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Biogenics are compounds produced by living organisms such as animals, plants, bacteria, etc. Probiotics and their biogenics are known for their antimicrobial potential. Therefore, the present study was designed to evaluate the antibiofilm potential of probiotic-derived biogenics in conjunction with zingerone against the Pseudomonas aeruginosa PAO1 biofilm. Cell-free supernatant (CFS) of potential probiotics Pediococcus acidilactici BNS5B and Lactobacillus fermentum PUM was found to inhibit the growth of Ps. aeruginosa PAO1 maximally among the nineteen isolated lactic acid bacteria. L. fermentum PUM produced precipitated protein fraction (PP), organic acids (OAs), exopolysaccharides (EPSs), biosurfactants (BSs) and various volatile antimicrobial compounds, while Ped. acidilactici BNS5B was found to produce PP, OA, EPS, BS and fewer volatile antimicrobial compounds only. More specifically, CFS and selected biogenics (OA and PP from L. fermentum PUM; OA from Ped. acidilactici BNS5B) of both potential probiotics showed synergy with zingerone against Ps. aeruginosa growth as observed by FIC index (

Metabolic syndrome a lifestyle disease, where diet and gut microbiota play a prodigious role in its initiation and progression. Prophylactic bio-interventions employing probiotics and prebiotics offer an alternate nutritional approach towards attenuating its progression. The present study aimed to evaluate the protective efficacy of a novel synbiotic (Lactiplantibacillus pentosus GSSK2 + isomalto-oligosaccharides) in comparison to orlistat in an experimental model of metabolic syndrome. It was observed that supplementation of synbiotic for 12 weeks to Sprague Dawley rats fed with high fat diet (HFD), ameliorated the morphometric parameters i.e. weight gain, abdominal circumference, Lee’s index, BMI and visceral fat deposition along with significantly increased fecal Bacteroidetes to Firmicutes ratio, elevated population of Lactobacillus spp., Akkermansia spp., Faecalibacterium spp., Roseburia spp. and decreased Enterobacteriaceae compared with HFD animals. Additionally, synbiotic administration to HFD animals exhibited improved glucose clearance, lipid biomarkers, alleviated oxidative stress, prevented leaky gut phenotype, reduced serum lipopolysaccharides and modulated the inflammatory, lipid and glucose metabolism genes along with restored histomorphology of adipose tissue, colon and liver compared with HFD animals. Taken together, the study highlights the protective potential of synbiotic in comparison with its individual components in ameliorating HFD-induced metabolic complications.

Probiotics, the beneficial bacteria produce active metabolites which could probably mimic their anticancer effect and prevent the risk associated with live bacteria. Thus, the study was designed to isolate effective lactic acid bacteria (LAB) and monitor anticancerous potential of their metabiotic extracts. Probiotics were isolated from different sources and their cell free supernatants (CFS) were screened for antigenotoxic and cytotoxic potentials using SOS Chromo Test and MTT assay on Caco-2 and HT-29 cells. Organic extracts of CFS were prepared and dissolved in different solvents. The isolate with most effective metabiotic extract in terms of cytotoxicity was classified for probiotic and phylogenetic characters and the metabiotic extract was characterized physiochemically. Among 60 isolated LAB, CFS of only 10 isolates showed antigenotoxicity more than 30% and four exhibited 70-80% cytotoxicity. Further, organic extracts of these four CFS dissolved in carboxymethyl cellulose showed 80-90% cytotoxicity. Interestingly, the most effective isolate was found to possess probiotic attributes and phylogenetic characterization revealed it to be Lactobacillus rhamnosus MD 14. Physiochemical characterization of its metabiotic extract indicated the presence of heat sensitive organic acids and proteins. To conclude, metabiotics produced by isolated probiotic L. rhamnosus MD 14 exhibited both antigenotoxic and cytotoxic potential against colon cancer.

