Effects of probiotics on Toll‑like receptor expression in ulcerative colitis rats induced by 2,4,6‑trinitro‑benzene sulfonic acid

Immunomodulatory effects of live and UV-killed Bacillus subtilis natto on inflammatory response in human colorectal adenocarcinoma cell line in vitro

Background and Objectives

Colorectal cancer (CRC) is a heterogeneous disease of the colon or rectum arising from adenoma precursors and serrated polyps. Recently, probiotics have been proposed as an effective and potential therapeutic approach for CRC prevention and treatment. Probiotics have been shown to alleviate inflammation by restoring the integrity of the mucosal barrier and impeding cancer progression.

Materials and Methods

In this study, we aimed to investigate the immunomodulatory effects of live and UV-killed Bacillus subtilis natto on the inflammatory response in CRC. Caco-2 cells were exposed to various concentrations of live and UV- killed B. subtilis natto, and cell viability was assessed using MTT assay. Gene expression analysis of IL-10, TGF-β, TLR2 and TLR4 was performed using RT-qPCR.

Results

Our findings showed that both live and UV-killed B. subtilis natto caused significant reduction in inflammatory response by decreasing the gene expression of TLR2 and TLR4, and enhancing the gene expression of IL-10 and TGF-β in Caco-2 cells as compared to control group.

Conclusion

The results of this study suggest that live and UV-killed B. subtilis natto may hold potential as a therapeutic supplement for modulating inflammation in CRC.

Combination of Simo Decoction and Golden Bifid alleviates functional dyspepsia through a mechanism involving intestinal microbiota and short-chain fatty acids

BACKGROUND AND STUDY AIMS

The integration of traditional Chinese medicine and Western medicine holds promise for the treatment of gastrointestinal disorders, which are influenced by intestinal microbiota and metabolites. This study reports a possible mechanism for the combination of Simo Decoction and Golden Bifid in functional dyspepsia (FD) by regulating intestinal microbiota and short-chain fatty acids (SCFAs).

PATIENTS AND METHODS

A mouse model of food stagnation was constructed and treated with Simo Decoction combined with different concentrations of Golden Bifid. Meta-genomics sequencing was conducted to analyze the cecum contents of the mice. Following analyses of the composition and abundance of intestinal microbiota, gas chromatography-mass spectrometry was performed to measure SCFAs in the colonic content of mice. Finally, ELISA was utilized to determine the levels of pro-inflammatory factors in the duodenal mucosa of mice and the infiltration of eosinophils in the duodenum was observed by immunohistochemical staining.

RESULTS

Combination of Simo Decoction and Golden Bifid more significantly alleviated dyspepsia in mice with food stagnation compared with Simo Decoction alone. The optimal ratio of combined treatment was 0.0075 mL/g (body weight) Simo Decoction and 0.0032 mg/g (body weight) Golden Bifid. The combined treatment increased the abundance of Bifidobacterium and Bacteroides in the intestine. The levels of SCFAs in the colonic contents of mice were increased after the combined treatment, contributing to diminished pro-inflammatory factors in the duodenal mucosa and reduced eosinophil infiltration.

CONCLUSION

Combination of Simo Decoction and Golden Bifid increases the abundance of Bacteroides and Bifidobacterium and promotes the production of SCFAs, which is instrumental for alleviation of FD.

Effects of probiotic supplementation on chronic inflammatory process modulation in colorectal carcinogenesis

The current study investigated the potential effects of probiotic supplementation on colorectal carcinogenesis chemically induced with 1,2-dimethylhydrazine (DMH) and treated with 5-fluorouracil (5FU)-based chemotherapy in mice. Animals were randomly allocated in five different groups: Control: which not receive any treatment throughout the experimental course; Colitis model group (DMH): treated with DMH; DMH+ 5FU: animals received I.P. (intraperitoneal) dose of chemotherapy on a weekly basis; DMH+PROB: animals received daily administrations (via gavage) of probiotics (Lactobacillus: acidophilus and paracasei, Bifidobacterium lactis and bifidum); and DMH+ PROB+ 5FU: animals received the same treatment as the previous groups. After ten-week treatment, mice's large intestine was collected and subjected to colon length, histopathological, periodic acid-schiff (PAS) staining and immunohistochemistry (TLR2, MyD88, NF-κB, IL-6, TLR4, TRIF, IRF-3, IFN-γ, Ki-67, KRAS, p53, IL-10, and TGF-β) analyzes. Variance (ANOVA) and Kruskal-Wallis tests were used for statistical analysis, at significance level p 0.05. Probiotics' supplementation has increased the production of Ki-67 cell-proliferation marker, reduced body weight, and colon shortening, as well as modulated the chronic inflammatory process in colorectal carcinogenesis by inhibiting NF-κB expression and mitigating mucin depletion. Thus, these findings lay a basis for guide future studies focused on probiotics' action mechanisms in tumor microenvironment which might have implications in clinical practice.

