Effect ofLactobacillus paracaseiNCC2461 on Antigen-Specific T-Cell Mediated Immune Responses in Aged Mice

Evaluation of the immunogenicity of auxotrophic Lactobacillus with CRISPR-Cas9D10A system-mediated chromosomal editing to express porcine rotavirus capsid protein VP4

Porcine rotavirus (PoRV) is an important pathogen, leading to the occurrence of viral diarrhoea . As the infection displays obvious enterotropism, intestinal mucosal immunity is the significant line of defence against pathogen invasion. Moreover, as lactic acid bacteria (LAB) show acid resistance, bile salt resistance and immune regulation, it is of great significance to develop an oral vaccine. Most traditional plasmid delivery vectors use antibiotic genes as selective markers, easily leading to antibiotic accumulation. Therefore, to select a food-grade marker in genetically engineering food-grade microorganisms is vital. Based on the CRISPR-Cas9D10A system, we constructed a stable auxotrophic Lactobacillus paracasei HLJ-27 (Lactobacillus △Alr HLJ-27) strain. In addition, as many plasmids replicate in the host bacteria, resulting in internal gene deletions. In this study,we used a temperature-sensitive gene editing plasmidto insert the VP4 gene into the genome, yielding the insertion mutant strains VP4/△Alr HLJ-27, VP4/△Alr W56, and VP4/W56. This recombinant bacterium efficiently induced secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses. These oral mucosal vaccines have the potential to act as an alternative to the application of antibiotics in the future and induce efficient immune responses against PEDV infection.

Nutraceuticals-Based Immunotherapeutic Concepts and Opportunities for the Mitigation of Cellular Senescence and Aging: A Narrative Review

The role of increased tissue senescent cell (SC) burden in driving the process of ageing and associated disorders is rapidly gaining attention. Amongst various plausible factors, impairment in immune functions is emerging as a critical regulator of known age-associated accumulation of SC. Immune cells dysfunctions with age are multi-faceted and are uniquely attributed to the independent processes of immunosenescence and cellular senescence which may collectively impair immune system mediated clearance of SC. Moreover, being functionally and phenotypically heterogenic, immune cells are also liable to be affected by senescence microenvironment in other tissues. Therefore, strategies aimed at improving immunosenescence and cellular senescence in immune cells can have pleiotropic effects on ageing physiology including the accumulation of SC. In this regard, nutraceutical's immunomodulatory attributes are well documented which may have implications in developing nutrition-oriented immunotherapeutic approaches against SC. In particular, the three diverse sources of bioactive ingredients, viz., phytochemicals, probiotic bacteria and omega-3-fatty acids have shown promising anti-immunosenescence and anti-cellular senescence potential in immune cells influencing aging and immunity in ways beyond modest stimulation of immune responses. The present narrative review describes the preventive and therapeutic attributes of phytochemicals such as polyphenols, probiotic microbes and omega-3-fatty acids in influencing the emerging nexus of immunosenescence, cellular senescence and SC during aging. Outstanding questions and nutraceuticals-based pro-longevity and niche research areas have been deliberated. Further research using integrative approaches is recommended for developing nutrition-based holistic immunotherapeutic strategies for 'healthy ageing'.

The Promising Role of Probiotics in Managing the Altered Gut in Autism Spectrum Disorders

Gastrointestinal symptoms (GIS) have been reported repeatedly in people with autism spectrum disorder (ASD) and studies have reported interesting correlations between severity of behavioral and gastrointestinal symptoms. Growing evidence indicates that the gut microbiota in ASD is altered with various shifts described at different taxonomic levels, pointing to the importance of considering the gut-brain axis in treatment of these disorders. Probiotics are live beneficial bacteria that are ingested as food or customized pills. These beneficial bacteria, when added in sufficient amounts, can correct the dysbiosis. Because probiotics have shown success in treating irritable bowel syndrome (IBS), it is plausible to investigate whether they can induce alleviation of behavioral symptoms as well. Probiotics show, in some clinical studies, their potential benefits (1) in improving gastrointestinal dysfunction, (2) in correcting dysbiosis, (3) in consequently reducing the severity of ASD symptoms. This review compiles data from selected studies that investigate these benefits and the mechanisms that mediate these effects, which include the production of metabolites, hormones, and neurotransmitters and the regulation of pro-inflammatory and regulatory cytokines. Future research based on more randomized, controlled studies with a larger population size and standardized use of strains, concentration of probiotics, duration of treatments, and methods of DNA extraction is still needed in this area, which may lead to more robust results.