Background and Objective: The cellular microenvironment, diet, and lifestyle play a key role in the occurrence of colorectal cancer. Due to its rising trend, attempts are being made to devise novel biointerventions as adjunct to conventional therapies to prevent this deadly disease. “Metabiotics,” the beneficial metabolic signatures of probiotics are emerging as potential anticancer agent due to their ability to alter metabolic processes in the gut lumen and reduce the severity of colon carcinogenesis. Although beneficial attributes of metabiotics have been elucidated in vitro, yet their anticancer mechanism in vivo needs to be explored. Thus, the present study was performed to envisage anticancer potential of metabiotic extract obtained from indigenous probiotic, Lactobacillus rhamnosus MD 14, in early experimental colon carcinogenesis. Materials and Methods: Sprague–Dawley rats were daily administered with low, medium, and high dose of metabiotic extract orally along with a single dose of weekly intraperitoneal injection of 1,2-dimethylhydrazine up to 6 weeks and monitored for the markers of early colon carcinogenesis. Results: It was observed that the medium dose of metabiotic extract attenuated early colon carcinogenesis by reducing fecal procarcinogenic enzymes, oxidants, aberrant crypt foci, vis-à-vis downregulating oncogenes [K-ras, β-catenin, Cox-2, nuclear factor kappa B (NF-κB)] and upregulating tumor suppressor p53 gene leading to almost normal colon histology. Conclusions: It can be suggested that metabiotics modulate experimental colorectal cancer and could be used as a promising alternative of probiotics, particularly in immunocompromised individuals.

Modulation of the gut microbiota by probiotics, is emerging as a promising approach for the management of metabolic diseases but due to their species and strain specific response, isolation of new probiotic strains is gaining importance. The present study was designed to assess the effect of isolated and well characterised indigenous probiotics, Lactobacillus pentosus GSSK2, Lactobacillus fermentum PUM and Lactobacillus plantarum GS26A in high fat diet (HFD) induced metabolic syndrome. It was observed that though supplementation of all three probiotics for 12 weeks to Sprague Dawley rats fed with HFD, ameliorated the anthropometric parameters, but L. pentosus GSSK2 showed maximum reduction in weight gain while maximum decrease in abdominal circumference, Lee’s index, BMI and visceral fat deposition was observed in L. plantarum GS26A compared with HFD animals. Further, administration of L. plantarum GS26A to HFD animals led to significant increase in lactic acid bacteria count and lipid excretion in feces followed by L. pentosus GSSK2 and L. fermentum PUM compared with counter controls. Additionally, both L. pentosus GSSK2 and L. plantarum GS26A exhibited improved glucose tolerance, liver biomarkers, alleviated oxidative stress and restored the histoarchitechture of adipose tissue, colon and liver compared with HFD animals. The study highlights the prophylactic potential of isolated probiotics in experimental metabolic syndrome model and revealed that amongst all three probiotics, L. pentosus GSSK2 and L. plantarum GS26A were equally effective and more promising than L. fermentum PUM in improving metabolic dysfunctions and may be employed as functional foods but needs to be correlated clinically.

Probiotics are known to modulate gut microbiota, intestinal barrier function and host immune response, but due to the species and strain specific response their mechanisms are not clearly understood. Thus, the present study was designed to isolate, assess the anti-inflammatory potential and underlying modulatory mechanisms of indigenous probiotics in murine macrophage cell line, RAW 264.7. Forty lactic acid bacteria (LAB) were isolated from different sources and monitored for their anti-inflammatory potential against lipopolysaccharide (LPS) induced inflammatory stress employing RAW 264.7 cells. Among these isolates, only four LAB isolates exhibited more than 90% nitric oxide inhibition and possessed the probiotic attributes. Further, these selected LAB isolates reduced the level of pro-inflammatory cytokines, TNF-α, IL-1β and IL-6, inhibited the phosphorylation of Mitogen Activated Protein Kinases (MAPKs) i.e. p38 MAPK, ERK1/2 and SAPK/JNK and expression of cyclooxygenase-2 (COX-2) in LPS stimulated RAW 264.7 cells. The in vitro analysis suggested that the selected probiotic isolates attenuated the LPS-induced inflammation by downregulating MAPK pathway vis-a-vis inhibiting COX-2 and can be employed as anti-inflammatory agents in various inflammatory diseases.