The inhibitory effects of live and UV-killed Akkermansia muciniphila and its derivatives on cytotoxicity and inflammatory response induced by Clostridioides difficile RT001 in vitro

Clostridioides difficile infection (CDI) is the leading cause of healthcare-acquired infections worldwide. Probiotics are widely recommended to prevent CDI and its recurrences. Akkermansia muciniphila, as a therapeutic symbiont colonizing the intestinal mucosal layer, is considered to be a promising next-generation probiotic. In this work, we assessed the inhibitory effects of A. muciniphila MucT and its derivatives on cytotoxicity and inflammatory response induced by C. difficile RT001 in Caco-2 cells. The results obtained from SEM revealed that the morphology of UV-killed A. muciniphila remained unchanged after UV inactivation. TEM analysis showed that A. muciniphila-isolated extracellular vesicles (EVs) were spherical and ranged from 50 to 200 nm in size. Toxigenic supernatant (Tox-S) of C. difficile RT001 (500 μg/ml) significantly (P <0.01) reduced the cell viability of Caco-2 cells. Caco-2 cells treated with live (MOI 10), UV-killed (MOI 10), cell-free supernatant (CFS, 106 cfu/ml), and EVs (20 μg/ml) of A. muciniphila exhibited over 90% viability in comparison to untreated control. The neutralized CFS preparation using A. muciniphila and its derivatives could notably reduce the expression level of inflammatory markers. Additionally, A. muciniphila and its derivatives modulated the production of IL-1β, TNF-α, and IL-10 in Tox-S stimulated Caco-2 cells. We demonstrated that A. muciniphila and its derivatives can modulate changes in the gut barrier-related genes and inflammatory response caused by C. difficile Tox-S in Caco-2 cells.

Role of probiotics in managing various human diseases, from oral pathology to cancer and gastrointestinal diseases

The imbalance of microbial composition and diversity in favor of pathogenic microorganisms combined with a loss of beneficial gut microbiota taxa results from factors such as age, diet, antimicrobial administration for different infections, other underlying medical conditions, etc. Probiotics are known for their capacity to improve health by stimulating the indigenous gut microbiota, enhancing host immunity resistance to infection, helping digestion, and carrying out various other functions. Concurrently, the metabolites produced by these microorganisms, termed postbiotics, which include compounds like bacteriocins, lactic acid, and hydrogen peroxide, contribute to inhibiting a wide range of pathogenic bacteria. This review presents an update on using probiotics in managing and treating various human diseases, including complications that may emerge during or after a COVID-19 infection.

The Anti-Inflammatory Effect of a Probiotic Cocktail in Human Feces Induced-Mouse Model

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract due to altered interaction between the immune system and the gut microbiota. The aim of this study was to investigate the role of a probiotic cocktail in modulating immune dysregulation induced in mice. Mice were divided into 5 groups (n = 5/group), and inflammation was induced in two separate groups by fecal microbiota transplantation (FMT) from the stool of human with IBD and dextran sulfate sodium (DSS). In the other two groups, the cocktail of Lactobacillus spp. and Bifidobacterium spp. (108CFU/kg/day) was administered daily for a total of 28days in addition to inducing inflammation. A group as a contcxsrol group received only water and food. The alteration of the selected genera of gut microbiota and the expression of some genes involved in the regulation of the inflammatory response were studied in the probiotic-treated and untreated groups by quantitative real-time PCR. The selected genera of gut microbiota of the FMT and DSS groups showed similar patterns on day 28 after each treatment. In the probiotic-treated groups, the population of the selected genera of gut microbiota normalized and the abundance of Firmicutes and Actinobacteria increased compared to the DSS and FMT groups. The expression of genes related to immune response and tight junctions was positively affected by the probiotic. Changes in the gut microbiota could influence the inflammatory status in the gut, and probiotics as a preventive or complementary treatment could improve the well-being of patients with inflammatory bowel disease symptoms.

Impact of Oral Probiotics in Amelioration of Immunological and Inflammatory Responses on Experimentally Induced Acute Diverticulitis

Acute diverticulitis is inflammation of a colon diverticulum; it represents a major cause of morbidity and mortality. The alteration of gut microbiota contributes to the promotion of inflammation and the development of acute diverticulitis disease. Probiotics can modify the gut microbiota, so they are considered a promising option for managing diverticulitis disease. This study aimed to investigate the potential protective effect of probiotics, alone or in combination with amoxicillin, on the experimentally induced model of acute diverticulitis disease. Forty-two rats were divided into seven groups as follows: control group: received water and food only; DSS group: received 3% dextran sulfate sodium (DSS) daily for 7 days; LPS group: injected with lipopolysaccharide (LPS) enema at the dose of (4 mg/kg); probiotics group: treated with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) each of which (4 × 108 CFU suspended in 2 ml distilled water) orally for 7 days; DSS/LPS group: received DSS and LPS; DSS/LPS treated with probiotics group; DSS/LPS treated with probiotics and amoxicillin group. The results revealed that both treatments (probiotics and probiotics-amoxicillin) attenuated DSS/LPS-induced diverticulitis, by restoring the colonic antioxidant status, ameliorating inflammation (significantly reduced TNF-α, interleukins, interferon-γ, myeloperoxidase activity, and C-reactive protein), decreasing apoptosis (through downregulating caspase-3), and reduction of the colon aerobic bacterial count. These probiotic strains were effective in preventing the development of the experimentally induced acute diverticulitis through the anti-inflammatory and immunomodulatory effects and have affected gut microbiota, so they can be considered a potential option in treating acute diverticulitis disease.

