Chronic intestinal pseudo-obstruction: associations with gut microbiota and genes expression of intestinal serotonergic pathway.

BACKGROUND: Pediatric chronic intestinal pseudo-obstruction (PIPO) is a rare disease characterized by symptoms and radiological signs suggestive of intestinal obstruction, in the absence of lumen-occluding lesions. It results from an extremely severe impairment of propulsive motility. The intestinal endocrine system (IES) jointly with the enteric nervous system (ENS) regulates secreto-motor functions via different hormones and bioactive messengers/neurotransmitters. The neurotransmitter 5-hydroxytryptamine (5-HT) (or serotonin) is linked to intestinal peristalsis and secretory reflexes. Gut microbiota and its interplay with ENS affect 5-HT synthesis, release, and the subsequent serotonin receptor activation. To date, the interplay between 5-HT and gut microbiota in PIPO remains largely unclear. This study aimed to assess correlations between mucosa associated microbiota (MAM), intestinal serotonin-related genes expression in PIPO. To this purpose, biopsies of the colon, ileum and duodenum have been collected from 7 PIPO patients, and 7 age-/sex-matched healthy controls. After DNA extraction, the MAM was assessed by next generation sequencing (NGS) of the V3-V4 region of the bacterial RNA 16 S, on an Illumina Miseq platform. The expression of genes implicated in serotoninergic pathway (TPH1, SLC6A4, 5-HTR3 and 5-HTR4) was established by qPCR, and correlations with MAM and clinical parameters of PIPO have been evaluated. RESULTS: Our results revealed that PIPO patients exhibit a MAM with a different composition and with dysbiosis, i.e. with a lower biodiversity and fewer less connected species with a greater number of non-synergistic relationships, compared to controls. qPCR results revealed modifications in the expression of serotonin-related intestinal genes in PIPO patients, when compared to controls. Correlation analysis do not reveal any kind of connection. CONCLUSIONS: For the first time, we report in PIPO patients a specific MAM associated to underlying pathology and an altered intestinal serotonin pathway. A possible dysfunction of the serotonin pathway, possibly related to or triggered by an altered microbiota, may contribute to dysmotility in PIPO patients. The results of our pilot study provide the basis for new biomarkers and innovative therapies targeting the microbiota or serotonin pathways in PIPO patients.

Poliprotect vs Omeprazole in the Relief of Heartburn, Epigastric Pain, and Burning in Patients Without Erosive Esophagitis and Gastroduodenal Lesions: A Randomized, Controlled Trial.

INTRODUCTION: In the treatment of upper GI endoscopy-negative patients with heartburn and epigastric pain or burning, antacids, antireflux agents, and mucosal protective agents are widely used, alone or as add-on treatment, to increase response to proton-pump inhibitors, which are not indicated in infancy and pregnancy and account for significant cost expenditure. METHODS: In this randomized, controlled, double-blind, double-dummy, multicenter trial assessing the efficacy and safety of mucosal protective agent Poliprotect (neoBianacid, Sansepolcro, Italy) vs omeprazole in the relief of heartburn and epigastric pain/burning, 275 endoscopy-negative outpatients were given a 4-week treatment with omeprazole (20 mg q.d.) or Poliprotect (5 times a day for the initial 2 weeks and on demand thereafter), followed by an open-label 4-week treatment period with Poliprotect on-demand. Gut microbiota change was assessed. RESULTS: A 2-week treatment with Poliprotect proved noninferior to omeprazole for symptom relief (between-group difference in the change in visual analog scale symptom score: [mean, 95% confidence interval] -5.4, -9.9 to -0.1; -6.2, -10.8 to -1.6; intention-to-treat and per-protocol populations, respectively). Poliprotect's benefit remained unaltered after shifting to on-demand intake, with no gut microbiota variation. The initial benefit of omeprazole was maintained against significantly higher use of rescue medicine sachets (mean, 95% confidence interval: Poliprotect 3.9, 2.8-5.0; omeprazole 8.2, 4.8-11.6) and associated with an increased abundance of oral cavity genera in the intestinal microbiota. No relevant adverse events were reported in either treatment arm. DISCUSSION: Poliprotect proved noninferior to standard-dose omeprazole in symptomatic patients with heartburn/epigastric burning without erosive esophagitis and gastroduodenal lesions. Gut microbiota was not affected by Poliprotect treatment. The study is registered in Clinicaltrial.gov (NCT03238534) and the EudraCT database (2015-005216-15).

