family Dehalobacterium, family Desulfitibacter; family Deferribacteraceae, order Deferribacterales, class Deferribacteres; and family Gemmatimonadaceae, order Gemmatimonadetes, and class Gemmatimonadales, whereas the miso diet decreased family Microbacteriaceae, order Micrococcales, class Actinobacteria, and family Lactobacillaceae. Miso suppressed high fat/high sucrose diet induced impaired glucose tolerance, low muscle strength, and muscle atrophy by improving dysbiosis and increasing short-chain fatty acids production and provides new insights into the preventive effects of fermented foods on sarcopenia.

Positive Health Outcomes Associated with Live Microbe Intake from Foods, Including Fermented Foods, Assessed using the NHANES Database.

BACKGROUND: Live dietary microbes have been hypothesized to contribute to human health but direct evidence is lacking. OBJECTIVES: This study aimed to determine whether the dietary consumption of live microbes is linked to improved health outcomes. METHODS: Data from the NHANES 2001-2018 were used to assess microbial intake and their adjusted associations with selected physiological parameters (e.g., blood pressure, anthropometric measures, and biomarkers) among adults aged 19 y and older. Regression models were constructed to assess the microbial intake with each physiological parameter and adjusted for demographics and other covariates. Microbial intake was assessed as both a continuous variable and a 3-level categorical variable. Fermented foods were assessed in a separate model. RESULTS: In continuous models, an additional 100-g intake of microbe-containing foods was associated with a lower systolic blood pressure (regression coefficient: -0.331; 95% CI: -0.447, -0.215 mm Hg), C-reactive protein (-0.013; 95% CI: -0.019, -0.008 mg/dL), plasma glucose -0.347; 95% CI: -0.570, -0.124 mg/dL), plasma insulin (-0.201; 95% CI: -0.304, -0.099 µU/mL), triglyceride (-1.389; 95% CI: -2.672, -0.106 mg/dL), waist circumference (-0.554; 95% CI: -0.679, -0.428 cm), and BMI -0.217; 95% CI: -0.273, -0.160 kg/m2) levels and a higher level of high density lipoprotein cholesterols (0.432; 95% CI: 0.289, 0.574 mg/dL). Patterns were broadly similar when microbial intake was assessed categorically and when fermented foods were assessed separately. CONCLUSIONS: To our knowledge, this study is the first to quantify, in a nationally representative data set of American adults and using stable sets of covariates in the regression models, the adjusted associations of dietary intakes of live microbes with a variety of outcomes, such as anthropometric measures, biomarkers, and blood pressure levels. Our findings suggest that foods with higher microbial concentrations are associated with modest health improvements across a range of outcomes.

Lysinibacillus capsici 38,328 isolated from agricultural soils as a promising probiotic candidate for intestinal health.

There is an increasing interest in the use of spore-forming Bacillus spp. as probiotic ingredients on the market. However, probiotics Bacillus species are insufficient, and more safe Bacillus species were required. In the study, traditional fermented foods and soil samples were collected from more than ten provinces in China, and 506 Bacillus were selected from 109 samples. Using the optimized procedure, we screened nine strains, which successfully passed the acid, alkali, bile salt, and trypsin resistance test. Drug sensitivity test results showed that three Bacillus out of the nine isolates exhibited antibiotic sensitivity to more than 29 antibiotics. The three strains sensitive to antibiotics were identified by 16S ribosomal RNA, recA, and gyrB gene analysis, two isolates (38,327 and 38,328) belong to the species Lysinibacillus capsici and one isolate (37,326) belong to Bacillus halotolerans. Moreover, the three strains were confirmed safe through animal experiments. Finally, L. capsici 38,327 and 38,328 showed protections in the Salmonella typhimurium infection mouse model, which slowed down weight loss, reduced bacterial load, and improved antioxidant capacity. Altogether, our data demonstrated that selected L. capsici strains can be used as novel probiotics for intestinal health.

Does kimchi deserve the status of a probiotic food?