Phytic acid, the main phosphate storage component of plant-based diet, is one of the prime causes of micronutrient deficiency in vegetarians due to the formation of non-degradable cation-phytic acid complex in gastrointestinal tract of monogastric animals that are devoid of phytase enzyme. Therefore, the present study was designed to isolate phytase producing probiotic from neonatal feces which may enhance the bioavailability of phosphorous micronutrient. Experimentally, 13 phytase producing lactic acid bacteria (LAB) were isolated from 28 neonatal fecal samples and characterized both phenotypically and for probiotic attributes. Among these, Isolate 5b exhibited potent probiotic potential with significant (p Pediococcus acidilactici BNS5B. Interestingly, it was found that phytase from P. acidilactici BNS5B significantly dephytinized phytic acid from modified diet (96.59%) and brown bread (88.89%) after 15 min of phytase treatment at 37°C. Therefore, this provides an opportunity to develop P. acidilactici BNS5B as a probiotic to be used as a supplement in feed/food of monogastric animals and humans. This also provides the rationale for further in vivo studies to use phytase producing probiotic in relation to maintaining and improving health.

Giardiasis is a re-emerging infectious disease with outbreaks reported globally specially in children and malnourished individuals leading to malabsorption, growth retardation, and severe diarrhea. Thus, in the present study, prophylactic administration of synbiotic as the functional food was used to assess its antigiardial potential in malnourished murine giardiasis. Interestingly, prior administration of synbiotic (Lactobacillus casei + inulin) even to malnourished-Giardia-infected mice led to increased body mass, small intestine mass, lactobacilli counts, and reduced severity of giardiasis as evident by decreased cyst and trophozoite counts. Synbiotic therapy further boosted the innate and acquired immune response resulting into increase in nitric oxide, antigiardial secretory IgA and IgG antibody levels along with IL-6 and IL-10 cytokines, and decreased levels of inflammatory TNF-α cytokine in both serum and intestinal fluid in malnourished-synbiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. More specifically, histopathological and scanning electron microscopy analysis of the small intestine also confirmed the modulatory potentials of synbiotic in malnourished-synbiotic-Giardia mice which had less cellular and mucosal damage compared with severely damaged, mummified, and blunted villi in malnourished-Giardia-infected mice. Taken together, this is the first experimental study to report that prior supplementation of synbiotic restored the gut morphology and improved the immune status of the malnourished-Giardia-infected mice, and could be considered as the prophylactic adjunct therapy for malnourished individuals.

Microorganisms develop biofilms on indwelling medical devices and are associated with biofilm-related infections, resulting in substantial morbidity and mortality. Therefore, to prevent and control biofilm-associated infections, the present study was designed to assess the anti-biofilm potential of postbiotics derived from probiotic organisms against most prevalent biofilm-forming Pseudomonas aeruginosa PAO1. Eighty lactic acid bacteria isolated from eight neonatal fecal samples possessed antibacterial activity against P. aeruginosa PAO1. Among these, only four lactic acid bacteria produced both bacteriocin and exopolysaccharides but only one isolate was found to maximally attenuate the P. aeruginosa PAO1 biofilm. More specifically, the phenotypic and probiotic characterization showed that the isolated lactic acid bacteria were gram positive, non-motile, and catalase and oxidase negative; tolerated acidic and alkaline pH; has bile salt concentration; showed 53% hydrophobicity; and was found to be non-hemolytic. Phylogenetically, the organism was found to be probiotic Lactobacillus fermentum with accession no. KT998657. Interestingly, pre-coating of a microtiter plate either with bacteriocin or with exopolysaccharides as well as their combination significantly (p

Colorectal cancer, the third most commonly diagnosed cancer, is a lifestyle disease where diet and gut microbiome contribute intricately in its initiation and progression. Prophylactic bio-interventions mainly probiotics offer an alternate approach towards reducing or delaying its progression. Therefore, the present study was designed wherein a robust protocol for the isolation, characterization, and identification of indigenous probiotics having antigenotoxic and anticancerous activity was followed along with their prophylactic potential assessment in early experimental colorectal carcinogenesis. Among forty-six isolated lactic acid bacterial strains, only three were selected on the basis of antigenotoxicity against N,N-Dimethyl dihydrazine dihydrochloride and 4-Nitroquinoline 1-oxide and probiotic attributes. All three selected probiotic strains exhibited anticancerous potential as is evident by the reduced Aberrant Crypt Foci, reduced fecal pH, enhanced fecal lactic acid bacteria and altered fecal enzymes (β-glucuronidase, nitroreductase, β-glucosidase) that modulated gut microbiota and microenvironment resulting into restored histoarchitecture of the colon. The results are a clear indicator of the prophylactic potential of selected indigenous probiotics which may be used as an alternative prophylactic biological therapy against colon carcinogenesis particularly in highly susceptible individuals.

