Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases

Implementation of the gut microbiota prevents anastomotic leaks in laparoscopic colorectal surgery for cancer:the results of the MIRACLe study

The aim of this pilot study was to evaluate the effects of a novel perioperative treatment for the implementation of the gut microbiota, to prevent anastomotic fistula and leakage (AL) in patients undergoing laparoscopic colorectal resections for cancer. A series of 60 patients who underwent elective colorectal surgery at S. Eugenio Hospital (Rome-Italy) between December 1, 2020 and November 30, 2021 and received a novel perioperative preparation following the MIRACLe (Microbiota Implementation to Reduce Anastomotic Colorectal Leaks) protocol (oral antibiotics, mechanical bowel preparation and perioperative probiotics), was compared to a group of 500 patients (control group) operated on between March 2015 and November 30, 2020, who received a standard ERAS protocol. In the MIRACLe Group only 1 anastomotic leak was registered. In this group the incidence of AL was just 1.7% vs. 6.4% in the control group (p = 0.238) and the incidence of surgical site infections (1.7% vs. 3.6%; p = 0.686), reoperations (1.7% vs. 4.2%; p = 0.547) and postoperative mortality (0% vs. 2.2%; p = 0.504) were lower. The postoperative outcomes were also better: the times to first flatus, to first stool and to oral feeding were shorter (1 vs. 2, 2 vs. 3 and 2 vs. 3 days, respectively; p < 0.001). Additionally, the postoperative recovery was faster, with a shorter time to discharge (4 vs. 6 days; p < 0.001). In this pilot study, the MIRACLe protocol appeared to be safe and considerably reduced anastomotic leaks in elective laparoscopic colorectal surgery for cancer, even if not statistically significant, due to the small number of cases.

Manipulation of Gut Microbiota as a Key Target for Crohn's Disease

Crohn's disease (CD) is an inflammatory bowel disease (IBD) sub-type characterized by transmural chronic inflammation of the gastrointestinal tract. Research indicates a complex CD etiology involving genetic predisposition and immune dysregulation in response to environmental triggers. The chronic mucosal inflammation has been associated with a dysregulated state, or dysbiosis, of the gut microbiome (bacteria), mycobiome (fungi), virome (bacteriophages and viruses), and archeaome (archaea) further affecting the interkingdom syntrophic relationships and host metabolism. Microbiota dysbiosis in CD is largely described by an increase in facultative anaerobic pathobionts at the expense of strict anaerobic Firmicutes, such as Faecalibacterium prausnitzii. In the mycobiome, reduced fungal diversity and fungal-bacteria interactions, along with a significantly increased abundance of Candida spp. and a decrease in Saccharomyces cerevisiae are well documented. Virome analysis also indicates a significant decrease in phage diversity, but an overall increase in phages infecting bacterial groups associated with intestinal inflammation. Finally, an increase in methanogenic archaea such as Methanosphaera stadtmanae exhibits high immunogenic potential and is associated with CD etiology. Common anti-inflammatory medications used in CD management (amino-salicylates, immunomodulators, and biologics) could also directly or indirectly affect the gut microbiome in CD. Other medications often used concomitantly in IBD, such as antibiotics, antidepressants, oral contraceptives, opioids, and proton pump inhibitors, have shown to alter the gut microbiota and account for increased susceptibility to disease onset or worsening of disease progression. In contrast, some environmental modifications through alternative therapies including fecal microbiota transplant (FMT), diet and dietary supplements with prebiotics, probiotics, and synbiotics have shown potential protective effects by reversing microbiota dysbiosis or by directly promoting beneficial microbes, together with minimal long-term adverse effects. In this review, we discuss the different approaches to modulating the global consortium of bacteria, fungi, viruses, and archaea in patients with CD through therapies that include antibiotics, probiotics, prebiotics, synbiotics, personalized diets, and FMT. We hope to provide evidence to encourage clinicians and researchers to incorporate these therapies into CD treatment options, along with making them aware of the limitations of these therapies, and indicate where more research is needed.