The anti-inflammatory effects of minocycline on lipopolysaccharide-induced paw oedema in rats: a histopathological and molecular study

Minocycline is a semi-synthetic antimicrobial agent with claimed anti-inflammatory properties reported from different experimental models. This study was aimed to evaluate the anti-inflammatory effects of minocycline, compared to the actions of two common anti-inflammatory agents, on lipopolysaccharide (LPS)-induced paw oedema through some clinical, histopathological, haematological and molecular analyses. Forty-eight rats were divided into eight groups (n = 6). In control group (Ctrl), each animal was injected with normal saline into its sub-plantar region of hind paw. In groups 2-7, hind paw oedema was induced by injection of LPS. One hour before injections, groups 1 (Ctrl) and 2 (LPS) were treated orally with distilled water, 3 and 4 with methylprednisolone (Pred) and meloxicam (Melo) and 5-7 with minocycline in doses of 50, 150 and 450 mg/kg (M50, M150 and M450, respectively). The 8th group (MC) was given minocycline (150 mg/kg) orally and normal saline was injected into sub-plantar region. Paw swelling and body temperature were assessed at 0, 2, 4, 6 and 24 h post-injections. At 24 h, samples of blood and liver, kidney, spleen and hind paw tissues were taken for haematological and histopathological examinations. Some samples of the paw were also obtained for molecular analysis of some inflammatory-related cytokines at mRNA level. Paw swelling and body temperature increased in all LPS-injected groups 2 h post-injection. In LPS group, they remained significantly increased up to 24 h; however, these parameters decreased to normal in Pred, Melo and all minocycline groups. The histological findings showed mild-to-moderate signs of inflammation in tissue samples of groups 2-6, but not in group M450. Additionally, gene expression of pro-inflammatory cytokines (IL-1β and IL-6) increased significantly in LPS group compared to other groups. In conclusion, this study supports the role of minocycline as an anti-inflammatory agent with effects comparable to those of meloxicam and methylprednisolone.

TRPV1 participates in the protective effect of propolis on colonic tissue of ulcerative colitis

OBJECTIVES

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) mainly characterized by inflammation, ulceration and erosion of colonic mucosa and submucosa. Transient receptor potential vanilloid 1 (TRPV1) is an important mediator of visceral pain and inflammatory bowel disease. This study aims to investigate the protective effect of water soluble propolis (WSP) on UC colon inflammatory tissue and the role of TRPV1.

METHODS

Male SD rats were randomly divided into 6 groups (n=8): a normal control (NC) group, an ulcerative colitis model (UC) group, a low-WSP (L-WSP) group, a medium-WSP (M-WSP) group, a high-WSP (H-WSP) group, and a salazosulfapyridine (SASP) group. The rats in the NC group drank water freely, and the other groups drank 4% dextran sulfate sodium (DSS) solution freely for 7 d to replicate the ulcerative colitis model. Based on the successful replication of the UC, the L-WSP, M-WSP, and H-WSP groups were given 50, 100, and 200 mg/kg of water-soluble propolis by gavage for 7 d, and the SASP group was given 100 mg/kg of sulfasalazine by gavage for 7 d. The body weight of rats in each group was measured at the same time every day, the fecal traits and occult blood were observed to record the disease activity index (DAI). After intragastric administration, the animals were sacrificed after fasted 24 h. Serum and colonic tissue were collected, and the changes of MDA, IL-6 and TNF-α were detected. The pathological changes of colon tissues were observed by HE staining, and the expression of TRPV1 in colon tissues was observed by Western blotting, immunohistochemistry, and immunofluorescence.

RESULTS

The animals in each group that drank DSS freely showed symptoms such as weight loss, decreased appetite, depressed state, and hematochezia, indicating that the model was successfully established. Compared with the NC group, DAI scores of other groups were increased (all P<0.05). MDA, IL-6, TNF-α in serum and colon tissues of the UC group were increased compared with the NC group (all P<0.01), and they were decreased after WSP and SASP treatment (all P<0.01). The results of showed that the colon tissue structure was obviously broken and inflammatory infiltration in the UC group, while the H-WSP group and the SASP group significantly improved the colon tissue and alleviated inflammatory infiltration. The expression of TRPV1 in colon tissues in the UC group was increased compared with the NC group (all P<0.01), and it was decreased after WSP and SASP treatment.

CONCLUSIONS

WSP can alleviate the inflammatory state of ulcerative colitis induced by DSS, which might be related to the inhibition of inflammatory factors release, and down-regulation or desensitization of TRPV1.

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.

Golden bifid might improve diarrhea-predominant irritable bowel syndrome via microbiota modulation

Objective

Gut microbiota might play a crucial role in the pathogenesis of irritable bowel syndrome (IBS), and probiotics supplement may be an effective treatment option. This study aims to explore the therapeutic effects of Golden bifid on the diarrhea-predominant IBS (IBS-D).

Methods

Twenty-one consecutive IBS-D patients were recruited based on Rome IV criteria. All patients took 2000 mg Golden bifid triple daily for 4 weeks. Gastrointestinal (GI) symptoms, psychological symptoms, small intestine bacterial overgrowth (SIBO) and fecal microbiota characteristics were evaluated in IBS-D patients before and after treatment.

