Postbiotic nanoparticles (postbiotics-NPs): a novel strategy for providing probiotics' health advantages through food consumption

In recent years, the term "postbiotics" has become increasingly popular in food microbiology, food science, and commercial products. This importance has been raised due to the safety issues associated with live bacterial cells. Postbiotics are defined as bioactive substances of probiotics. It confers unique health-promoting functions with its chemical structure, safe profile, and long shelf life. Meanwhile, postbiotics nanoparticles (postbiotics-NPs) can be considered novel postbiotic delivery systems to deliver bioactive components with health benefits and therapeutic aims, promote the shelf-life of food products, and develop novel functional foods. The present scientific literature shows that nanotechnology approaches are not yet mature enough to be used in postbiotic delivery systems. For all of that, the potential applications of postbiotics-NPs in the food industry and biomedical fields will be a new trend in the future.

Use of Postbiotic as Growth Promoter in Poultry Industry: A Review of Current Knowledge and Future Prospects

Health-promoting preparations of inanimate microorganisms or their components are postbiotics. Since probiotics are sensitive to heat and oxygen, postbiotics are stable during industrial processing and storage. Postbiotics boost poultry growth, feed efficiency, intestinal pathogen reduction, and health, making them acceptable drivers of sustainable poultry production. It contains many important biological properties, such as immunomodulatory, antioxidant, and anti-inflammatory responses. Postbiotics revealed promising antioxidant effects due to higher concentrations of uronic acid and due to some enzyme's production of antioxidants, e.g., superoxide dismutase, glutathione peroxidase, and nicotinamide adenine dinucleotide oxidases and peroxidases. Postbiotics improve intestinal villi, increase lactic acid production, and reduce Enterobacteriaceae and fecal pH, all of which lead to a better immune reaction and health of the gut, as well as better growth performance. P13K/AKT as a potential target pathway for postbiotics-improved intestinal barrier functions. Similarly, postbiotics reduce yolk and plasma cholesterol levels in layers and improve egg quality. It was revealed that favorable outcomes were obtained with various inclusion levels at 1 kg and 0.5 kg. According to several studies, postbiotic compounds significantly increased poultry performance. This review article presents the most recent research investigating the beneficial results of postbiotics in poultry.

Probing the functional and therapeutic properties of postbiotics in relation to their industrial application

Functional foods are gaining significant research attention of researchers due to their health-endorsing properties due to their bioactive components either living cells (probiotics) or nonviable cells (prebiotics). The term "postbiotic" specifies the soluble substances, such as enzymes, peptides, teichoic acids, muropeptides derived from peptidoglycans, polysaccharides, cell surface proteins, and organic acids, that are secreted by living bacteria or released after bacterial lysis. Due to various signaling molecules which may have antioxidant, immunomodulatory, antiinflammatory, antihypertensive, and antiproliferative activities, postbiotics offer great potential to be used in pharmaceutical, food, and nutraceutical industries, to promote health and ailment prevention. This recent review is a landmark of information relevant to the production of postbiotics along with salient features to use in various fields ranging from food to immunomodulation and selective and effective therapy. It also puts forward the concept that postbiotics are way more effective than probiotics in the veterinary, food as well as medical field which ultimately helps in reducing the disease burden along with human health.

Development and characterization of a novel sodium alginate based active film supplemented with Lactiplantibacillus plantarum postbiotic