Kimchi is a traditional fermented vegetable side dish in Korea and has become a global health food. Kimchi undergoes spontaneous fermentation, mainly by lactic acid bacteria (LAB) originating from its raw ingredients. Numerous LAB, including the genera Leuconostoc, Weissella, and Lactobacillus, participate in kimchi fermentation, reaching approximately 9-10 log colony forming units per gram or milliliter of food. The several health benefits of LAB (e.g., antioxidant and anti-inflammatory properties) combined with their probiotic potential in complex diseases including obesity, cancer, atopic dermatitis, and immunomodulatory effect have generated an interest in the health effects of LAB present in kimchi. In order to estimate the potential of kimchi as a probiotic food, we comprehensively surveyed the health functionalities of kimchi and kimchi LAB, and their effects on human gut environment, highlighting the probiotics function.

Fermented food: Should patients with cardiometabolic diseases go back to an early neolithic diet?

Fermentation has been used since the Early Neolithic period to preserve foods. It has inherent organoleptic and nutritive properties that bestow health benefits, including reducing inflammation and oxidative stress, supporting the growth of salutogenic microbiota, enhancing intestinal mucosal protection and promoting beneficial immunometabolic health effects. The fermentation of food with specific microbiota increases the production salutogenic bioactive compounds that can activate Nrf2 mediated cytoprotective responses and mitigate the effects of the 'diseasome of aging' and its associated inflammageing, which presents as a prominent feature of obesity, type-2 diabetes, cardiovascular and chronic kidney disease. This review discusses the importance of fermented food in improving health span, with special reference to cardiometabolic diseases.

The inhibitory effects of plant additives on biogenic amine formation in fermented foods - a review.

Fermented food has unique properties and high nutritional value, and thus, should constitute a basic element of a balanced and health-promoting diet. However, it can accumulate considerable amount of biogenic amines (BAs), which ingested in excess can lead to adverse health effects. The application of plant-derived additives represents a promising strategy to ensure safety or enhance the functional and organoleptic properties of fermented food. This review summarizes currently available data on the application of plant-origin additives with the aim to reduce BA content in fermented products. The importance of ensuring fermented food safety has been highlighted considering the growing evidence of beneficial effects resulting from the consumption of this type of food, as well as the increasing number of individuals sensitive to BAs. The examined plant-origin additives reduced the BA concentration to varying degrees, and their efficacy depended on the type of additive, matrix, autochthonous, and inoculated microorganisms, as well as the manufacturing conditions. The main mechanisms of action include antimicrobial effects and the inhibition of microbial decarboxylases. Further research on the optimization of bioactive substances extraction, standardization of their chemical composition, and development of detailed procedures for its use in fermented products manufacturing are needed.

HACCP plan for microbiological hazards associated with fermented crab, Episesarma mederi H. Milne Edwards 1853.

AIMS: To develop a model HACCP plan related to the microbiological hazards for the traditional fermented crab. METHODS AND RESULTS: The microbiological and chemical characteristics of commercial products were surveyed. Microbiological hazard analysis was performed for raw materials and during processing. Critical control points (CCPs) were determined using a decision tree, with CCP1 as saturated salt preparation and CCP2 as fermentation. The critical limit (CL) of CCP1 was at 100°C for 20 min applied to brining and of CCP2 was at 25% NaCl for the brine applied to fermented crab. Isolated microbial hazards and type strains were used for the validation of the CLs. Monitoring and verification of the proposed HACCP plan were carried out, and an effective HACCP plan was established. CONCLUSIONS: The HACCP plan promoted the safe consumption of fermented crab with the provided CCPs at the saturated salt preparation and fermentation steps. The effective CLs to ensure microbiological hazards as safe at the CCPs provide the best support for an effective plan. The hazards were reduced significantly after the HACCP plan had been applied.

A comprehensive assessment of the antimicrobial and immunomodulatory effects of frequently consumed fermented foods: insights in the management of COVID-19.