Solvent Casting and UV Photocuring for Easy and Safe Fabrication of Nanocomposite Film Dressings.

The aim of this work was to optimize and characterize nanocomposite films based on gellan gum methacrylate (GG-MA) and silver nanoparticles (AgNPs) for application in the field of wound dressing. The films were produced using the solvent casting technique coupled with a photocuring process. The UV irradiation of GG-MA solutions containing glycerol as a plasticizer and different amounts of silver nitrate resulted in the concurrent crosslinking of the photocurable polymer and a reduction of Ag ions with consequent in situ generation of AgNPs. In the first part of the work, the composition of the films was optimized, varying the concentration of the different components, the GG-MA/glycerol and GG-MA/silver nitrate weight ratios as well as the volume of the film-forming mixture. Rheological analyses were performed on the starting solutions, whereas the obtained films were characterized for their mechanical properties. Colorimetric analyses and swelling studies were also performed in order to determine the AgNPs release and the water uptake capacity of the films. Finally, microbiological tests were carried out to evaluate the antimicrobial efficacy of the optimized films, in order to demonstrate their possible application as dressings for the treatment of infected hard-to-heal wounds, which is a demanding task for public healthcare.

Fecal Microbial Transplantation impact on gut microbiota composition and metabolome, microbial translocation and T-lymphocyte immune activation in recurrent Clostridium difficile infection patients.

This short communication reports the preliminary results of Fecal Microbial Transplantation (FMT) impact on microbiota, microbial translocation (MT), and immune activation in four recurrent Clostridium difficile infection (R-CDI) patients. After FMT a restore of gut microbiota composition with a significant increase of fecal acetyl-putrescine and spermidine and fecal acetate and butyrate, a decrease of immune activation of T cells CD4+ and CD8+levels, and of LPS binding protein (LBP) level, were observed. Preliminary results indicate that FMT seems to be helpful not only as a CDI radical cure, with an impact on fecal microbiota and metabolome profiles, but also on MT and immune activation.

Behaviour of Bdellovibrio bacteriovorus in the presence of Gram-positive Staphylococcus aureus.

The present study aimed to characterize the behavior of Bdellovibrio bacteriovorus in the presence of Staphylococcus aureus. B. bacteriovorus was co-cultured with S. aureus or Pseudomonas aeruginosa or Streptococcus mutans, in planktonic and sessile conditions. Co-cultures were studied by Field-Emission Scanning Electron Microscopy (FESEM), Scanning Transmission Electron Microscopy (STEM), turbidimetry, quantitative PCR (qPCR), and sequencing of gene Bd0108 of B. bacteriovorus. Results indicated that B. bacteriovorus comparably inhibited planktonic growth of P. aeruginosa and S. aureus, but not of S. mutans. FESEM and STEM showed that B. bacteriovorus interacts with S. aureus affecting its cell wall and membrane. Sequencing of gene Bd0108 did not reveal any of the mutations that can arise from the host-interaction (hit) locus. Although some Gram-negative species are reported to be B. bacteriovorus prey, it seems that in case of nutrient deficiency this predatory bacterium can also take advantage of some Gram-positive species. B. bacteriovorus behaviour in the presence of S. aureus is relevant for its possible therapeutic use in several pathologies, like cystic fibrosis in which S. aureus and P. aeruginosa frequently coexist as infectious agents.

Violacein, an indole-derived purple-colored natural pigment produced by Janthinobacterium lividum, inhibits the growth of head and neck carcinoma cell lines both in vitro and in vivo.