Cancer-Associated Microbiota: From Mechanisms of Disease Causation to Microbiota-Centric Anti-Cancer Approaches

Helicobacter pylori infection is the only well-established bacterial cause of cancer. However, due to the integral role of tissue-resident commensals in maintaining tissue-specific immunometabolic homeostasis, accumulated evidence suggests that an imbalance of tissue-resident microbiota that are otherwise considered as commensals, can also promote various types of cancers. Therefore, the present review discusses compelling evidence linking tissue-resident microbiota (especially gut bacteria) with cancer initiation and progression. Experimental evidence supporting the cancer-causing role of gut commensal through the modulation of host-specific processes (e.g., bile acid metabolism, hormonal effects) or by direct DNA damage and toxicity has been discussed. The opportunistic role of commensal through pathoadaptive mutation and overcoming colonization resistance is discussed, and how chronic inflammation triggered by microbiota could be an intermediate in cancer-causing infections has been discussed. Finally, we discuss microbiota-centric strategies, including fecal microbiota transplantation, proven to be beneficial in preventing and treating cancers. Collectively, this review provides a comprehensive understanding of the role of tissue-resident microbiota, their cancer-promoting potentials, and how beneficial bacteria can be used against cancers.

Cell-free probiotic supernatant (CFS) treatment alleviates indomethacin-induced enterocolopathy in BALB/c mice by down-modulating inflammatory response and oxidative stress: potential alternative targeted treatment

Probiotics and their metabolites appear to be a promising approach that targets both the intestinal inflammation and dysbiosis in bowel diseases. In this context, the emergence of the probiotic cell-free supernatant (CFS) has attracted more attention as a safe and targeted alternative therapy with reduced side effects. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) can cause significant intestinal alterations and inflammation, leading to experimental enterocolopathy resembling Crohn disease. Therefore, we investigated the effect of CFS supplementation on the inflammation and the mucosal intestinal alterations induced by NSAIDs, indomethacin. In the current study, a murine model of intestinal inflammation was generated by the oral gavage (o.g) of indomethacin (10 mg/kg) to BALB/C mice. A group of mice treated with indomethacin was concomitantly treated orally by CFS for 5 days. The Body Health Condition index was monitored, and histological scores were evaluated. Moreover, oxidative and pro-inflammatory markers were assessed. Interestingly, we observed that CFS treatment attenuated the severity of the intestinal inflammation in our enterocolopathy model and resulted in the improvement of the clinical symptoms and the histopathological features. Notably, nitric oxide, tumor necrosis factor alpha, malondialdehyde, and myeloperoxidase levels were down-modulated by CFS supplementation. Concomitantly, an attenuation of NF-κB p65, iNOS, COX2 expression in the ileum and the colon was reported. Collectively, our data suggest that CFS treatment has a beneficial effect in experimental enterocolopathy model and could constitute a good therapeutic candidate for alleviating inflammatory responses and to maintain mucosal homeostasis during chronic and severe conditions of intestinal inflammation.

Mechanisms of Kwashiorkor-Associated Immune Suppression: Insights From Human, Mouse, and Pig Studies

Malnutrition refers to inadequate energy and/or nutrient intake. Malnutrition exhibits a bidirectional relationship with infections whereby malnutrition increases risk of infections that further aggravates malnutrition. Severe malnutrition (SM) is the main cause of secondary immune deficiency and mortality among children in developing countries. SM can manifest as marasmus (non-edematous), observed most often (68.6% of all malnutrition cases), kwashiorkor (edematous), detected in 23.8% of cases, and marasmic kwashiorkor, identified in ~7.6% of SM cases. Marasmus and kwashiorkor occur due to calorie-energy and protein-calorie deficiency (PCD), respectively. Kwashiorkor and marasmic kwashiorkor present with reduced protein levels, protein catabolism rates, and altered levels of micronutrients leading to uncontrolled oxidative stress, exhaustion of anaerobic commensals, and proliferation of pathobionts. Due to these alterations, kwashiorkor children present with profoundly impaired immune function, compromised intestinal barrier, and secondary micronutrient deficiencies. Kwashiorkor-induced alterations contribute to growth stunting and reduced efficacy of oral vaccines. SM is treated with antibiotics and ready-to-use therapeutic foods with variable efficacy. Kwashiorkor has been extensively investigated in gnotobiotic (Gn) mice and piglet models to understand its multiple immediate and long-term effects on children health. Due to numerous physiological and immunological similarities between pigs and humans, pig represents a highly relevant model to study kwashiorkor pathophysiology and immunology. Here we summarize the impact of kwashiorkor on children's health, immunity, and gut functions and review the relevant findings from human and animal studies. We also discuss the reciprocal interactions between PCD and rotavirus-a highly prevalent enteric childhood pathogen due to which pathogenesis and immunity are affected by childhood SM.