Results

After 4-week treatment of Golden bifid, the GI symptoms such as abdominal pain (2.90 ± 1.04 vs. 1.90 ± 1.26, P = 0.002), abdominal distension (2.00 ± 1.34 vs. 1.29 ± 1.31, P = 0.007), diarrhea (3.24 ± 1.37 vs. 1.81 ± 1.21, P = 0.001), defecatory urgency (3.48 ± 1.03 vs. 2.33 ± 1.35, P = 0.000) and incomplete evacuation (2.71 ± 1.15 vs. 1.76 ± 1.26, P = 0.003) were significantly alleviated in IBS-D patients. The Self-Rating Depression Scale (SDS) decreased significantly (46.19 ± 11.36 vs. 43.33 ± 9.65, P = 0.041), and SIBO could be eradicated in 25% (4/16) of IBS-D patients with SIBO. Meanwhile, the abundance of Unclassified Lachnospiraceae and Dorea in genus level and Unclassified Lachnospiraceae, Bacterium Dorea, Bacterium Butyricicoccus and Dorea formicigenerans ATCC 27755 in species level were increased in fecal microbiota (P < 0.05).

Conclusions

Golden bifid could improve most of GI symptoms and depressive symptoms in IBS-D patients and eradicate a small proportion of SIBO in those IBS-D patients with SIBO. What's more, Golden bifid could also modulate the fecal microbiota in IBS-D patients, which implied that the Golden bifid might improve IBS-D via microbiota modulation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41043-022-00302-0.

Protective effects of amoxicillin and probiotics on colon disorders in an experimental model of acute diverticulitis disease

Acute diverticulitis disease is associated with inflammation and infection in the colon diverticula and may lead to severe morbidity. This study aimed to evaluate and compare the protective effects of amoxicillin antibiotic, either alone or in combination with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis), in a rat model of acute diverticulitis disease. Acute diverticulitis was induced, in albino rats, by adding 3% weight/volume of dextran sulfate sodium (DSS) to the rats’ drinking water; daily for 7 days, in addition to injecting lipopolysaccharide (LPS) enema (4 mg/kg). The impact of treatments was assessed by measuring the physiological and immunological parameters and evaluating colon macroscopic and microscopic lesions. The results showed that both treatments (especially probiotics with amoxicillin) alleviated the adverse effects of DSS and LPS. This was obvious through the modulation of the rats’ body weight and the colon weight-to-length ratio. Also, there was a significant (p < 0.001) decrease in the colon macroscopic lesion score. The pro-inflammatory cytokines [(TNF)-α, (IL)-1β, (IFN)-γ, and (IL)-18]; in the colon tissue; were significantly (p < 0.001) decreased. Also, both treatments significantly ameliorated the elevation of myeloperoxidase activity and C-reactive protein levels, in addition to improving the histopathological alterations in the colon tissue. In conclusion, amoxicillin and probiotics–amoxicillin were effective in preventing the development of experimentally induced acute diverticulitis, through their anti-inflammatory and immunomodulatory effects. Furthermore, this study has explored the role of probiotics in preventing DSS/LPS-induced acute diverticulitis, so it can be applied as a promising treatment option for acute diverticulitis disease.

Natural compounds as safe therapeutic options for ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology. Several conventional treatments for UC such as corticosteroids, immunosuppressive agents, tumor necrosis factor antagonist, integrin blockers, and interleukin antagonist, and salicylates are available but are associated with the various limitations and side-effects. None of the above treatments helps to achieve the ultimate goal of the therapy, i.e., maintenance of remission in the long-term. Natural remedies for the treatment of UC show comparatively less side effects as compared to conventional approaches, and affordable. The current review presents details on the role of herbal drugs in the treatment and cure of UC. Google, PubMed, Web of Science, and Scopus portals have been searched for potentially relevant literature to get the latest developments and updated information related to use of natural drugs in the treatment of UC. Natural products have been used over centuries to treat UC. Some of the essential herbal constituents exhibiting antiulcerogenic activity include gymnemic acid (Gymnema sylvestre), shagoal (Zingiber officinale), catechin (Camellia sinensis), curcumin (Curcuma longa), arctigenin (Arctium lappa), and boswellic acid (Boswellia serrata). Although many plant-derived products have been recommended for UC, further research to understand the exact molecular mechanism is still warranted to establish their usefulness clinically.

Anti-inflammatory/anti-apoptotic impact of betulin attenuates experimentally induced ulcerative colitis: An insight into TLR4/NF-kB/caspase signalling modulation

Ulcerative colitis (UC) is an inflammatory bowel disease with limited therapeutic management approaches. The present study evaluated the potential therapeutic impact of betulin on acetic acid (AA)-induced UC in rats. UC was induced by intracolonic instillation of AA (3% v/v). Rats were treated with betulin (8 mg/kg, I.P., once daily) four days post AA instillation and for 14 consecutive days. Betulin attenuated AA-induced UC as evidenced by retracted macroscopic scores, serum CRP titre and LDH activity, attenuated histopathological hallmarks of UC including mucosal necrosis, haemorrhage, congestion and inflammatory cells infiltration. Moreover, betulin dampened UC-associated colonic inflammatory load with modulation of TLR4/NF-kB axis and reduction in colonic inflammatory cytokines; TNF-α, IL1β and IL-6. Nevertheless, betulin suppressed colonic apoptosis with reduced colonic caspase-3 and caspase-8 expression. The current findings confirm a beneficial therapeutic impact of betulin against UC. The prospective underlying mechanisms include down-regulation of TLR4/NF-κB and the subsequent downstream signalling pathways.