Violacein (VIO; 3-[1,2-dihydro-5-(5-hydroxy-1H-indol-3-yl)-2-oxo-3H-pyrrol-3-ylidene]-1,3-dihydro-2H-indol-2-one), an indole-derived purple-colored pigment, produced by a limited number of Gram-negative bacteria species, including Chromobacterium violaceum and Janthinobacterium lividum, has been demonstrated to have anti-cancer activity, as it interferes with survival transduction signaling pathways in different cancer models. Head and neck carcinoma (HNC) represents the sixth most common and one of the most fatal cancers worldwide. We determined whether VIO was able to inhibit head and neck cancer cell growth both in vitro and in vivo. We provide evidence that VIO treatment of human and mouse head and neck cancer cell lines inhibits cell growth and induces autophagy and apoptosis. In fact, VIO treatment increased PARP-1 cleavage, the Bax/Bcl-2 ratio, the inhibition of ERK1 and ERK2 phosphorylation, and the expression of light chain 3-II (LC3-II). Moreover, VIO was able to induce p53 degradation, cytoplasmic nuclear factor kappa B (NF-κB) accumulation, and reactive oxygen species (ROS) production. VIO induced a significant increase in ROS production. VIO administration was safe in BALB/c mice and reduced the growth of transplanted salivary gland cancer cells (SALTO) in vivo and prolonged median survival. Taken together, our results indicate that the treatment of head and neck cancer cells with VIO can be useful in inhibiting in vivo and in vitro cancer cell growth. VIO may represent a suitable tool for the local treatment of HNC in combination with standard therapies.

Protective Role of Postbiotic Mediators Secreted by Lactobacillus rhamnosus GG Versus Lipopolysaccharide-induced Damage in Human Colonic Smooth Muscle Cells.

BACKGROUND: Some beneficial effects of probiotics may be due to secreted probiotic-derived factors, identified as "postbiotic" mediators. The aim of this study was to evaluate whether supernatants harvested from Lactobacillus rhamnosus GG (LGG) cultures (ATCC53103 strain) protect colonic human smooth muscle cells (HSMCs) from lipopolysaccharide (LPS)-induced myogenic damage. MATERIALS AND METHODS: LGG was grown in de Man, Rogosa, Share medium at 37°C and samples were collected in middle and late exponential, stationary, and overnight phases. Supernatants were recovered by centrifugation, filtered, and stored at -20°C. The primary HSMCs culture was exposed for 24 hours to purified LPS of a pathogen strain of Escherichia coli (O111:B4) (1 µg/mL) with and without supernatants. Postbiotic effects were evaluated on the basis of HSMCs morphofunctional alterations and interleukin-6 (IL-6) production. Data are expressed as mean±SE (P<0.05 significant). RESULTS: LPS induced persistent, significant, 20.5%±0.7% cell shortening and 34.5%±2.2% decrease in acetylcholine-induced contraction of human HSMCs. These morphofunctional alterations were paralleled to a 365.65%±203.13% increase in IL-6 production. All these effects were dose-dependently reduced by LGG supernatants. Supernatants of the middle exponential phase already partially restored LPS-induced cell shortening by 57.34%±12.7% and IL-6 increase by 145.8%±4.3% but had no effect on LPS-induced inhibition of contraction. Maximal protective effects were obtained with supernatants of the late stationary phase with LPS-induced cell shortening restored by 84.1%±4.7%, inhibition of contraction by 85.5%±6.4%, and IL-6 basal production by 92.7%±1.2%. CONCLUSIONS: LGG-derived products are able to protect human SMCs from LPS-induced myogenic damage. Novel insights have been provided for the possibility that LGG-derived products could reduce the risk of progression to postinfective motor disorders.

Eubiosis and dysbiosis: the two sides of the microbiota.

The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiota.

The Shigella flexneri OspB effector: an early immunomodulator.

Through the action of the type three secretion system (T3SS) Shigella flexneri delivers several effectors into host cells to promote cellular invasion, multiplication and to exploit host-cell signaling pathways to modulate the host innate immune response. Although much progress has been made in the understanding of many type III effectors, the molecular and cellular mechanism of the OspB effector is still poorly characterized. In this study we present new evidence that better elucidates the role of OspB as pro-inflammatory factor at very early stages of infection. Indeed, we demonstrate that, during the first hour of infection, OspB is required for full activation of ERK1/2 and p38 MAPKs and the cytosolic phospholipase A(2) (cPLA(2)). Activation of cPLA(2) ultimately leads to the production and secretion of PMN chemoattractant metabolite(s) uncoupled with release of IL-8. Moreover, we also present evidence that OspB is required for the development of the full and promptly inflammatory reaction characteristic of S. flexneri wild-type infection in vivo. Based on OspB and OspF similarity (both effectors share similar transcription regulation, temporal secretion into host cells and nuclear localization) we hypothesized that OspB and OspF effectors may form a pair aimed at modulating the host cell response throughout the infection process, with opposite effects. A model is presented to illustrate how OspB activity would promote S. flexneri invasion and bacterial dissemination at early critical phases of infection.