Probiotic bacteria as modulators of cellular senescence: emerging concepts and opportunities

Probiotic bacteria are increasingly gaining importance in human nutrition owing to their multifaceted health beneficial effects. Studies have also shown that probiotic supplementation is useful in mitigating age-associated oxi-inflammatory stress, immunosenescence, and gut dysbiosis thereby promoting health and longevity. However, our current understanding of the process of aging suggests a strong interrelationship between the accumulation of senescent cells and the development of aging phenotype, including the predisposition to age-related disorders. The present review studies the documented pro-longevity effects of probiotics and highlights how these beneficial attributes of probiotics could be related to the mitigation of cellular senescence. We present a perspective that to fully understand and comprehend the anti-aging characteristics of probiotic bacteria; it is imperative that probiotics or their synbiotic amalgamation with plant polyphenols, be studied under the purview of cellular senescence, that may ultimately help devise probiotic-based anti-senescence strategies.

Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance

It is well-established that the nutritional deficiency or inadequacy can impair immune functions. Growing evidence suggests that for certain nutrients increased intake above currently recommended levels may help optimize immune functions including improving defense function and thus resistance to infection, while maintaining tolerance. This review will examine the data representing the research on prominent intervention agents n-3 polyunsaturated fatty acids (PUFA), micronutrients (zinc, vitamins D and E), and functional foods including probiotics and tea components for their immunological effects, working mechanisms, and clinical relevance. Many of these nutritive and non-nutritive food components are related in their functions to maintain or improve immune function including inhibition of pro-inflammatory mediators, promotion of anti-inflammatory functions, modulation of cell-mediated immunity, alteration of antigen-presenting cell functions, and communication between the innate and adaptive immune systems. Both animal and human studies present promising findings suggesting a clinical benefit of vitamin D, n-3 PUFA, and green tea catechin EGCG in autoimmune and inflammatory disorders, and vitamin D, vitamin E, zinc, and probiotics in reduction of infection. However, many studies report divergent and discrepant results/conclusions due to various factors. Chief among them, and thus call for attention, includes more standardized trial designs, better characterized populations, greater consideration for the intervention doses used, and more meaningful outcome measurements chosen.

The positive benefit of Lactobacillus paracasei NCC2461 ST11 in healthy volunteers with moderate to severe dandruff

Dandruff is a common persistent, relapsing inflammatory condition affecting the scalp. An imbalanced proportion of the major bacterial and fungal populations colonising the scalp, a skin barrier dysfunction, and hyperseborrhoea are three main etiological factors of dandruff. The efficacy of Lactobacillus paracasei NCC 2461 ST11 (ST11) to manage dandruff and to restore a balanced scalp microbiome was assessed. Sixty healthy male volunteers aged 18 to 60 years with moderate to severe dandruff consumed on a daily basis a sachet containing ST11 (1×109 cfu) or a placebo for 56 days. Clinical efficacy (free and adherent dandruff, erythema, scalp seborrhoea, global clinical score), subject self-assessments, safety reporting as well as scalp microbiota assessments were performed every two weeks (day 1, 15, 29, 43, 57 and 64/follow-up). Free and adherent dandruff, erythema and the global clinical score improved significantly (all P<0.05) over time in the ST11 group and as compared to the placebo when day 57 was compared to day 1. Self-assessments paralleled these findings. ST11 enhanced restoring the scalp microbiota after 56 days of supplementation when compared to the placebo. No adverse events were reported. Regular intake of ST11 over 56 days is safe and reduces significantly the severity of signs and symptoms of moderate to severe dandruff. Its efficacy is potentially due to its positive impact on the skin barrier and skin immune system.

