Probiotics for the prevention of Hirschsprung-associated enterocolitis

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is a leading cause of serious morbidity and potential mortality in children with Hirschsprung's disease (HD). People with HAEC suffer from intestinal inflammation, and present with diarrhoea, explosive stools, and abdominal distension. Probiotics are live microorganisms with beneficial health effects, which can optimise gastrointestinal function and gut flora. However, the efficacy and safety of probiotic supplementation in the prevention of HAEC remains unclear.

OBJECTIVES

To assess the effects of probiotic supplements used either alone or in combination with pharmacological interventions on the prevention of Hirschsprung-associated enterocolitis.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, the China BioMedical Literature database (CBM), the World Health Organization International Clinical Trials Registry, ClinicalTrials.gov, the Chinese Clinical Trials Registry, Australian New Zealand Clinical Trials Registry, and Clinical Trials Registry-India, from database inception to 27 February 2022. We also searched the reference lists of relevant articles and reviews for any additional trails.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics and placebo, or any other non-probiotic intervention, for the prevention of HAEC were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the included studies; disagreements were resolved by discussion with a third review author. We assessed the certainty of evidence using the GRADE approach. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous outcomes.

MAIN RESULTS

We included two RCTs, with a total of 122 participants. We judged the overall risk of bias as high. We downgraded the evidence due to risk of bias (random sequence generation, allocation concealment, and blinding) and small sample size. The evidence is very uncertain about the effect of probiotics on the occurrence of HAEC (OR 0.58, 95% CI 0.10 to 3.43; I² = 74%; 2 studies, 120 participants; very low-certainty evidence). We found one included study that did not measure serious adverse events and one included study that reported no serious adverse events related to probiotics. Probiotics may result in little to no difference between probiotics and placebo in relation to the severity of children with HAEC at Grade I (OR 0.66, 95% CI 0.14 to 3.16; I² = 25%; 2 studies, 120 participants; low-certainty evidence). The effects of probiotics on the severity of HAEC at Grade II are very uncertain (OR 1.14, 95% CI 0.01 to 136.58; I² = 86%; 2 studies, 120 participants; very low-certainty evidence). Similarly, the evidence suggests that probiotics results in little to no difference in relation to the severity of HAEC at Grade III (OR 0.43, 95% CI 0.05 to 3.45; I² = 0%; 2 studies, 120 participants; low-certainty evidence). No overall mortality or withdrawals due to adverse events were reported. Probiotics may result in little to no difference in the recurrence of episodes of HAEC compared to placebo (OR 0.85, 95% CI 0.24 to 3.00; 1 study, 60 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There is currently not enough evidence to assess the efficacy or safety of probiotics for the prevention of Hirschsprung-associated enterocolitis when compared with placebo. The presence of low- to very-low certainty evidence suggests that further well-designed and sufficiently powered RCTs are needed to clarify the true efficacy of probiotics.

Discovery of the bioactive peptides secreted by Bifidobacterium using integrated MCX coupled with LC-MS and feature-based molecular networking

Probiotics can release many bioactive peptides that confer a myriad of benefits to the host health. However, exploring new bioactive peptides secreted by probiotics is hampered by lots of matrix-related interference peptides from the medium, and the low abundance. To this end, a new approach integrating mixed-mode cationic exchange based solid-phase extraction (MCX-SPE) coupled with liquid chromatography-mass spectrometry (LC-MS) and feature-based molecular networking (FBMN) was developed. FBMN's intuitive visualization results enabled twenty-five novel peptides to be quickly discovered and characterized from the cultures of three strains of Bifidobacterium, B. animalis, B. longum, and B. pseudolongum. Interestingly, four were uniquely secreted by B. animalis treated with gypenosides, and one showed ACE inhibitory effect with an IC₅₀ value of 193.22 μM. Consequently, this approach could serve as a powerful tool for quickly discovering bioactive peptides from the complex metabolites of probiotics, which contributes to the development of functional foods and nutraceuticals.

Atopic Dermatitis as a Multifactorial Skin Disorder. Can the Analysis of Pathophysiological Targets Represent the Winning Therapeutic Strategy?