Women Skin Microbiota Modifications during Pregnancy.

Several studies have shown fluctuations in the maternal microbiota at various body sites (gut, oral cavity, and vagina). The skin microbiota plays an important role in our health, but studies on the changes during pregnancy are limited. Quantitative and qualitative variations in the skin microbiota in pregnant woman could indeed play important roles in modifying the immune and inflammatory responses of the host. These alterations could induce inflammatory disorders affecting the individual's dermal properties, and could potentially predict infant skin disorder in the unborn. The present study aimed to characterize skin microbiota modifications during pregnancy. For this purpose, skin samples were collected from 52 pregnant women in the first, second, and third trimester of non-complicated pregnancies and from 17 age- and sex-matched healthy controls. The skin microbiota composition was assessed by next generation sequencing (NGS) of the V3-V4 region of the bacterial rRNA 16S. Our results indicate that from the first to the third trimester of pregnancy, changes occur in the composition of the skin microbiota, microbial interactions, and various metabolic pathways. These changes could play a role in creating more advantageous conditions for fetal growth.

Microevolution in fimH gene of mucosa-associated Escherichia coli strains isolated from pediatric patients with inflammatory bowel disease.

Several studies reported increased numbers of mucosa-associated Escherichia coli strains in patients with inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC). The majority of E. coli strains possess type 1 fimbriae, whose tip fibrillum protein, FimH, naturally undergoes amino acid replacements, an important process in the adaptation of commensal E. coli strains to environmental changes, like those observed in IBD and urinary tract infections. In this study, we analyzed mutational patterns in the fimH gene of 52 mucosa-associated E. coli strains isolated from IBD and non-IBD pediatric patients, in order to investigate microevolution of this genetic trait. FimH-positive strains were also phylogenetically typed and tested for their adhesive ability on Caco-2 cells. Specific FimH alleles for each grouping feature were found. Mutations G66S and V27A were related to CD, while mutations A242V, V163A, and T74I were attributed to UC. Otherwise, the G66S, N70S, and S78N mutations were specifically attributed to B2/D phylogroups. The N70S and A119V mutations were related to adhesive E. coli strains. Phylogroup B2, adhesive, and IBD E. coli strains showed a higher site substitution rate (SSR) in the fimH gene, together with a higher number of mutations. The degree of naïve mucosal inflammation was related to specific FimH alleles. Moreover, we could suggest that the V27A mutation is pathoadaptive for the CD intestinal habitat, while we could also suggest that both the N70S and S78N mutations are related to the more virulent E. coli B2 phylogroup. In conclusion, we found some FimH variants that seem to be more involved than others in the evolution of IBD pathogenesis.

A potential role of Escherichia coli pathobionts in the pathogenesis of pediatric inflammatory bowel disease.

Through genomic analysis of mucosa-associated Escherichia coli strains, we found a close genetic association among isolates from pediatric inflammatory bowel disease (IBD) patients. A specific E. coli pathovar, adherent-invasive E. coli (AIEC), was found in Crohn's disease (CD) adult patients - this pathovar has enhanced adhesive and invasive properties, mainly due to the mannose-bonding FimH protein. We aimed to characterize 52 mucosa-associated E. coli strains isolated from pediatric IBD and non-IBD patients. Eleven E. coli strains, showing a strong similarity in fimH gene sequence to that of E. coli AIEC LF82, were characterized for fimH gene sequence, genomic profiling, adhesive and invasive ability, and phylogrouping. The results were compared with E. coli strains AIEC LF82 and MG1655. The 11 E. coli isolates showed 82.4% ± 1.4% fimH sequence similarity and 80.6% ± 1.3% genomic similarity to strain AIEC LF82. All these strains harbored V27A and S78N FimH mutations, as found in LF82. Nine of them belonged to the more virulent B2 and D phylogroups. Neuraminidase treatment, mimicking inflamed mucosa, enhanced adhesion of all 11 strains by 3.5-fold, but none showed invasion ability. It could be argued that the 11 selected strains could be a branch of an E. coli subpopulation (pathobionts), that could take advantage in an inflamed context because of a suitable genomic and (or) genetic backdrop.