Effects of probiotic supplementation on abdominal pain severity in pediatric patients with irritable bowel syndrome: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Probiotic supplementation has been used to alleviate abdominal pain in children and adolescents with irritable bowel syndrome (IBS), but the evidence is not compelling. Thus, a systematic review and meta-analysis of randomized clinical trials (RCTs) were performed to investigate the effects of probiotic supplementation on abdominal pain in pediatric patients with IBS.

METHODS

PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, and Embase were the available databases searched to find relevant randomized clinical trials up to April 2021. The effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

Seven RCTs with 441 participants were included, from which the meta-analysis demonstrated that probiotic supplementation has a significant effect on reducing abdominal pain in pediatric patients with IBS (WMD = - 2.36; 95% CI - 4.12 to - 0.60; P = 0.009). Although our study involved children and adolescents (≤ 18 years), the effects of probiotic supplementation seem to be more potent in patients under 10 years old (WMD = - 2.55; 95% CI - 2.84 to - 2.27) compared to patients aged 10-18 years (WMD = - 1.70; 95% CI - 2.18 to - 1.22). The length of supplementation longer than four weeks was more effective (WMD = - 2.43; 95% CI - 2.76 to - 2.09).

CONCLUSION

Probiotic supplementation can reduce abdominal pain in pediatric patients with IBS.

The Beneficial Effect of Probiotics Supplementation on Penicillin-Induced Focal Seizure in Rats

The focal epilepsy is a chronic neurological brain disorder which affects millions of people in the world. There is emerging evidence that changes in the gut microbiota may have effects on epileptic seizures. In the present study, we examined the effect of probiotics on penicillin-induced focal seizure model in rats. Male Wistar Albino rats (n: 21) were randomly divided into three groups: control (no medication), penicillin and penicillin + probiotic. Probiotic VSL#3 (12.86 bn living bacteria/kg/day) was given by gavage for 30 days. The seizures were induced by intracortical injection of penicillin G (500 IU) into the cortex. An ECoG recordings were made for 180 min after penicillin G application. The spike frequency and the amplitude were used to assess the severity of seizures. Tumor necrosis factor (TNF-α), nitric oxide (NO) and interleukin (IL-6) levels in the brain were studied biochemically. Our results indicated that probiotic supplementation improved focal seizures through increasing the latency (p < 0.001) and decreasing the spike frequency (p < 0.01) compared to the penicillin group. Penicillin-induced seizure in rats significantly enhanced TNF-α (p < 0.01), NO (p < 0.01) and IL-6 (p < 0.05) compared to the control. Probiotic supplementation significantly decreased IL-6 (p < 0.05), TNF-α (p < 0.01) and NO (p < 0.001) compared to the penicillin group. When the body weights were compared before and after the experiment, there was no difference between the control and penicillin groups, but it was observed that the body weight decreased after probiotic supplementation in the penicillin + probiotic group. Probiotic supplementation may have anti-seizure effect by reducing proinflammatory cytokine and NO levels in epileptic rat brain.

Role of zonula occludens in gastrointestinal and liver cancers

A growing body of evidence suggests that tight junction (TJ) proteins play a crucial role in the pathogenesis of various diseases, including gastrointestinal (GI) cancer and hepatocellular carcinoma (HCC). TJ proteins primarily maintain the epithelial and endothelial cells intact together through integral proteins however, recent reports suggest that they also regulate gene expression necessary for cell proliferation, angiogenesis, and metastasis through adapter proteins such as zonula occludens (ZO). ZO proteins are membrane-associated cytosolic scaffolding proteins that modulate cell proliferation by interacting with several transcription factors. Reduced ZO proteins in GI cancer and HCC are correlated with tumor development and poor prognosis. Pubmed has searched for using the keyword ZO and gastric cancer, ZO and cancer, and ZO and HCC for the last ten years to date. This review summarized the role of ZO proteins in cell proliferation and their expression in GI cancer and HCC. Furthermore, therapeutic interventions targeting ZO in GI and liver cancers are reviewed.

