Feeding probiotic Lactobacillus rhamnosus (MTCC 5897) fermented milk to suckling mothers alleviates ovalbumin-induced allergic sensitisation in mice offspring

Role of gut microbiota in infectious and inflammatory diseases

Thousands of microorganisms compose the human gut microbiota, fighting pathogens in infectious diseases and inhibiting or inducing inflammation in different immunological contexts. The gut microbiome is a dynamic and complex ecosystem that helps in the proliferation, growth, and differentiation of epithelial and immune cells to maintain intestinal homeostasis. Disorders that cause alteration of this microbiota lead to an imbalance in the host’s immune regulation. Growing evidence supports that the gut microbial community is associated with the development and progression of different infectious and inflammatory diseases. Therefore, understanding the interaction between intestinal microbiota and the modulation of the host’s immune system is fundamental to understanding the mechanisms involved in different pathologies, as well as for the search of new treatments. Here we review the main gut bacteria capable of impacting the immune response in different pathologies and we discuss the mechanisms by which this interaction between the immune system and the microbiota can alter disease outcomes.

Short-Term Intake of Theobroma grandiflorum Juice Fermented with Lacticaseibacillus rhamnosus ATCC 9595 Amended the Outcome of Endotoxemia Induced by Lipopolysaccharide

Endotoxemia is a condition caused by increasing levels of lipopolysaccharide (LPS) characterized by an impaired systemic response that causes multiple organ dysfunction. Lacticaseibacillus rhamnosus ATCC 9595 is a strain with probiotic potential which shows immunomodulatory properties. The incorporation of this bacterium in food rich in bioactive compounds, such as cupuaçu juice (Theobroma grandiflorum), could result in a product with interesting health properties. This work evaluated the effects of the oral administration of cupuaçu juice fermented with L. rhamnosus on the outcome of LPS-induced endotoxemia in mice. C57BL/6 mice (12/group) received oral doses (100 µL) of saline solution and unfermented or fermented cupuaçu juice (10⁸ CFU/mL). After 5 days, the endotoxemia was induced by an intraperitoneal injection of LPS (10 mg/kg). The endotoxemia severity was evaluated daily using a score based on grooming behavior, mobility, presence of piloerection, and weeping eyes. After 6 h and 120 h, the mice (6/group) were euthanized for analysis of cell counts (in peritoneal lavage and serum) and organ weight. L. rhamnosus grew in cupuaçu juice and produced organic acids without the need for supplementation. The bacteria counts were stable in the juice during storage at 4 °C for 28 days. The fermentation with L. rhamnosus ATCC 9595 changed the metabolites profile of cupuaçu juice due to the biotransformation and enhancement of some compounds. In general, the administration of L. rhamnosus-fermented juice allowed a significant improvement in several characteristics of endotoxemic status (weight loss, hypothermia, severity index, cell migration). In addition, treatment with fermented juice significantly reduced the weight of the spleen, liver, intestine, and kidneys compared to the saline-treated endotoxemic group. Taken together, our data show that short-term intake therapy of cupuaçu juice fermented with L. rhamnosus ATCC 9595 can reduce systemic inflammation in an experimental model of LPS-induced endotoxemia in mice.

Dairy-Based Probiotic-Fermented Functional Foods: An Update on Their Health-Promoting Properties

Numerous studies have shown a link between the consumption of fermented dairy foods and improved health outcomes. Since the early 2000s, especially probiotic-based fermented functional foods, have had a revival in popularity, mostly as a consequence of claims made about their health benefits. Among them, fermented dairy foods have been associated with obesity prevention and in other conditions such as chronic diarrhea, hypersensitivity, irritable bowel syndrome, Helicobacter pylori infection, lactose intolerance, and gastroenteritis which all are intimately linked with an unhealthy way of life. A malfunctioning inflammatory response may affect the intestinal epithelial barrier’s ability to function by interfering with the normal metabolic processes. In this regard, several studies have shown that fermented dairy probiotics products improve human health by stimulating the growth of good bacteria in the gut at the same time increasing the production of metabolic byproducts. The fermented functional food matrix around probiotic bacteria plays an important role in the survival of these strains by buffering and protecting them from intestinal conditions such as low pH, bile acids, and other harsh conditions. On average, cultured dairy products included higher concentrations of lactic acid bacteria, with some products having as much as 109/mL or g. The focus of this review is on fermented dairy foods and associated probiotic products and their mechanisms of action, including their impact on microbiota and regulation of the immune system. First, we discussed whey and whey-based fermented products, as well as the organisms associated with them. Followed by the role of probiotics, fermented-product-mediated modulation of dendritic cells, natural killer cells, neutrophils, cytokines, immunoglobulins, and reinforcement of gut barrier functions through tight junction. In turn, providing the ample evidence that supports their benefits for gastrointestinal health and related disorders.