The present study was designed to envisage the antigiardial efficacy of killed probiotic and probiotic protein (PP) of Lactobacillus rhamnosus GG in murine giardiasis. Experimentally, it was observed that animal administered either with probiotic protein emulsified with adjuvant (PP(E) + Giardia) or killed probiotic (killed probiotic (i/p) + Giardia) had significantly reduced Giardia cycle with respect to observed severity and duration of giardiasis compared with Giardia-infected mice. Further, it was found that animals belonging to PP(E) + Giardia and killed probiotic (i/p) + Giardia had significantly high levels of antigiardial IgA antibody and nitric oxide both in serum and in intestinal fluid compared with Giardia-infected and counter control mice. Histopathologyically, also animals belonging to PP(E) + Giardia and killed probiotic (i/p) + Giardia animals had intact mucosal epithelium lining, basal crypts, and normal villi along with increased goblet cells compared with severe microvillus atrophy, vacuolated epithelial cells, and ileitis in Giardia-infected mice. This is the first-ever study to demonstrate that prior administration of either killed probiotics or probiotic protein of effective probiotic reduced both the severity and the duration of giardiasis mainly by modulating the gut microbiome and morphology along with mucosal immunity, but animals belonging to PP(E) + Giardia had better response than killed probiotic (i/p) + Giardia suggesting that probiotic components do have adjuvant potential and may be used as the vaccine candidate for gastrointestinal diseases.

Acinetobacter baumannii is an emerging multi-drug resistant pathogen causing significant mortality in hospitalized ICU patients which demands developing new methods for prevention and treatment. A. baumannii 19606 proteome was analysed in silico through the online tool Vaxign for finding potential vaccine candidates. The selected nuclease (NucAb) was predicted to possess all the attributes of a promising vaccine candidate like outer membrane localization, high adhesin probability (0.53), one transmembrane helix only, non-homology to human proteins and presence of B-cell and T-cell epitopes binding with high affinity (percentile rank≤1) to HLA alleles prevalent at high frequency in North Indian populations. nucAb gene was highly prevalent (100%) among the clinical isolates (40/40) and conserved (>98%) among NCBI sequenced Acinetobacter strains. It was cloned in pET28a, purified and its immunoprotective potential was validated in murine pneumonia model. Immunization of BALB/c mice with recombinant NucAb (25μg) elicited high antibody titre (1-5×10(5)) which reduced bacterial load by 5 log cycles in lungs of mice challenged with optimized lethal dose (10(8)CFU). Lung histopathology revealed marked suppression of inflammation. Pro-inflammatory cytokines (TNF-α and IL-6) levels were reduced significantly and anti-inflammatory (IL-10) cytokine increased in lungs and serum leading to decreased severity and slow progression of disease. Though active immunization showed low survival rate (20%), passive immunization improved the survival (40%). This is the first study reporting an outer membrane nuclease as a vaccine candidate in Gram negative bacterium, A. baumannii through reverse vaccinology approach.

Epidemiological and experimental observations have shown that nonsteroidal anti-inflammatory drugs especially selective cyclooxygenase-2 (COX-2) inhibitors and probiotics reduce the incidence risk of colon cancer. Therefore, the present study was designed to assess the prophylactic potentials of probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus GG) in conjunction with celecoxib, a selective cox-2 inhibitor in 1,2 dimethylhydrazine dihydrochloride (DMH)-induced experimental colon carcinogenesis, a well-established, well appreciated and widely used model for colorectal cancer that shares many similarities to human sporadic colorectal cancer with respect to response to some promotional and preventive agents. More specifically, it was observed that L. rhamnosus GG + celecoxib + DMH-treated animals had significantly reduced aberrant crypt foci (ACF) count and the expression of procarcinogenic molecular markers (β-catenin, NF-κB, and COX-2) in early experimental colon carcinogenesis compared with probiotic-DMH, celecoxib-DMH or DMH-treated animals. This is the first ever such study to demonstrate that probiotic in conjunction with celecoxib can be opted as an alternate prophylactic strategy in highly susceptible individuals to reduce both the incidence and severity of the life style diseases as prevention is better than cure.