Evaluation of the anti-proliferative activity of violacein, a natural pigment of bacterial origin, in urinary bladder cancer cell lines.

Violacein is a natural pigment, a pyrrolidone, and a bisindole derived from the condensation of two tryptophan molecules, which gives a blue violet color to several gram-negative violacein-producing bacteria. Violacein production provides a competitive advantage against antagonistic species or predators. In addition, the compound has antibacterial, antifungal, antiviral, and antioxidant activities. Several studies on colon, breast, and head and neck cancer lines have already demonstrated the anti-proliferative potential of violacein. Bladder cancer is one of the most common types of cancer in urology. The therapeutic approach is mainly based on surgery, chemotherapy, and immunotherapy. The aim of the present study was to evaluate the anti-proliferative activity of violacein against the human bladder cancer cell lines, HTB4 (T24) and HTB9 (5637), using low-grade and high-grade transitional cell carcinoma models, respectively, which has never been assayed before. For this purpose, the potential violacein anti-proliferative effect on T24 and 5637 cells was evaluated by studying the cell viability, proliferation, cell cycle, and caspase-3 activation. The results showed that violacein had anti-proliferative activity in the two cell lines, which was greater for the second-stage bladder cancer cell line (5637), and a different mode of action against the two cell lines.

Gut Microbiota Structure and Metabolites, Before and After Treatment in Early Rheumatoid Arthritis Patients: A Pilot Study.

Rheumatoid Arthritis (RA) is a chronic systemic autoimmune disease. Modifications of gut microbiota seem to be associated with the disease, but the impact of gut microbiota on therapies' outcome remains unclear. A role of T cells in RA pathogenesis has been addressed, particularly on the Th17/Treg cells balance. Our study aimed to evaluate in early RA (ERA) patients compared to a control group, fecal gut microbiota composition, short-chain fatty acids concentrations, and the levels of circulating Th17/Treg and their own cytokines, before and after 3 months of standard treatment (Methotrexate (MTX) plus glucocorticoids). Fecal microbiota characterization was carried out on 19 ERA patients and 20 controls matched for sex and age. Significant decreased biodiversity levels, and a partition on the base of the microbiota composition, between the ERA patients at baseline compared to controls, were observed. The co-occurrent analysis of interactions revealed a characteristic clustered structure of the microbial network in controls that is lost in ERA patients where an altered connection between microbes and clinical parameters/metabolites has been reported. Microbial markers such as Acetanaerobacterium elongatum, Cristiansella massiliensis, and Gracilibacter thermotolerans resulted significantly enriched in control group while the species Blautia gnavus emerged to be more abundant in ERA patients. Our results showed an alteration in Th17/Treg balance with higher Th17 levels and lower Treg levels in ERA group respect to control at baseline, those data improved after therapy. Treatment administration and the achievement of a low disease activity/remission appear to exert a positive pressure on the structure of intestinal microbiota with the consequent restoration of biodiversity, of the structure of microbial network, and of the abundance of taxa that became closer to those presented by the subject without the disease. We also found an association between Blautia gnavus and ERA patients characterized by a significant reduction of propionic acid level. Furthermore significant differences highlighted at baseline among controls and ERA patients are no more evident after treatment. These data corroborate the role played by gut microbiota in the disease and suggest that therapy aimed to restore gut microbiota would improve treatment outcome.

Relationship between sleep disorders and gut dysbiosis: what affects what?

Sleep plays a fundamental role in maintaining good psycho-physical health, it can influence hormone levels, mood, and weight. Recent studies, focused on the interconnection between intestinal microbiome and sleep disorders, have shown the growing importance of a healthy and balanced intestinal microbiome for the hosts health. Normally, gut microbiota and his host are linked by mutualistic relationship, that in some conditions, can be compromised by shifts in microbiota's composition, called dysbiosis. Both sleep problems and dysbiosis of the gut microbiome can lead to metabolic disorders and, in this review, we will explore what is present in literature on the link between sleep pathologies and intestinal dysbiosis.

Chronic Intestinal Pseudo-Obstruction: Is There a Connection with Gut Microbiota?