Probiotics and gut microbiota: mechanistic insights into gut immune homeostasis through TLR pathway regulation

Consumption of probiotics as a useful functional food improves the host's wellbeing, and, when paired with prebiotics (indigestible dietary fibre/carbohydrate), often benefits the host through anaerobic fermentation.

Potential probiotic Lacticaseibacillus rhamnosus MTCC-5897 attenuates Escherichia coli induced inflammatory response in intestinal cells

Probiotics are microbes having tremendous potential to prevent gastrointestinal disorders. In current investigation, immunomodulatory action of probiotic Lacticaseibacillus rhamnosus MTCC-5897 was studied during exclusion, competition and displacement of Escherichia coli on intestinal epithelial (Caco-2) cells. The incubation of intestinal cells with Escherichia coli, enhanced downstream signalling and activated nuclear factor kappa B (NF-κB). This significantly increased (p < 0.01) the pro-inflammatory cytokines (IL-8, TNF-α, IFN-ϒ) expression. While, incubation of epithelial cells with Lacticaseibacillus rhamnosus during exclusion and competition with Escherichia coli, counteracted these enhanced expressions. The immunomodulatory feature of Lacticaseibacillus rhamnosus was also highlighted with increased (p < 0.05) transcription of toll-like receptor-2 (TLR-2) and single Ig IL-1-related receptor (SIGIRR) along with diminished expression of TLR-4. Likewise, attenuation (p < 0.05) of E. coli-mediated enhanced nuclear translocation of NF-κB p-65 subunit by Lacticaseibacillus rhamnosus during exclusion was confirmed with western blotting. Thus, present finding establishes the prophylactic potential of Lacticaseibacillus rhamnosus against exclusion of Escherichia coli in intestinal cells.

Potential Probiotic Lactobacillus rhamnosus (MTCC-5897) Inhibits Escherichia coli Impaired Intestinal Barrier Function by Modulating the Host Tight Junction Gene Response

Probiotic as a preventive medicine is emerging as an indispensable tool in addressing the foodborne infections or gastrointestinal disorders. The present study was sought to determine the in vitro prophylactic potential of probiotic Lactobacillus rhamnosus (LR: MTCC-5897) against Escherichia coli (ATCC 14948) induced impairment in intestinal barrier function using Caco-2 cells. Intestinal cells exposed to E. coli demonstrated significantly higher phenol red flux (p < 0.05) and concomitantly decreased TEER (0.69 ± 0.01) in contrast to control or L. rhamnosus (10⁹ cfu/mL)-treated cells. However, E. coli-induced barrier hyperpermeability was restored to significant extents (p < 0.01) when E. coli were excluded, competed or displaced by probiotic LR. Similarly, exposure of Caco-2 cells to E. coli reduced the mRNA expression of key tight junction genes, viz. Zo-1, Claudin-1, Occludin and Cingulin which however were restored significantly (p < 0.05) with L. rhamnosus treatment during exclusion or competition than displacement assays. The protective behaviour of probiotic LR against E. coli can also be observed in immunofluorescent and electron micrograph where intact cellular morphology along with preserved distribution and localisation of key integrity proteins can be found in LR-treated cells in contrast to distorted and disorganised distribution observed with E. coli exposure. In conclusion, L. rhamnosus inhibited and re-established E. coli-impaired intestinal barrier function by improving the expression and distribution of key junction protein and hence could serve an essential food additive to address the various health complications especially those associated with gastrointestinal tract.