In Vitro Anti-Inflammatory Activity of Peptides Obtained by Tryptic Shaving of Surface Proteins of Streptococcus thermophilus LMD-9

Streptococcus thermophilus, a lactic acid bacterium widely used in the dairy industry, is consumed regularly by a significant proportion of the population. Some strains show in vitro anti-inflammatory activity which is not fully understood. We hypothesized that peptides released from the surface proteins of this bacterium during digestion could be implied in this activity. Consequently, we prepared a peptide hydrolysate by shaving and hydrolysis of surface proteins using trypsin, and the origin of peptides was checked by liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis. Most of the identified peptides originated from bacterial cell surface proteins. The anti-inflammatory activity of peptide hydrolysate was investigated under inflammatory conditions in two cell models. Peptide hydrolysate significantly decreased secretion of pro-inflammatory cytokine IL-8 in lipopolysaccharide (LPS)-stimulated human colon epithelial HT-29 cells. It also reduced the production of pro-inflammatory cytokines IL-8, IL-1β and the protein expression levels of Pro-IL-1β and COX-2 in LPS-stimulated THP-1 macrophages. The results showed that peptides released from bacterial surface proteins by a pancreatic protease could therefore participate in an anti-inflammatory activity of S. thermophilus LMD-9 and could prevent low-grade inflammation.

Functional Microbes and Their Incorporation into Foods and Food Supplements: Probiotics and Postbiotics

Life expectancy has dramatically increased over the past 200 years, but modern life factors such as environmental exposure, antibiotic overuse, C-section deliveries, limited breast-feeding, and diets poor in fibers and microbes could be associated with the rise of noncommunicable diseases such as overweight, obesity, diabetes, food allergies, and colorectal cancer as well as other conditions such as mental disorders. Microbial interventions that range from transplanting a whole undefined microbial community from a healthy gut to an ill one, e.g., so-called fecal microbiota transplantation or vaginal seeding, to the administration of selected well-characterized microbes, either live (probiotics) or not (postbiotics), with efficacy demonstrated in clinical trials, may be effective tools to treat or prevent acute and chronic diseases that humans still face, enhancing the quality of life.

Altered gut microbiota composition with antibiotic treatment impairs functional recovery after traumatic peripheral nerve crush injury in mice: effects of probiotics with butyrate producing bacteria

OBJECTIVE

Antibiotics (ABX) are widely used for life-threatening infections and also for routine surgical operations. Compelling evidence suggests that ABX-induced alterations of gut microbiota composition, termed dysbiosis, are linked with diverse disease states including neurological and neurodegenerative conditions. To combat the consequences of dysbiosis, probiotics (PBX) are widely used. ABX-induced dysbiosis is reported to impair neurological function after spinal cord injury. Traumatic peripheral nerve injury (TPNI) results in profound neurologic impairment and permanent disability. It is unknown whether ABX treatment-induced dysbiosis has any impact on TPNI-induced functional recovery, and if so, what role medical-grade PBX could have on TPNI recovery.

RESULTS

In this study, ABX-induced dysbiosis and PBX-induced microbiota enrichment models were used to explore the potential role of gut microbiome in TPNI. Stool analysis with 16S ribosomal RNA (rRNA) gene sequencing confirmed ABX-induced dysbiosis and revealed that ABX-induced changes could be partially restored by PBX administration with an abundance of butyrate producing bacteria. Pre-injury ABX significantly impaired, but pre-injury PBX significantly improved post-TPNI functional recovery. Importantly, post-injury PBX protected against pre-injury ABX-induced functional impairment. These findings demonstrate that reestablishment of gut microbiota composition with butyrate producing PBX during ABX-induced dysbiosis could be a useful adjuvant therapy for TPNI.

Gestational Diabetes, Colorectal Cancer, Bariatric Surgery, and Weight Loss among Diabetes Mellitus Patients: A Mini Review of the Interplay of Multispecies Probiotics

Diabetes mellitus has been steadily increasing over the past decades and is one of the most significant global public health concerns. Diabetes mellitus patients have an increased risk of both surgical and post-surgical complications. The post-surgical risks are associated with the primary condition that led to surgery and the hyperglycaemia per se. Gut microbiota seems to contribute to glucose homeostasis and insulin resistance. It affects the metabolism through body weight and energy homeostasis, integrating the peripheral and central food intake regulatory signals. Homeostasis of gut microbiota seems to be enhanced by probiotics pre and postoperatively. The term probiotics is used to describe some species of live microorganisms that, when administered in adequate amounts, confer health benefits on the host. The role of probiotics in intestinal or microbial skin balance after abdominal or soft tissue elective surgeries on DM patients seems beneficial, as it promotes anti-inflammatory cytokine production while increasing the wound-healing process. This review article aims to present the interrelation of probiotic supplements with DM patients undergoing elective surgeries.

