Probiotics for induction of remission in ulcerative colitis

Impact of perinatal administration of probiotics on immune cell composition in neonatal mice

BACKGROUND

Newborns and especially preterm infants are much more susceptible to infections than adults. The pathogens causing infections in newborns are often detectable in the intestinal flora of affected children even before disease onset. Therefore, it seems reasonable to prevent dysbiosis in newborns and preterm infants. An approach followed in many neonatal intensive care units (NICUs) is to prevent infections in preterm infants with probiotics however their mechanisms of action of probiotics are incompletely understood. Here, we investigated the effect of perinatal probiotic exposure on immune cells in newborn mice.

METHODS

Pregnant mice were orally treated with a combination of Lactobacillus acidophilus and Bifidobacterium bifidum (Infloran®) from mid-pregnancy until the offspring were harvested. Immune cell composition in organs of the offspring were analyzed by flow cytometry.

RESULTS

Perinatal probiotic exposure had profound effects on immune cell composition in the intestine, liver and lungs of newborn mice with reduction of myeloid and B cells and induction of T cells in the probiotic treated animals' organs at weaning. Furthermore, probiotic exposure had an effect on T cell development in the thymus.

CONCLUSION

Our results contribute to a better understanding of the interaction of probiotics with the developing immune system.

IMPACT

probiotics have profound effects on immune cell composition in intestines, livers and lungs of newborn mice. probiotics modulate T cell development in thymus of newborn mice. effects of probiotics on neonatal immune cells are particularly relevant in transition phases of the microbiome. our results contribute to a better understanding of the mechanisms of action of probiotics in newborns.

Crosstalk between gut microbiota and gut resident macrophages in inflammatory bowel disease

Macrophages residing in the gut maintain gut homeostasis by orchestrating patho-gens and innocuous antigens. A disturbance in macrophages leads to gut inflamma-tion, causing conditions such as inflammatory bowel disease (IBD). Macrophages ex-hibit remarkable plasticity, as they are sensitive to various signals in the tissue micro-environment. During the recent decades, gut microbiota has been highlighted refer-ring to their critical roles in immunity response. Microbiome-derived metabolites and products can interact with macrophages to participate in the progression of IBD. In this review, we describe recent findings in this field and provide an overview of the current understanding of microbiota-macrophages interactions in IBD, which may lead to the development of new targets and treatment options for patients with IBD.

Probiotics for the treatment of ulcerative colitis: a review of experimental research from 2018 to 2022

Ulcerative colitis (UC) has become a worldwide public health problem, and the prevalence of the disease among children has been increasing. The pathogenesis of UC has not been elucidated, but dysbiosis of the gut microbiota is considered the main cause of chronic intestinal inflammation. This review focuses on the therapeutic effects of probiotics on UC and the potential mechanisms involved. In animal studies, probiotics have been shown to alleviate symptoms of UC, including weight loss, diarrhea, blood in the stool, and a shortened colon length, while also restoring intestinal microecological homeostasis, improving gut barrier function, modulating the intestinal immune response, and attenuating intestinal inflammation, thereby providing theoretical support for the development of probiotic-based microbial products as an adjunctive therapy for UC. However, the efficacy of probiotics is influenced by factors such as the bacterial strain, dose, and form. Hence, the mechanisms of action need to be investigated further. Relevant clinical trials are currently lacking, so the extension of animal experimental findings to clinical application requires a longer period of consideration for validation.

Preclinical evidence of probiotics in ulcerative colitis: a systematic review and network meta-analysis

The imbalance of gastrointestinal microbial composition has been identified as the main factor of chronic inflammatory diseases. At present, probiotics have a beneficial effect on the microbial composition of the human gastrointestinal tract, but it is still controversial and the specific mechanism is unknown. The purpose of this network meta-analysis is to compare the mechanism of different probiotics on ulcerative colitis. PubMed, Embase, and Web of Science were searched till 16 November 2022. The SYRCLE risk bias assessment tool was used to assess the quality of the research studies. A total of 42 studies, 839 ulcerative colitis models, and 24 kinds of probiotics were finally included. The results showed that L. rhamnosus has the best effect in relieving weight loss and improving the Shannon index in the ulcerative colitis model. E. faecium has the best effect in reducing colon injury; L. reuteri has the best effect in reducing the DAI; L. acidophilus has the best effect in reducing the HIS index and increasing the expression of tight junction protein ZO-1; and L. coryniformis has the best effect in reducing the content of serum pro-inflammatory factor TNF-α. It indicated that probiotics can improve ulcerative colitis by improving histopathological manifestations, reducing inflammatory reaction, and repairing the mucosal barrier, and different probiotics showed different effects. However, considering the limitations of this study, preclinical studies that require more large samples and high-quality and more reliable and rigorous experimental designs and reports need to be conducted in the future. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#record details, identifier CRD42022383383.

Fecal transplantation for treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, relapsing disease of the gastrointestinal (GI) tract that is thought to be associated with a complex interplay between the immune system, the GI tract lining, the environment, and the gut microbiome, leading to an abnormal inflammatory response in genetically susceptible individuals. An altered composition of the gut's native microbiota, known as dysbiosis, may have a major role in the pathogenesis of ulcerative colitis (UC) and Crohn disease (CD), two subtypes of IBD. There is growing interest in the correction of this underlying dysbiosis using fecal microbiota transplantation (FMT).

OBJECTIVES

To evaluate the benefits and safety profile of FMT for treatment of IBD in adults and children versus autologous FMT, placebo, standard medication, or no intervention.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two clinical trial registries, and the reference sections of published trials through 22 December 2022.