Background Colorectal cancer has been found to be attenuated either with prophylactic manipulation of gut microbiome with probiotics or celecoxib, a non-steroidal anti-inflammatory drug mainly by suppressing early pro-carcinogenic markers in various experimental studies. Therefore, the present study was designed to assess the prophylactic potential of combinatorial administration of probiotics (Lactobacillus rhamnosus GG, Lactobacillus acidophilus) and celecoxib in experimental colon carcinogenesis. Methods Six groups of Spraugue Dawely rats received probiotics L.rhamnosus GG or/and L.acidophilus in combination with celecoxib one week prior to the inducement of tumor by 1,2-dimethylhydrazine (DMH) and the treatment continued for 18 weeks. Prophylactic potentials of probiotics and celecoxib were determined by employing various methods such as tumor incidence, tumor burden, tumor multiplicity, apoptosis, caspase activity, expression of proto-oncogene K-ras and tumor suppressor p53 gene in colonic tumors. Results Interestingly, it was found that one week prior supplementation of both probiotics and celecoxib reduced tumor burden, tumor multiplicity, down-regulated the expression of anti-apoptotic Bcl-2, proto-oncogene K-ras and up-regulated pro-apoptotic Bax as well as tumor suppressor p53 in L.rhamnosus GG + celecoxib+DMH animals compared with counter controls and DMH-treated. Conclusions It can be concluded that such combinatorial approach may be useful in reducing the burden and severity of disease in highly susceptible individuals but needs to be validated clinically. Electronic supplementary material The online version of this article (10.1186/s12885-018-4999-9) contains supplementary material, which is available to authorized users.

Malaria in pregnancy poses a great health risk to mother and her fetus and results into complications, such as abortion, still birth, intra uterine growth retardation, and low birth weight. The heavy infiltration of Plasmodium falciparum-infected RBCs in the intervillous spaces of placenta seems to be responsible for all the complications observed. Infected RBCs in the placenta cause an inflammatory environment with increase in inflammatory cells and cytokines which is deleterious to the placenta. Increased inflammatory responses in the infected placenta result into oxidative stress that in turn causes oxidative stress-induced placental cell death. Moreover, heat shock proteins that are produced in high concentration in stressed cells to combat the stress have been reported in fewer concentrations in malaria-infected placenta. Pathologies associated with placental malaria seems to be the effect of a change in immune status from antibody-mediated immune response to cell-mediated immune response resulting into excess inflammation, oxidative stress, apoptosis, and decreased heat shock protein expression. However, we also need to study other aspects of pathologies so that better drugs can be designed with new molecular targets.

The inexorable increase in the incidence of colorectal cancer has led to growing interest in its prevention by natural interventions. Thus, the present study was designed with the aim of delineating the antioxidative and antitumorigenic effects of synbiotics in experimental colon carcinogenesis. It was observed that administration of a synbiotic, before 1,2 dimethylhydrazine dihydrochloride (DMH)-induced colon carcinogenesis in Sprague-Dawley rats, led to increased body weight and growth rate, and decreased tumor incidence compared with the DMH-only-treated group of animals. Most notably, the level of malondialdehyde, a measure of lipid peroxidation, decreased, and levels of the antioxidants, glutathione reductase, superoxide dismutase, and glutathione peroxidase increased in animals in the Lactobacillus acidophilus+DMH, inulin+DMH, and synbiotic+DMH groups compared with DMH-only-treated animals. Histopathological observations of the colon also documented fewer dysplastic changes and increased the number of goblet cells in the probiotic-treated, prebiotic-treated, and synbiotic-treated animals compared with DMH-only-treated animals. Taken together, the present study shows that the use of synbiotics is a better prophylactic strategy than the use of probiotic and prebiotic alone because of the greater increase in antioxidants associated with the higher degree of attenuation of DMH-induced tumorigenesis.