The significant role of nutraceutical compounds in ulcerative colitis treatment

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) mainly affecting the colon and the rectum. Its main characters are represented by relapsing and remitting mucosal inflammation, starting in the rectum and typically extending continuously proximally through part or the entire colon. UC pathogenesis depends on multiple factors, such as genetic predisposition, defects in the epithelial barrier, dysregulated immune responses, and environmental causes. The most frequent symptoms are abdominal pain, weight loss, mucus discharge, bloody diarrhoea, incontinence, nocturnal defecations, fever, and anemia. Existing therapies for UC include 5-aminosalicylic acid (5-ASA) and its derivatives, steroids, immunosuppressants and biological drugs. However, limited efficacy and unwanted adverse effects hardly limit these strategies of treatment. In the last decades, research studies have been driven towards complementary and alternative medicines for the treatment of UC. Various nutraceuticals have exhibited promising results in modulating intestinal inflammation meanwhile improving symptoms. These compounds possess a wide spectrum of positive health effects evidenced by in vitro studies, characterized by their involvement in antioxidant defenses, cell proliferation, and gene expression. The present review analyzes the available data about the different types of nutraceuticals and their potential effectiveness as adjuvant therapy of IBD, with particular emphasis to UC.

Different Types and Functional Effects of Probiotics on Human Health through Regulating Glucose Homeostasis

With the increasing improvement of people's living standards, hyperglycemia has become one of the most frequent diseases in the world. The current drug therapy may have some negative effects and even cause some complications. As one of the most popular functional ingredients, probiotic bacteria have been proven to play important roles in balancing the glucose homeostasis level in animal and human clinic trials. In this perspective, we sorted three types of probiotics, discussed probiotic safety evaluation, and listed the known probiotic functional foods that assist to control glucose homeostasis. Then, the further summarization of the mechanisms on how probiotic bacteria could regulate glucose homeostasis and the developing trend of probiotic functional foods were discussed.

Fermentation products of Danshen relieved dextran sulfate sodium-induced experimental ulcerative colitis in mice

With the increased incidence and recognition, ulcerative colitis (UC) has become a global public health problem in the world. Although many immunosuppressant and biological drugs have been used for UC treatment, the cure rate is still very low. It is necessary to find some safe and long-term used medicine for UC cure. Recently, the Chinese traditional herb Danshen has been investigated in the treatment of UC. However, it is a limitation of Danshen that many of the active components in Danshen are not easily absorbed by the human body. Probiotics could convert macromolecules into smaller molecules to facilitate absorption. Thus, Lactobacillus rhamnosus (F-B4-1) and Bacillus subtillis Natto (F-A7-1) were screened to ferment Danshen in this study. The fermented Danshen products were gavaged in the dextran sulfate sodium (DSS)-induced UC model mice. Danshen had better results to attenuate symptoms of DSS-induced UC after fermented with F-B4-1 and F-A7-1. Loss of body weight and disease activity index (DAI) were reduced. The abnormally short colon lengths and colonic damage were recovered. And fermented Danshen had the better inhibitory effect than Danshen itself on pro-inflammatory cytokine expression during DSS-induced UC. The results indicated that compared with Danshen, fermented Danshen relieved DSS-induced UC in mice more effectively. Danshen fermented by probiotics might be an effective treatment to UC in clinic stage in the future.

Corrigendum to “Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases”

Correction to: Cheng FS, Pan D, Chang B, Jiang M, Sang LX. Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases. World J Clin Cases 2020; 8: 1361-1384. We are the team of Min Jiang and Li-Xuan Sang from the First Affiliated Hospital, China Medical University. Now we solemnly declare that the studies mentioned in this article[1] evaluated the probiotic formulation known as VSL#3 before January 31, 2016. The probiotic formulation is now commonly referred to as De Simone Formulation. In addition, the product currently known as VSL#3 is not the same as De Simone Formulation. De Simone Formulation is now available as Visbiome in the United States and Vivomixx in Europe.