SELECTION CRITERIA

We included randomized controlled trials that studied adults and children with UC or CD. Eligible intervention arms used FMT, defined as the delivery of healthy donor stool containing gut microbiota to a recipient's GI tract, to treat UC or CD.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion. Our primary outcomes were: 1. induction of clinical remission, 2. maintenance of clinical remission, and 3. serious adverse events. Our secondary outcomes were: 4. any adverse events, 5. endoscopic remission, 6. quality of life, 7. clinical response, 8. endoscopic response, 9. withdrawals, 10. inflammatory markers, and 11. microbiome outcomes. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 12 studies with 550 participants. Three studies were conducted in Australia; two in Canada; and one in each of the following: China, the Czech Republic, France, India, the Netherlands, and the USA. One study was conducted in both Israel and Italy. FMT was administered in the form of capsules or suspensions and delivered by mouth, nasoduodenal tube, enema, or colonoscopy. One study delivered FMT by both oral capsules and colonoscopy. Six studies were at overall low risk of bias, while the others had either unclear or high risk of bias. Ten studies with 468 participants, of which nine studies focused on adults and one focused on children, reported induction of clinical remission in people with UC at longest follow-up (range 6 to 12 weeks) and showed that FMT may increase rates of induction of clinical remission in UC compared to control (risk ratio (RR) 1.79, 95% confidence interval (CI) 1.13 to 2.84; low-certainty evidence). Five studies showed that FMT may increase rates of induction of endoscopic remission in UC at longest follow-up (range 8 to 12 weeks); however, the CIs around the summary estimate were wide and included a possible null effect (RR 1.45, 95% CI 0.64 to 3.29; low-certainty evidence). Nine studies with 417 participants showed that FMT may result in little to no difference in rates of any adverse events (RR 0.99, 95% CI 0.85 to 1.16; low-certainty evidence). The evidence was very uncertain about the risk of serious adverse events (RR 1.77, 95% CI 0.88 to 3.55; very low-certainty evidence) and improvement in quality of life (mean difference (MD) 15.34, 95% CI -3.84 to 34.52; very low-certainty evidence) when FMT was used to induce remission in UC. Two studies, of which one also contributed data for induction of remission in active UC, assessed maintenance of remission in people with controlled UC at longest follow-up (range 48 to 56 weeks). The evidence was very uncertain about the use of FMT for maintenance of clinical remission (RR 2.97, 95% CI 0.26 to 34.42; very low-certainty evidence) and endoscopic remission (RR 3.28, 95% CI 0.73 to 14.74; very low-certainty evidence). The evidence was also very uncertain about the risk of serious adverse events, risk of any adverse events, and improvement in quality of life when FMT was used to maintain remission in UC. None of the included studies assessed use of FMT for induction of remission in people with CD. One study with 21 participants reported data on FMT for maintenance of remission in people with CD. The evidence was very uncertain about the use of FMT for maintenance of clinical remission in CD at 24 weeks (RR 1.21, 95% CI 0.36 to 4.14; very low-certainty evidence). The evidence was also very uncertain about the risk of serious or any adverse events when FMT was used to maintain remission in CD. None of the studies reported data on use of FMT for maintenance of endoscopic remission or improvement in quality of life in people with CD.

AUTHORS' CONCLUSIONS

FMT may increase the proportion of people with active UC who achieve clinical and endoscopic remission. The evidence was very uncertain about whether use of FMT in people with active UC impacted the risk of serious adverse events or improvement in quality of life. The evidence was also very uncertain about the use of FMT for maintenance of remission in people with UC, as well as induction and maintenance of remission in people with CD, and no conclusive statements could be made in this regard. Further studies are needed to address the beneficial effects and safety profile of FMT in adults and children with active UC and CD, as well as its potential to promote longer-term maintenance of remission in UC and CD.

A systematic review on selection characterization and implementation of probiotics in human health

Probiotics are live bacteria found in food that assist the body's defence mechanisms against pathogens by reconciling the gut microbiota. Probiotics are believed to aid with gut health, the immune system, and brain function, among other factors. They've furthermore been shown to help with constipation, high blood pressure, and skin issues. The global probiotics market has been incrementally growing in recent years, as consumers' demand for healthy diets and wellness has continued to increase. This has prompted the food industry to develop new probiotic-containing food products, as well as researchers to explore their specific characteristics and impacts on human health. Although most probiotics are fastidious microorganisms that are nutritionally demanding and sensitive to environmental conditions, they become less viable as they are processed and stored. In this review we studied the current literature on the fundamental idea of probiotic bacteria, their medical benefits, and their selection, characterization, and implementations.

Graphical Abstract

Maggot extracts chemo-prevent inflammation and tumorigenesis accompanied by changes in the intestinal microbiome and metabolome in AOM/DSS-induced mice

Inflammatory responses and intestinal microbiome play a crucial role in the progression of colitis-associated carcinoma (CAC). The traditional Chinese medicine maggot has been widely known owing to its clinical application and anti-inflammatory function. In this study, we investigated the preventive effects of maggot extract (ME) by intragastric administration prior to azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced CAC in mice. The results showed that ME had superior advantages in ameliorating disease activity index score and inflammatory phenotype, in comparison with the AOM/DSS group. The number and size of polypoid colonic tumors were decreased after pre-administration of ME. In addition, ME was found to reverse the downregulation of tight junction proteins (zonula occluden-1 and occluding) while suppressing the levels of inflammatory factors (IL-1β and IL-6) in models. Moreover, Toll-like receptor 4 (TLR4) mediated intracellular nuclear factor-κB (NF-κB)-containing signaling cascades, including inducible nitric oxide synthase and cyclooxygenase-2, and exhibited decreasing expression in the mice model after ME pre-administration. 16s rRNA analysis and untargeted-metabolomics profiling of fecal samples inferred that ME revealed ideal prevention of intestinal dysbiosis in CAC mice, accompanied by and correlated with alterations in the composition of metabolites. Overall, ME pre-administration might be a chemo-preventive candidate in the initiation and development of CAC.

