The Probiotic Mixture VSL#3 Alters the Morphology and Secretion Profile of Both Polarized and Unpolarized Human Macrophages in a Polarization-Dependent Manner

M1-like, but not M0- or M2-like, macrophages, reduce RSV infection of primary bronchial epithelial cells in a media-dependent fashion

Respiratory syncytial virus (RSV) is a common childhood infection that in young infants can progress into severe bronchiolitis and pneumonia. Disease pathogenesis results from both viral mediated and host immune processes of which alveolar macrophages play an important part. Here, we investigated the role of different types of alveolar macrophages on RSV infection using an in vitro co-culture model involving primary tissue-derived human bronchial epithelial cells (HBECs) and human blood monocyte-derived M0-like, M1-like, or M2-like macrophages. It was hypothesized that the in vitro model would recapitulate previous in vivo findings of a protective effect of macrophages against RSV infection. It was found that macrophages maintained their phenotype for the 72-hour co-culture time period and the bronchial epithelial cells were unaffected by the macrophage media. HBEC infection with RSV was decreased by M1-like macrophages but enhanced by M0- or M2-like macrophages. The medium used during the co-culture also impacted the outcome of the infection. This work demonstrates that alveolar macrophage phenotypes may have differential roles during epithelial RSV infection, and demonstrates that an in vitro co-culture model could be used to further investigate the roles of macrophages during bronchial viral infection.

Traditional Chinese medicine prescription Shenling BaiZhu powder to treat ulcerative colitis: Clinical evidence and potential mechanisms

Ulcerative colitis (UC), characterized by syndromes including abdominal pain, bloody stool, diarrhea, weight loss, and repeated relapse, is a non-specific inflammatory intestinal disease. In recent years, with the changing dietary habits in China, the incidence of UC has shown an upward trend. UC belongs to the category of recorded as “diarrhea,” “chronic dysentery,” and “hematochezia” in traditional Chinese medicine (TCM), and Shenling BaiZhu powder (SLBZP) is one of the most effective and commonly used prescriptions. In this review, we aim to systematically summarize the clinical application and pharmacological mechanism of SLBZP in the treatment of UC to provide a theoretical basis for its clinical use and experimental evaluation of SLBZP. Our results showed that both SLBZP and SLBZP in combination with chemical drugs, have a significant therapeutic effect against UC with few adverse reactions. Furthermore, combined therapy was better than western medicine. Further, pathophysiological studies indicated that SLBZP has anti-inflammatory, immunomodulatory, antioxidant effects, regulation relative cell signal transduction and regulation of gut microbiota. Although evidence suggests superior therapeutic efficacy of SLBZP for treating UC and the relative mechanism has been studied extensively, various shortcomings limit the existing research on the topic. There is a lack of UC animal models, especially UC with TCM syndromes, with no uniform standard and certain differences between the animal model and clinical syndrome. The dosage, dosage form, and therapeutic time of SLBZP are inconsistent and lack pharmacological verification, and clinical trial data are not detailed or sufficiently rigorous. In addition, SLSZP is composed of multiple Chinese drugs that contain massive numbers of ingredients and which or several components contribute to therapeutic effects. How they work synergistically together remains unknown. Therefore, on the one hand, large sample prospective cohort studies to clarify the clinical efficacy and safety of SLBZP in the treatment of UC are needed. In contrast, researchers should strengthen the study of the molecular biological mechanism of active ingredients and its synergistic actions, clarifying the mechanism of SLBZP in treating UC by multi-component, multi-target, and multi-pathway.

Structure and function of non-digestible carbohydrates in the gut microbiome

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

Current Status of M1 and M2 Macrophages Pathway as Drug Targets for Inflammatory Bowel Disease

Chronic inflammation of the gastrointestinal system is mediated by both the immune system activity and homeostasis, mainly through releasing of various cytokines and chemokines, as well as the transmigration of the inflammatory cells to the affected site. In between, macrophages are key mediators of the immune system, nearly located all over the gastrointestinal tract. Macrophages have vital influence on the inflammatory condition with both pro-inflammatory and anti-inflammatory functions. Their polarization status has been linked to numerous metabolic disorders such as inflammatory bowel disease (IBD). The equilibrium between the phenotypes and functions of inflammatory M1 and anti-inflammatory M2 cells is regulated by both extracellular and intracellular stimuli, determining how the disease progresses. Thereby, factors that interchange such balance in the direction of increasing M2 macrophages offer unique approaches for future management of IBD. This study reflects the novel IBD treatment targets via the immune system's pathway, reporting the latest treatments that regulate the M1/M2 macrophages distribution in a way to favor IBD.