Probiotics: A Promising Candidate for Management of Colorectal Cancer

Colorectal cancer (CRC) is the World's third most frequently diagnosed cancer type. It accounted for about 9.4% mortality out of the total incidences of cancer in the year 2020. According to estimated facts by World Health Organization (WHO), by 2030, 27 million new CRC cases, 17 million deaths, and around 75 million people living with the disease will appear. The facts and evidence that establish a link between the intestinal microflora and the occurrence of CRC are quite intuitive. Current shortcomings of chemo- and radiotherapies and the unavailability of appropriate treatment strategies for CRC are becoming the driving force to search for an alternative approach for the prevention, therapy, and management of CRC. Probiotics have been used for a long time due to their beneficial health effects, and now, it has become a popular candidate for the preventive and therapeutic treatment of CRC. The probiotics adopt different strategies such as the improvement of the intestinal barrier function, balancing of natural gut microflora, secretion of anticancer compounds, and degradation of carcinogenic compounds, which are useful in the prophylactic treatment of CRC. The pro-apoptotic ability of probiotics against cancerous cells makes them a potential therapeutic candidate against cancer diseases. Moreover, the immunomodulatory properties of probiotics have created interest among researchers to explore the therapeutic strategy by activating the immune system against cancerous cells. The present review discusses in detail different strategies and mechanisms of probiotics towards the prevention and treatment of CRC.

Lactobacillus fermentum CQPC06 in naturally fermented pickles prevents non-alcoholic fatty liver disease by stabilizing the gut-liver axis in mice

Herein, we used a HFD/F to induce NAFLD in mice and intervened with CQPC06 to determine the preventive effect of CQPC06 on NAFLD and its potential regulatory mechanism. C57BL/6J mice were fed with LFD, HFD/F, HFD/F supplemented with CQPC06, and HFD/F supplemented with LDBS for 8 weeks to test the properties of the probiotic. Biochemical and molecular biology methods were used to determine the levels of related indexes in mouse serum, liver tissue, epididymal fat, small intestine tissue, and feces. The results showed that CQPC06 exhibited satisfactory probiotic properties, significantly inhibited mouse weight gain, and decreased the liver index and serum lipid levels, including ALT, AKP, AST, TC, TG, LDL-C, LPS, and HDL-C levels. The HOMA-IR index calculated based on the blood glucose levels and serum insulin levels showed that the HOMA-IR index of NAFLD mice treated with CQPC06 significantly decreased. From the molecular biology level, CQPC06 significantly increased the mRNA and protein expression of PPAR-α, CYP7A1, CPT1, and LPL in NAFLD mouse livers, and decreased the expression of PPAR-γ and C/EBP-α. Furthermore, CQPC06 enhanced the expression of ZO-1, occludin, and claudin-1 in the small intestine of NAFLD mice, and decreased the expression of CD36. CQPC06 decreased the level of Firmicutes and increased the levels of Bacteroides and Akkermansia in the feces of NAFLD mice, and the ratio of Firmicutes/Bacteroides was significantly decreased. CQPC06 is highly resistant in vitro and survived in the gastrointestinal tract and exerted its probiotic effect, altered the intestinal microecology of NAFLD mice, and played an important role in NAFLD prevention through the unique anatomical advantages of the gut-liver axis. There was a clear preventive effect with high concentrations of CQPC06 and it was stronger than that of l-carnitine.

Rebuilding Microbiome for Mitigating Traumatic Brain Injury: Importance of Restructuring the Gut-Microbiome-Brain Axis

Traumatic brain injury (TBI) is a damage to the brain from an external force that results in temporary or permanent impairment in brain functions. Unfortunately, not many treatment options are available to TBI patients. Therefore, knowledge of the complex interplay between gut microbiome (GM) and brain health may shed novel insights as it is a rapidly expanding field of research around the world. Recent studies show that GM plays important roles in shaping neurogenerative processes such as blood-brain-barrier (BBB), myelination, neurogenesis, and microglial maturation. In addition, GM is also known to modulate many aspects of neurological behavior and cognition; however, not much is known about the role of GM in brain injuries. Since GM has been shown to improve cellular and molecular functions via mitigating TBI-induced pathologies such as BBB permeability, neuroinflammation, astroglia activation, and mitochondrial dysfunction, herein we discuss how a dysbiotic gut environment, which in fact, contributes to central nervous system (CNS) disorders during brain injury and how to potentially ward off these harmful effects. We further opine that a better understanding of GM-brain (GMB) axis could help assist in designing better treatment and management strategies in future for the patients who are faced with limited options.