In this study, sodium alginate based biodegradable films were prepared by the supplementation with postbiotics of Lactiplantibacillus plantarum subsp. plantarum (L. plantarum) W2 strain and the effect of probiotics (probiotic-SA film) and postbiotics (postbiotic-SA film) incorporation on physical, mechanical (tensile strength and elongation at break), barrier (oxygen and water vapor permeability), thermal and antimicrobial properties of the films were investigated. The pH, titratable acidity and brix of the postbiotic was 4.02, 1.24 % and 8.37, respectively while gallic acid, protocatechuic acid, myricetin and catechin were the major phenolic compounds. Mechanical and barrier properties of the alginate-based films were improved by probiotic or postbiotic supplementation while postbiotic showed a more pronounced (P < 0.05) effect. Thermal analysis showed that postbiotics supplementation increased thermal stability of the films. In FTIR spectra, the absorption peaks at 2341 and 2317 cm^-1 for probiotic-SA and postbiotic-SA edible films confirmed the incorporation of probiotics/postbiotics of L. plantarum W2 strain. Postbiotic supplemented films showed strong antibacterial activity against gram-positive (L. monocytogenes, S. aureus and B. cereus) and one gram-negative bacterial strain (E. coli O157:H7) while probiotic incorporation did not add an antibacterial effect to the films. SEM images revealed that the supplementation of postbiotics provided a rougher and rigid film surface. Overall, this paper brought a new perspective for development of novel active biodegradable films by incorporation of postbiotics with improved performance.

Probiotic properties and proteomics analysis of ethanol-induced Lactococcus lactis subsp. lactis IL1403

Our previous study indicated that ethanol-induced intracellular extracts (E-IEs) of Lactococcus lactis subsp. Lactis IL1403 (L. lactis IL1403) alleviated hangovers more effectively in mice than untreated intracellular extracts (U-IEs), but the material basis was unclear. Considering that stress-related proteins might play a significant role, the effects of ethanol induction on probiotic properties of L. lactis IL1403 and the associated stress response mechanism were initially explored in this study. E-IEs of L. lactis IL1403 showed better biological activities, significantly increased bacteria survival rates in oxidative stress environments, increased ADH activity, and enhanced proliferation in RAW264.7 and AML-12 cells. Proteomic analyses revealed that 414 proteins were significantly changed in response to ethanol induction. The expression of proteins involved in the universal stress response, DNA repair, oxidative stress response, and ethanol metabolism was rapidly upregulated under ethanol stress, and quantitative real-time PCR (qRT-PCR) results were consistent with proteomic data. KEGG pathway analysis indicated that citrate metabolism, starch and sucrose metabolism, and pyruvate metabolism were significantly enriched during ethanol stress to increase energy requirements and survival rates of stressed cells. Based on this observation, the active induction is an effective strategy for increasing the biological activity of L. lactis IL1403. Exploring the molecular mechanism and material basis of their functions in vivo can help us understand the adaptive regulatory mechanism of microorganisms.

Recent advances in understanding of multifaceted changes in the vaginal microenvironment: implications in vaginal health and therapeutics

The vagina endures multifaceted changes from neonatal to menopausal phases due to hormonal flux, metabolite deposition, and microbial colonization. These features have important implications in women's health. Several pre-factors show dynamic characteristics according to the phases that shift the vaginal microbiota from anaerobes to aerobes which is a hallmark of healthy vaginal environment. These factors include oestrogen levels, glycogen deposition, and vaginal microstructure. In the adult phase, Lactobacillus is highly dominant and regulates pH, adherence, aggregation, immune modulation, synthesis of bacteriocins, and biosurfactants (BSs) which are antagonistic to pathogens. Maternal factors are protective by favouring the colonization of lactobacilli in the vagina in the neonatal phase, which diminishes with age. The dominance of lactobacilli and dysbiosis in the adult phase depends on intrinsic and extrinsic factors in women, which vary between ethnicities. Recent developments in probiotics used against vaginal microbiome dysbiosis have shown great promise in restoring the normal microbiota including preventing the loss of beneficial bacteria. However, further in-depth studies are warranted to ensure long-term protection by probiotics. This review highlights various aspects of the vaginal microenvironment in different phases of growth and diverse ethnicities. Furthermore, it discusses future trends for formulating more effective population-specific probiotics and implications of paraprobiotics and postbiotics as effective therapeutics.