Malaria infection during pregnancy is a risk factor for foetus survival and is associated with abortion, premature delivery and low birth weight of infants in malaria endemic regions. In these regions, prophylactic measures and treatment mainly rely on chloroquine and sulphadoxine pyrimethamine, but their efficacy in reducing the placental pathology has not been studied. Therefore, the present study was designed to assess the effectiveness of chloroquine and sulphadoxine pyrimethamine treatment in reducing the placental pathology of Plasmodium berghei infected BALB/c mice. It was observed that pregnant-infected mice, treated either with chloroquine or sulphadoxine pyrimethamine had significantly lower percent parasitaemia, 100% survival and delivered normally compared with untreated pregnant-infected mice. Interestingly, antimalarial treatment significantly reduced malondialdehyde (MDA) levels, measure of lipid peroxidation and number of apoptotic cells in the placentae of pregnant-infected treated mice. Histologically also no morphological and cellular alterations were observed in the placentae of pregnant-infected treated mice. Taken together, the study shows the effectiveness of chloroquine and sulphadoxine pyrimethamine treatment, when administered in second trimester in abrogating malaria induced oxidative stress, apoptosis and histopathological alterations in the placenta, leading to normal foetal development.

Various antiprotozoal drugs have been used to counteract the spread of giardiasis. However, due to increase in resistance to these compounds, there is an urgent need to find a natural biocompatible product to fight the pathogen in more healthy and effective way. The present study was designed to compare the therapeutic effect of probiotic Lactobacillus casei alone and in conjunction with antiprotozoal drugs on the outcome of giardiasis in murine model. BALB/c mice were challenged with Giardia intestinalis trophozoites, and 1 day after infection, these mice were treated with either probiotic alone or in conjunction with antiprotozoal drugs. Cyst, trophozoite, and lactobacilli counts were monitored vis-a-vis histopathological alterations in the small intestine. It was found that albendazole administered orally 1 day after Giardia infection was the most effective antiprotozoal drug among albendazole, tinidazole, metronidazole, and nitazoxanide. It reduced both the severity and duration of giardiasis. More specifically, oral administration of the probiotic L. casei in conjunction with albendazole further reduced the Giardia infection as was evident by the restored normal gut morphology. This suggests that probiotics and antiprotozoal drugs in combination may be the better alternative therapy for treatment of gastrointestinal diseases and enhanced recovery.

The present study describes the in vivo modulatory potential of Lactobacillus rhamnosus GG (LGG), an effective probiotic, in Giardia intestinalis-infected BALB/c mice. Experimentally, it was observed that oral administration of lactobacilli prior or simultaneous with Giardia trophozoites to mice, efficiently (p < 0.05) reduced both the severity and duration of giardiasis. More specifically, probiotics fed, Giardia-infected mice, showed a significant increase in the levels of antioxidants [reduced glutathione (GSH) and superoxide dismutase (SOD)] and intestinal disaccharidases [sucrase and lactase] and decreased levels of oxidants in the small intestine, in comparison with Giardia-infected mice. Histopathological findings also revealed almost normal cellular morphology of the small intestine in probiotic-fed Giardia-infected mice compared with fused enterocytes, villous atrophy and increased infiltration of lymphocytes in Giardia-infected mice. The results of the present study has shed new light on the anti-oxidative properties of LGG in Giardia mediated tissue injury, thereby suggesting that the effects of probiotic LGG are biologically plausible and could be used as an alternative microbial interference therapy.

Diet makes an important contribution to colorectal cancer (CRC) risk implying risks for CRC are potentially reducible. Therefore, the probiotics have been suggested as the prophylactic measure in colon cancer. In this study, different probiotics were used to compare their protective potential against 1,2 dimethylhydrazine dihydrochloride (DMH)-induced chemical colon carcinogenesis in Sprague Dawley rats. Animals belonging to different probiotic groups were fed orally with 1 × 10(9) lactobacilli daily for 1 week, and then a weekly injection of DMH was given intraperitoneally for 6 wks with daily administration of probiotic. Lactobacillus GG and L.acidophilus + DMH-treated animals had maximum percent reduction in ACF counts. A significant decrease (P < 0.05) in fecal nitroreductase activity was observed in L.casei + DMH and L.plantarum + DMH-treated rats whereas β-glucuronidase activity decreased in L.GG + DMH and L.acidophilus + DMH-treated rats. Animals treated with Bifidobacterium bifidum + DMH had significant decreased β-glucosidase activity. However, not much difference was observed in the colon morphology of animals belonging to various probiotic + DMH-treated rats compared with DMH-treated alone. The results indicated that probiotics, L.GG, and L.acidophilus can be used as the better prophylactic agents for experimental colon carcinogenesis.