Protective effects of potential probiotic Lactobacillus rhamnosus (MTCC-5897) fermented whey on reinforcement of intestinal epithelial barrier function in a colitis-induced murine model

Fermented foods provide essential nutritional components and bioactive molecules that have beneficial effects on several gastrointestinal disorders. In the present investigation, the potential protective effects of whey fermented with probiotic Lactobacillus rhamnosus MTCC-5897 on gastrointestinal health in a murine ulcerative colitis model induced by dextran sulfate sodium (DSS) were evaluated. Pre-consumption of whey fermented with probiotic L. rhamnosus (PFW) before colitis induction significantly reduced (p < 0.01) the disease activity index and improved (p < 0.05) the hematological parameters and histological scores. The considerably diminished levels (p < 0.01) of pro-inflammatory markers (IL-4, TNF-α, CRP and MPO activity) and the enhanced (p < 0.05) levels of the anti-inflammatory cytokine TGF-β with IgA in the intestine upon feeding PFW appeared to prevent inflammation on colitis induction. Transcriptional modulations in pathogen recognition receptors (TLR-2/4) and tight junctional genes (ZO-1, occludin, claudin-1) along with localized distribution of junctional (claudin-1, occludin and ZO-1) and cytoskeleton (actin) proteins improved immune homeostasis and intestinal barrier integrity. Besides, significantly reduced (p < 0.05) levels of the FITC-dextran marker in serum upon consumption of PFW directly confirmed the healthy status of the host gut.

Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation

In order to inhibit pathogenic complications and to enhance animal and poultry growth, antibiotics have been extensively used for many years. Antibiotics applications not only affect target pathogens but also intestinal beneficially microbes, inducing long-lasting changes in intestinal microbiota associated with diseases. The application of antibiotics also has many other side effects like, intestinal barrier dysfunction, antibiotics residues in foodstuffs, nephropathy, allergy, bone marrow toxicity, mutagenicity, reproductive disorders, hepatotoxicity carcinogenicity, and antibiotic-resistant bacteria, which greatly compromise the efficacy of antibiotics. Thus, the development of new antibiotics is necessary, while the search for antibiotic alternatives continues. Probiotics are considered the ideal antibiotic substitute; in recent years, probiotic research concerning their application during pathogenic infections in humans, aquaculture, poultry, and livestock industry, with emphasis on modulating the immune system of the host, has been attracting considerable interest. Hence, the adverse effects of antibiotics and remedial effects of probiotics during infectious diseases have become central points of focus among researchers. Probiotics are live microorganisms, and when given in adequate quantities, confer good health effects to the host through different mechanisms. Among them, the regulation of host immune response during pathogenic infections is one of the most important mechanisms. A number of studies have investigated different aspects of probiotics. In this review, we mainly summarize recent discoveries and discuss two important aspects: (1) the application of probiotics during pathogenic infections; and (2) their modulatory effects on the immune response of the host during infectious and non-infectious diseases.

Intestinal Immunomodulation and Shifts on the Gut Microbiota of BALB/c Mice Promoted by Two Bifidobacterium and Lactobacillus Strains Isolated from Human Samples

Bifidobacterium animalis subsp. lactis IPLA 20020 and Lactobacillus gasseri IPLA 20212, two strains isolated from human samples, were evaluated for safety and influence over the intestinal microbiota and cytokine production by the intestinal tissue of adult BALB/c mice. Mice were divided into four groups receiving during 8 days PBS or a suspension of each strain, prepared fresh or lyophilized (bifidobacteria), at an amount of 4x10⁸ viable cells/day. This dose could be comparable to the probiotic intake of a human adult who consumed about 100-200 mL of functional fermented milk per day, considering the usual level of probiotics in commercial products. No microbial translocation to liver or alterations in food intake, weight, and behavior were observed in treated mice. Intestinal content of secretory immunoglobulin A (s-IgA) was not affected, discarding any adverse effect on the mucosa-associated immunity. The profile of intestinal proinflammatory/regulatory cytokines after intervention evidenced that the microbial strain administered and its cellular state (fresh or lyophilized) as well as the host tissue analyzed (small or large intestine) influenced the immune response and suggests a moderate shift towards a T helper 1 profile (Th1) in the large intestine after the administration of both strains. Changes on relative levels of some intestinal microbial groups were evidenced after intervention. It is noteworthy that butyrate was positively associated with a balanced pro-Th1 immune response. Therefore, B. animalis subsp. lactis IPLA20020 and L. gasseri IPLA 20212 could be considered potential probiotic candidates to be included in functional foods for balancing the intestinal immune response.