Atopic dermatitis (AD) is a pathological skin condition with complex aetiological mechanisms that are difficult to fully understand. Scientific evidence suggests that of all the causes, the impairment of the skin barrier and cutaneous dysbiosis together with immunological dysfunction can be considered as the two main factors involved in this pathological skin condition. The loss of the skin barrier function is often linked to dysbiosis and immunological dysfunction, with an imbalance in the ratio between the pathogen Staphylococcus aureus and/or other microorganisms residing in the skin. The bibliographic research was conducted on PubMed, using the following keywords: 'atopic dermatitis', 'bacterial therapy', 'drug delivery system' and 'alternative therapy'. The main studies concerning microbial therapy, such as the use of bacteria and/or part thereof with microbiota transplantation, and drug delivery systems to recover skin barrier function have been summarized. The studies examined show great potential in the development of effective therapeutic strategies for AD and AD-like symptoms. Despite this promise, however, future investigative efforts should focus both on the replication of some of these studies on a larger scale, with clinical and demographic characteristics that reflect the general AD population, and on the process of standardisation, in order to produce reliable data.

In Vitro and In Vivo Biological Activity of Berberine Chloride against Uropathogenic E. coli Strains Using Galleria mellonella as a Host Model

Berberine is an alkaloid of the protoberberine type used in traditional oriental medicine. Its biological activities include documented antibacterial properties against a wide variety of microorganisms; nonetheless, its use against Escherichia coli strains isolated from urinary infections has not yet been widely investigated in vivo. The emergence of antimicrobial resistance requires new therapeutic approaches to ensure the continued effectiveness of antibiotics for the treatment and prevention of urinary infections. Moreover, uropathogenic Escherichia coli (UPEC) has developed several virulence factors and resistance to routine antibiotic therapy. To this end, several in vitro and in vivo tests were conducted to assess the activity of berberine on uropathogenic E. coli strains. Galleria mellonella as an infection model was employed to confirm the in vivo translatability of in vitro data on berberine activity and its influence on adhesion and invasion proprieties of E. coli on human bladder cells. In vitro pre-treatment with berberine was able to decrease the adhesive and invasive UPEC ability. In vivo treatment increased the larvae survival infected with UPEC strains and reduced the number of circulating pathogens in larvae hemolymph. These preliminary findings demonstrated the efficacy and reliability of G. mellonella as in vivo model for pre-clinical studies of natural substances.

Postsynaptic damage and microglial activation in AD patients could be linked CXCR4/CXCL12 expression levels

Alzheimer's disease (AD) is one of the most common forms of dementia with still unknown pathogenesis. Several cytokines and chemokines are involved in the pathogenesis of AD. Among the chemokines, the CXCR4/CXCL12 complex has been shown to play an important role in the pathogenetic development of AD. We investigated the expression levels of CXCR4 / CXCL12 in fifteen brain regions of healthy non-demented subjects (NDHC) (2139 sample) and AD patients (1170 sample) stratified according to sex and age. Furthermore, we correlated their expressions with the Neurogranin (NRGN) and CHI3L1 levels, two inflamm-aging markers. We highlighted that CXCR4 gene expression levels were age-correlated in the brain of NDHC subjects and that AD nullified this correlation. A similar trend, but diametrically opposite was observed for CXCL12. Its expression was decreased during the aging in both sexes, and in the brains of AD patients, it underwent an inversion of the trend, only and exclusively in females. Brains of AD patients expressed high CXCR4 and CHI3L1, and low CXCL12 and Neurogranin levels compared to NDHC subjects. Both CXCR4 and CXCL12 correlated significantly with CHI3L1 and Neurogranin expression levels, regardless of disease. Furthermore, we showed a selective modulation of CXCL12 and CXCR4 only in specific brain regions. Taken together our results demonstrate that CXCL12 and CXCR4 are linked to Neurogranin and CHI3L1 expression levels and the relationship between postsynaptic damage and microglial activation in AD could be shown using all these genes. Further confirmations are needed to demonstrate the close link between these genes.

