Genetically engineered Escherichia coli Nissle 1917 synbiotic counters fructose-induced metabolic syndrome and iron deficiency

Gene Expression and Metabolome Analysis Reveals Anti-Inflammatory Impacts of 11,17diHDoPE on PM10-Induced Mouse Lung Inflammation

Oxylipins, the metabolites of polyunsaturated fatty acids, are vital in regulating cell proliferation and inflammation. Among these oxylipins, specialized pro-resolving mediators notably contribute to inflammation resolution. Previously, we showed that the specialized pro-resolving mediators isomer 11,17dihydroxy docosapentaenoic acid (11,17diHDoPE) can be synthesized in bacterial cells and exhibits anti-inflammatory effects in mammalian cells. This study investigates the in vivo impact of 11,17diHDoPE in mice exposed to particulate matter 10 (PM10). Our results indicate that 11,17diHDoPE significantly mitigates PM10-induced lung inflammation in mice, as evidenced by reduced pro-inflammatory cytokines and pulmonary inflammation-related gene expression. Metabolomic analysis reveals that 11,17diHDoPE modulates inflammation-related metabolites such as threonine, 2-keto gluconic acid, butanoic acid, and methyl oleate in lung tissues. In addition, 11,17diHDoPE upregulates the LA-derived oxylipin pathway and downregulates arachidonic acid- and docosahexaenoic acid-derived oxylipin pathways in serum. Correlation analyses between gene expression and metabolite changes suggest that 11,17diHDoPE alleviates inflammation by interfering with macrophage differentiation. These findings underscore the in vivo role of 11,17diHDoPE in reducing pulmonary inflammation, highlighting its potential as a therapeutic agent for respiratory diseases.

Crosstalk between intestinal flora and human iron metabolism: the role in metabolic syndrome-related comorbidities and its potential clinical application

The interaction of iron and intestinal flora, both of which play crucial roles in many physiologic processes, is involved in the development of Metabolic syndrome (MetS). MetS is a pathologic condition represented by insulin resistance, obesity, dyslipidemia, and hypertension. MetS-related comorbidities including type 2 diabetes mellitus (T2DM), obesity, metabolism-related fatty liver (MAFLD), hypertension polycystic ovary syndrome (PCOS), and so forth. In this review, we examine the interplay between intestinal flora and human iron metabolism and its underlying mechanism in the pathogenesis of MetS-related comorbidities. The composition and metabolites of intestinal flora regulate the level of human iron by modulating intestinal iron absorption, the factors associated with iron metabolism. On the other hand, the iron level also affects the abundance, composition, and metabolism of intestinal flora. The crosstalk between these factors is of significant importance in human metabolism and exerts varying degrees of influence on the manifestation and progression of MetS-related comorbidities. The findings derived from these studies can enhance our comprehension of the interplay between intestinal flora and iron metabolism, and open up novel potential therapeutic approaches toward MetS-related comorbidities.

Serum Iron Levels, Dietary Iron Intake, and Supplement Use in Relation to Metabolic Syndrome in Adolescents: A Cross-Sectional Study

The objective of this study was to investigate the potential associations between serum iron levels, dietary iron intake, and iron supplementation, and the prevalence of metabolic syndrome (MetS) in adolescents A cross-sectional analysis was conducted, utilizing data from adolescents participating in the 2003-2018 cycle of the National Health and Nutrition Examination Survey (NHANES). Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) pertaining to serum iron, dietary iron, and iron supplementation were derived through multivariate logistic regression models. Additionally, a restricted cubic spline (RCS) regression model was applied to explore the nonlinear relationship between dietary iron and serum iron concerning MetS. The study encompassed 4858 American adolescents aged 12 to 19, among whom 413 (8.5%) manifested MetS. The study cohort exhibited an average age of 15.52 years, comprising 2551 males (52.51%) and 2307 females (47.49%). Relative to individuals in the lowest serum iron quartile, those in the highest quartile for serum iron (OR = 0.33, 95% CI 0.21-0.50), the highest quartile for dietary iron (OR = 0.53, 95% CI 0.32-0.89), and those utilizing iron supplements (OR = 0.61, 95% CI 0.37-0.99) evinced a diminished prevalence of MetS, even post adjustment for potential confounding variables. A non-linear relationship was discerned between serum iron and MetS, exhibiting a statistically significant negative correlation when serum iron concentrations exceeded the inflection point (serum iron = 8.66 µmol/L, P for nonlinear < 0.001). This investigation reveals that higher levels of serum iron, increased dietary iron intake, and the use of iron supplements are linked to a lower prevalence of MetS in US adolescents. These findings suggest that dietary modifications could play a role in promoting the health of adolescents.