Effect of mesalazine combined with probiotics on inflammation and immune function of patients with inflammatory bowel disease

OBJECTIVE

To determine the effects of mesalazine combined with probiotics on inflammation and immune function of patients with inflammatory bowel disease (IBD).

METHODS

In this retrospective study, a total of 116 patients with IBD treated in Renmin Hospital of Wuhan University from September 2018 to September 2021 were enrolled and divided into a control group (n=55, treated with mesalazine alone) and a research group (n=61, treated with mesalazine combined with probiotics) according to the treatment regimen. The two groups were compared in the levels of inflammatory factors, immune factors, adverse reactions, clinical efficacy and improvement of patients' disease condition before and after treatment. Logistic regression was used to analyze the independent risk factors of infection in patients with IBD at 6 months after admission.

RESULTS

The research group showed a significantly higher the total effective rate than the control group (P<0.05), and there was no notable difference between the two groups in the incidence of adverse reactions (P>0.05). In addition, compared with the control group, the research group showed significantly lower levels of immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and had significantly lower scores of clinical activity index (CAI) and endoscopic activity index (EAI) after treatment (all P<0.05). Higher IgG, IgM, IL-6, CRP and EAI levels at admission were independent risk factors for infection in patients with IBD.

CONCLUSION

Mesalazine combined with probiotics can substantially improve the disease condition of patients with IBD, improve their immune ability and reduce their inflammation level, with a good safety profile.

Quality of Life in Inflammatory Bowel Diseases (IBDs) Patients after Surgery

Inflammatory Bowel Diseases (IBDs) are chronic, relapsing and disabling diseases that affect the gastrointestinal tract. This relapsing course is often unpredictable with severe flares and the need for intensive medical treatment, hospitalization, or emergent/urgent surgery, all of which significantly impact patients' quality of life (QoL). QoL in IBD patients is significantly lower than in the general population, and depression and anxiety have been shown to have a higher prevalence than in healthy individuals, especially during disease flares. Complications requiring hospitalization and repeated surgeries are not uncommon during the disease course and significantly affect QoL in IBD patients. Patient-reported outcome measures (PROMs) can be used to measure the impact of chronic disease on QoL from the patient's perspective. The use of PROMs in IBD patients undergoing surgery could help to investigate the impact of the surgical procedure on QoL and determine whether there is any improvement or worsening. This review summarizes the use of PROMs to assess QoL after various surgical procedures required for IBD treatment.

[Role of the gut microbiome in the pathogenesis and treatment of inflammatory bowel diseases]

Inflammatory bowel diseases (IBD) are systemic diseases that mainly manifest in the gastrointestinal tract. Due to chronically impaired intestinal homeostasis, they often require permanent and in some cases systemic therapy. The exact causes of IBD are largely unknown. It is postulated that these complex diseases arise in genetically susceptible individuals through a misdirected immune response, promoted by barrier defects, environmental toxins, and the gut microbiome. In this regard, the importance of the microbiome and its pathogenic changes (dysbiosis) in the pathogenesis of IBD is increasingly coming into focus. This review article presents the current state of research on the role of the microbiome in the development of IBD. Therapeutic approaches aimed at correcting intestinal dysbiosis are also discussed.

Probiotic-Based Intervention in the Treatment of Ulcerative Colitis: Conventional and New Approaches

Although there are number of available therapies for ulcerative colitis (UC), many patients are unresponsive to these treatments or experience secondary failure during treatment. Thus, the development of new therapies or alternative strategies with minimal side effects is inevitable. Strategies targeting dysbiosis of gut microbiota have been tested in the management of UC due to the unquestionable role of gut microbiota in the etiology of UC. Advanced molecular analyses of gut microbiomes revealed evident dysbiosis in UC patients, characterized by a reduced biodiversity of commensal microbiota. Administration of conventional probiotic strains is a commonly applied approach in the management of the disease to modify the gut microbiome, improve intestinal barrier integrity and function, and maintain a balanced immune response. However, conventional probiotics do not always provide the expected health benefits to a patient. Their benefits vary significantly, depending on the type and stage of the disease and the strain and dose of the probiotics administered. Their mechanism of action is also strain-dependent. Recently, new candidates for potential next-generation probiotics have been discovered. This could bring to light new approaches in the restoration of microbiome homeostasis and in UC treatment in a targeted manner. The aim of this paper is to provide an updated review on the current options of probiotic-based therapies, highlight the effective conventional probiotic strains, and outline the future possibilities of next-generation probiotic and postbiotic supplementation and fecal microbiota transplantation in the management of UC.

Gastrointestinal Microbiome and Multiple Health Outcomes: Umbrella Review

In recent years, there has been growing concern about the impact of the gastrointestinal microbiome on human health outcomes. To clarify the evidence for a link between the gastrointestinal microbiome and a variety of health outcomes in humans, we conducted an all-encompassing review of meta-analyses and systematic reviews that included 195 meta-analyses containing 950 unique health outcomes. The gastrointestinal microbiome is related to mortality, gastrointestinal disease, immune and metabolic outcomes, neurological and psychiatric outcomes, maternal and infant outcomes, and other outcomes. Existing interventions for intestinal microbiota (such as probiotics, fecal microbiota transplant, etc.) are generally safe and beneficial to a variety of human health outcomes, but the quality of evidence is not high, and more detailed and well-designed randomized controlled trials are necessary.