Probiotic Bacteria for Healthier Aging: Immunomodulation and Metabolism of Phytoestrogens

Age-related degeneration gives rise to a number of pathologies, many of them associated with imbalances of the microbiota and the gut-associated immune system. Thus, the intestine is considered a key target organ to improve the quality of life in senescence. Gut microbiota can have a powerful impact in the deterioration linked to aging by its nutritional and immunomodulatory activity. Reduced numbers of beneficial species and low microbial biodiversity in the elderly have been linked with pathogenesis of many diseases. A healthy lifestyle with an elderly customized diet including probiotics can contribute to reducing the chronic proinflammatory status and other age-related pathologies. Beneficial effects of probiotic lactic acid bacteria and bifidobacteria to alleviate some of these disorders based on their immunomodulatory properties as well as their capacity to produce bioactive metabolites from dietary phytoestrogens are summarized. On one hand, the preservation of gut barrier integrity and an increased ability to fight infections are the main reported immune benefits of probiotics. On the other hand, the intake of a diet rich in phytoestrogens along with the presence of selected probiotic bacteria may lead to the production of equol, enterolignans, and urolithins, which are considered protective against chronic diseases related to aging.

Supplementation with Lactobacillus plantarum WCFS1 Prevents Decline of Mucus Barrier in Colon of Accelerated Aging Ercc1-/Δ7 Mice

Although it is clear that probiotics improve intestinal barrier function, little is known about the effects of probiotics on the aging intestine. We investigated effects of 10-week bacterial supplementation of Lactobacillus plantarum WCFS1, Lactobacillus casei BL23, or Bifidobacterium breve DSM20213 on gut barrier and immunity in 16-week-old accelerated aging Ercc1^−/Δ7 mice, which have a median lifespan of ~20 weeks, and their wild-type littermates. The colonic barrier in Ercc1^−/Δ7 mice was characterized by a thin (< 10 μm) mucus layer. L. plantarum prevented this decline in mucus integrity in Ercc1^−/Δ7 mice, whereas B. breve exacerbated it. Bacterial supplementations affected the expression of immune-related genes, including Toll-like receptor 4. Regulatory T cell frequencies were increased in the mesenteric lymph nodes of L. plantarum- and L. casei-treated Ercc1^−/Δ7 mice. L. plantarum- and L. casei-treated Ercc1^−/Δ7 mice showed increased specific antibody production in a T cell-dependent immune response in vivo. By contrast, the effects of bacterial supplementation on wild-type control mice were negligible. Thus, supplementation with L. plantarum – but not with L. casei and B. breve – prevented the decline in the mucus barrier in Ercc1^−/Δ7 mice. Our data indicate that age is an important factor influencing beneficial or detrimental effects of candidate probiotics. These findings also highlight the need for caution in translating beneficial effects of probiotics observed in young animals or humans to the elderly.

Immune modulation property of Lactobacillus paracasei NCC2461 (ST11) strain and impact on skin defences

The gut intestinal tract harbours a complex microbiota. Disturbances in the microbiota composition have been associated with several immune dysfunctions such as inflammatory diseases. Specific strains of probiotics have shown to beneficially influence the composition and/or metabolic activity of the endogenous microbiota. Taking advantage of the plasticity of the immune system, the probiotic strain NCC2461 (i.e. ST11 or CNCM I-2116) supports and/or restores homeostasis in reaction to different physiopathological conditions. The potential of NCC2461 to modulate both mucosal and systemic immune functions led us to test its impact on skin physiology. Even though clear mechanisms explaining gut-skin interaction are still lacking, a set of experimental and clinical data reviewed herein have shown that NCC2461 exerts its effects beyond the gut and confers benefits at the skin level. It contributes to the reinforcement of skin barrier function, decreases skin sensitivity and modulates the skin immune system leading to the preservation of skin homeostasis.

