Evaluation of the expression of I-FABP and L-FABP in a necrotizing enterocolitis model after the use of Lactobacillus acidophilus

Probiotics, their prophylactic and therapeutic applications in human health development: A review of the literature

Antibiotics do not differentiate between good and bad germs, disrupting normal microflora and causing vitamin deficiency in the human body. They also kill healthy bacteria in the gut and genital tract on a large scale, weakening the host's defense mechanism. Probiotics are a colony of bacteria that live in our intestines and are regarded as a metabolic 'organ' due to their beneficial effects on human health, including metabolism and immunological function. They are used in clinical settings to prevent and treat conditions such as diarrhoea, colon cancer, hypertension, diabetes, acute pancreatitis, Helicobacter pylori infection, ventilator-associated pneumonia, migraine and autism. Probiotics may modify immunological activity by increasing innate and adaptive immune responses, altering microbial habitat in the intestine, improving gut barrier function, competitive adherence to the mucosa and epithelium, and producing antimicrobial compounds. The aim of this study is to index that further in depth researches to be conducted on probiotics pivotal role in the prophylaxis and therapeutic usage for a variety of disease that may or may not have treatment alternatives. Key words such as probiotics, microbiota, prophylactics, and therapeutic applications were searched extensively in research databases such as PubMed, PubMed Central (PMC), Scopus, Web of Science, Research Gate, Google Scholar, and Cochrane Library. This concise narrative review article summarized primarily the history, selection, mechanism/mode of action, recent advances in prophylactic and therapeutic applications, and future directions in the use of probiotics for prophylactic and therapeutic applications.

Ursodeoxycholic acid protects neonatal rats from necrotizing enterocolitis: a biochemical, histopathological, and immunohistochemical study

BACKGROUND

The pathophysiology of necrotizing enterocolitis (NEC) includes the massive production of endogenous cytokines with exaggerated activation of inflammatory pathways. Ursodeoxycholic acid (UDCA) has been used as an anti-inflammatory, antioxidant, and anti-apoptotic agent. We investigated the possible protective effects of UDCA in a neonatal rat pup model of NEC.

METHODS

We randomly divided rat pups into three groups: a control group, a non-treated NEC group, and a UDCA-treated NEC group. We induced NEC by feeding formula enterally and via hypoxia/reoxygenation. Intestinal samples were collected for histopathological and immunohistochemical evaluation. Blood samples were taken for biochemical analyses.

RESULTS

UDCA significantly reduced the extents of terminal ileal and jejunal injuries compared to the NEC group (p < .01), reduced Bax and caspase-3 immunoreactivities (both p < .01), and lowered serum levels of platelet-activating factor and intestinal fatty acid-binding protein (p < .01, p = .023, respectively).

CONCLUSIONS

In a rat model of NEC, UDCA protects against adverse intestinal histological, immunohistochemical, and biochemical changes. UDCA significantly reduces the effects of NEC on the rat pup intestine.

Bifidobacterium breve BBG-001 and intestinal barrier function in preterm babies: Exploratory Studies from the PiPS Trial

BACKGROUND

Uncertainty remains about the role of probiotics to prevent necrotising enterocolitis (NEC) some of which arises from the variety of probiotic interventions used in different trials, many with no prior evidence of potential efficacy. Mechanistic studies of intestinal barrier function embedded in a large probiotic trial could provide evidence about which properties of probiotics might be important for NEC prevention thus facilitating identification of strains with therapeutic potential.

METHODS

Intestinal permeability, stool microbiota, SCFAs and mucosal inflammation were assessed from the second postnatal week in babies enrolled to a randomised controlled trial of B. breve BBG-001 (the PiPS trial). Results were compared by allocation and by stool colonisation with the probiotic.

RESULTS

Ninety-four preterm babies were recruited across six nested studies. B. breve BBG-001 content was higher by allocation and colonisation; Enterobacteriaceae and acetic acid levels were higher by colonisation. No measure of intestinal barrier function showed differences. The PiPS trial found no evidence of efficacy to reduce NEC.

CONCLUSIONS

That the negative results of the PiPS trial were associated with failure of this probiotic to modify intestinal barrier function supports the possibility that the tests described here have the potential to identify strains to progress to large clinical trials.

IMPACT

Uncertainty about the therapeutic role of probiotics to prevent necrotising enterocolitis is in part due to the wide range of bacterial strains with no previous evidence of efficacy used in clinical trials. We hypothesised that mechanistic studies embedded in a probiotic trial would provide evidence about which properties of probiotics might be important for NEC prevention. The finding that the probiotic strain tested, Bifidobacterium breve BBG-001, showed neither effects on intestinal barrier function nor clinical efficacy supports the possibility that these tests have the potential to identify strains to progress to large clinical trials.