Gastrointestinal Microbiota and Their Manipulation for Improved Growth and Performance in Chickens

The gut of warm-blooded animals is colonized by microbes possibly constituting at least 100 times more genetic material of microbial cells than that of the somatic cells of the host. These microbes have a profound effect on several physiological functions ranging from energy metabolism to the immune response of the host, particularly those associated with the gut immune system. The gut of a newly hatched chick is typically sterile but is rapidly colonized by microbes in the environment, undergoing cycles of development. Several factors such as diet, region of the gastrointestinal tract, housing, environment, and genetics can influence the microbial composition of an individual bird and can confer a distinctive microbiome signature to the individual bird. The microbial composition can be modified by the supplementation of probiotics, prebiotics, or synbiotics. Supplementing these additives can prevent dysbiosis caused by stress factors such as infection, heat stress, and toxins that cause dysbiosis. The mechanism of action and beneficial effects of probiotics vary depending on the strains used. However, it is difficult to establish a relationship between the gut microbiome and host health and productivity due to high variability between flocks due to environmental, nutritional, and host factors. This review compiles information on the gut microbiota, dysbiosis, and additives such as probiotics, postbiotics, prebiotics, and synbiotics, which are capable of modifying gut microbiota and elaborates on the interaction of these additives with chicken gut commensals, immune system, and their consequent effects on health and productivity. Factors to be considered and the unexplored potential of genetic engineering of poultry probiotics in addressing public health concerns and zoonosis associated with the poultry industry are discussed.

Postbiotics as the new frontier in food and pharmaceutical research

Food is the essential need of human life and has nutrients that support growth and health. Gastrointestinal tract microbiota involves valuable microorganisms that develop therapeutic effects and are characterized as probiotics. The investigations on appropriate probiotic strains have led to the characterization of specific metabolic byproducts of probiotics named postbiotics. The probiotics must maintain their survival against inappropriate lethal conditions of the processing, storage, distribution, preparation, and digestion system so that they can exhibit their most health effects. Conversely, probiotic metabolites (postbiotics) have successfully overcome these unfavorable conditions and may be an appropriate alternative to probiotics. Due to their specific chemical structure, safe profile, long shelf-life, and the fact that they contain various signaling molecules, postbiotics may have anti-inflammatory, immunomodulatory, antihypertensive properties, inhibiting abnormal cell proliferation and antioxidative activities. Consequently, present scientific literature approves that postbiotics can mimic the fundamental and clinical role of probiotics, and due to their unique characteristics, they can be applied in an oral delivery system (pharmaceutical/functional foods), as a preharvest food safety hurdle, to promote the shelf-life of food products and develop novel functional foods or/and for developing health benefits, and therapeutic aims. This review addresses the latest postbiotic applications with regard to pharmaceutical formulations and commercial food-based products. Potential postbiotic applications in the promotion of host health status, prevention of disease, and complementary treatment are also reviewed.

Precision Postbiotics and Mental Health: the Management of Post-COVID-19 Complications

The health catastrophe originated by COVID-19 pandemic construed profound impact on a global scale. However, a plethora of research studies corroborated convincing evidence conferring severity of infection of SARS-CoV-2 with the aberrant gut microbiome that strongly speculated its importance for development of novel therapeutic modalities. The intense exploration of probiotics has been envisaged to promote the healthy growth of the host, and restore intestinal microecological balance through various metabolic and physiological processes. The demystifying effect of probiotics cannot be defied, but there exists a strong skepticism related to their safety and efficacy. Therefore, molecular signature of probiotics termed as "postbiotics" are of paramount importance and there is continuous surge of utilizing postbiotics for enhancing health benefits, but little is explicit about their antiviral effects. Therefore, it is worth considering their prospective role in post-COVID regime that pave the way for exploring the pastoral vistas of postbiotics. Based on previous research investigations, the present article advocates prospective role of postbiotics in alleviating the health burden of viral infections, especially SARS-CoV-2. The article also posits current challenges and proposes a futuristic model describing the concept of "precision postbiotics" for effective therapeutic and preventive interventions that can be used for management of this deadly disease.