Expectations for employing Escherichia coli Nissle 1917 in food science and nutrition

As a promising probiotic strain, Escherichia coli Nissle 1917 (EcN) has been demonstrated to confer beneficial effects on intestinal health, immune function, and pathogen prevention. Additionally, EcN has also been widely studied due to its clear genomic information, tractable gene regulation, and simple growth conditions. This review summarizes the various applications potential of EcN in food science and nutrition, including inflammation prevention, tumor-targeting therapy, antibacterial agents for food, and nutrient production with a focus on specific case studies. Moreover, we highlight the major challenges of employing EcN in food science and nutrition, including regulatory approval, stability during food processing, and consumer acceptance. Finally, we conclude with a discussion on perspectives related to employing EcN in food science and nutrition.

Protective effects of E. coli Nissle 1917 on chickens infected with Salmonella pullorum

The probiotic E. coli Nissle 1917 (EcN) plays an important role in regulating the microbial components of the gut and preventing inflammation of the gastrointestinal tract. Currently, the long-term use of antibiotics for the treatment of lethal white diarrhea in chicks caused by Salmonella has led to increased morbidity and mutation rates. Therefore, we want to use EcN as an antibiotic alternative as an alternative approach to prevent Salmonella-induced white diarrhea in chickens. To date, there are no reports of EcN being used for the prevention and control of Salmonella pullorum (S. pullorum) in chickens. In vitro, pretreatment with EcN significantly decreased the cellular invasion of S. pullorum CVCC533 in a chicken fibroblast (DF-1) cell model. Then, 0-day-old egg-laying chickens were orally inoculated with EcN at a dose of 10⁹ CFU/100 μL at either Day 1 (EcN1) or both Day 1 and Day 4 (EcN2). Then, S. pullorum CVCC533 was used to challenge the cells at a dose of 1.0 × 10⁷ CFU/100 μL on Day 8. Next, the body weights and survival rates were recorded for 14 consecutive days, and the colonization of S. pullorum in the spleen and liver at 7 days post-challenge (dpc) was determined. Chicken feces were also collected at 2, 4, 6 and 8 dpc to evaluate the excretion of pathogenic bacteria in feces. The liver, duodenum and rectum samples were collected and analyzed by pathological histology at 7 dpc to evaluate the protective effect of EcN on the mucosa, villi and crypts of the small intestine. The spleen and bursa were collected, and the immune organ index was calculated. In addition, the contents of the cecum of chicks were collected at 7 dpc for 16S rRNA sequencing to detect the distribution of microbial communities in the intestine. The results showed that EcN was able to protect against CVCC533 challenge, as shown by decreased body weight loss, mortality and shedding of pathogenic bacteria in fecal samples in the EcN1 plus Salmonella challenge group (EcN1S) but not the EcN2 plus Salmonella challenge group (EcN2S). The pathogenic changes in the liver, duodenum and rectum also demonstrated that one dose but not two doses of EcN effectively prolonged the length of the pilus with decreased crypt depth, indicating its protective effects against S. pullorum. In addition, the 16S rRNA sequencing results suggested that EcN could enlarge the diversity of intestinal flora, decrease the abundance of pathogenic bacteria and increase the abundance of beneficial bacteria, such as Lactobacillus. In conclusion, EcN has shown moderate protection against S. pullorum challenge in chickens.

Native and Engineered Probiotics: Promising Agents against Related Systemic and Intestinal Diseases

Intestinal homeostasis is a dynamic balance involving the interaction between the host intestinal mucosa, immune barrier, intestinal microecology, nutrients, and metabolites. Once homeostasis is out of balance, it will increase the risk of intestinal diseases and is also closely associated with some systemic diseases. Probiotics (Escherichia coli Nissle 1917, Akkermansia muciniphila, Clostridium butyricum, lactic acid bacteria and Bifidobacterium spp.), maintaining the gut homeostasis through direct interaction with the intestine, can also exist as a specific agent to prevent, alleviate, or cure intestinal-related diseases. With genetic engineering technology advancing, probiotics can also show targeted therapeutic properties. The aims of this review are to summarize the roles of potential native and engineered probiotics in oncology, inflammatory bowel disease, and obesity, discussing the therapeutic applications of these probiotics.