Update on gut microbiota in gastrointestinal diseases

The human gut is a complex microbial ecosystem comprising approximately 100 trillion microbes collectively known as the “gut microbiota”. At a rough estimate, the human gut microbiome contains almost 3.3 million genes, which are about 150 times more than the total human genes present in the human genome. The vast amount of genetic information produces various enzymes and physiologically active substances. Thus, the gut microbiota contributes to the maintenance of host health; however, when healthy microbial composition is perturbed, a condition termed “dysbiosis”, the altered gut microbiota can trigger the development of various gastrointestinal diseases. The gut microbiota has consequently become an extremely important research area in gastroenterology. It is also expected that the results of research into the gut microbiota will be applied to the prevention and treatment of human gastrointestinal diseases. A randomized controlled trial conducted by a Dutch research group in 2013 showed the positive effect of fecal microbiota transplantation (FMT) on recurrent Clostridioides difficile infection (CDI). These findings have led to the development of treatments targeting the gut microbiota, such as probiotics and FMT for inflammatory bowel diseases (IBD) and other diseases. This review focuses on the association of the gut microbiota with human gastrointestinal diseases, including CDI, IBD, and irritable bowel syndrome. We also summarize the therapeutic options for targeting the altered gut microbiota, such as probiotics and FMT.

Early fecal microbiome transfer after donor defecation determines response in patients with moderate to severe ulcerative colitis

BACKGROUND

Fecal microbiome transfer (FMT) targeting gut microbiome dysbiosis is an emerging therapy for ulcerative colitis (UC). There is however no consensus on protocols for performing FMT in UC, especially in relation to time after donor feces defecation.

METHODS

This is a single-center retrospective analysis of patients with moderate-severe UC (total Mayo Clinic score ≥6 and endoscopic Mayo Clinic subscore of ≥2) treated with FMT between September 2017 and December 2019 at Dayanand Medical College and Hospital, Ludhiana, India. Fresh fecal samples from unrelated healthy voluntary donors were administered through colonoscopy at weeks 0, 2, 6, 10, 14, 18, and 22. Time interval between donor feces defecation and FMT procedure was recorded for each FMT session and the mean time of seven sessions was designated aika. Impact of aika on clinical response and safety of FMT was evaluated.

RESULTS

During the study period, 123 adult patients (mean age 33.75±11.97 years, 61.8% [n=76] males) with moderate-severe UC (mean total Mayo Clinic and endoscopic Mayo Clinic scores 7.49±1.60 and 2.50±0.50, respectively) were treated with FMT. The mean aika was 2.29±0.75 h. The aika was smaller in patients who responded to FMT as compared to non-responders (2.13±0.75 h vs. 2.71±0.76 h, p=0.0002) as well as in patients achieving clinical remission (2.15±0.76 h vs. 2.42±0.76 h, p=0.05). There was no significant impact of aika on adverse effects except for the incidence of borborygmi after FMT, which was higher in patients with aika ≤2 h.

CONCLUSION

Early FMT after donor feces defecation favorably impacts the clinical response rates in patients with active UC.

Antibiotics for the induction and maintenance of remission in ulcerative colitis

BACKGROUND

Antibiotics have been considered to treat ulcerative colitis (UC) due to their antimicrobial properties against intestinal bacteria linked to inflammation. However, there are concerns about their efficacy and safety.

OBJECTIVES

To determine whether antibiotic therapy is safe and effective for the induction and maintenance of remission in people with UC.

SEARCH METHODS

We searched five electronic databases on 10 December 2021 for randomised controlled trials (RCTs) comparing antibiotic therapy to placebo or an active comparator.

SELECTION CRITERIA

We considered people with UC of all ages, treated with antibiotics of any type, dose, and route of administration for inclusion. Induction studies required a minimum duration of two weeks for inclusion. Maintenance studies required a minimum duration of three months to be considered for inclusion.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome for induction studies was failure to achieve remission and for maintenance studies was relapse, as defined by the primary studies.

MAIN RESULTS

We included 12 RCTs (847 participants). One maintenance of remission study used sole antibiotic therapy compared with 5-aminosalicylic acid (5-ASA). All other trials used concurrent medications or standard care regimens and antibiotics as an adjunct therapy or compared antibiotics with other adjunct therapies to examine the effect on induction of remission. There is high certainty evidence that antibiotics (154/304 participants) compared to placebo (175/304 participants) result in no difference in failure to achieve clinical remission (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.74 to 1.06). A subgroup analysis found no differences when steroids, steroids plus 5-ASA, or steroids plus 5-ASA plus probiotics were used as additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (102/168 participants) compared to placebo (121/175 participants) may result in no difference in failure to achieve clinical response (RR 0.75, 95% CI 0.47 to 1.22). A subgroup analysis found no differences when steroids or steroids plus 5-ASA were used as additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (6/342 participants) compared to placebo (5/349 participants) may result in no difference in serious adverse events (RR 1.19, 95% CI 0.38 to 3.71). A subgroup analysis found no differences when steroids were additional therapies to antibiotics and placebo. There is low certainty evidence that antibiotics (3/342 participants) compared to placebo (1/349 participants) may result in no difference in withdrawals due to adverse events (RR 2.06, 95% CI 0.27 to 15.72). A subgroup analysis found no differences when steroids or steroids plus 5-ASA were additional therapies to antibiotics and placebo. It is unclear if there is any difference between antibiotics in combination with probiotics compared to no treatment or placebo for failure to achieve clinical remission (RR 0.68, 95% CI 0.39 to 1.19), serious adverse events (RR 1.00, 95% CI 0.07 to 15.08), or withdrawals due to adverse events (RR 1.00, 95% CI 0.07 to 15.08). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to 5-ASA for failure to achieve clinical remission (RR 2.20, 95% CI 1.17 to 4.14). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to probiotics for failure to achieve clinical remission (RR 0.47, 95% CI 0.23 to 0.94). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to 5-ASA for failure to maintain clinical remission (RR 0.71, 95% CI 0.47 to 1.06). The certainty of the evidence is very low. It is unclear if there is any difference between antibiotics compared to no treatment for failure to achieve clinical remission in a mixed population of people with active and inactive disease (RR 0.56, 95% CI 0.29 to 1.07). The certainty of the evidence is very low. For all other outcomes, no effects could be estimated due to a lack of data.