COVID-19, which is caused by the novel coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), is the deadliest outbreak of this millennium. Despite adopting several precautionary strategies and guidelines, COVID-19 has spread rapidly, and the number of cases is still in escalation across the world. The various immune-boosting drugs with severe side effects and the vaccines approved after negotiated clinical trials have been struggling to cope with the emergence of new variants of the virus. Nevertheless, given a large number of asymptomatic cases, a high magnitude of recovery rate, and a relatively higher prevalence of morbidity and mortality among immunologically compromised individuals, those affected by an illness, and the elderly, it appears that a healthy microbiome and the associated immune responses are the key factors for survival. Incidentally, the consumption of traditionally popular and nutritious fermented foods, which are composed of biologically functional ingredients and several health-promoting probiotics, offers promising health benefits through the improvement of the immune system in general. Given the progress in functional food research, it has become crucial to understand the impact of a healthy microbiome and the immunomodulatory roles of fermented foods on the battles to combat infectious diseases. Based on the evidence of the impact of probiotics-based fermented foods, the beneficial roles of a few frequently consumed fermented foods in the management of various infections have been resolutely discussed in the present study, with a focus on their antagonistic and immune-modulating effects in the context of the current COVID-19 pandemic.

The altered production and property of saliva induced by ingesting fermented food ingredients affect the oral microbiome composition in mice.

Oral functions are diverse and critical to human health. Therefore, insufficient secretion or poor quality of saliva, which is secreted into the oral cavity and plays various roles, could have a crucial influence on the oral microenvironment and be associated with systemic disease development. Here, we investigated the effects of food ingredients on saliva quantity and quality, including fermented ones. Through the in vitro submandibular glands' organ culture analyses, we found that "Yomo gyutto," fermented Japanese mugwort (Artemisia princeps), altered the expression of aquaporin-5, a water channel protein. We also found that Yomo gyutto increased saliva volume, along with the amount of α-amylase in mice, and caused changes in the oral microbiome composition of mice. These results suggested that by ingesting Yomo gyutto, we could directly and effectively manipulate the quantity and quality of saliva secreted from the salivary glands, potentially altering the oral microbiome composition for individual health.

Relationship between microorganisms and volatile components in each fermentation process in the kusaya gravy that plays an important role in the manufacturing of kusaya, a traditional Japanese fermented fish product.

The relationship between the microbiota and volatile components of kusaya gravy involved in the manufacturing of kusaya, a traditional Japanese fermented fish product, in the Izu Islands (Niijima and Hachijojima) and the fermentation processes are not clear. In this study, we aimed to investigate the relationship between the microbiota and volatile compounds involved in the manufacturing and management of kusaya gravy. 16S ribosomal RNA (rRNA) gene-based amplicon sequencing revealed that the microbiota in kusaya gravy was significantly different between the two islands, and the microbiota hardly changed during each fermentation process. Gas chromatography-mass spectrometry analysis also revealed that the volatile components were strongly related to the microbiota in kusaya gravy, with Hachijojima samples containing sulfur-containing compounds and Niijima samples containing short-chain fatty acids. Therefore, our findings suggest that kusaya gravy is a characteristic fermented gravy with a stable microbiota, and the fermented pickling gravy is fermented by microorganisms.

Directionally controlling flavor compound profile based on the structure of synthetic microbial community in Chinese liquor fermentation.

Most traditional fermented foods are produced by spontaneous fermentation. It is difficult to produce traditional fermented foods with desired flavor compound profile. In this study, using Chinese liquor fermentation as a case, we aimed to directionally control flavor compound profile in food fermentation. Twenty key flavor compounds were identified in 80 Chinese liquor fermentations. Six microbial strains, identified as high producers of these key flavor compounds, were used to generate the minimal synthetic microbial community. A mathematical model was established to link the structure of the minimal synthetic microbial community and the profile of these key flavor compounds. This model could generate the optimal structure of synthetic microbial community to produce flavor compounds with desired profile. This work provided a strategy to realize the directional control of flavor compound profile via controlling the structure of the synthetic microbial community in Chinese liquor fermentation.