Therapeutic Potential of Escherichia coli Nissle 1917 in Clinically Remission-attained Ulcerative Colitis Patients: A Hospital-based Cohort Study

Background/Aims

Escherichia coli Nissle 1917 (EcN) alone therapy is as effective as mesalamine in inducing and maintaining remission in ulcerative colitis (UC). The efficacy and safety of EcN in combination with standard therapies have not been studied. This study examined the changes in the inflammation markers and symptoms following the additional administration of EcN to patients showing the clinical remission of UC.

Methods

UC patients who received EcN after being in clinical remission for more than 3 months at Kosin University Gospel Hospital between 2013 and 2018 were evaluated through the retrospective medical-record-based review. The partial Mayo score, fecal calprotectin (FC), BMI, hemoglobin, serum cholesterol, serum albumin levels, and the safety profiles were examined at 3rd and 6th months after initiating EcN.

Results

Ninety-four patients were included. After 3 months of treatment, there was no significant change in FC (156.3 μg/g to 141.1 μg/g) (p=0.653). On the other hand, partial Mayo score decreased significantly from 0.085 to 0.014 (p=0.025), and the bodyweight (p=0.001), BMI (p<0.001), hemoglobin (p=0.009), and cholesterol level increased (p=0.148). One patient (1.1%) experienced a serious adverse event with UC flare-up, and 14 patients (14.9%) discontinued EcN due to adverse events; all developed within 3 months.

Conclusions

Additional administration of EcN to clinically remission-attained UC patients may improve the UC symptoms without changing the FC levels. EcN-associated adverse events develop within the early few weeks.

Functional investigation of the chromosomal ccdAB and hipAB operon in Escherichia coli Nissle 1917

Toxin-antitoxin systems (TASs) have attracted much attention due to their important physiological functions. These small genetic factors have been widely studied mostly in commensal Escherichia coli strains, whereas the role of TASs in the probiotic E. coli Nissle 1917 (EcN) is still elusive. Here, the physiological role of chromosomally encoded type II TASs in EcN was examined. We showed that gene pair ECOLIN_00240-ECOLIN_00245 and ECOLIN_08365-ECOLIN_08370 were two functional TASs encoding CcdAB and HipAB, respectively. The homologs of CcdAB and HipAB were more conserved in E. coli species belonging to pathogenic groups, suggesting their important roles in EcN. CRISPRi-mediated repression of ccdAB and hipAB significantly reduced the biofilm formation of EcN in the stationary phase. Moreover, ccdAB and hipAB were shown to be responsible for the persister formation in EcN. Biofilm and persister formation of EcN controlled by the ccdAB and hipAB were associated with the expression of genes involved in DNA synthesis, SOS response, and stringent response. Besides, CRISPRi was proposed to be an efficient tool in annotating multiple TASs simultaneously. Collectively, our results advance knowledge and understanding of the role of TASs in EcN, which will enhance the utility of EcN in probiotic therapy.

Key points

• Two TASs in EcN were identified as hipAB and ccdAB.

• Knockdown of HipAB and CcdAB resulted in decreased biofilm formation of EcN.

• Transcriptional silencing of hipAB and ccdAB affected the persister formation of EcN.

• An attractive link between TASs and stress response was unraveled in EcN.

• CRISPRi afforded a fast and in situ annotation of multiple TASs simultaneously.

Current Models of Fatty Liver Disease; New Insights, Therapeutic Targets and Interventions

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disorders ranging from simple steatosis to steatosis with inflammation and fibrosis. NAFLD is currently the most prevalent chronic liver disease worldwide, with a global prevalence of 25%, and is soon projected to be the leading cause for liver transplantation in the US. Alarmingly, few effective pharmacotherapeutic approaches are currently available to block or attenuate development and progression of NAFLD. Preclinical models are critical for unraveling the complex and multi-factorial etiology of NAFLD and for testing potential therapeutics. Here we review preclinical models that have been instrumental in highlighting molecular and cellular mechanisms underlying the pathogenesis of NAFLD and in facilitating early proof-of-concept investigations into novel intervention strategies.

Designer probiotics for the prevention and treatment of human diseases

Various studies have shown the beneficial effects of probiotics in humans. The use of synthetic biology to engineer programmable probiotics that specifically targets cancer, infectious agents, or other metabolic diseases has gained much interest since the last decade. Developments made in synthetic probiotics as therapeutics within the last three years will be discussed in this review.