AUTHORS' CONCLUSIONS

There is high certainty evidence that there is no difference between antibiotics and placebo in the proportion of people who achieve clinical remission at the end of the intervention period. However, there is evidence that there may be a greater proportion of people who achieve clinical remission and probably a greater proportion who achieve clinical response with antibiotics when compared with placebo at 12 months. There may be no difference in serious adverse events or withdrawals due to adverse events between antibiotics and placebo. No clear conclusions can be drawn for any other comparisons. A clear direction for future research appears to be comparisons of antibiotics and placebo (in addition to standard therapies) with longer-term measurement of outcomes. Additionally. As there were single studies of other head-to-head comparisons, there may be scope for future studies in this area.

Next-Generation Probiotics for Inflammatory Bowel Disease

Engineered probiotics represent a cutting-edge therapy in intestinal inflammatory disease (IBD). Genetically modified bacteria have provided a new strategy to release therapeutically operative molecules in the intestine and have grown into promising new therapies for IBD. Current IBD treatments, such as corticosteroids and immunosuppressants, are associated with relevant side effects and a significant proportion of patients are dependent on these therapies, thus exposing them to the risk of relevant long-term side effects. Discovering new and effective therapeutic strategies is a worldwide goal in this research field and engineered probiotics could potentially provide a viable solution. This review aims at describing the proceeding of bacterial engineering and how genetically modified probiotics may represent a promising new biotechnological approach in IBD treatment.

Treatment of Inflammatory Bowel Disease: A Comprehensive Review

Inflammatory bowel disease (IBD), as a global disease, has attracted much research interest. Constant research has led to a better understanding of the disease condition and further promoted its management. We here reviewed the conventional and the novel drugs and therapies, as well as the potential ones, which have shown promise in preclinical studies and are likely to be effective future therapies. The conventional treatments aim at controlling symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures and/or surgical resection if necessary. However, a considerable fraction of patients do not respond to available treatments or lose response, which calls for new therapeutic strategies. Diverse therapeutic options are emerging, involving small molecules, apheresis therapy, improved intestinal microecology, cell therapy, and exosome therapy. In addition, patient education partly upgrades the efficacy of IBD treatment. Recent advances in the management of IBD have led to a paradigm shift in the treatment goals, from targeting symptom-free daily life to shooting for mucosal healing. In this review, the latest progress in IBD treatment is summarized to understand the advantages, pitfalls, and research prospects of different drugs and therapies and to provide a basis for the clinical decision and further research of IBD.

Probiotics and Vitamin D/Vitamin D Receptor Pathway Interaction: Potential Therapeutic Implications in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic conditions of unknown etiology and immunomediated pathogenesis. In the last years, the comprehension of the complex mechanisms involved in the intestinal mucosal homeostasis, and the analysis of the alterations potentially leading to inflammatory pathologic states, has consistently increased. Specifically, the extraordinary impulse in the field of research of the intestinal microbiome has opened the door to the investigation of possible novel approaches to the diagnosis, management and therapeutic applications in IBD. In line with that, administration of probiotic bacteria has been intensely evaluated, leading to much more exciting results in experimental models than in clinical practice. Considering the consistent heterogeneity of the available studies on probiotics, the increased knowledge of the properties of the single bacterial species would ideally lead to unravel potential mechanisms of action that may bring therapeutic applications in specific pathologic condition. Among the relevant molecular pathways for mucosal homeostasis maintenance, the vitamin D/vitamin D receptor (VDR) pathway has been intensely studied in the very last years. In fact, besides osteometabolic functions, the vitamin D exerts important homeostatic effects in the organism at multiple levels, such as immunomodulation, inflammation control, and microbiota regulation, which are likely to play a relevant role in intestinal mucosa protection. In the present review, recent findings about probiotic applications in IBD and mechanisms of action linking vitamin D/VDR pathway to IBD are reported. Available evidence for probiotic effect on vitamin D/VDR are reviewed and potential future application in IBD patients are discussed. At present, many aspects of IBD pathogenesis are still obscure, and current therapeutic options for IBD treatment are at best suboptimal. The increasing comprehension of the different pathways involved in IBD pathogenesis will lead to novel findings ideally leading to potential clinical applications. Microbiota manipulation and vitamin/VDR pathway appear a promising field for future research and therapeutic developments.