Chronic intestinal pseudo-obstruction (CIPO) is a rare clinical syndrome characterized by severe impairment of gastrointestinal (GI) motility, and its symptoms are suggestive of partial or complete intestinal obstruction in the absence of any lesion restricting the intestinal lumen. Diagnosis and therapy of CIPO patients still represent a significant challenge for clinicians, despite their efforts to improve diagnostic workup and treatment strategies for this disease. The purpose of this review is to better understand what is currently known about the relationship between CIPO patients and intestinal microbiota, with a focus on the role of the enteric nervous system (ENS) and the intestinal endocrine system (IES) in intestinal motility, underling the importance of further studies to deeply understand the causes of gut motility dysfunction in these patients.

Achromobacter xylosoxidans genomic characterization and correlation of randomly amplified polymorphic DNA profiles with relevant clinical features [corrected] of cystic fibrosis patients.

Achromobacter xylosoxidans is an emerging pathogen increasingly being isolated from respiratory samples of cystic fibrosis (CF) patients. Its role and clinical significance in lung pathogenesis have not yet been clarified. The aim of the present study was to genetically characterize A. xylosoxidans strains isolated from CF patients by use of randomly amplified polymorphic DNA (RAPD) profiles and to look for a possible correlation between RAPD profiles and the patients' clinical features, such as their spirometry values, the presence of concomitant chronic bacterial flora at the time of isolation, and the persistent or intermittent presence of A. xylosoxidans strains. A set of 106 strains of A. xylosoxidans were typed by RAPD analysis, and their profiles were analyzed by agglomerative hierarchical classification (AHC) and associated with the patient characteristics mentioned above by factorial discriminant analysis (FDA). The overall results obtained in this study showed that (i) there is a marked genetic relationship between strains isolated from the same patients at different times, (ii) characteristic RAPD profiles are associated with different predicted classes for forced expiratory volume in 1 s (FEV1%), (iii) some characteristic RAPD profiles are associated with different concomitant chronic flora (CCF) profiles, and (iv) there is a significant division of RAPD profiles into "persistent strains" and "intermittent strains" of A. xylosoxidans. These findings seem to imply that the lung habitats found in CF patients are capable of shaping and selecting the colonizing bacterial flora, as seems to be the case for the A. xylosoxidans strains studied.

A distinctive 'microbial signature' in celiac pediatric patients.

BACKGROUND: Celiac Disease (CD) is an autoimmune disorder of the small intestine in which dietary gluten ingestion leads to a chronic enteropathy. Recently, scientific evidence suggested a potential role of gut microbiota in CD. To have a snapshot of dominant duodenal microbiota we analyzed the mucosa-associated microbiota of 20 children with CD, before and after a gluten-free diet (GFD) regimen, and of 10 controls. Total DNA was extracted from duodenal biopsies and amplification products of 16S ribosomal DNA were compared by temporal temperature gradient gel electrophoresis (TTGE). TTGE profiles were analyzed by statistical multivariate analysis. RESULTS: The average number of bands in TTGE profiles was significantly higher (P < 0.0001) in active (n.b. 16.7 +/- 0.7) and inactive states (n.b. 13.2 +/- 0.8) than in controls (n.b. 3.7 +/- 1.3). Mean interindividual similarity index was 54.9% +/- 14.9% for active disease, 55.6% +/- 15.7% for remission state and 21.8% +/- 30.16% for controls. Similarity index between celiac children before and after GFD treatment was 63.9% +/- 15.8%. Differences in microbiota biodiversity were among active and remission state (P = 0.000224) and amid active CD and controls (P < 0.001). Bacteroides vulgatus and Escherichia coli were detected more often in CD patients than in controls (P < 0.0001). CONCLUSIONS: Overall, the results highlighted a peculiar microbial TTGE profile and a significant higher biodiversity in CD pediatric patients' duodenal mucosa. The possible pathophysiological role of these microbial differences needs further characterization.

Insight into the Possible Use of the Predator Bdellovibrio bacteriovorus as a Probiotic.

The gut microbiota is a complex microbial ecosystem that coexists with the human organism in the intestinal tract. The members of this ecosystem live together in a balance between them and the host, contributing to its healthy state. Stress, aging, and antibiotic therapies are the principal factors affecting the gut microbiota composition, breaking the mutualistic relationship among microbes and resulting in the overgrowth of potential pathogens. This condition, called dysbiosis, has been linked to several chronic pathologies. In this review, we propose the use of the predator Bdellovibrio bacteriovorus as a possible probiotic to prevent or counteract dysbiotic outcomes and look at the findings of previous research.