Evaluation of the efficacy of probiotic VSL#3 and synbiotic VSL#3 and yacon-based product in reducing oxidative stress and intestinal permeability in mice induced to colorectal carcinogenesis

The objective of the present study was to evaluate the effect of probiotic VSL#3 isolated or associated with a yacon-based product (synbiotic) on oxidative stress modulation and intestinal permeability in an experimental model of colorectal carcinogenesis. Forty-five C57BL/6J mice were divided into three groups: control (standard diet AIN-93 M); probiotic (standard diet AIN-93 M and multispecies probiotic VSL#3, 2.25 × 10⁹ CFU), and synbiotic (standard diet AIN-93 M with yacon-based product, 6% fructooligosaccharides and inulin, and probiotic VSL#3, 2.25 × 10⁹ CFU). The experimental diets were provided for 13 weeks. The probiotic and the yacon-based product showed antioxidant activity, with the percentage of DPPH radical scavenging equal to 69.7 ± 0.4% and 74.3 ± 0.1%, respectively. These findings contributed to reduce hepatic oxidative stress: the control group showed higher concentration of malondialdehyde (1.8-fold, p = 0.007 and 1.5-fold, p = 0.035) and carbonylated protein (2-fold, p = 0.008 and 5.6-fold, p = 0.000) compared to the probiotic and synbiotic groups, respectively. Catalase enzyme activity increased 1.43-fold (p = 0.014) in synbiotic group. The crypt depth increased 1.2-fold and 1.4-fold with the use of probiotic and synbiotic, respectively, compared to the control diet (p = 0.000). These findings corroborate the reduction in intestinal permeability in the probiotic and synbiotic groups, as measured by the percentage of urinary lactulose excretion (CON: 0.93 ± 0.62% × PRO: 0.44 ± 0.05%, p = 0.048; and CON: 0.93 ± 0.62% × SYN: 0.41 ± 0.12%, p = 0.043). In conclusion, the probiotic and synbiotic showed antioxidant activity, which contributed to the reduction of oxidative stress markers. In addition, they protected the mucosa from damage caused by chemical carcinogen and reduced intestinal permeability. PRACTICAL APPLICATION: The relationship between intestinal health and the occurrence of various organic disorders has been demonstrated in many studies. The use of probiotics and prebiotics is currently one of the main targets for modulation of intestinal health. We demonstrated that the use of a commercial mix of probiotic bacteria (VSL#3) isolated or associated with a yacon-based prebiotic, rich in fructooligosaccharides and inulin, is able to reduce the oxidative stress and intestinal permeability in a colorectal carcinogenesis model. These compounds have great potential to be used as a food supplement, or as ingredients in the development of food products.

Crosstalk between Gut and Brain in Alzheimer's Disease: The Role of Gut Microbiota Modulation Strategies

The gut microbiota (GM) represents a diverse and dynamic population of microorganisms and about 100 trillion symbiotic microbial cells that dwell in the gastrointestinal tract. Studies suggest that the GM can influence the health of the host, and several factors can modify the GM composition, such as diet, drug intake, lifestyle, and geographical locations. Gut dysbiosis can affect brain immune homeostasis through the microbiota-gut-brain axis and can play a key role in the pathogenesis of neurodegenerative diseases, including dementia and Alzheimer's disease (AD). The relationship between gut dysbiosis and AD is still elusive, but emerging evidence suggests that it can enhance the secretion of lipopolysaccharides and amyloids that may disturb intestinal permeability and the blood-brain barrier. In addition, it can promote the hallmarks of AD, such as oxidative stress, neuroinflammation, amyloid-beta formation, insulin resistance, and ultimately the causation of neural death. Poor dietary habits and aging, along with inflammatory responses due to dysbiosis, may contribute to the pathogenesis of AD. Thus, GM modulation through diet, probiotics, or fecal microbiota transplantation could represent potential therapeutics in AD. In this review, we discuss the role of GM dysbiosis in AD and potential therapeutic strategies to modulate GM in AD.

Interactions between gut microbiota and skeletal muscle

The gut microbiota is now recognized as a major contributor to the host’s nutrition, metabolism, immunity, and neurological functions. Imbalanced microbiota (ie, dysbiosis) is linked to undernutrition-induced stunting, inflammatory and metabolic diseases, and cancers. Skeletal muscle also takes part in the interorgan crosstalk regulating substrate metabolism, immunity, and health. Here, we review the reciprocal influence of gut microbiota and skeletal muscle in relation to juvenile growth, performance, aging, and chronic diseases. Several routes involving the vascular system and organs such as the liver and adipose tissue connect the gut microbiota and skeletal muscle, with effects on fitness and health. Therapeutic perspectives arise from the health benefits observed with changes in gut microbiota and muscle activity, further encouraging multimodal therapeutic strategies.