The Efficacy of Probiotics in the Management of Helicobacter Pylori: A Systematic Review

Helicobacter pylori is a Gram-negative microorganism that causes chronic dyspepsia, gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma. Various antibiotic regimens are employed to eradicate it; however, antibiotic resistance has skyrocketed in recent years, resulting in a reduction in eradication rates. As a result, numerous novel therapeutic approaches are being adopted in clinical practice, and probiotics are being extensively investigated. Probiotics are living bacteria that, when consumed, offer many medicinal advantages that may be accomplished by altering the amount or activity of gut flora. Their beneficial influence on gut health, immune system modulation, and cancer therapy is the subject of extensive investigation. This is owing to their perceived safety and simplicity of use. The primary objective of this review is to learn about and investigate the function of probiotics in the eradication of H. pylori, either alone or in conjunction with traditional treatments.

Data have been collected from PubMed, PubMed Central, Medline, Cochrane, and Google Scholar, and relevant articles have been chosen following the PRISMA guidelines. Our search resulted in 2489 records, of which 123 full-text articles were screened for eligibility. Two reviewers independently performed the quality appraisal of 16 relevant articles, and ultimately 11 high-quality studies are included in this review. In conclusion, probiotic monotherapy does not have a significant effect on the eradication rates of H. pylori, but in conjunction with standard treatment regimens, there was mild improvement in the eradication rates but a significant reduction of side effects due to antibiotics.

Therapeutic Advances in Gut Microbiome Modulation in Patients with Inflammatory Bowel Disease from Pediatrics to Adulthood

There is mounting evidence that the gut microbiota plays an important role in the pathogenesis of inflammatory bowel disease (IBD). For the past decade, high throughput sequencing-based gut microbiome research has identified characteristic shifts in the composition of the intestinal microbiota in patients with IBD, suggesting that IBD results from alterations in the interactions between intestinal microbes and the host’s mucosal immune system. These studies have been the impetus for the development of new therapeutic approaches targeting the gut microbiome, such as nutritional therapies, probiotics, fecal microbiota transplant and beneficial metabolic derivatives. Innovative technologies can further our understanding of the role the microbiome plays as well as help to evaluate how the different approaches in microbiome modulation impact clinical responses in adult and pediatric patients. In this review, we highlight important microbiome studies in patients with IBD and their response to different microbiome modulation therapies, and describe the differences in therapeutic response between pediatric and adult patient cohorts.

Fecal Microbial Transplantation versus Mesalamine Enema for Treatment of Active Left-Sided Ulcerative Colitis-Results of a Randomized Controlled Trial

BACKGROUND AND AIMS

Ulcerative colitis (UC) is a chronic inflammatory disease. Fecal microbial transplantation (FMT) is a promising alternative treatment.

METHODS

This multicenter, open-label, noninferiority trial randomized patients with active left-sided UC (Mayo score 4-10) equally to FMT or 5-aminosalicylic acid (5-ASA) enemas. FMT enemas were administered five times in the first week and then once weekly for 5 weeks. 5-ASA enemas were administered daily for 2 weeks and then every other day. The primary study endpoint was clinical remission, with a total Mayo score ≤2 at week 12 with no subscore >1.

RESULTS

Sixty-one patients were screened; 45 were enrolled and randomized to FMT (n = 23) or 5-ASA (n = 22). Twenty-one FMT and 22 5-ASA patients completed at least the week 4 study visit and were included in the mITT analysis. Twelve FMT (57%) and eight 5-ASA patients achieved the primary study endpoint. FMT noninferiority with 10% margin was confirmed (95% CI: -7.6%, 48.9%). Adverse events occurred in 12 FMT (57%) and 13 5-ASA (59%) patients. Increased microbial diversity persisted 3 months after FMT.

CONCLUSION

FMT is an effective treatment for left-sided UC and increased recipient microbiome diversity. Targeted microbiome modification may improve FMT efficacy. Further investigation is needed to guide donor and patient selection.

Nutritional Aspects of Pediatric Gastrointestinal Diseases

In the last decade, the role of nutritional management in pediatric gastrointestinal diseases has gained increasing popularity. Disease-specific diets have been introduced as conventional treatments by international guidelines. Patients tend to more willingly accept food-based therapies than drugs because of their relatively “harmless” nature. Apart from a diet’s therapeutic role, nutritional support is crucial in maintaining growth and improving clinical outcomes in pediatric patients. Despite the absence of classical “side effects”, however, it should be emphasized that any dietary modification might have negative consequences on children’s growth and development. Hence, expert supervision is always advised, in order to support adequate nutritional requirements. Unfortunately, the media provide an inaccurate perception of the role of diet for gastrointestinal diseases, leading to misconceptions by patients or their caregivers that tends to overestimate the beneficial role of diets and underestimate the potential adverse effects. Moreover, not only patients, but also healthcare professionals, have a number of misconceptions about the nutritional benefits of diet modification on gastrointestinal diseases. The aim of this review is to highlight the role of diet in pediatric gastrointestinal diseases, to detect misconceptions and to give a practical guide for physicians on the basis of current scientific evidence.

The role of the microbiome in gastrointestinal inflammation

The microbiome plays an important role in maintaining human health. Despite multiple factors being attributed to the shaping of the human microbiome, extrinsic factors such diet and use of medications including antibiotics appear to dominate. Mucosal surfaces, particularly in the gut, are highly adapted to be able to tolerate a large population of microorganisms whilst still being able to produce a rapid and effective immune response against infection. The intestinal microbiome is not functionally independent from the host mucosa and can, through presentation of microbe-associated molecular patterns (MAMPs) and generation of microbe-derived metabolites, fundamentally influence mucosal barrier integrity and modulate host immunity. In a healthy gut there is an abundance of beneficial bacteria that help to preserve intestinal homoeostasis, promote protective immune responses, and limit excessive inflammation. The importance of the microbiome is further highlighted during dysbiosis where a loss of this finely balanced microbial population can lead to mucosal barrier dysfunction, aberrant immune responses, and chronic inflammation that increases the risk of disease development. Improvements in our understanding of the microbiome are providing opportunities to harness members of a healthy microbiota to help reverse dysbiosis, reduce inflammation, and ultimately prevent disease progression.