Effect of a Growing-up Milk Containing Synbiotics on Immune Function and Growth in Children: A Cluster Randomized, Multicenter, Double-blind, Placebo Controlled Study

Common infectious diseases, such as diarrhea, are still the major cause of death in children under 5-years-old, particularly in developing countries. It is known that there is a close relationship between nutrition and immune function. To evaluate the effect of a growing-up milk containing synbiotics on immune function and child growth, we conducted a cluster randomized, multicenter, double-blind, placebo controlled clinical trial in children between 18 and 36 months of age in Vietnam. Eligible children from eight and seven kindergartens were randomly assigned to receive test and isocaloric/ isoproteic control milk, respectively, for 5 months. We found that the blood immunoglobulin A (IgA) level and growth parameters were increased in the test group. Compared to the control group, there was also a trend of decreased vitamin A deficiency and fewer adverse events in the test group. These data suggest that a growing-up milk containing synbiotics may be useful in supporting immune function and promoting growth in children.

Intragastric and Intranasal Administration of Lactobacillus paracasei NCC2461 Modulates Allergic Airway Inflammation in Mice

Introduction. Preclinical and clinical evidences for a role of oral probiotics in the management of allergic diseases are emerging. Aim. We aimed at testing the immunomodulatory effects of intranasal versus intragastric administration of Lactobacillus paracasei NCC2461 in a mouse model of allergic airway inflammation and the specificity of different probiotics by comparing L. paracasei NCC2461 to Lactobacillus plantarum NCC1107. Methods. L. paracasei NCC2461 or L. plantarum NCC1107 strains were administered either intragastrically (NCC2461) or intranasally (NCC2461 or NCC1107) to OVA-sensitized mice challenged with OVA aerosols. Inflammatory cell recruitment into BALF, eotaxin and IL-5 production in the lungs were measured. Results. Intranasal L. paracasei NCC2461 efficiently protected sensitized mice upon exposure to OVA aerosols in a dose-dependent manner as compared to control mice. Inflammatory cell number, eotaxin and IL-5 were significantly reduced in BALF. Intranasal supplementation of L. paracasei NCC2461 was more potent than intragastric application in limiting the allergic response and possibly linked to an increase in T regulatory cells in the lungs. Finally, intranasal L. plantarum NCC1107 reduced total and eosinophilic lung inflammation, but increased neutrophilia and macrophages infiltration. Conclusion. A concerted selection of intervention schedule, doses, and administration routes (intranasal versus intragastric) may markedly contribute to modulate airway inflammation in a probiotic strain-specific manner.

Literature-related discovery: Potential treatments and preventatives for SARS

Literature-related discovery (LRD) is the linking of two or more previously disjoint concepts in order to produce novel, interesting, plausible, and intelligible connections (i.e., potential discovery). LRD has been used to identify potential treatments or preventative actions for challenging medical problems, among myriad other applications. Severe acute respiratory syndrome (SARS) was the first pandemic of the 21st century. SARS was eventually controlled through increased hygienic measures (e.g., face mask protection, frequent hand washing, living quarter disinfection), travel restrictions, and quarantine. According to recent reviews of SARS, none of the drugs that were used during the pandemic worked. For the present paper, SARS was selected as the first application of LRD to an infectious disease. The main goal of this research was to identify non-drug non-surgical treatments that would 1) prevent the occurrence, or 2) reduce the progression rate, or 3) stop/reverse the progression of SARS. The MeSH taxonomy of Medline was used to restrict potential discoveries to selected semantic classes, and to identify potential discoveries efficiently. To enhance the volume of potential discovery, databases were used in addition to Medline. These included the Science Citation Index (SCI) and, in contrast to previous work, a full text database. Because of the richness of the full text, 'surgical' queries were developed that targeted the exact types of potential discovery of interest while eliminating clutter more efficiently.

Development of the human gastrointestinal microbiota and insights from high-throughput sequencing

Little was known about the development of the gastrointestinal (GI) tract microbiota, until recently, because of difficulties in obtaining sufficient sequence information from enough people or time points. Now, with decreased costs of DNA sequencing and improved bioinformatic tools, we can compare GI tract bacterial communities among individuals, of all ages from infancy to adulthood. Some key recent findings are that the initial bacterial community, even in the GI tract, depends strongly on delivery mode; that the process of early development of the microbiota is highly unstable and idiosyncratic; that the microbiota differs considerably among children from different countries; and that older adults have substantially different GI tract communities than younger adults, indicating that the GI tract microbiota can change throughout life. We relate these observations to different models of evolution including the evolution of senescence and suggest that probiotics be selected based on patient age. Studies of the microbiota in older people might tell us which probiotics could increase longevity. Drug metabolism varies among individuals with different microbial communities, so age- and region-specific clinical trials are required to ensure safety and efficacy.