Probiotic Supplements on Oncology Patients' Treatment-Related Side Effects: A Systematic Review of Randomized Controlled Trials

Cancer affects more than 19.3 million people and has become the second leading cause of death worldwide. Chemo- and radiotherapy, the most common procedures in these patients, often produce unpleasant treatment-related side effects that have a direct impact on the quality of life of these patients. However, innovative therapeutic strategies such as probiotics are being implemented to manage these complications. Thus, this study aimed to evaluate the efficacy of probiotics supplements as a therapeutic strategy in adult oncology treatment-related side effects. A systematic review of randomized controlled trials was conducted in PubMed, Scielo, ProQuest and OVID databases up to and including January 2021, following the PRISMA guidelines. The quality of the included studies was assessed by the Jadad Scale. Twenty clinical trials published between 1988 and 2020 were included in this review. Seventeen studies (85%) revealed predominantly positive results when using probiotics to reduce the incidence of treatment-related side effects in oncology patients, while three studies (15%) reported no impact in their findings. This study sheds some light on the significance of chemotherapy and radiotherapy in altering the composition of gut microbiota, where probiotic strains may play an important role in preventing or mitigating treatment-related side effects.

Probiotics in Cancer

In recent years, the consumption of over-the-counter probiotics to promote health has grown rapidly worldwide and become an independent industry. In medicine, various studies have demonstrated that probiotics can help improve the immune system and intestinal health. They are usually safe, but in some rare cases, they may cause concerning adverse reactions. Although the use of probiotics has been widely popularized in the public, the results of many probiotic clinical trials are contradictory. Particularly in cancer patients, the feasibility of probiotic management providing benefits by targeting cancer and lessening anticancer side effects requires further investigation. This review summarizes the interactions between probiotics and the host as well as current knowledge on the pros and cons of utilizing probiotics in cancer patients.

Toll-like receptor 4 (TLR4) antagonists as potential therapeutics for intestinal inflammation

Gastrointestinal inflammation is a hallmark of highly prevalent disorders, including cancer treatment-induced mucositis and ulcerative colitis. These disorders cause debilitating symptoms, have a significant impact on quality of life, and are poorly managed. The activation of toll-like receptor 4 (TLR4) has been proposed to have a major influence on the inflammatory signalling pathways of the intestinal tract. Inhibition of TLR4 has been postulated as an effective way to treat intestinal inflammation. However, there are a limited number of studies looking into the potential of TLR4 antagonism as a therapeutic approach for intestinal inflammation. This review surveyed available literature and reported on the in vitro, ex vivo and in vivo effects of TLR4 antagonism on different models of intestinal inflammation. Of the studies reviewed, evidence suggests that there is indeed potential for TLR4 antagonists to treat inflammation, although only a limited number of studies have investigated treating intestinal inflammation with TLR4 antagonists directly. These results warrant further research into the effect of TLR4 antagonists in the intestinal tract.

Gut Microbiota Status in COVID-19: An Unrecognized Player?

Infection with the SARS-CoV-2 virus causes cardiopulmonary and vascular complications, ranging in severity. Understanding the pathogenic mechanisms of the novel SARS-CoV2 infection and progression can provide potential novel targets for its prevention and/or treatment. Virus microbiota reciprocal interactions have been studied in a variety of viral infections. For example, the integrity of Coronavirus particles can be disrupted by surfactin, a bacterial surface molecule that targets other viruses, including that of influenza A. In this light, intestinal microbiota likely influences COVID-19 virulence, while from its side SARS-CoV-2 may affect the intestinal microbiome promoting dysbiosis and other deleterious consequences. Hence, the microbiota pre-existing health status and its alterations in the course of SARS-CoV-2 infection, are likely to play an important, still underscored role in determining individual susceptibility and resilience to COVID-19. Indeed, the vast majority of COVID-19 worst clinical conditions and fatalities develop in subjects with specific risk factors such as aging and the presence of one or more comorbidities, which are intriguingly characterized also by unhealthy microbiome status. Moreover, these comorbidities require complex pharmacological regimens known as "polypharmacy" that may further affect microbiota integrity and worsen the resilience to viral infections. This complex situation may represent a further and underestimated risk with regard to COVID-19 clinical burden for the elderly and comorbid people. Here, we discuss the possible biological, physiopathological, and clinical implications of gut microbiota in COVID-19 and the strategies to improve/maintain its healthy status as a simple and adjunctive strategy to reduce COVID-19 virulence and socio-sanitary burden.