Cutting Edge: Probiotics and Fecal Microbiota Transplantation in Immunomodulation

Probiotics are commensal or nonpathogenic microbes that confer beneficial effects on the host through several mechanisms such as competitive exclusion, antibacterial effects, and modulation of immune responses. Some probiotics have been found to regulate immune responses via immune regulatory mechanisms. T regulatory (Treg) cells, T helper cell balances, dendritic cells, macrophages, B cells, and natural killer (NK) cells can be considered as the most determinant dysregulated mediators in immunomodulatory status. Recently, fecal microbiota transplantation (FMT) has been defined as the transfer of distal gut microbial communities from a healthy individual to a patient's intestinal tract to cure some immune disorders (mainly inflammatory bowel diseases). The aim of this review was followed through the recent literature survey on immunomodulatory effects and mechanisms of probiotics and FMT and also efficacy and safety of probiotics and FMT in clinical trials and applications.

TLR Activation and Allergic Disease: Early Life Microbiome and Treatment

PURPOSE OF REVIEW

Allergy and asthma are growing problems in the developed world. The accelerated increase of these diseases may be related to microbiome modification that leads to aberrant activation of Toll-like receptors (TLRs). Current research supports the concept that changes in microbial communities in early life impact TLR activation, resulting in an altered risk for the development of asthma and allergies.

RECENT FINDINGS

Prenatal and early childhood events that generate microbiome modification are closely related with TLR activation. Early childhood exposure to a rich array of TLR agonists, particularly lipopolysaccharide, strongly predicts protection against allergic disease later in life even when other lifestyle factors are accounted for. Genetic deletion of TLR signaling components in mice results in reduced function of tolerogenic cell populations in the gut. In contrast, weak TLR signaling can promote allergic sensitization later in life. This review summarizes the role of TLR signaling in microbiome-mediated protection against allergy.

Intestinal dysbacteriosis potentiates ovalbumin-induced allergic airway inflammation by inhibiting microRNA-130a to upregulate tumor necrosis factor α

Allergic airway diseases (AAD), including chronic disorders such as allergic rhinitis, are resulted from complicated immunological interactions. Intestinal dysbacteriosis (ID) has been implicated in immune response to respiratory infections. We aimed to investigate the effect of ID on a mouse model of AAD, and the potential molecular factors involved. Ovalbumin (OVA) was employed to sensitize and challenge mice to elicit allergic inflammation in the upper as well as the lower airways. OVA-induced AAD model mice and control mice were raised with or without antibiotics treatment to establish the combinational AAD + ID mouse model. Characteristic symptoms of AAD were evaluated in regard to allergic symptoms, serum OVA specific IgE level, as well as inflammation cells, cytokines and microRNA expression profile in nasal lavage fluid (NALF) and bronchoalveolar lavage fluid (BALF). In AAD mice, ID caused increased nasal rubbing, sneezing, serum OVA specific IgE level and pro-inflammatory cytokine tumor necrosis factor α (TNF-α) in NALF and BALF. ID also inhibited microRNA-130a of AAD mice. Further molecular experiments indicated that microRNA-130a could specifically target and repress TNF-α. ID increases the susceptibility to AAD and allergic inflammatory response, possibly by inhibiting microRNA-130a to upregulate TNF-α.

Flavanol-Rich Cocoa Powder Interacts with Lactobacillus rhamnossus LGG to Alter the Antibody Response to Infection with the Parasitic Nematode Ascaris suum

