The protective potency of probiotic bacteria and their microbial products against enteric infections-review

Lactobacillus plantarum and Lactobacillus brevis Alleviate Intestinal Inflammation and Microbial Disorder Induced by ETEC in a Murine Model

The purpose of this research is to explore the positive effects of Lactobacillus plantarum and Lactobacillus brevis on the tissue damage and microbial community in mice challenged by Enterotoxigenic Escherichia coli (ETEC). Twenty-four mice were divided into four groups randomly: the CON group, ETEC group, LP-ETEC group and LB-ETEC group. Our results demonstrated that, compared with the ETEC group, the LP-ETEC and LB-ETEC groups experienced less weight loss and morphological damage of the jejunum. We measured proinflammatory factors of colonic tissue and found that L. plantarum and L. brevis inhibited the expression of proinflammatory factors such as IL-β, TNF-α, and IL-6 and promoted that of the tight junction protein such as claudin-1, occludin, and ZO-1. Additionally, L. plantarum and L. brevis altered the impact of ETEC on the intestinal microbial community of mice, significantly increased the abundance of probiotics such as Lactobacillus, and reduced that of pathogenic bacteria such as Proteobacteria, Clostridia, Epsilonproteobacteria, and Helicobacter. Therefore, we believe that L. plantarum and L. brevis can stabilize the intestinal microbiota and inhibit the growth of pathogenic bacteria, thus protecting mice from the gut inflammation induced by ETEC.

Effect of lactic acid bacteria-treated King grass silage on the performance traits and serum metabolites in New Zealand white rabbits (Oryctolagus cuniculus)

This study examined the effects of Lactobacillus plantarum and Pediococcus acidilactici-treated silage of King grass (Pennisetum purpureophoides) on the productive traits and blood biochemistry of New Zealand white (NZW) rabbits. King grass was ensiled without or with L. plantarum (T1), P. acidilactici (T2) and P. acidilactici + L. plantarum (T3). A total of 72 male NZW rabbits (6 weeks) of similar weight and appearance were housed in groups in metallic cages in a completely randomized design. The performance traits, daily feed intake, body weight gain and feed convention ratio were not affected by the silage treatment. Triglyceride and alanine aminotransferase (ALT) concentration was increased (p < .05) in T2 (0.92 mmol/L) compared to the other treatments. The superoxide dismutase (SOD), phosphorous (P) and magnesium (Mg) increased (p < .05) in T1 (658.01 nmol/ml, 5.1 mg/kg and 2.43 mg/kg, respectively) compared to the control and other experimental groups. Cu and Mn decreased (p < .05), while Zn increased (p < .05) in the treated groups compared to the control. The CP decreased (p < .05) in the treatment groups compared to the control. Neutral detergent fibre (NDF) increased (p < .05) in T2 (54.40%) compared to the other treatments. The inoculation of lactic acid bacteria-treated King grass silage supplementation positively affected rabbit performance and improved blood cholesterol profile, antioxidant status and improve nutrients digestibility.

Probiotics for the Treatment of Symptomatic Uncomplicated Diverticular Disease: Rationale and Current Evidence

Changes in the colonic microbiota are critical to the pathogenesis of diverticular complications such as diverticulitis and peridiverticular abscesses. However, more subtle changes in microbiota composition may well be important to the more chronic manifestations of diverticulosis. Some studies have shown the presence of bacterial overgrowth in subgroups of patients with diverticular disease and recent studies, using molecular biology techniques, found an increase of proteobacteria and actinobacteria in patients with symptomatic uncomplicated diverticular disease (SUDD), compared with healthy controls. The use of probiotics to modulate intestinal microecology in SUDD appears therefore rational. Although several investigations evaluating the clinical efficacy of probiotics have been performed, no definitive results have yet been achieved, mainly due to the heterogeneity of the available studies. Most of the studies used probiotics in combination with poorly absorbed antimicrobials or anti-inflammatory drugs. In only 4 studies, there was a harm using probiotics alone, but only 1 was a placebo-controlled, double-blind trial. The analysis of the available evidence reveals a poor quality of the published studies, whose design was heterogeneous, with only 2 out of 11 trials being double-blind and randomized. Therefore, available data can only suggest a benefit of probiotics in SUDD, but do not allow any evidence-based definite conclusion. As a consequence, current guidelines state that there is insufficient evidence to recommend probiotics for symptom relief in patients with diverticular disease.