Probiotics in Medicine: A Long Debate

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called “microbiota-gut-liver axis” as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the “microbiota-gut-brain axis.” Moreover, recently the “gut-lung axis” in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Anti-Inflammatory and Chemopreventive Effects of Bryophyllum pinnatum (Lamarck) Leaf Extract in Experimental Colitis Models in Rodents

Inflammatory bowel diseases, mainly ulcerative colitis and Crohn's disease are characterized by chronic inflammation in the intestine. Currently several therapeutic strategies available to treat inflammatory bowel diseases. Though, most treatments can be associated with serious adverse effects what justifies the search for new treatments. In this sense, we highlight the interest in herbal products rich in bioactive compounds which immunomodulatory and antioxidant properties as is the case of Bryophyllum pinnatum (Crassulaceae). This plant is used in traditional medicine in Brazil for treating inflammatory diseases. We hypothesized that hydroethanolic B. pinnatum leaf extract has intestinal anti-inflammatory effects on two experimental colitis models: 2.4-dinitrobenzene sulfonic acid (DNBS) in rats, and dextran sulfate sodium (DSS) in mice. Ultra-fast liquid chromatography method used for the quantification of the main compounds indicated good linearity, specificity, selectivity, precision, robustness and accuracy. The major flavonoids (mg/g of the extract) quantified were: quercetin 3-O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranoside (35.56 ± 0.086 mg/g), kaempferol 3-O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranoside (4.66 ± 0.076 mg/g) and quercetin-3-O-rhamnopyranoside (4.56 ± 0.026 mg/g). The results obtained in the DNBS and DSS models indicate that extract has both chemopreventive and anti-inflammatory effects, observing a significant reduction in the disease activity index score, and less macroscopic and microscopic damage. The extract promoted downregulation of Toll-like receptor and kappa B p65 nuclear factor gene expression, leading to a reduction in pro-inflammatory and oxidative mediators, chemokines, and cell adhesion molecules. This immunomodulatory property was proposed that one of the possible action mechanisms of extract. An improvement in intestinal damage was also associated with a reduction in oxidative stress and infiltration of leukocytes, as evidenced by the reduction in malonaldialdehyde and myeloperoxidase activity and increase in total glutathione in the colonic tissue. Moreover, the extract improved the cytoarchitecture of the colonic tissue and the integrity of the intestinal epithelial barrier by restoring the expression of the proteins associated with mucosa protection. In view of the beneficial effects showed by the B. pinnatum leaf extract in preclinical rodent models of colitis there is the potential to conduct some future clinical studies to ensure safe and effective development of a phytotherapeutic treatment for human inflammatory bowel diseases.

[Mechanism of Jiawei Huangqin decoction for treating ulcerative colitis in mice: the role of STAT3/NF-kB/IL-6 pathway]

OBJECTIVE

To investigate the therapeutic effect of Jiawei Huangqin (JWHQ) decoction on ulcerative colitis (UC) and the regulation of STAT3/NF-kB/IL-6 pathway.

METHODS

Forty-eight mice were randomized into blank control group, model group, positive control (Sulfasalazine) group, and low-, moderate- and high-dose JWHQ Decoction groups (n=8). In all but the blank control groups, the mice were given 3% DSS in drinking water to induce UC, followed 7 days later by treatment with saline (blank control and model groups) or JWHQ Decoction by gavage (10 mL/k) for 7 consecutive days. After the treatment, the mice were euthanized and the colon length was measured and the histopathological changes were observed with HE staining. The expression levels of STAT3, NF-κB, and IL-6 in the colon tissues were detected with RT-qPCR and Western blotting.

RESULTS

Compared with those in the blank control group, the colon length was significantly shortened and the pathological score of the colon tissue was significantly higher in all the other 5 groups (P < 0.05). Compared with those in the model group, the colon length was significantly longer and the pathological scores were obviously reduced in all the 4 treatment groups (P < 0.05). JWHQ Decoction at the high dose produced significantly better therapeutic effects than the positive drug in terms of the colon length (P < 0.05) and the colon histopathological score (P < 0.05); high-dose JWHQ Decoction also showed better effect than the other two doses (P < 0.05), whose effects were comparable (P > 0.05). The mouse models of UC showed significantly increased expression levels of STAT3, NF-κB, and IL-6 in the colon tissue (P < 0.01), which were obviously lowered by the positive drug and JWHQ Decoction (P < 0.01), especially at the high dose (P < 0.01). JWHQ Decoction at the moderate dose produced similar effects with the positive drug on STAT3, NF-kB and IL-6 levels (P > 0.05), and their effects were stronger than those of low-dose JWHQ Decoction (P < 0.05).

CONCLUSIONS

JWHQ Decoction can improve UC in mice possibly by down-regulating the expression of STAT3, NF-kB and IL-6 in colonic tissue to affect the STAT3/NF-kB/IL-6 pathway.

Protective Effects of Clostridium Butyricum in a Murine Model of Dextran Sodium Sulfate-Induced Colitis That Involve Inhibition of the TLR2 Signaling Pathway and T Helper 17 Cells

BACKGROUND

This study aimed to investigate the role of Clostridium butyricum (C. butyricum) in conjunction with the Toll-like receptor2 (TLR2) signaling pathway and T helper 17 (Th17) cells in dextran sodium sulfate (DSS)-induced colitis in mice.

METHODS

Forty 8-week-old BALB/c mice were randomly divided into 5 groups of 8 mice for 7 days: control, DSS (5% DSS), DSS+C. butyricum (1 × 10⁹ CFU), DSS+C. butyricum (1 × 10⁸ CFU) and DSS+C. butyricum (1 × 10⁷ CFU) groups. We assessed the disease activity index (DAI) and histological damage scores. The expression levels of TLR2, myeloid differentiation factor 88 (MyD88), nuclear factor kappa-B p65 (NF-κBp65), interleukin (IL) 17 (IL17), IL23 and retineic acid receptor related orphan nuclear receptor gamma t (RORγt) were determined through immunohistochemical staining, western blot and quantitative real-time PCR (qRT-PCR). The expression levels of CD3⁺CD4⁺IL17⁺ cells in peripheral blood were measured by flow cytometry.