Anti-Inflammatory and Immunomodulatory Effects of Probiotics in Gut Inflammation: A Door to the Body

Hosting millions of microorganisms, the digestive tract is the primary and most important part of bacterial colonization. On one side, in cases of opportunistic invasion, the abundant bacterial population inside intestinal tissues may face potential health problems such as inflammation and infections. Therefore, the immune system has evolved to sustain the host-microbiota symbiotic relationship. On the other hand, to maintain host immune homeostasis, the intestinal microflora often exerts an immunoregulatory function that cannot be ignored. A field of great interest is the association of either microbiota or probiotics with the immune system concerning clinical uses. This microbial community regulates some of the host's metabolic and physiological functions and drives early-life immune system maturation, contributing to their homeostasis throughout life. Changes in gut microbiota can occur through modification in function, composition (dysbiosis), or microbiota-host interplays. Studies on animals and humans show that probiotics can have a pivotal effect on the modulation of immune and inflammatory mechanisms; however, the precise mechanisms have not yet been well defined. Diet, age, BMI (body mass index), medications, and stress may confound the benefits of probiotic intake. In addition to host gut functions (permeability and physiology), all these agents have profound implications for the gut microbiome composition. The use of probiotics could improve the gut microbial population, increase mucus-secretion, and prevent the destruction of tight junction proteins by decreasing the number of lipopolysaccharides (LPSs). When LPS binds endothelial cells to toll-like receptors (TLR 2, 4), dendritic cells and macrophage cells are activated, and inflammatory markers are increased. Furthermore, a decrease in gut dysbiosis and intestinal leakage after probiotic therapy may minimize the development of inflammatory biomarkers and blunt unnecessary activation of the immune system. In turn, probiotics improve the differentiation of T-cells against Th2 and development of Th2 cytokines such as IL-4 and IL-10. The present narrative review explores the interactions between gut microflora/probiotics and the immune system starting from the general perspective of a biological plausibility to get to the in vitro and in vivo demonstrations of a probiotic-based approach up to the possible uses for novel therapeutic strategies.

The effect of probiotics on lipid profile & anthropometric indices in diabetic nephropathy; a systematic review and meta-analysis of clinical trials

Purpose

Recent trials have demonstrated the possible improvements in lipid profile & anthropometric indices after probiotics supplementation. We aimed to reanalyze the related literature to explore the efficacy of probiotics in Diabetic Nephropathy (DN) patients.

Methods

PubMed, Embase, Web of science, google scholar, Scopus, and Cochrane Library databases were systematically searched to find the related data on diabetic nephropathy population. All Randomized controlled trials (RCTs) that investigated the effect of probiotics on serum lipid markers (High-Density Lipoprotein [HDL], Triglyceride, Total Cholesterol, TC-to-HDL ratio, Low-Density Lipoprotein, Very Low-Density Lipoprotein) and anthropometric indices (Body Weight, Body Mass Index, waist-to-hip ratio) were included (PROSPERO No.CRD42020186189). Meta-analysis was performed using the random-effect model.

Results

Of 156 studies, seven were eligible for inclusion. Lipid biomarkers had a marginal reduction (except for HDL; WMD = 2.59 mg/dl; 95% CI = -0.28, 5.47; P = 0.077); whereas anthropometric indices increased in a non-significant manner.

Conclusion

There is limited evidence to support the efficacy of probiotics for the modulation of lipid profile and anthropometric indices in DN patients.

Graphical abstract

Probiotics did not beneficial effect on lipid profile & anthropometric markers in Diabetic Nephropathy; anyway, more trials should be conducted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00765-8.

Viral Infections, the Microbiome, and Probiotics

Viral infections continue to cause considerable morbidity and mortality around the world. Recent rises in these infections are likely due to complex and multifactorial external drivers, including climate change, the increased mobility of people and goods and rapid demographic change to name but a few. In parallel with these external factors, we are gaining a better understanding of the internal factors associated with viral immunity. Increasingly the gastrointestinal (GI) microbiome has been shown to be a significant player in the host immune system, acting as a key regulator of immunity and host defense mechanisms. An increasing body of evidence indicates that disruption of the homeostasis between the GI microbiome and the host immune system can adversely impact viral immunity. This review aims to shed light on our understanding of how host-microbiota interactions shape the immune system, including early life factors, antibiotic exposure, immunosenescence, diet and inflammatory diseases. We also discuss the evidence base for how host commensal organisms and microbiome therapeutics can impact the prevention and/or treatment of viral infections, such as viral gastroenteritis, viral hepatitis, human immunodeficiency virus (HIV), human papilloma virus (HPV), viral upper respiratory tract infections (URTI), influenza and SARS CoV-2. The interplay between the gastrointestinal microbiome, invasive viruses and host physiology is complex and yet to be fully characterized, but increasingly the evidence shows that the microbiome can have an impact on viral disease outcomes. While the current evidence base is informative, further well designed human clinical trials will be needed to fully understand the array of immunological mechanisms underlying this intricate relationship.