Nigerian foods of probiotics relevance and chronic metal exposure: a systematic review

Probiotics are functional foods with a wide armamentarium of health benefits in man including metal chelation. Given the unacceptable blood lead levels and the near ignorance or negligence of heavy metals in both diagnoses and management of diseases in Nigeria, it is feared that these metals are involved in the aetiogenesis of several ailments from preeclampsia, metabolic syndrome, cancer, etc. This is an insight on Nigerian fermented foods and their possible role as metal chelators in the management of the chronic heavy metal exposure in Nigeria. One hundred and five articles fulfilled the inclusion criteria. Google scholar, PubMed and SCOPUS were searched for articles reporting fermented foods and probiotics in Nigeria. Only studies published in English Language were included, but there was no limitation in year of study. One hundred and five articles fulfilled the inclusion criteria. Studies from some African countries suggest that fermented foods of probiotics relevance have effectively shown metal chelation properties. Consumption of Nigerian fermented foods may hold a promise in checking the high body burden of heavy metals in Nigeria. Graphic abstract.

Surface Modifications for Improved Delivery and Function of Therapeutic Bacteria

Live therapeutic bacteria (LTBs) hold promise to treat microbiome-related diseases. However, few approaches to improve the colonization of LTBs in the gastrointestinal tract exist, despite colonization being a prerequisite for efficacy of many LTBs. Here, a modular platform to rapidly modify the surface of LTBs to enable receptor-specific interactions with target surfaces is reported. Inspired by bacterial adhesins that facilitate colonization, synthetic adhesins (SAs) are developed for LTBs in the form of antibodies conjugated to their surface. The SA platform is nontoxic, does not alter LTB growth kinetics, and can be used with any antibody or bacterial strain combination. By improving adhesion, SA-modified bacteria demonstrate enhanced in vitro pathogen exclusion from cell monolayers. In vivo kinetics of SA-modified LTBs is tracked in the feces and intestines of treated mice, demonstrating that SA-modified bacteria alter short-term intestinal transit and improve LTB colonization and pharmacokinetics. This platform enables rapid formation of an intestinal niche, leading to an increased maximum concentration and a 20% improvement in total LTB exposure. This work is the first application of traditional pharmacokinetic analysis to design and evaluate LTB drug delivery systems and provides a platform toward controlling adhesion, colonization, and efficacy of LTBs.

Vitamin E for Prevention of Biofilm-caused Healthcare-associated Infections

The healthcare-associated infections (HCAIs) occur in patients both in nosocomial environments and in community. More often HCAIs are associated to the use of medical devices and bacterial biofilm development on these equipments. Due to the clinical and economic relevance of this topic, new strategies for the treatment of infections caused by biofilm proliferation are unceasingly searched by scientists.

The present study investigated the role of vitamin E to reduce the biofilm formation for a larger panel of human pathogens, including strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Acinetobacter baumannii, Pseudomonas aeruginosa and Pseudomonas putida.

This potential activity was tested by placing a preparation of vitamin E (α-Tocopheryl acetate) as interface between the bacterial culture and the polystyrene walls of a 96 well plate at different concentrations of glucose, used as a biofilm enhancer.

The Staphylococcus genus was further investigated by spreading the vitamin E on a silicone catheter lumen and evaluating its influence on the bacterial colonization.

From our results, vitamin E has been able to interfere with bacterial biofilm and prevent in vitro biofilm formation. Furthermore, the ability of Staphylococcus aureus and Staphylococcus epidermidis to colonize the catheter surface decreased as a result of vitamin E application.

Galleria mellonella as a consolidated in vivo model hosts: New developments in antibacterial strategies and novel drug testing

A greater ethical conscience, new global rules and a modified perception of ethical consciousness entail a more rigorous control on utilizations of vertebrates for in vivo studies. To cope with this new scenario, numerous alternatives to rodents have been proposed. Among these, the greater wax moth Galleria mellonella had a preponderant role, especially in the microbiological field, as demonstrated by the growing number of recent scientific publications. The reasons for its success must be sought in its peculiar characteristics such as the innate immune response mechanisms and the ability to grow at a temperature of 37°C. This review aims to describe the most relevant features of G. mellonella in microbiology, highlighting the most recent and relevant research on antibacterial strategies, novel drug tests and toxicological studies. Although solutions for some limitations are required, G. mellonella has all the necessary host features to be a consolidated in vivo model host.

