Functional Microbes and Their Incorporation into Foods and Food Supplements: Probiotics and Postbiotics

The role of dietary intake of live microbes in the association between leisure-time physical activity and depressive symptoms: a population-based study

Current research has shown promising associations between factors such as diet, total physical activity, and mental health outcomes, acknowledging the intricate interplay between these variables. However, the role of dietary intake of live microbes, coupled with leisure-time physical activity (LTPA), in their relationship to depressive symptoms necessitates further exploration. The present study examined a cohort of 25 747 individuals who participated in the National Health and Nutrition Examination Survey between the years 2007 and 2018. Patient's Health Questionnaire (PHQ-9) was employed, whereby individuals scoring ≥ 10 were classified as exhibiting symptoms of depression. LTPA status was reported by the Global Physical Activity Questionnaire and calculated by metabolic equivalent-minutes/week. Foods consumed by participants were evaluated by live microbes per gram, which were categorized into three groups: low, medium, and high. After controlling for all covariates, findings indicated that LTPA was negatively associated with depressive symptoms (OR (95% confidence interval (CI): 0.983 (0.976, 0.990), p < 0.001). Participating in more LTPA was positively correlated with consuming all three levels of dietary live microbes (low, β (95% CI): 0.086 (0.063, 0.109); medium, β (95% CI): 0.009 (0.007, 0.012); high, β (95% CI): 0.002 (0.001, 0.002)). Moreover, taking more foods with medium live microbes was associated with lower depressive likelihood (OR (95% CI): 0.931(0.882, 0.982), p = 0.010). Intake of medium and high levels of live microbes mediated the association between LTPA and depressive symptoms by 4.15% and 0.83%, respectively. Dietary intake of foods containing medium and high levels of live microbes may be a mediator of LTPA's negative association with depressive symptoms.

Dietary patterns interfere with gut microbiota to combat obesity

Obesity and obesity-related metabolic disorders are global epidemics that occur when there is chronic energy intake exceeding energy expenditure. Growing evidence suggests that healthy dietary patterns not only decrease the risk of obesity but also influence the composition and function of the gut microbiota. Numerous studies manifest that the development of obesity is associated with gut microbiota. One promising supplementation strategy is modulating gut microbiota composition by dietary patterns to combat obesity. In this review, we discuss the changes of gut microbiota in obesity and obesity-related metabolic disorders, with a particular emphasis on the impact of dietary components on gut microbiota and how common food patterns can intervene in gut microbiota to prevent obesity. While there is promise in intervening with the gut microbiota to combat obesity through the regulation of dietary patterns, numerous key questions remain unanswered. In this review, we critically review the associations between dietary patterns, gut microbes, and obesity, aiming to contribute to the further development and application of dietary patterns against obesity in humans.

Oat-based postbiotics ameliorate high-sucrose induced liver injury and colitis susceptibility by modulating fatty acids metabolism and gut microbiota

High-sucrose (HS) consumption leads to metabolic disorders and increases susceptibility to colitis. Postbiotics hold great potentials in combating metabolic diseases and offer advantages in safety and processability, compared with living probiotics. We developed innovative oat-based postbiotics and extensively explored how they could benefit in rats with long-term high-sucrose consumption. The postbiotics fermented with Lactiplantibacillus plantarum (OF-1) and OF-5, the one fermented with the optimal selection of five probiotics (i.e., L. plantarum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lactobacillus acidophilus, and Bifidobacterium lactis) alleviated HS induced liver injury, impaired fatty acid metabolism and inflammation through activating AMPK/SREBP-1c pathways. Moreover, oat-based postbiotics restored detrimental effects of HS on fatty acid profiles in liver, as evidenced by the increases in polyunsaturated fatty acids and decreases in saturated fatty acids, with OF-5 showing most pronounced effects. Furthermore, oat-based postbiotics prevented HS exacerbated susceptibility to dextran sodium sulfate caused colitis and reconstructed epithelial tight junction proteins in colons. Oat-based postbiotics, in particular OF-5 notably remodeled gut microbiota composition, e.g., enriching the relative abundances of Akkermansia, Bifidobacterium, Alloprevotella and Prevotella, which may play an important role in the liver-colon axis responsible for improvements of liver functions and reduction of colitis susceptibility. The heat-inactivated probiotics protected against HS-induced liver and colon damage, but such effects were less pronounced compared with oat-based postbiotics. Our findings emphasize the great value of oat-based postbiotics as nutritional therapeutics to combat unhealthy diet induced metabolic dysfunctions.