How oral probiotics affect the severity of an experimental model of progressive multiple sclerosis? Bringing commensal bacteria into the neurodegenerative process

A growing number of studies support that the bidirectional interactions between the gut microbiota, the immune system and the CNS are relevant for the pathophysiology of MS. Several studies have reported alterations in the gut microbiome of MS patients. In addition, a variety of studies in animal models of MS have suggested that specific members of the gut commensal microbiota can exacerbate or ameliorate neuroinflammation. Probiotics represent oral nontoxic immunomodulatory agents that would exert benefits when using in combination with current MS therapy. Here we investigate the effect of Vivomixx on the gut microbiome and central and peripheral immune responses in a murine model of primary progressive MS. Vivomixx administration was associated with increased abundance of many taxa such as Bacteroidetes, Actinobacteria, Tenericutes and TM7. This was accompanied by a clear improvement of the motor disability of Theiler's virus infected mice; in the CNS Vivomixx reduced microgliosis, astrogliosis and leukocyte infiltration. Notably, the presence of Breg cells (CD19⁺CD5⁺CD1d^high) in the CNS was enhanced by Vivomixx, and while spinal cord gene expression of IL-1β and IL-6 was diminished, the probiotic promoted IL-10 gene expression. One of the most significant findings was the increased plasma levels of butyrate and acetate levels in TMEV-mice that received Vivomixx. Peripheral immunological changes were subtle but interestingly, the probiotic restricted IL-17 production by Th17-polarized CD4⁺ T-cells purified from the mesenteric lymph nodes of Theiler's virus infected mice. Our data reinforce the beneficial effects of oral probiotics that would be coadjuvant treatments to current MS therapies.

Nutritional Targeting of the Microbiome as Potential Therapy for Malnutrition and Chronic Inflammation

Homeostatic interactions with the microbiome are central for a healthy human physiology and nutrition is the main driving force shaping the microbiome. In the past decade, a wealth of preclinical studies mainly using gnotobiotic animal models demonstrated that malnutrition and chronic inflammation stress these homeostatic interactions and various microbial species and their metabolites or metabolic activities have been associated with disease. For example, the dysregulation of the bacterial metabolism of dietary tryptophan promotes an inflammatory environment and susceptibility to pathogenic infection. Clinical studies have now begun to evaluate the therapeutic potential of nutritional and probiotic interventions in malnutrition and chronic inflammation to ameliorate disease symptoms or even prevent pathogenesis. Here, we therefore summarize the recent progress in this field and propose to move further towards the nutritional targeting of the microbiome for malnutrition and chronic inflammation.

Probiotic Strains and Intervention Total Doses for Modulating Obesity-Related Microbiota Dysbiosis: A Systematic Review and Meta-analysis

Obesity is a growing health threat worldwide. Administration of probiotics in obesity has also parallelly increased but without any protocolization. We conducted a systematic review exploring the administration pattern of probiotic strains and effective doses for obesity-related disorders according to their capacity of positively modulating key biomarkers and microbiota dysbiosis. Manuscripts targeting probiotic strains and doses administered for obesity-related disorders in clinical studies were sought. MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched using keywords during the last fifteen years up to April 2020. Two independent reviewers screened titles, abstracts, and then full-text papers against inclusion criteria according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. From 549 interventional reports identified, we filtered 171 eligible studies, from which 24 full-text assays were used for calculating intervention total doses (ITD) of specific species and strains administered. Nine of these reports were excluded in the second-step because no specific data on gut microbiota modulation was found. Six clinical trials (CT) and 9 animal clinical studies were retained for analysis of complete outcome prioritized (body mass index (BMI), adiposity parameters, glucose, and plasma lipid biomarkers, and gut hormones). Lactobacillus spp. administered were double compared to Bifidobacterium spp.; Lactobacillus as single or multispecies formulations whereas most Bifidobacteria only through multispecies supplementations. Differential factors were estimated from obese populations' vs. obesity-induced animals: ITD ratio of 2 × 106 CFU and patterns of administrations of 11.3 weeks to 5.5 weeks, respectively. Estimation of overall probiotics impact from selected CT was performed through a random-effects model to pool effect sizes. Comparisons showed a positive association between the probiotics group vs. placebo on the reduction of BMI, total cholesterol, leptin, and adiponectin. Moreover, negative estimation appeared for glucose (FPG) and CRP. While clinical trials including data for positive modulatory microbiota capacities suggested that high doses of common single and multispecies of Lactobacillus and Bifidobacterium ameliorated key obesity-related parameters, the major limitation was the high variability between studies and lack of standardized protocols. Efforts in solving this problem and searching for next-generation probiotics for obesity-related diseases would highly improve the rational use of probiotics.