Novel Insights into the Role of Probiotics in Respiratory Infections, Allergies, Cancer, and Neurological Abnormalities

The Probiotic Strain Lactobacillus acidophilus CL1285 Reduces Fat Deposition and Oxidative Stress and Increases Lifespan in Caenorhabditis elegans

Caenorhabditis elegans was recently shown to be a powerful model for studying and identifying probiotics with specific functions. Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2, which are three bacteria that were marketed by Bio-K+, were evaluated using the nematode C. elegans to study fat accumulation, lifespan, and resistance to oxidative stress. Although the general effects of probiotics in terms of protection against oxidative stress were highlighted, the CL1285 strain had an interesting and specific feature, namely its ability to prevent fat accumulation in nematodes; this effect was verified by both the Oil Red and Nile Red methods. This observed phenotype requires daf-16 and is affected by glucose levels. In addition, in a daf-16- and glucose-dependent manner, CL1285 extended the lifespan of C. elegans; this effect was unique to CL1285 and not found in the other L. acidophilus subtypes in this study. Our findings indicate that L. acidophilus CL1285 impacts fat/glucose metabolism in C. elegans and provides a basis to further study this probiotic, which could have potential health benefits in humans and/or in mammals.

The respiratory microbiota and its impact on health and disease in dogs and cats: A One Health perspective

Healthy lungs were long thought of as sterile, with presence of bacteria identified by culture representing contamination. Recent advances in metagenomics have refuted this belief by detecting rich, diverse, and complex microbial communities in the healthy lower airways of many species, albeit at low concentrations. Although research has only begun to investigate causality and potential mechanisms, alterations in these microbial communities (known as dysbiosis) have been described in association with inflammatory, infectious, and neoplastic respiratory diseases in humans. Similar studies in dogs and cats are scarce. The microbial communities in the respiratory tract are linked to distant microbial communities such as in the gut (ie, the gut-lung axis), allowing interplay of microbes and microbial products in health and disease. This review summarizes considerations for studying local microbial communities, key features of the respiratory microbiota and its role in the gut-lung axis, current understanding of the healthy respiratory microbiota, and examples of dysbiosis in selected respiratory diseases of dogs and cats.

The effect of synbiotic adjunct therapy on clinical and paraclinical outcomes in hospitalized COVID-19 patients: A randomized placebo-controlled trial

Therapeutic approaches with immune-modulatory effects such as probiotics and prebiotics adjuvant therapy may be essential to combat against COVID-19 pandemic. The present trial aimed to reveal the efficacy of synbiotic supplementation on clinical and paraclinical outcomes of hospitalized COVID-19 patients. The current randomized placebo-controlled trial enrolled 78 hospitalized patients with confirmed COVID-19 infection. Participants were randomly allocated to intervention and control groups that received synbiotic or placebo capsules twice daily for 2 weeks, respectively. The synbiotic capsule contains multi-strain probiotics such as Lactobacillus (L.) rhamnosus, L. helveticus, L. casei, Bifidobacterium (B.) lactis, L. acidophilus, B. breve, L. bulgaricus, B. longum, L. plantarum, B. bifidum, L. gasseri, and Streptococcus (S.) thermophilus (10⁹  CFU), as well as fructooligosaccharides prebiotic agent. Besides COVID-19 clinical features, levels of proinflammatory interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), liver and renal function markers, as well as hematological parameters, were assessed during follow-up. The serum level of IL-6 was significantly decreased in the intervention group compared to the placebo after 2 weeks of intervention (p = 0.002). A significant difference was found regarding the count of white blood cells (WBC) within the synbiotic group from pre to post-treatment (p = 0.004). The levels of ESR (p = 0.935) and CRP (p = 0.952) had a higher reduction trend in the synbiotic group relative to the placebo, with no significant between-group differences. Other findings had no statistical differences between groups. Our results provide the support that synbiotic adjuvant therapy for 2 weeks can be effective to modulate inflammatory responses against COVID-19 infection.

Probiotics Mechanism of Action on Immune Cells and Beneficial Effects on Human Health

Immune cells and commensal microbes in the human intestine constantly communicate with and react to each other in a stable environment in order to maintain healthy immune activities. Immune system-microbiota cross-talk relies on a complex network of pathways that sustain the balance between immune tolerance and immunogenicity. Probiotic bacteria can interact and stimulate intestinal immune cells and commensal microflora to modulate specific immune functions and immune homeostasis. Growing evidence shows that probiotic bacteria present important health-promoting and immunomodulatory properties. Thus, the use of probiotics might represent a promising approach for improving immune system activities. So far, few studies have been reported on the beneficial immune modulatory effect of probiotics. However, many others, which are mainly focused on their metabolic/nutritional properties, have been published. Therefore, the mechanisms behind the interaction between host immune cells and probiotics have only been partially described. The present review aims to collect and summarize the most recent scientific results and the resulting implications of how probiotic bacteria and immune cells interact to improve immune functions. Hence, a description of the currently known immunomodulatory mechanisms of probiotic bacteria in improving the host immune system is provided.