Antimicrobial resistance of Enterococcus faecium strains isolated from commercial probiotic products used in cattle and swine

Probiotics, an antibiotic alternative, are widely used as feed additives for performance benefits in cattle and swine production systems. Among bacterial species contained in probiotics, Enterococcus faecium is common. Antimicrobial resistance (AMR), particularly multidrug resistance, is a common trait among enterococci because of their propensity to acquire resistance and horizontally transfer AMR genes. Also, E. faecium is an opportunistic pathogen, and in the United States, it is the second most common nosocomial pathogen. There has been no published study on AMR and virulence potential in E. faecium contained in probiotic products used in cattle and swine in the United States. Therefore, our objectives were to determine phenotypic susceptibilities or resistance to antimicrobials, virulence genes (asa1, gelE, cylA, esp, and hyl) and assess genetic diversity of E. faecium isolated from commercial products. Twenty-two commercially available E. faecium-based probiotic products used in cattle (n = 13) and swine (n = 9) were procured and E. faecium was isolated and species confirmed. Antimicrobial susceptibility testing to determine minimum inhibitory concentrations was done by micro-broth dilution method using National Antimicrobial Resistance Monitoring Systems Gram-positive Sensititre panel plate (CMV3AGPF), and categorization of strains as susceptible or resistant was as per Clinical Laboratory and Standards Institute's guidelines. E. faecium strains from 7 products (3 for swine and 4 for cattle) were pan-susceptible to the 16 antimicrobials tested. Strains from 15 products (6 for swine and 9 for cattle) exhibited resistance to at least one antimicrobial and a high proportion of strains was resistant to lincomycin (10/22), followed by tetracycline (4/22), daptomycin (4/22), ciprofloxacin (4/22), kanamycin (3/22), and penicillin (2/22). Four strains were multidrug resistant, with resistant phenotypes ranging from 3 to 6 antimicrobials or class. None of the E. faecium strains were positive for any of the virulence genes tested. The clonal relationships among the 22 E. faecium strains were determined by pulsed-field gel electrophoresis (PFGE) typing. A total of 10 PFGE patterns were observed with 22 strains and a few of the strains from different probiotic products had identical (100% Dice similarity) PFGE patterns. In conclusion, the E. faecium strains in a few commercial probiotics exhibited AMR to medically-important antimicrobials, but none contained virulence genes.

Evaluation of hyaluronic acid-P40 conjugated cream in a mouse model of dermatitis induced by oxazolone

P40 is a particulate fraction or fragment isolated from Corynebacterium granulosum, which exhibits a wide spectrum of pharmacological functions including antitumor, antibacterial, phagocytic, antiviral and cytokine induction effects. In the present study, the immunomodulatory potential of P40-conjugated with hyaluronic acid was assessed in a mouse model of dermatitis induced by oxazolone. Oxazolone-induced allergic contact dermatitis is a T cell-mediated Th2-like hypersensitivity reaction, which mimics the corresponding reaction in humans. Female cluster of differentiation-1 mice were sensitized on days 0 and 1 by the application of 2% oxazolone onto a shaved back. The disease was induced by re-challenge on day 7 using 15% oxazolone in the inner and outer of the left ears of the mice. Mice were topically treated with hyaluronic acid-P40 conjugate cream or with placebo to the inner and outer surface of the left ear for 7 consecutive days starting from 1 h after the sensitization. A significant reduction in ear thickness and weight and in edema and leukocyte recruitment were observed in the mice treated with hyaluronic-P40 conjugate cream compared with mice treated with the cream base alone (P<0.05). Thus, P40-conjugated with hyaluronic acid may constitute an innovative dermatitis treatment.

Impact of gut microbiota on diabetes mellitus

Various functions of the gut are regulated by sophisticated interactions among its functional elements, including the gut microbiota. These microorganisms play a crucial role in gastrointestinal mucosa permeability. They control the fermentation and absorption of dietary polysaccharides to produce short-chain fatty acids, which may explain their importance in the regulation of fat accumulation and the subsequent development of obesity-related diseases, suggesting that they are a crucial mediator of obesity and its consequences. In addition, gut bacteria play a crucial role in the host immune system, modulation of inflammatory processes, extraction of energy from the host diet and alterations of human gene expression. Dietary modulation of the human colonic microbiota has been shown to confer a number of health benefits to the host. Simple therapeutic strategies targeted at attenuating the progression of chronic low-grade inflammation and insulin resistance are urgently required to prevent or slow the development of diabetes in susceptible individuals. The main objective of this review is to address the pathogenic association between gut microbiota and diabetes, and to explore any novel related therapeutic targets. New insights into the role of the gut microbiota in diabetes could lead to the development of integrated strategies using probiotics to prevent and treat these metabolic disorders.