Human milk oligosaccharides combine with Bifidobacterium longum to form the "golden shield" of the infant intestine: metabolic strategies, health effects, and mechanisms of action

Human milk oligosaccharides (HMOs) are the third most important nutrient in human milk and are the gold standard for infant nutrition. Due to the lack of an enzyme system capable of utilizing HMOs in the infant intestine, HMOs cannot be directly utilized. Instead, they function as natural prebiotics, participating in the establishment of the intestinal microbiota as a "bifidus factor." A crucial colonizer of the early intestine is Bifidobacterium longum (B. longum), particularly its subspecies B. longum subsp. infantis, which is the most active consumer of HMOs. However, due to the structural diversity of HMOs and the specificity of B. longum strains, studies on their synergy are limited. An in-depth investigation into the mechanisms of HMO utilization by B. longum is essential for applying both as synbiotics to promote early intestinal development in infants. This review describes the colonization advantages of B. longum in the infant intestinal tract and its metabolic strategies for HMOs. It also summarizes recent studies on the effect and mechanism of B. longum and HMOs in infant intestinal development directly or indirectly through the action of metabolites. In conclusion, further structural analysis of HMOs and a deeper understanding of the interactions between B. longum and HMOs, as well as clinical trials, are necessary to lay the foundation for future practical applications as synbiotics.

Probiotic and postbiotic analytical methods: a perspective of available enumeration techniques

Probiotics are the largest non-herbal/traditional dietary supplements category worldwide. To be effective, a probiotic strain must be delivered viable at an adequate dose proven to deliver a health benefit. The objective of this article is to provide an overview of the various technologies available for probiotic enumeration, including a general description of each technology, their advantages and limitations, and their potential for the future of the probiotics industry. The current "gold standard" for analytical quantification of probiotics in the probiotic industry is the Plate Count method (PC). PC measures the bacterial cell's ability to proliferate into detectable colonies, thus PC relies on cultivability as a measure of viability. Although viability has widely been measured by cultivability, there has been agreement that the definition of viability is not limited to cultivability. For example, bacterial cells may exist in a state known as viable but not culturable (VBNC) where the cells lose cultivability but can maintain some of the characteristics of viable cells as well as probiotic properties. This led to questioning the association between viability and cultivability and the accuracy of PC in enumerating all the viable cells in probiotic products. PC has always been an estimate of the number of viable cells and not a true cell count. Additionally, newer probiotic categories such as Next Generation Probiotics (NGPs) are difficult to culture in routine laboratories as NGPs are often strict anaerobes with extreme sensitivity to atmospheric oxygen. Thus, accurate quantification using culture-based techniques will be complicated. Another emerging category of biotics is postbiotics, which are inanimate microorganisms, also often referred to as tyndallized or heat-killed bacteria. Obviously, culture dependent methods are not suitable for these products, and alternative methods are needed for their quantification. Different methodologies provide a more complete picture of a heterogeneous bacterial population versus PC focusing exclusively on the eventual multiplication of the cells. Alternative culture-independent techniques including real-time PCR, digital PCR and flow cytometry are discussed. These methods can measure viability beyond cultivability (i.e., by measuring cellular enzymatic activity, membrane integrity or membrane potential), and depending on how they are designed they can achieve strain-specific enumeration.