Anti-Helicobacter pylori activity of potential probiotic Lactiplantibacillus pentosus SLC13

BACKGROUND

Here, we aimed to evaluate and compare the anti-Helicobacter pylori activity of potential probiotic Lactiplantibacillus pentosus SLC13 to Lactobacillus gasseri BCRC 14619 T and Lacticaseibacillus rhamnosus LGG. Phenotypic assays including growth curve, cell adhesion, and cellular cytotoxicity were performed to characterize SLC13. Anti-H. pylori activity of lactobacilli was determined by the disk diffusion method and co-culture assay. Exopolysaccharide (EPS) was extracted from lactobacilli to test its immune modulation activity, and IL-8 expression in AGS and GES-1 was determined by RT-qPCR.

RESULTS

All three lactobacilli strains were tolerant to the simulated gastrointestinal conditions. SLC13 showed the highest adhesion ability to AGS and GES-1 cells, compared to LGG and BCRC 14619 T. The coculture assays of SLC13, LGG, and BCRC 14619 T with cells for 4 h showed no significant cytotoxic effects on cells. All tested strains exhibited an inhibitory effect against H. pylori J99. The cell-free supernatant (CFS) of three strains showed activity to inhibit H. pylori urease activity in a dose-dependent manner and the CFS of SLC13 had the highest urease inhibitory activity, compared to LGG and BCRC 14619 T. Only the treatment of AGS cells with SLC13 EPS significantly decreased the IL-8 expression induced by H. pylori infection as compared to cells treated with LGG and BCRC 14619 T EPS.

CONCLUSIONS

SLC13 possesses potent antimicrobial activity against H. pylori growth, infection, and H. pylori-induced inflammation. These results suggest that SLC13 and its derivatives have the potential as alternative agents against H. pylori infection and alleviate inflammatory response.

Probiotics in Allergic Rhinitis Management: Is There a Positioning for Them?

Allergic rhinitis (AR) is a widespread medical condition affecting up to 40% of the general population. Type 2 inflammation determines typical nasal symptoms. In addition, gut and respiratory dysbiosis are present in AR patients. Probiotics have several beneficial effects on immunity, inflammatory pathways, and anti-infective properties. Namely, probiotic supplementation could restore immune response, promote eubiosis, and switch off inflammation. Thus, probiotics have also been investigated in AR. In addition, there is accumulating evidence that some specific strains of probiotics may improve AR. Five meta-analyses on probiotics in AR management were consistently published in the first half of 2022. The conclusions, although not definitive, argue for the possible use of probiotics as part of an add-on strategy in managing patients with allergic rhinitis.

Anti-Campylobacter Probiotics: Latest Mechanistic Insights

The Campylobacter genus is the leading cause of human gastroenteritis, with the consumption of contaminated poultry meat as the main route of infection. Probiotic bacteria, such as Lactobacillus, Bacillus, Escherichia coli Nissle, and Bifidobacterium species, have a great immunomodulatory capacity and exhibit antipathogenic effects through various molecular mechanisms. Reducing Campylobacter levels in livestock animals, such as poultry, will have a substantial benefit to humans as it will reduce disease transmissibility through the food chain. Moreover, probiotic-based strategies might attenuate intestinal inflammatory processes, which consequently reduce the severity of Campylobacter disease progression. At a molecular level, probiotics can also negatively impact on the functionality of various Campylobacter virulence and survival factors (e.g., adhesion, invasion), and on the associated colonization proteins involved in epithelial translocation. The current review describes recent in vitro, in vivo, and preclinical findings on probiotic therapies, aiming to reduce Campylobacter counts in poultry and reduce the pathogen's virulence in the avian and human host. Moreover, we focused in particular on probiotics with known anti-Campylobacter activity seeking to understand the biological mechanisms involved in their mode of action.

Probiotics in Children with Asthma

A type-2 immune response usually sustains wheezing and asthma in children. In addition, dysbiosis of digestive and respiratory tracts is detectable in patients with wheezing and asthma. Probiotics may rebalance immune response, repair dysbiosis, and mitigate airway inflammation. As a result, probiotics may prevent asthma and wheezing relapse. There is evidence that some probiotic strains may improve asthma outcomes in children. In this context, the PROPAM study provided evidence that two specific strains significantly prevented asthma exacerbations and wheezing episodes. Therefore, oral probiotics could be used as add-on asthma therapy in managing children with asthma, but the choice should be based on documented evidence.