Probiotics as beneficial microbes in aquaculture: an update on their multiple modes of action: a review

Wide and discriminate use of antibiotics has resulted in serious biological and ecological concerns, especially the emergence of antibiotic resistance. Probiotics, known as beneficial microbes, are being proposed as an effective and eco-friendly alternative to antibiotics. They were first applied in aquaculture species more than three decades ago, but considerable attention had been given only in the early 2000s. Probiotics are defined as live or dead, or even a component of the microorganisms that act under different modes of action in conferring beneficial effects to the host or to its environment. Several probiotics have been characterized and applied in fish and a number of them are of host origin. Unlike some disease control alternatives being adapted and proposed in aquaculture where actions are unilateral, the immense potential of probiotics lies on their multiple mechanisms in conferring benefits to the host fish and the rearing environment. The staggering number of probiotics papers in aquaculture highlights the multitude of advantages from these microorganisms and conspicuously position them in the dynamic search for health-promoting alternatives for cultured fish. This paper provides an update on the use of probiotics in finfish aquaculture, particularly focusing on their modes of action. It explores the contemporary understanding of their spatial and nutritional competitiveness, inhibitory metabolites, environmental modification capability, immunomodulatory potential and stress-alleviating mechanism. This timely update affirms the importance of probiotics in fostering sustainable approaches in aquaculture and provides avenues in furthering its research and development.

Enterococcus faecium NCIMB 10415 modulates epithelial integrity, heat shock protein, and proinflammatory cytokine response in intestinal cells

Probiotics have shown positive effects on gastrointestinal diseases; they have barrier-modulating effects and change the inflammatory response towards pathogens in studies in vitro. The aim of this investigation has been to examine the response of intestinal epithelial cells to Enterococcus faecium NCIMB 10415 (E. faecium), a probiotic positively affecting diarrhea incidence in piglets, and two pathogenic Escherichia coli (E. coli) strains, with specific focus on the probiotic modulation of the response to the pathogenic challenge. Porcine (IPEC-J2) and human (Caco-2) intestinal cells were incubated without bacteria (control), with E. faecium, with enteropathogenic (EPEC) or enterotoxigenic E. coli (ETEC) each alone or in combination with E. faecium. The ETEC strain decreased transepithelial resistance (TER) and increased IL-8 mRNA and protein expression in both cell lines compared with control cells, an effect that could be prevented by pre- and coincubation with E. faecium. Similar effects were observed for the increased expression of heat shock protein 70 in Caco-2 cells. When the cells were challenged by the EPEC strain, no such pattern of changes could be observed. The reduced decrease in TER and the reduction of the proinflammatory and stress response of enterocytes following pathogenic challenge indicate the protective effect of the probiotic.

Expression of Heat Shock Proteins and Cytokines in Response to Ethanol Induced Damage in the Small Intestine of ICR Mice

Background/Aims

Ethanol administration causes intestinal epithelial cell damage by increasing intestinal permeability and the translocation of endotoxins from intestinal bacterial flora. Heat shock proteins (HSPs) are associated with recovery and protection from cell damage. The aim of the current study was to investigate differences in the expression of HSPs in the small intestine and the biochemical changes attributable to ethanol-induced intestinal damage.

Methods

Ethanol (20%) was injected intraperitoneally (2.75 g/kg, 5.5 g/kg, 8.25 g/kg) in ICR mice and the same volume of saline was administered to controls. After 1 hour, the proximal, middle, and distal segments were taken from the small intestine and the degree of damage was analyzed. In each segment, the expression of HSPs was analyzed by western blotting. The expression of inflammatory mediators including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), and antioxidant enzyme such as glutathione-S-transferase were compared using real-time polymerase chain reaction assays.