Milk fermented with Lactobacillus rhamnosus R0011 induces a regulatory cytokine profile in LPS-challenged U937 and THP-1 macrophages

Fermented dairy products have become attractive functional foods for the delivery of probiotics and their biologically active metabolites. The aim of this study was to examine the immunomodulatory activity of milk fermented with the probiotic lactic acid bacterium Lactobacillus rhamnosus R0011 (LrF) on macrophages challenged with lipopolysaccharide (LPS), a potent pro-inflammatory stimulus. To this end, human THP-1 or U937 monocytes were differentiated into resting macrophages then stimulated with LPS and co-incubated with the LrF or with milk controls. Levels of pro-inflammatory and immunoregulatory cytokines were determined by enzyme-linked immunosorbent assays. Culturing of LPS-stimulated U937 macrophages with either the whole or filtered LrF resulted in an increase in Interleukin (IL)-1Ra production relative to the negative control. THP-1 macrophages cultured with the LrF demonstrated an increase in LPS-induced IL-10 and IL-1β production, while production of LPS-induced IL-6, sCD54, IL-8, IL-1β, TNF-α, IL-12p70 and Transforming Growth Factor-β (TGF-β) was unaffected. Further, the LrF induced the expression of DC-SIGN and CD206, markers of immunoregulatory M2 macrophage polarization, in LPS-challenged THP-1 macrophages. Taken together, milk fermented with L. rhamnosus R0011 increased regulatory cytokine production from LPS-challenged U937 and THP-1 macrophages, while simultaneously up-regulating the production of IL-1β and expression of DC-SIGN and CD206, a profile characteristic of polarization into the immunoregulatory M2 macrophage phenotype.

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Milk fermented with Lactobacillus rhamnosus R0011 (Lrf) induces a regulatory macrophage phenotype.

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Modulation of cytokine profiles induced by lipopolysaccharide challenge consistent with an alternatively activated (M2) macrophage phenotype.

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Fermented milk conditioning induced macrophage expression of genes characteristic of M2 macrophage polarization (DC-SIGN and CD206).

Probiotic Cell-Free Supernatants Exhibited Anti-Inflammatory and Antioxidant Activity on Human Gut Epithelial Cells and Macrophages Stimulated with LPS

The incidence of inflammatory bowel disease is increasing all over the world, especially in industrialized countries. The aim of the present work was to verify the anti-inflammatory activity of metabolites. In particular, cell-free supernatants of Lactobacillus acidophilus, Lactobacillus casei, Lactococcus lactis, Lactobacillus reuteri, and Saccharomyces boulardii have been investigated. Metabolites produced by these probiotics were able to downregulate the expression of PGE-2 and IL-8 in human colon epithelial HT-29 cells. Moreover, probiotic supernatants can differently modulate IL-1β, IL-6, TNF-α, and IL-10 production by human macrophages, suggesting a peculiar anti-inflammatory activity. Furthermore, supernatants showed a significant dose-dependent radical scavenging activity. This study suggests one of the mechanisms by which probiotics exert their anti-inflammatory activity affecting directly the intestinal epithelial cells and the underlying macrophages. This study provides a further evidence to support the possible use of probiotic metabolites in preventing and downregulating intestinal inflammation as adjuvant in anti-inflammatory therapy.

Use of Probiotics and Oral Health

PURPOSE OF REVIEW

The purpose of this study is to critically assess recent studies concerning the use of probiotics to control periodontal diseases, dental caries and halitosis (oral malodour).

RECENT FINDINGS

Clinical studies have shown that probiotics when allied to conventional periodontal treatment can ameliorate microbial dysbiosis and produce significant improvement in clinical indicators of disease. However, this effect is often not maintained by the host after the end of probiotic use. Current probiotics also show limited effects in treating caries and halitosis. Novel approaches based up on replacement therapy and using highly abundant health-associated oral species, including nitrate-reducing bacteria, have been proposed to improve persistence of probiotic strains and maintain oral health benefits.