Effects of probiotics on experimental necrotizing enterocolitis: a systematic review and meta-analysis

BackgroundMeta-analyses of randomized controlled trials (RCTs) suggest that probiotics decrease the risk of necrotizing enterocolitis (NEC) in preterm infants. Many animal RCTs have evaluated probiotics for preventing NEC. We systematically reviewed the literature on this topic.MethodsThe protocol for systematic review of animal intervention studies (SYRCLE) was followed. Medline, Embase, ISI Web of Science, e-abstracts from the Pediatric Academic Society meetings, and other neonatal conferences were searched in December 2015 and August 2016. RCTs comparing probiotics vs. placebo/no probiotic were included.ResultsA total of 29 RCTs were included (Rats: 16, Mice: 7, Piglets: 3, Quail: 2, Rabbit: 1; N~2,310), with 21 reporting on histopathologically confirmed NEC; remaining 8 assessed only pathways of probiotic benefits. Twenty of the 21 RCTs showed that probiotics significantly reduced NEC. Pooling of data was possible for 16/21 RCTs. Meta-analysis using random-effects model showed that probiotics significantly decreased the risk of NEC (203/641 (31.7%) vs. 344/571 (60.2%); relative risk: 0.51; 95% confidence interval (CI): 0.42-0.62; P<0.00001; I2=44%; number needed to treat: 4; 95% CI: 2.9, 4.3).ConclusionProbiotics significantly reduced NEC via beneficial effects on immunity, inflammation, tissue injury, gut barrier, and intestinal dysbiosis.

Prebiotic galacto-oligosaccharides mitigate the adverse effects of iron fortification on the gut microbiome: a randomised controlled study in Kenyan infants

OBJECTIVE

Iron-containing micronutrient powders (MNPs) reduce anaemia in African infants, but the current high iron dose (12.5 mg/day) may decrease gut Bifidobacteriaceae and Lactobacillaceae, and increase enteropathogens, diarrhoea and respiratory tract infections (RTIs). We evaluated the efficacy and safety of a new MNP formula with prebiotic galacto-oligosaccharides (GOS) combined with a low dose (5 mg/day) of highly bioavailable iron.

DESIGN

In a 4-month, controlled, double-blind trial, we randomised Kenyan infants aged 6.5-9.5 months (n=155) to receive daily (1) a MNP without iron (control); (2) the identical MNP but with 5 mg iron (2.5 mg as sodium iron ethylenediaminetetraacetate and 2.5 mg as ferrous fumarate) (Fe group); or (3) the identical MNP as the Fe group but with 7.5 g GOS (FeGOS group).

RESULTS

Anaemia decreased by ≈50% in the Fe and FeGOS groups (p<0.001). Compared with the control or FeGOS group, in the Fe group there were (1) lower abundances of Bifidobacterium and Lactobacillus and higher abundances of Clostridiales (p<0.01); (2) higher abundances of virulence and toxin genes (VTGs) of pathogens (p<0.01); (3) higher plasma intestinal fatty acid-binding protein (a biomarker of enterocyte damage) (p<0.05); and (4) a higher incidence of treated RTIs (p<0.05). In contrast, there were no significant differences in these variables comparing the control and FeGOS groups, with the exception that the abundance of VTGs of all pathogens was significantly lower in the FeGOS group compared with the control and Fe groups (p<0.01).

CONCLUSION

A MNP containing a low dose of highly bioavailable iron reduces anaemia, and the addition of GOS mitigates most of the adverse effects of iron on the gut microbiome and morbidity in African infants.

TRIAL REGISTRATION NUMBER

NCT02118402.

Intestinal fatty acid binding protein Ala54Thr polymorphism is associated with peripheral atherosclerosis combined with type 2 diabetes mellitus

BACKGROUND

Intestinal fatty acid-binding protein 2 (FABP2) is expressed in enterocytes and binds saturated and unsaturated long-chain fatty acids. The FABP2 Ala54Thr polymorphism has been reported to effect lipid metabolism. The aim of the present study was to assess the relationship between this polymorphism and peripheral atherosclerosis combined with type 2 diabetes mellitus (T2DM) in an Egyptian population.

METHODS

The study was performed on 100 T2DM patients with peripheral atherosclerosis and 100 control subjects. The Ala54Thr polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism, whereas serum FABP2 levels were determined using ELISA. Fasting blood glucose, fasting serum insulin concentrations, HbA1c, lipid profile, body mass index (BMI) and systolic and diastolic blood pressure (SBP and DBP, respectively) were determined.

RESULTS

There was a higher frequency of the Thr54 allele among the patient group (P = 0.002). In Ala54/Thr54 heterozygotes and carriers of the rare Thr54/Thr54 genotype, there were significant increases in BMI and FABP2. Those with the Thr54/Thr54 genotype had significantly decreased high-density lipoprotein cholesterol (HDL-C) concentrations; in addition, those with the Thr54/Thr54 genotype had significantly higher SBP and DBP than subjects with the Ala54/Ala54 and Ala54/Thr54 genotypes. There was a positive correlation between FABP2 levels and BMI, SBP and DBP, and a negative correlation with HDL-C.