Results

In the control group, HSP70 increased in all segments of small intestine. Additionally, increases in the expression of HSP40 and HSP90 in the distal regions and an increase in HSP32 in the middle regions were observed. After ethanol treatment, greater histological damage was observed in the distal small intestine and significant decreases in HSPs were observed generally. Increased expression of IL-1β, TNF-α, and COX-2 was observed in small intestinal tissues exposed to ethanol-induced damage. However, there was no significant difference in the expression of an antioxidant enzyme.

Conclusions

Significant differences in the expression of HSPs in different intestinal regions were observed. These differences may have been attributable to the distribution of intestinal bacteria.

Beneficial effects of dietary probiotics mixture on hemato-immunology and cell apoptosis of Labeo rohita fingerlings reared at higher water temperatures

Probiotics play an important role in growth increment, immune enhancement and stress mitigation in fish. Increasing temperature is a major concern in present aquaculture practices as it markedly deteriorates the health condition and reduces the growth in fish. In order to explore the possibilities of using probiotics as a counter measure for temperature associated problems, a 30 days feeding trial was conducted to study the hemato-immunological and apoptosis response of Labeo rohita (8.3±0.4 g) reared at different water temperatures, fed with or without dietary supplementation of a probiotic mixture (PM) consisting of Bacillus subtilis, Lactococcus lactis and Saccharomyces cerevisiae) (10¹¹ cfu kg⁻¹). Three hundred and sixty fish were randomly distributed into eight treatment groups in triplicates, namely, T1(28°C+BF(Basal feed)+PM), T2(31°C+BF+PM), T3(34°C+BF+PM), T4(37°C+BF+PM), T5(28°C+BF), T6(31°C+BF), T7(34°C+BF) and T8(37°C+BF). A significant increase (P<0.01) in weight gain percentage was observed in the probiotic fed fish even when reared at higher water temperature (34–37°C). Respiratory burst assay, blood glucose, erythrocyte count, total serum protein, albumin, alkaline phosphatase and acid phosphatase were significantly higher (P<0.01) in the probiotic fed groups compared to the non-probiotic fed groups. A significant (P<0.01) effect of rearing temperature and dietary probiotic mixture on serum myeloperoxidase activity, HSP70 level and immunoglobulin production was observed. Degree of apoptosis in different tissues was also significantly reduced in probiotic-supplemented groups. Hence, the present results show that a dietary PM could be beneficial in enhancing the immune status of the fish and also help in combating the stress caused to the organism by higher rearing water temperature.

Lactobacillus plantarum ZLP001: In vitro Assessment of Antioxidant Capacity and Effect on Growth Performance and Antioxidant Status in Weaning Piglets

The objective of this study was to evaluate the antioxidant capacity of Lactobacillus plantarum ZLP001 and its effects on growth performance and antioxidant status in weaning piglets. The survival in hydrogen peroxide and free radical-scavenging activity of Lactobacillus plantarum ZLP001 were analysed in vitro. The Lactobacillus plantarum ZLP001 showed high viability in 1.0 mmol/L hydrogen peroxide and high scavenging ability against hydroxyl, superoxide anion, and DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals which was dose dependent. Ninety-six weaning piglets were selected (7.45±0.79 kg) and divided into three groups comprising of negative control without any supplementation, treatment group with supplemented 6.8×10(7) Lactobacillus plantarum ZLP001 CFU/g of diet, and positive control with antibiotic treatment (chlorotetracycline, 80 mg/kg diet). The results showed that Lactobacillus plantarum ZLP001 supplementation enhanced feed conversion rates in piglets compared with control (p<0.05). Supplementation of Lactobacillus plantarum ZLP001 increased the concentration of superoxide dismutase (p<0.05), glutathione peroxidase (p<0.01) and catalase in serum (p<0.10), while decreased the concentration of malondialdehyde (p<0.05). The present study implies that the strain Lactobacillus plantarum ZLP001 had high antioxidant ability and its supplementation improved the growth performance and antioxidant status of weaning piglets, so it can be considered useful to alleviate oxidative stress and increase productive performance of pigs. (Key Words: Probiotic, Antioxidant Capacity, Weaning Piglet).