Paraprobiotics and Postbiotics-Current State of Scientific Research and Future Trends toward the Development of Functional Foods

The potential of paraprobiotics and postbiotics to be used as beneficial agents for human health has caused an effort by the scientific community to gather information about the bioactivity of these compounds and production methods. Understanding the evolution of scientific research in this area of study is important to understand the future perspectives and the main bottlenecks of scientific and technological development involving these compounds. In this scenario, this review work used a bibliometric analysis tool intending to improve the scientific documentation, bringing information and communicating the results to the scientific community through the quantitative analysis of the current literature, available in one of the main databases, the Web of Science, also providing recent information on the evolution and future perspectives in the field of paraprobiotic and postbiotic development. The results of this study showed that the main studies discuss the bioactivity of these compounds. Concerning the development of functional foods, there is a need for extensive research on production methods and the interaction of these compounds with food. However, it concluded that much still needs to be studied to prove the claims of bioactivity, especially when used for the development of functional foods.

Dysbiosis of Gut Microbiota Contributes to Uremic Cardiomyopathy via Induction of IFNγ-Producing CD4+ T Cells Expansion

Uremic cardiomyopathy (UCM) correlates with chronic kidney disease (CKD)-induced morbidity and mortality. Gut microbiota has been involved in the pathogenesis of certain cardiovascular disease, but the role of gut microbiota in the pathogenesis of UCM remains unknown. Here, we performed a case-control study to compare the gut microbiota of patients with CKD and healthy controls by 16S rRNA (rRNA) gene sequencing. To test the causative relationship between gut microbiota and UCM, we performed fecal microbiota transplantation (FMT) in 5/6th nephrectomy model of CKD. We found that opportunistic pathogens, particularly Klebsiella pneumoniae (K. pneumoniae), are markedly enriched in patients with CKD. FMT from CKD patients aggravated diastolic dysfunction in the mouse model. The diastolic dysfunction was associated with microbiome-dependent increases in heart-infiltrating IFNγ+ CD4+ T cells. Monocolonization with K. pneumoniae increased cardiac IFNγ+ CD4+ T cells infiltration and promoted UCM development of the mouse model. A probiotic Bifidobacterium animalis decreased the relative abundance of K. pneumoniae, reduced levels of cardiac IFNγ+ CD4+ T cells and ameliorated the severity of diastolic dysfunction in the mice. Thus, the aberrant gut microbiota in CKD patients, especially K. pneumoniae, contributed to UCM pathogenesis through the induction of heart-infiltrating IFNγ+ CD4+ T cells expansion, proposing that a Gut Microbiota-Gut-Kidney-Heart axis could play a critical role in elucidating the etiology of UCM, and suggesting that modulation of the gut bacteria may serve as a promising target for the amelioration of UCM. IMPORTANCE Uremic cardiomyopathy (UCM) correlates tightly with increased mortality in patients with chronic kidney disease (CKD), yet the pathogenesis of UCM remains incompletely understood, limiting therapeutic approaches. Our study proposed that a Gut Microbiota-Gut-Kidney-Heart axis could play a critical role in understanding etiology of UCM. There is a major need in future clinical trials of patients with CKD to explore if modulation of gut microbiota by fecal microbiota transplantation (FMT), probiotics or antibiotics can alleviate cardiac dysfunction, reduce mortality, and improve life quality.

Probiotics media: significance, challenges, and future perspective - a mini review

The health benefits associated with probiotics have increased their application in pharmaceutical formulations and functional food development. High production of probiotic biomass requires a cost-effective production method and nutrient media optimization. The biomass production of probiotics can be enhanced by optimizing growth parameters such as substrate, pH, incubation time, etc. For economical industrial production of probiotic biomass, it is required to design a new medium with low cost. Wastes from the food industries are promising components for the development of the low-cost medium. Industrial wastes such as cheese whey and corn steep liquor are excellent examples of reliable sources of nitrogen for the biomass production of probiotic bacteria. The increased yield of biomass reduced the cost of production. This review focuses on the importance of probiotic media for biomass production and its challenges.

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