RESULTS

C. butyricum dose-dependently decreased DAI and histological damage scores in DSS mice and down-regulated the mRNA and protein levels of TLR2, MyD88 and NF-κBp65 in mouse colon tissue (all P < 0.05). In addition, C. butyricum dose-dependently decreased the levels of CD3⁺CD4⁺IL17⁺ cells in peripheral blood and down-regulated the mRNA and protein levels of IL17, IL23 and RORγt in mouse colon tissue (all P < 0.05). Moreover, the effect of C. butyricum on TLR2 was positively correlated with IL17, IL23 and RORγt.

CONCLUSIONS

C. butyricum exerts a dose-dependently protective effect on acute intestinal inflammation induced by DSS in mice, by inhibiting the TLR2 signaling pathway, down-regulating the expression of IL23 and RORγt, and inhibiting the secretion of IL17.

Intestinal Dysbiosis and the Developing Lung: The Role of Toll-Like Receptor 4 in the Gut-Lung Axis

Background

In extremely premature infants, postnatal growth restriction (PNGR) is common and increases the risk of developing bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). Mechanisms by which poor nutrition impacts lung development are unknown, but alterations in the gut microbiota appear to play a role. In a rodent model, PNGR plus hyperoxia causes BPD and PH and increases intestinal Enterobacteriaceae, Gram-negative organisms that stimulate Toll-like receptor 4 (TLR4). We hypothesized that intestinal dysbiosis activates intestinal TLR4 triggering systemic inflammation which impacts lung development.

Methods

Rat pups were assigned to litters of 17 (PNGR) or 10 (normal growth) at birth and exposed to room air or 75% oxygen for 14 days. Half of the pups were treated with the TLR4 inhibitor TAK-242 from birth or beginning at day 3. After 14 days, pulmonary arterial pressure was evaluated by echocardiography and hearts were examined for right ventricular hypertrophy (RVH). Lungs and serum samples were analyzed by western blotting and immunohistochemistry.

Results

Postnatal growth restriction + hyperoxia increased pulmonary arterial pressure and RVH with trends toward increased plasma IL1β and decreased IκBα, the inhibitor of NFκB, in lung tissue. Treatment with the TLR4 inhibitor attenuated PH and inflammation.

Conclusion

Postnatal growth restriction induces an increase in intestinal Enterobacteriaceae leading to PH. Activation of the TLR4 pathway is a promising mechanism by which intestinal dysbiosis impacts the developing lung.

The protective effects of enriched citrulline fermented milk with Lactobacillus helveticus on the intestinal epithelium integrity against Escherichia coli infection

This study examined the protective effects of citrulline enriched-fermented milk with live Lactobacillus helveticus ASCC 511 (LH511) on intestinal epithelial barrier function and inflammatory response in IPEC-J2 cells caused by pathogenic Escherichia coli. Five percent (v/v) of fermented milk with live LH511 and 4 mM citrulline (5%LHFM_Cit-4mM) significantly stimulated the population of IPEC-J2 cells by 36% as determined by MTT assay. Adhesion level of LH511 was significantly increased by 9.2% when incubated with 5%LHFM_Cit-4mM and 5%LHFM_Cit-4mM reduced the adhesion of enterohemorrhagic (EHEC) and entero-invasive (EIEC) E. coli in IPEC-J2 cells by 35.79% and 42.74%, respectively. Treatment with 5%LHFM_Cit-4mM ameliorated lipopolysaccharide (LPS) from E. coli O55:B5 induced activated inflammatory cytokines expression (TNF-α, IL-6 and IL-8) and concentration (IL-6 and IL-8) and early apoptosis. It restored the transepithelial electrical resistance (TEER) and regulated the expression and distribution of tight junction (TJ) proteins (zonula occluden-1 (ZO-1), occludin and claudin-1), toll-like receptors (TLRs) (TLR2 and TLR4) and negative regulators of TLRs signalling pathway (A20 and IRAK-M). In conclusion, our findings suggested that 5%LHFM_Cit-4mM might have the positive effects on improving and maintaining the intestinal epithelial cell integrity and inflammatory response under both normal and pathogenic LPS-stimulated conditions.

Involvement of TLR4/ CXCL9/ PREX-2 pathway in the development of hepatocellular carcinoma (HCC) and the promising role of early administration of lactobacillus plantarum in Wistar rats

BACKGROUND AND AIM

Improvement of gut microbiota may help in preventing the progression of cirrhosis. We supposed that Lactobacillus Plantarum (L. Plantarum) protects the cirrhotic liver through suppression of TLR4/ CXCL9/ PREX-2.

METHODOLOGY

Rats were divided into two groups. Group I, lasts for six weeks and Group II lasts for 12 weeks. Each group was subdivided into: naïve, Lactobacillus Plantarum (L. Plantarum), thioacetamide (TAA) and TAA + L. Plantarum. Liver function tests, α fetoprotein (AFP) levels, CXCL9, PREX-2 and TLR4 expression were assessed. Histological studies were performed.