Aquaculture and stress management: a review of probiotic intervention

To meet the ever-increasing demand for animal protein, aquaculture continuously requires new techniques to increase the production yield. However, with every step towards intensification of aquaculture practices, there is an increase in stress level on the animal as well as on the environment. Feeding practices in aqua farming usually plays an important role, and the addition of various additives to a balanced feed formula to achieve better growth is a common practice among the fish and shrimp culturists. Probiotics, also known as 'bio-friendly agents', such as LAB (Lactobacillus), yeasts and Bacillus sp., can be introduced into the culture environment to control and compete with pathogenic bacteria as well as to promote the growth of the cultured organisms. In addition, probiotics are non-pathogenic and non-toxic micro-organisms, having no undesirable side effects when administered to aquatic organisms. Probiotics are also known to play an important role in developing innate immunity among the fishes, and hence help them to fight against any pathogenic bacterias as well as against environmental stressors. The present review is a brief but informative compilation of the different essential and desirable traits of probiotics, their mode of action and their useful effects on fishes. The review also highlights the role of probiotics in helping the fishes to combat against the different physical, chemical and biological stress.

Functional properties of Lactobacillus strains isolated from dairy products

Twenty-four acid- and bile-tolerant lactobacilli isolates from dairy products were identified and further in vitro characterized for the presence of functional traits potentially useful for probiotic applications, which included desirable and undesirable traits, such as biofilm formation, ability to inhibit intestinal pathogens, antibiotic susceptibility, and enzyme activity. The majority of examined strains were susceptible to certain antimicrobial agents (streptomycin, gentamicin, clindamycin, erythromycin, tetracycline, quinupristin-dalfopristin), except for three strains of Lactobacillus rhamnosus with minimal inhibitory concentration levels for streptomycin higher than the microbiological breakpoints (≥32 μg/mL), which are considered as resistant. Undesirable traits such as α-chymotrypsin or N-acetyl-β-glucosaminidase activities were not detected, but low β-glucuronidase, and moderate and high β-glucosidase activities were recorded in nine strains, which were eliminated from further examination together with three isolates showing unsuitable antibiotic resistance. Of the remaining 12 isolates, 4 (Lactobacillus fermentum 202, Lactobacillus gallinarum 7001, L. rhamnosus 183, and Lactobacillus plantarum L2-1) manifested an outstanding potential to inhibit selected intestinal pathogens in an agar spot test, including Escherichia coli and Salmonella spp., and simultaneously demonstrated strong biofilm-forming capacity. In conclusion, the results of our in vitro experiments showed that the above four strains had a potential probiotic value and met the criteria to be identified as a possible probiotic microorganism, with the necessity of verification through well-designed in vivo experimental, clinical, and technological studies before the strains can be used as probiotics or as starter probiotic cultures.

Live and heat-inactivated lactobacilli from feces inhibit Salmonella typhi and Escherichia coli adherence to Caco-2 cells

A quantitative approach has been proposed to evaluate the competitive inhibition of Escherichia coli and Salmonella typhi by live and heat-inactivated laboratory isolated Lactobacillus sp. on adhesion to monolayer of Caco-2 cells. Three species of Lactobacillus (L. casei, L. acidophilus, L. agilis) isolated from human neonate feces and two commercial probiotic strains (L. casei, L. acidophilus) have been compared for probiotic activity. All lactobacilli were able to attach to the Caco-2 cells, however, the degree of adhesion was bacterial strain-dependent. The adhesion indices of the two commercial probiotic strains were not significantly different from the values obtained for the other two similar fecal strains (p > 0.01). The inhibition of attachment of the pathogenic bacteria by inactivated cells of fecal L. acidophilus was examined and compared to the results of live bacteria. The inhibition pattern was similar for live and heat-inactivated L. acidophilus (p > 0.01). The number of attached pathogenic bacteria to the Caco-2 cells decreased when the number of L. acidophilus increased from 10(6) to 10(9) CFU/mL. The heat-inactivated L. acidophilus displayed similar probiotic activity compared to the live bacteria.