SUMMARY

Probiotics have potential in the management of multifactorial diseases such as the periodontal diseases and caries, by more effectively addressing the host-microbial interface to restore homeostasis that may not be achieved with conventional treatments.

The Probiotic VSL#3 Modulates Colonic Macrophages, Inflammation, and Microflora in Acute Trinitrobenzene Sulfonic Acid Colitis

The probiotic mixture VSL#3 attenuates colitis in patients with Inflammatory Bowel Disease (IBD) and in animal models of this condition, but the mechanisms involved are incompletely understood. VSL#3 alters macrophage morphology and secretory profile in vitro in a polarization-dependent manner. We examined the effect of VSL#3 on macrophages in acute trinitrobenzene sulfonic acid-induced colitis. Rats were randomized to normal, colitis, or colitis+VSL#3 groups. After sacrifice, the colons were evaluated for macroscopic and microscopic damage. Serum cytokine levels were measured, and microbiome analysis undertaken. Total and M1 colonic macrophages, and total and proliferating hepatic macrophages were assessed by double immunofluorescence staining. Colitis+VSL#3 rats had lower macroscopic damage, with less microscopic damage in the proximal colon, compared with colitis alone. Colitis significantly increased colonic macrophage infiltration, which was significantly reduced by VSL#3 treatment. VSL#3 did not decrease the colitis-induced surge of colonic M1 macrophages or hepatic macrophages. VSL#3 reduced colitis-induced serum cytokine levels, and induced restoration of colonic transcript levels for pro-inflammatory, anti-inflammatory, and barrier proteins to, or past, normal levels. Fecal bacteria distribution changed between groups. In summary, the probiotic VSL#3 reduces colitis severity, colonic macrophage infiltration, and serum cytokine levels, but does not dampen the pro-inflammatory phenotype of M1 macrophages.

Probiotic Bacillus amyloliquefaciens SC06 Induces Autophagy to Protect against Pathogens in Macrophages

Probiotics are increasingly applied in popularity in both humans and animals. Decades of research has revealed their beneficial effects, including the immune modulation in intestinal pathogens inhibition. Autophagy—a cellular process that involves the delivery of cytoplasmic proteins and organelles to the lysosome for degradation and recirculation—is essential to protect cells against bacterial pathogens. However, the mechanism of probiotics-mediated autophagy and its role in the elimination of pathogens are still unknown. Here, we evaluated Bacillus amyloliquefaciens SC06 (Ba)-induced autophagy and its antibacterial activity against Escherichia coli (E. coli) in murine macrophage cell line RAW264.7 cells. Western blotting and confocal laser scanning analysis showed that Ba activated autophagy in a dose- and time-dependent manner. Ba-induced autophagy was found to play a role in the elimination of intracellular bacteria when RAW264.7 cells were challenged with E. coli. Ba induced autophagy by increasing the expression of Beclin1 and Atg5-Atg12-Atg16 complex, but not the AKT/mTOR signaling pathway. Moreover, Ba pretreatment attenuated the activation of JNK in RAW264.7 cells during E. coli infection, further indicating a protective role for probiotics via modulating macrophage immunity. The above findings highlight a novel mechanism underlying the antibacterial activity of probiotics. This study enriches the current knowledge on probiotics-mediated autophagy, and provides a new perspective on the prevention of bacterial infection in intestine, which further the application of probiotics in food products.

Colonic macrophage polarization in homeostasis, inflammation, and cancer

Our review focuses on the colonic macrophage, a monocyte-derived, tissue-resident macrophage, and the role it plays in health and disease, specifically in inflammatory conditions such as inflammatory bowel disease and cancer of the colon and rectum. We give special emphasis to macrophage polarization, or phenotype, in these different states. We focus on macrophages because they are one of the most numerous leukocytes in the colon, and because they normally contribute to homeostasis through an anti-inflammatory phenotype. However, in conditions such as inflammatory bowel disease, proinflammatory macrophages are increased in the colon and have been linked to disease severity and progression. In colorectal cancer, tumor cells may employ anti-inflammatory macrophages to promote tumor growth and dissemination, whereas proinflammatory macrophages may antagonize tumor growth. Given the key roles that this cell type plays in homeostasis, inflammation, and cancer, the colonic macrophage is an intriguing therapeutic target. As such, potential macrophage-targeting strategies are discussed.