RESULTS

TAA induced significant deterioration in liver functions and increased AFP. There was periportal cirrhosis, vacuolated hepatocytes, decrease hepatocyte parrafin-1 (hep par-1) expression, increase proliferating cell nuclear antigen (PCNA) positive nuclei and cytokeratin AE1/AE3. The PCR results showed significant increase in TLR4, CXCL9 and PREX-2 expression. Early administration of L. Plantarum significantly decreased the expression of TLR4, CXCL9 and PREX-2 together with improvement in liver function and prevented the pathological changes.

CONCLUSIONS

The cirrhotic complications induced by TAA are through activation of TLR4/ CXCL9/ PREX-2 pathway and could be prevented by the early administration of L. Plantarum.

Regulatory T cells and Toll-like receptor 2 and 4 mRNA expression in infants with colic treated with Lactobacillus reuteri DSM17938

Regulatory T cells induce immune homeostasis and the expression of Toll like receptors (TLRs); subsequent inflammatory cytokine release may be involved. Recent studies have shown a microbial imbalance in the gut of colicky infants (with a prevalence of gram-negative bacteria, such as Escherichia coli), and accumulating evidence has shown the efficacy of a probiotic (Lactobacillus reuteri) in breastfed subjects, but the underlying mechanism remains undefined. The study enrolled 59 infants younger than 60 days, of whom 34 subjects had colic and 25 were healthy controls. With a double-blind, placebo-controlled randomised study performed in our unit from October 2016 to July 2017, infants with colic were randomly assigned to receive oral daily L. reuteri DSM17938 (1×108 cfu) or placebo for 28 days. Peripheral blood was collected to assess the expression of FoxP3, TLR2 and TLR4 mRNA using real-time TaqMan RT-PCR at baseline and after the study period. Our findings showed increased mRNA expression of the transcription factor forkhead box P3 (FoxP3) in infants treated with L. reuteri DSM 17938 for 28 days (P<0.009) and increased TLR2 and TLR4 mRNA expression in both treated and placebo subjects. After L. reuteri administration for 28 days in infants with colic, we observed a significant decrease in daily crying time (302.3±19.86 min/day on day 0 vs 76.75±22.15 min/day on day 28, P=0.001). This study provides evidence that the observed increase in FoxP3 expression and reduction in crying time might be responses to probiotic treatment, while the increase in TLR2 and TLR4 mRNA expression might be related to age. Exploiting these new findings may lead to an unprecedented level of therapeutic control over immune tolerance using probiotics.

Effect of Lactobacillus acidophilus KLDS 1.0738 on miRNA expression in in vitro and in vivo models of β-lactoglobulin allergy

This study aims to investigate the correlation between the ability of L. acidophilus to modulate miRNA expression and prevent Th17-dominated β-lactoglobulin (β-Lg) allergy. In vitro immunomodulation was evaluated by measuring splenocyte proliferation, Th17-related immune response and miRNA expression in β-Lg-sensitized splenocytes cultured with live L. acidophilus. Next, the allergic mouse model was used to evaluate anti-allergy capability of lactobacilli. The β-Lg challenge led to induction of up-regulation of miR-146a, miR-155, miR-21 and miR-9 expression in both in vivo and in vitro, along with increased Th17-related cytokine levels and mRNA expression of RORγt and IL-17. However, treatment of live L. acidophilus significantly suppressed hypersensitivity responses and Th17 cell differentiation. Moreover, administration of live L. acidophilus reduced expression of four miRNAs, especially miR-146a and miR-155. In addition, the decreased expression of the miRNAs in the spleen of the L. acidophilus-treated group was closely associated with decrease of IL-17 and RORγt mRNA expression.

Effects of a probiotic (SLAB51™) on clinical and histologic variables and microbiota of cats with chronic constipation/megacolon: a pilot study

Chronic constipation (CC) and idiopathic megacolon (IMC) occur frequently in cats. The aim of the study was to investigate the effects of a multi-strain probiotic (SLAB51™) in constipated cats (n=7) and in patients with megacolon and constipation (n=3). Ten pet cats with a diagnosis of chronic constipation, non-responsive to medical management received orally 2×1011 bacteria daily for 90 days. For microbiota analysis, selected bacterial groups were analysed by qPCR. Histological samples in megacolons were evaluated for interstitial cells of Cajal (ICC), enteric neurons, and neuronal apoptosis. Biopsies were compared at baseline (T0) and after the end of treatment (T1), and with those obtained from healthy control tissues (archived material from five healthy cats). Constipated cats displayed significantly lower ICC, and cats with idiopathic megacolon had significantly more apoptotic enteric neurons than controls. After treatment with SLAB51™, significant decreases were observed for feline chronic enteropathy activity index (FCEAI) (P=0.006), faecal consistency score, and mucosal histology scores (P<0.001). In contrast, a significant increase of ICC was observed after probiotic therapy. Lactobacillus spp. and Bacteroidetes were increased significantly after treatment (comparing constipated cats before and after treatment, and control healthy cats to constipated cats after treatment), but no other differences in microbiota were found between healthy controls and constipated cats. Treatment with SLAB51™ in cats with chronic constipation and idiopathic megacolon showed significant clinical improvement after treatment, and histological parameters suggest a potential anti-inflammatory effect of SLAB51™, associated with a reduction of mucosal infiltration, and restoration of the number of interstitial cells of Cajal.