The biological activities of postbiotics in gastrointestinal disorders

According to outcomes from clinical studies, an intricate relationship occurs between the beneficial microbiota, gut homeostasis, and the host's health status. Numerous studies have confirmed the health-promoting effects of probiotics, particularly in gastrointestinal diseases. On the other hand, the safety issues regarding the consumption of some probiotics are still a matter of debate, thus to overcome the problems related to the application of live probiotic cells in terms of clinical, technological, and economic aspects, microbial-derived biomolecules (postbiotics) were introducing as a potential alternative agent. Presently scientific literature confirms that the postbiotic components can be used as promising tools for both prevention and treatment strategies in gastrointestinal disorders with less undesirable side-effects, particularly in infants and children. Future head-to-head trials are required to distinguish appropriate strains of parent cells, optimal dosages of postbiotics, and assessment of the cost-effectiveness of postbiotics compared to alternative drugs. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the treatment of some important gastrointestinal disorders.

Paraprobiotics and Postbiotics of Probiotic Lactobacilli, Their Positive Effects on the Host and Action Mechanisms: A Review

Lactobacilli comprise an important group of probiotics for both human and animals. The emerging concern regarding safety problems associated with live microbial cells is enhancing the interest in using cell components and metabolites derived from probiotic strains. Here, we define cell structural components and metabolites of probiotic bacteria as paraprobiotics and postbiotics, respectively. Paraprobiotics and postbiotics produced from Lactobacilli consist of a wide range of molecules including peptidoglycans, surface proteins, cell wall polysaccharides, secreted proteins, bacteriocins, and organic acids, which mediate positive effect on the host, such as immunomodulatory, anti-tumor, antimicrobial, and barrier-preservation effects. In this review, we systematically summarize the paraprobiotics and postbiotics derived from Lactobacilli and their beneficial functions. We also discuss the mechanisms underlying their beneficial effects on the host, and their interaction with the host cells. This review may boost our understanding on the benefits and molecular mechanisms associated with paraprobiotics and probiotics from Lactobacilli, which may promote their applications in humans and animals.

Molecular mechanisms of postbiotics in colorectal cancer prevention and treatment

The occurrence of colorectal cancer (CRC) has been rising expeditiously and anticipated that 2.4 million new occasions of CRC will be detected yearly around the world until the year 2035. Due to some side-effects and complications of conventional CRC therapies, bioactive components such as microbial-derived biomolecules (postbiotics) have been attaining great significance by researchers for adjuvant therapy in CRC patients. The term 'postbiotics' encompasses an extensive range of complex micro- and macro-molecules (<50, 50-100, and 100< kDa) such as inactivated microbial cells, cell fractions or metabolites, which confer various physiological health benefits to the host when administered in adequate amounts. Postbiotics modulate the composition of the gut microbiota and the functionality of the immune system, as well as promote the CRC treatment effectiveness and reduces its side-effects in CRC patients due to possessing anti-oxidant, anti-proliferative, anti-inflammatory, and anti-cancer activities. Presently scientific literature confirms that postbiotics with their unique characteristics in terms of clinical (safe origin), technological (stability), and economic (low production costs) aspects can be used as promising tools for both prevent and adjuvant treat strategies in CRC patients without any serious undesirable side-effects. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the prevention and treatment of CRC.

Potential Health-Promoting Benefits of Paraprobiotics, Inactivated Probiotic Cells

Viability plays an important role in the beneficial microbes (probiotics) to produce health benefits. However, this idea has been changed after the invention of the term "paraprobiotics," indicating that non-viable microbes could produce health benefits similar to those produced by live probiotics. Occasionally, it might be dangerous to administer live probiotics to people with weak immunity. In such cases, ingestion of paraprobiotics could be a potential alternative. The definition of paraprobiotics refers to the use of inactivated (non-viable) microbial cells or cell fractions to provide health benefits to the consumer. Paraprobiotics have attracted much attention because of their long shelf life, safety, and beneficial effects, such as modulation of immunity, modification of biological responses, reduction of cholesterol, anti-inflammatory, and antiproliferative properties. These features indicate that paraprobiotics may play a vital role in improving the health of the consumer by enhancing particular physiological functions, even though the exact underlying mechanisms have not yet been completely elucidated. In this mini-review, we briefly discuss the historical backgrounds of paraprobiotics and evidence of their health-promoting effects, prophylactic, and therapeutic properties.