Effect of probiotics on oxidative stress and inflammatory status in diabetic nephropathy: A systematic review and meta-analysis of clinical trials

This systematic review and meta-analysis was performed to evaluate the effect of probiotics on serum high sensitivity-C reactive protein (hs-CRP) and oxidative stress biomarkers among patients with Diabetic Nephropathy (DN). Electronic databases were searched through May 10, 2020. Seven trials that included 340 patients were identified for analysis. Meta-analysis indicated that probiotics significantly reduced hs-CRP (WMD = -1.53 mg/L; 95% CI = -2.38, -0.69; P < 0.001) and Malondialdehyde (MDA) (WMD = -0.62 ɥmol/L; 95% CI = -1.18, -0.06; P = 0.030) levels in DN patients, whereas they increased Glutathione (GSH) (WMD = 73.84 ɥmol/L; 95% CI = 24.3, 123.29; P = 0.003) and Total Antioxidant Capacity (TAC) (WMD = 26.54 mmol/L; 95% CI = 6.23, 46.85; P = 0.010). Therefore, probiotics may improve hs-CRP and oxidative stress biomarkers in DN population.

Efficacy of Dietary Supplements in Inflammatory Bowel Disease and Related Autoimmune Diseases

The microbiome is an important contributor to a variety of fundamental aspects of human health, including host metabolism, infection, and the immune response. Gut dysbiosis has been identified as a contributor to the errant immune response in a variety of immune-mediated inflammatory diseases (IMIDs), such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and psoriatic disease (psoriasis and psoriatic arthritis). Given this, probiotics and prebiotics have been investigated as therapeutic options in these disease states. In our review, we highlight the current evidence on prebiotics and probiotics as well as other supplements (such as fish oils, vitamin D, and curcumin) as therapies for IBD. Recommendations, however, regarding the specific use of such supplements in IBD have been lacking, particularly from professional societies, often due to study limitations related to small sample sizes and design heterogeneity. Hence, we additionally examine the literature on the use of prebiotics, probiotics, and other supplements in related IMIDs, namely RA and psoriasis/psoriatic arthritis, as these diseases share many approved therapeutic options with IBD. Based on these combined findings, we offer additional evidence that may help guide clinicians in their treatment of patients with IBD (and other IMIDs) and provide recommendations on potential next steps in therapeutic research in this area.

Probiotics for induction of remission in Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, in which the pathogenesis is believed to be partly influenced by the gut microbiome. Probiotics can be used to manipulate the microbiome and have therefore been considered as a potential therapy for CD. There is some evidence that probiotics benefit other gastrointestinal conditions, such as irritable bowel syndrome and ulcerative colitis, but their efficacy in CD is unclear. This is the first update of a Cochrane Review previously published in 2008.

OBJECTIVES

To assess the efficacy and safety of probiotics for the induction of remission in CD.

SEARCH METHODS

The following electronic databases were searched: MEDLINE (from inception to 6 July 2020), Embase (from inception to 6 July 2020), the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane IBD Review Group Specialised Trials Register, World Health Organization (WHO) International Clinical Trials Registry, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared probiotics with placebo or any other non-probiotic intervention for the induction of remission in CD were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of included studies. The primary outcome was clinical remission. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for dichotomous outcomes.

MAIN RESULTS

There were two studies that met criteria for inclusion. One study from Germany had 11 adult participants with mild-to-moderate CD, who were treated with a one-week course of corticosteroids and antibiotics (ciprofloxacin 500 mg twice daily and metronidazole 250 mg three times a day), followed by randomised assignment to Lactobacillus rhamnosus strain GG (two billion colony-forming units per day) or corn starch placebo. The other study from the United Kingdom (UK) had 35 adult participants with active CD (CDAI score of 150 to 450) randomised to receive a synbiotic treatment (comprised of freeze-dried Bifidobacterium longum and a commercial product) or placebo. The overall risk of bias was low in one study, whereas the other study had unclear risk of bias in relation to random sequence generation, allocation concealment, and blinding. There was no evidence of a difference between the use of probiotics and placebo for the induction of remission in CD (RR 1.06; 95% CI 0.65 to 1.71; 2 studies, 46 participants) after six months. There was no difference in adverse events between probiotics and placebo (RR 2.55; 95% CI 0.11 to 58.60; 2 studies, 46 participants). The evidence for both outcomes was of very low certainty due to risk of bias and imprecision.

AUTHORS' CONCLUSIONS

The available evidence is very uncertain about the efficacy or safety of probiotics, when compared with placebo, for induction of remission in Crohn's disease. There is a lack of well-designed RCTs in this area and further research is needed.

Probiotics and Probiotic-Derived Functional Factors-Mechanistic Insights Into Applications for Intestinal Homeostasis

Advances in our understanding of the contribution of the gut microbiota to human health and the correlation of dysbiosis with diseases, including chronic intestinal conditions such as inflammatory bowel disease (IBD), have driven mechanistic investigations of probiotics in intestinal homeostasis and potential clinical applications. Probiotics have been shown to promote intestinal health by maintaining and restoring epithelial function, ensuring mucosal immune homeostasis, and inhibiting pathogenic bacteria. Recent findings reveal an approach for defining previously unrecognized probiotic-derived soluble factors as potential mechanisms of probiotic action. This review focuses on the impact of probiotics and probiotic-derived functional factors, including probiotic products and metabolites by probiotics, on the cellular responses and signaling pathways involved in maintaining intestinal homeostasis. Although there is limited information regarding the translation of probiotic treatment outcomes from in vitro and animal studies to clinical applications, potential approaches for increasing the clinical efficacy of probiotics for IBD, such as those based on probiotic-derived factors, are highlighted in this review. In this era of precision medicine and targeted therapies, more basic, preclinical, and clinical evidence is needed to clarify the efficacy of probiotics in maintaining intestinal health and preventing and treating disease.