CONCLUSIONS

The Thr54 allele of the FABP2 Ala54Thr polymorphism was associated with an increased incidence of peripheral atherosclerosis combined with T2DM in the population studied.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

Impact of probiotics on necrotizing enterocolitis

A large number of randomized placebo-controlled clinical trials and cohort studies have demonstrated a decrease in the incidence of necrotizing enterocolitis with administration of probiotic microbes. These studies have prompted many neonatologists to adopt routine prophylactic administration of probiotics while others await more definitive studies and/or probiotic products with demonstrated purity and stable numbers of live organisms. Cross-contamination and inadequate sample size limit the value of further traditional placebo-controlled randomized controlled trials. Key areas for future research include mechanisms of protection, optimum probiotic species or strains (or combinations thereof) and duration of treatment, interactions between diet and the administered probiotic, and the influence of genetic polymorphisms in the mother and infant on probiotic response. Next generation probiotics selected based on bacterial genetics rather than ease of production and large cluster-randomized clinical trials hold great promise for NEC prevention.

Can probiotics modulate human disease by impacting intestinal barrier function?

Intestinal barrier integrity is a prerequisite for homeostasis of mucosal function, which is balanced to maximise absorptive capacity, while maintaining efficient defensive reactions against chemical and microbial challenges. Evidence is mounting that disruption of epithelial barrier integrity is one of the major aetiological factors associated with several gastrointestinal diseases, including infection by pathogens, obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome and inflammatory bowel disease. The notion that specific probiotic bacterial strains can affect barrier integrity fuelled research in which in vitro cell lines, animal models and clinical trials are used to assess whether probiotics can revert the diseased state back to homeostasis and health. This review catalogues and categorises the lines of evidence available in literature for the role of probiotics in epithelial integrity and, consequently, their beneficial effect for the reduction of gastrointestinal disease symptoms.

[Value of combined measurement of intestinal fatty acid-binding protein and fecal calprotectin in diagnosis of necrotizing enterocolitis in full-term neonates]

OBJECTIVE

To study the value of combined measurement of intestinal fatty acid-binding protein (I-FABP) and fecal calprotectin (FC) in the diagnosis of necrotizing enterocolitis (NEC) in full-term neonates.

METHODS

A total of 36 full-term neonates with NEC (case group) and 39 neonates without digestive system diseases (control group) were enrolled as study subjects. ELISA was used to measure the serum I-FABP level and fecal FC level, and the clinical value of I-FABP combined with FC in the diagnosis of NEC was evaluated.

RESULTS

The case group had significantly higher I-FABP and FC levels than the control group (P<0.05). In the case group, serum I-FABP level was positively correlated with fecal FC level (r=0.71, P<0.05). In the diagnosis of NEC, I-FABP alone, FC alone, and I-FABP/FC combination had sensitivities of 83.3%, 81.5%, and 79.5%, specificities of 72.5%, 75.8%, and 86.3%, and areas under the ROC curve (AUCs) of 0.82, 0.81, and 0.88. The combined measurement showed significantly higher specificity and AUC than single measurement (P<0.05).

CONCLUSIONS

Children with NEC have significant increases in I-FABP and FC levels, and there is a correlation between them. Combined measurement of I-FABP and FC can increase the specificity of the diagnosis of NEC.

Prevention of Necrotizing Enterocolitis Through Manipulation of the Intestinal Microbiota of the Premature Infant

PURPOSE

In spite of four decades of research, necrotizing enterocolitis (NEC) remains the most common gastrointestinal complication in premature infants with high mortality and long-term morbidity. The composition of the intestinal microbiota of the premature infant differs dramatically from that of the healthy term infant and appears to be an important risk factor for NEC.

METHODS

We review the evidence of an association between intestinal dysbiosis and NEC and summarize published English language clinical trials and cohort studies involving attempts to manipulate the intestinal microbiota in premature infants.

FINDINGS

Promising NEC prevention strategies that alter the intestinal microbiota include probiotics, prebiotics, synbiotics, lacteroferrin, and human milk feeding.

IMPLICATIONS

Shaping the intestinal microbiota of the premature infant through human milk feeding and dietary supplements decreases the risk of NEC. Further studies to identify the ideal microbial composition and the most effective combination of supplements are indicated.

The Endocannabinoid System and Its Role in Regulating the Intrinsic Neural Circuitry of the Gastrointestinal Tract

Endocannabinoids are important neuromodulators in the central nervous system. They regulate central transmission through pre- and postsynaptic actions on neurons and indirectly through effects on glial cells. Cannabinoids (CBs) also regulate neurotransmission in the enteric nervous system (ENS) of the gastrointestinal (GI) tract. The ENS consists of intrinsic primary afferent neurons, interneurons, and motor neurons arranged in two ganglionated plexuses which control all the functions of the gut. Increasing evidence suggests that endocannabinoids are potent neuromodulators in the ENS. In this review, we will highlight key observations on the localization of CB receptors and molecules involved in the synthesis and degradation of endocannabinoids in the ENS. We will discuss endocannabinoid signaling mechanisms, endocannabinoid tone and concepts of CB receptor metaplasticity in the ENS. We will also touch on some examples of enteric neural signaling in relation neuromuscular, secretomotor, and enteroendocrine transmission in the ENS. Finally, we will briefly discuss some key future directions.