Intake of a milk-based wolfberry formulation enhances the immune response of young-adult and aged mice

Aging is associated with alterations of immune responses. Wolfberry, a popular Chinese functional ingredient, is prized for its anti-aging properties; however, little is known about the immunological effect of wolfberry intake. The purpose of this study was to examine the effect of dietary intake of a milk-based formulation of wolfberry, named Lacto-Wolfberry, on in vivo and ex vivo parameters of adaptive immunity in young-adult and aged mice. Over 44 days, young-adult (2 months) and aged (21 months) C57BL/6J mice were fed ad libitum with a controlled diet and received drinking water supplemented or not with 0.5% (wt/vol) Lacto-Wolfberry. All mice were immunized on day 15 and challenged on day 22 with a T cell- dependent antigen, keyhole limpet hemocyanin (KLH). Lacto-Wolfberry supplementation significantly increased in vivo systemic immune markers that are known to decline with aging. Indeed, both antigen-(KLH) specific humoral response and cell-mediated immune responses in young-adult and aged mice were enhanced when compared to their respective controls. No significant effect of Lacto-Wolfberry supplementation was observed on ex vivo spleen cells proliferative response to mitogens and on splenocyte T cell subsets. In conclusion, dietary intake of Lacto-Wolfberry may favorably modulate the poor responsiveness to antigenic challenge observed with aging.

Oral administration ofLactobacillus acidophilusinduces IL-12 production in spleen cell culture of BALB/c mice bearing transplanted breast tumour

Lactic acid bacteria can affect the maturation of immune cells and their products not only in the gut but also on the systemic immune organs such as lymph nodes and spleen. In the present work, we studied the effects of oral administration ofLactobacillus acidophiluson the immune responses of BALB/c mice bearing transplanted breast tumour. Two groups of female inbred BALB/c mice, each containing nine mice as test and control, were used. TheL. acidophilusATCC4356 strain was inoculated in DeMan–Rogosa–Sharpe broth and cultivated for 24 h at 37°C. Then, it was collected by centrifugation, and was washed and suspended in PBS. Afterwards, 0·5 ml/d of this suspension, which contained 2·7 × 108 colony forming units/ml of bacteria, was orally administered to the mice by gavage, 14 d before tumour transplantation and 30 d after that with 3-d intervals. Similar to the test mice, the control mice received an equal volume of PBS. The results showed that oral administration ofL. acidophilusincreased the production of IL-12 (P < 0·05) and decreased the level of transforming growth factor β (P = 0·05) in the splenocyte culture. Moreover, the growth rate of tumour in the test mice decreased (P < 0·01), and the results of delayed-type hypersensitivity assay after 48 h were risen (P < 0·05) in comparison with the controls. Results suggest that daily consumption ofL. acidophiluscan improve the production of immunomodulatory cytokine IL-12 in the splenocyte culture, which was stimulated by tumour antigen in BALB/c mice bearing transplanted breast tumour. But further studies are needed to find out some other possible mechanisms of this effect.

The role of the immune system in regulating the microbiota

A diverse population of bacteria, archaea and fungi, collectively known as the microbiota, abounds within the gastrointestinal tract of the mammalian host. This microbial population makes many important contributions to host physiology through inter-kingdom signalling and by providing nutrients that have both local and systemic effects. In a healthy state the overall host-microbial interaction is symbiotic; however, a growing number of diseases have been associated with a dysregulated microbiota. To avoid these consequences, the host exerts substantial effort to maintain proper regulation of the microbiota with respect to localization and composition. Although important to maintaining microbial balance, the host immune response can also be the cause of a disrupted microbiota, contributing to disease severity. Here, we discuss the role of the host in both maintaining and disrupting a balanced gastrointestinal microbiota.