A post hoc analysis on the effects of a probiotic mixture on asthma exacerbation frequency in schoolchildren

Asthma is usually characterised by chronic airway inflammation [1]. Furthermore, respiratory infections frequently precede asthma exacerbations in children, mainly in allergic subjects [2–4]. As a result, dampening inflammation and preventing respiratory infections are essential in the therapeutical strategy. It has been underscored by the pathogenic relevance of dysbiosis, as it has been evidenced that the children with asthma present dysbiosis of the gut and lung microbiome [5]. The dysbiosis affects the immune response and, consequently, induces airways inflammation, and airflow limitation [6]. These events constituted the premise of using probiotics to modulate the immune response to restore the microbiota and immune balance [7]. Probiotics are defined as “live microorganisms which confer a beneficial effect on the host”, according to the World Health Organization [8].

The present randomised, placebo-controlled, double-blind study showed that a probiotic mixture significantly reduced the number of asthma exacerbations in schoolchildrenhttps://bit.ly/382LYKV

The Contribution of Gut Microbiota and Endothelial Dysfunction in the Development of Arterial Hypertension in Animal Models and in Humans

The maintenance of the physiological values of blood pressure is closely related to unchangeable factors (genetic predisposition or pathological alterations) but also to modifiable factors (dietary fat and salt, sedentary lifestyle, overweight, inappropriate combinations of drugs, alcohol abuse, smoking and use of psychogenic substances). Hypertension is usually characterized by the presence of a chronic increase in systemic blood pressure above the threshold value and is an important risk factor for cardiovascular disease, including myocardial infarction, stroke, micro- and macro-vascular diseases. Hypertension is closely related to functional changes in the endothelium, such as an altered production of vasoconstrictive and vasodilator substances, which lead to an increase in vascular resistance. These alterations make the endothelial tissue unresponsive to autocrine and paracrine stimuli, initially determining an adaptive response, which over time lead to an increase in risk or disease. The gut microbiota is composed of a highly diverse bacterial population of approximately 10¹⁴ bacteria. A balanced intestinal microbiota preserves the digestive and absorbent functions of the intestine, protecting from pathogens and toxic metabolites in the circulation and reducing the onset of various diseases. The gut microbiota has been shown to produce unique metabolites potentially important in the generation of hypertension and endothelial dysfunction. This review highlights the close connection between hypertension, endothelial dysfunction and gut microbiota.

The Probiotics in Pediatric Asthma Management (PROPAM) Study in the Primary Care Setting: A Randomized, Controlled, Double-Blind Trial with Ligilactobacillus salivarius LS01 (DSM 22775) and Bifidobacterium breve B632 (DSM 24706)

Background

Type-2 inflammation commonly marks asthma in childhood. Also, gut and lung dysbiosis is detectable in patients with asthma. Strain-related probiotic supplementation may restore a physiological immune response, dampen airway inflammation, and repair dysbiosis. Therefore, the probiotics in pediatric asthma management (PROPAM) study is aimed at demonstrating that Ligilactobacillus salivarius LS01 (DSM 22775) and Bifidobacterium breve B632 (DSM 24706) mixture could reduce asthma exacerbations in children, followed in a primary care setting.

Methods

The study was randomized, placebo-controlled, and double-blind. It involved 11 Italian primary care pediatricians. The probiotic mixture (containing Ligilactobacillus salivarius LS01 1 × 10⁹ live cells and Bifidobacterium breve B632 1 × 10⁹ live cells) or placebo was taken twice daily (1 sachet in the morning and 1 in the evening) for eight weeks and subsequently once daily for a further eight weeks. Outcomes included number, severity, and duration of asthma exacerbations, intensity of maintenance and as need treatments, and safety.

Results

The per-protocol population included 422 children (mean age seven years, 240 males and 182 females). The probiotic mixture significantly reduced the number of asthmatic exacerbations (OR = 3.17). In addition, the number of children with two exacerbations was less than a third in the active group (OR = 3.65).

Conclusions

This PROPAM study demonstrated that probiotic strains Ligilactobacillus salivarius LS01 (DSM 22775) and Bifidobacterium breve B632 (DSM 24706) were safe and significantly reduced by more than a third the frequency of asthma exacerbations. At present, the first-line treatment of asthma is still drug-based, but specific strains of probiotics may be auxiliary remedies.