Labeling quality and molecular characterization studies of products containing Lactobacillus spp. strains

The objective of the study was to characterize at species level by phenotypic and different molecular methods the strains of Lactobacillus spp. used as constituents of five oral and four vaginal products. Susceptibilities to representative antibiotics were evaluated. In addition, total viable counts at mid and 3 months to deadline of shelf life, in the different formulations and the presence of eventual contaminant microorganisms were investigated.In all oral products the molecular characterization at species level of the strains of Lactobacillus spp. confirmed the strains stated on the label, except for one strain cited on the label as Lactobacillus casei, that our study characterized as Lactobacillus paracasei. In oral products total viable cell content complied with content claimed on the label. In three out four vaginal products (one product claimed "bacillo di Döderlein"), molecular characterization complied with the bacterial name stated on the label. Two vaginal products reported viable counts on the label that were confirmed by our study. The other vaginal products, which did not report bacterial counts on the label, showed a similar decrease of viable counts at different dates to deadline compared to the others. From all the tested products, contaminant microorganisms and acquired resistance to representative antibiotics by the probiotic strains were not detected.

Oxidative stress-related responses of Bifidobacterium longum subsp. longum BBMN68 at the proteomic level after exposure to oxygen

Bifidobacterium longum subsp. longum BBMN68, an anaerobic probiotic isolated from healthy centenarian faeces, shows low oxygen (3 %, v/v) tolerance. To understand the effects of oxidative stress and the mechanisms protecting against it in this strain, a proteomic approach was taken to analyse changes in the cellular protein profiles of BBMN68 under the following oxygen-stress conditions. Mid-exponential phase BBMN68 cells grown in MRS broth at 37 °C were exposed to 3 % O2 for 1 h (I) or 9 h (II), and stationary phase cells were subjected to 3 % O2 for 1 h (III). Respective controls were grown under identical conditions but were not exposed to O2. A total of 51 spots with significant changes after exposure to oxygen were identified, including the oxidative stress-protective proteins alkyl hydroperoxide reductase C22 (AhpC) and pyridine nucleotide-disulfide reductase (PNDR), and the DNA oxidative damage-protective proteins DNA-binding ferritin-like protein (Dps), ribonucleotide reductase (NrdA) and nucleotide triphosphate (NTP) pyrophosphohydrolases (MutT1). Changes in polynucleotide phosphorylase (PNPase) plus enolase, which may play important roles in scavenging oxidatively damaged RNA, were also found. Following validation at the transcriptional level of differentially expressed proteins, the physiological and biochemical functions of BBMN68 Dps were further proven by in vitro and in vivo tests under oxidative stress. Our results reveal the key oxidative stress-protective proteins and DNA oxidative damage-protective proteins involved in the defence strategy of BBMN68 against oxygen, and provide the first proteomic information toward understanding the responses of Bifidobacterium and other anaerobes to oxygen stress.

Effects of FR-91 on immune cells from healthy individuals and from patients with non-Hodgkin lymphoma

The immune system is subject to destruction and dysfunction as a result of attacks by pathogenic and environmental agents. In addition, many clinical situations exist in which it is desirable to stimulate or suppress the immune system. The present study evaluated the screening efficacy of flow cytometric lymphocyte subset typing in peripheral blood mononuclear cells from healthy individuals (HI) and from patients with non-Hodgkin lymphoma (NHL) treated with different concentrations of FR-91, a standardized lysate of microbial cells belonging to the Bacillus genus, and in vitro cytokine production. Increased expression of subset markers (CD3, CD4, CD8) in NHL and CD3 in HI suggests an immunomodulating effect of FR-91. In addition the results of cytokine production also demonstrated a clear effect of FR-91 on both populations. A significant increase of IL-6, IL-12, IFN-gamma and TNF-alpha was observed in the HI group after treatment with FR-91. In a similar manner an increase of IL-2, IL-6, IL-12, IFN-gamma and TNF-alpha was also observed in the NHL group. In conclusion FR-91 seems to affect lymphocyte subpopulations, in vitro cytokine production, as well as mitogen-induced lymphocyte activation in a dose-dependent manner in both healthy individuals and NHL patients.