Consumption of the probiotic bacteria LactobacillusrhamnosusLGG and flavanol-rich cocoa have purported immune modulating effects. This study compared the host response to infection with Ascaris suum in three-month-old pigs fed a standard growth diet supplemented with a vehicle control: LGG, cocoa powder (CP) or LGG + CP. Pigs were inoculated with infective A. suum eggs during Week 5 of dietary treatment and euthanized 17 days later. Lactobacillus abundance was increased in pigs fed LGG or LGG + CP. Specific anti-A. suum IgG2 antibodies were decreased (p < 0.05) in LGG + CP-fed pigs compared to pigs fed CP alone. Pigs fed LGG had significantly reduced expression (p < 0.05) of Eosinophil peroxidase (EPX), Interleukin 13 (IL-13), Eotaxin 3 (CCL26), Toll-like receptor 2 (TLR2), TLR4, and TLR9 and Interleukin-1Beta (IL1B) in the tracheal-bronchial lymph node (TBLN) independent of CP treatment. These results suggested that feeding LGG significantly reduced the localized prototypical Th2-related markers of infection with A. suum in the TBLN. Although feeding CP does not appear to affect the A. suum-induced Th2-associated cytokine response, feeding LGG + CP reduced anti-A. suum antibodies and delayed intestinal expulsion of parasitic larvae from the intestine.

The regulation of immune cells by Lactobacilli: a potential therapeutic target for anti-atherosclerosis therapy

Atherosclerosis is an inflammatory disease regulated by several immune cells including lymphocytes, macrophages and dendritic cells. Gut probiotic bacteria like Lactobacilli have been shown immunomodificatory effects in the progression of atherogenesis. Some Lactobacillus stains can upregulate the activity of regulatory T-lymphocytes, suppress T-lymphocyte helper (Th) cells Th1, Th17, alter the Th1/Th2 ratio, influence the subsets ratio of M1/M2 macrophages, inhibit foam cell formation by suppressing macrophage phagocytosis of oxidized low-density lipoprotein, block the activation of the immune system with dendritic cells, which are expected to suppress the atherosclerosis-related inflammation. However, various strains can have various effects on inflammation. Some other Lactobacillus strains were found have potential pro-atherogenic effect through promote Th1 cell activity, increase pro-inflammatory cytokines levels as well as decrease anti-inflammatory cytokines levels. Thus, identifying the appropriate strains is essential to the therapeutic potential of Lactobacilli as an anti-atherosclerotic therapy.

Dietary Fiber Intake Regulates Intestinal Microflora and Inhibits Ovalbumin-Induced Allergic Airway Inflammation in a Mouse Model

Background

Recently, academic studies suggest that global growth of airway allergic disease has a close association with dietary changes including reduced consumption of fiber. Therefore, appropriate dietary fiber supplementation might be potential to prevent airway allergic disease (AAD).

Objective

We investigated whether dietary fiber intake suppressed the induction of AAD and tried to elucidate the possible underlying mechanisms.

Methods

The control mice and AAD model mice fed with 4% standard-fiber chow, while low-fiber group of mice fed with a 1.75% low-fiber chow. The two fiber-intervened groups including mice, apart from a standard-fiber diet, were also intragastric (i.g.) administrated daily with poorly fermentable cellulose or readily fermentable pectin (0.4% of daily body weight), respectively. All animals except normal mice were sensitized and challenged with ovalbumin (OVA) to induce airway allergic inflammation. Hallmarks of AAD were examined by histological analysis and ELISA. The variation in intestinal bacterial composition was assessed by qualitative analysis of 16S ribosomal DNA (rDNA) content in fecal samples using real-time PCR.

Results

Low-fiber diet aggravated inflammatory response in ovalbumin-induced allergic mice, whereas dietary fiber intake significantly suppressed the allergic responses, attenuated allergic symptoms of nasal rubbing and sneezing, decreased the pathology of eosinophil infiltration and goblet cell metaplasia in the nasal mucosa and lung, inhibited serum OVA-specific IgE levels, and lowered the levels of Th2 cytokines in NALF and BALF, but, increased Th1 (IFN-γ) cytokines. Additionally, dietary fiber intake also increased the proportion of Bacteroidetes and Actinobacteria, and decreased Firmicutes and Proteobacteria. Levels of probiotic bacteria, such as Lactobacillus and Bifidobacterium, were upgraded significantly.

Conclusion

Long-term deficiency of dietary fiber intake increases the susceptibility to AAD, whereas proper fiber supplementation promotes effectively the balance of Th1/Th2 immunity and then attenuates allergic inflammatory responses significantly, as well as optimizes the structure of intestinal microbiota, which suggests potential for novel preventive and therapeutic intervention.