Colorectal cancer is closely associated with environment, diet and lifestyle. Normally it is treated with surgery, radiotherapy or chemotherapy but increasing systemic toxicity, resistance and recurrence is prompting scientists to devise new potent and safer alternate prophylactic or therapeutic strategies. Among these, probiotics, prebiotics, synbiotics, and metabiotics are being considered as the promising candidates. Metabiotics or probiotic derived factors can optimize various physiological functions of the host and offer an additional advantage to be utilized even in immunosuppressed individuals. Interestingly, anti colon cancer potential of probiotic strains has been attributable to metabiotics that have epigenetic, antimutagenic, immunomodulatory, apoptotic, and antimetastatic effects. Thus, it’s time to move one step further to utilize metabiotics more smartly by avoiding the risks associated with probiotics even in certain normal/or immuno compromised host. Here, an attempt is made to provide insight into the adverse effects associated with probiotics and beneficial aspects of metabiotics with main emphasis on the modulatory mechanisms involved in colon cancer.

Malnutrition induces a state of growth retardation and immunologic depression, enhancing the host susceptibility to various infections. In the present study, it was observed that prebiotic supplementation either prior or simultaneously with Giardia infection in malnourished mice significantly reduced the severity of giardiasis and increased the body and small intestine mass, along with increased lactobacilli counts in faeces compared with malnourished-Giardia-infected mice. More specifically, prebiotic supplementation significantly increased the levels of anti-giardial IgG and IgA antibodies and anti-inflammatory cytokines IL-6 and IL-10 and reduced the pro-inflammatory cytokine TNF-α, along with increased levels of nitric oxide in both the serum and intestinal fluid of malnourished-prebiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. Histopathology and scanning electron microscopy of the small intestine also revealed less cellular and mucosal damage in the microvilli of prebiotic-supplemented malnourished-Giardia-infected mice compared with severely damaged mummified and blunted villi of malnourished-Giardia-infected mice. This is the first study to report that prebiotic supplementation modulated the gut morphology and improved the immune status even in malnourished-Giardia-infected mice.

Acinetobacter baumannii is emerging as a serious nosocomial pathogen with multidrug resistance that has made it difficult to cure and development of efficacious treatment against this pathogen is direly needed. This has led to investigate vaccine approach to prevent and treat A. baumannii infections. In this work, an outer membrane putative pilus assembly protein, FilF, was predicted as vaccine candidate by in silico analysis of A. baumannii proteome and was found to be conserved among the A. baumannii strains. It was cloned and expressed in E. coli BL21(DE3) and purified by Ni-NTA chromatography. Immunization with FilF generated high antibody titer (64,000) and provided 50% protection against a standardized lethal dose (10(8) CFU) of A. baumannii in murine pneumonia model. FilF immunization reduced the bacterial load in lungs by 2 and 4 log cycles, 12 and 24 h post infection as compared to adjuvant control; reduced the levels of pro-inflammatory cytokines TNF-α, IL-6, IL-33, IFN-γ, and IL-1β significantly and histology of lung tissue supported the data by showing considerably reduced damage and infiltration of neutrophils in lungs. These results demonstrate the in vivo validation of immunoprotective efficacy of a protein predicted as a vaccine candidate by in silico proteomic analysis and open the possibilities for exploration of a large array of uncharacterized proteins.

Malarial infection during pregnancy has been associated with maternal anemia and death, abortion, still-birth and is a major cause of low birth weight, an important risk factor for infant morbidity and mortality in endemic areas. The present study was designed to delineate the oxidative stress in various organs (liver, spleen, kidney, brain and placenta) of pregnant Plasmodium berghei infected BALB/c mice. It was observed that pregnant-infected mice had higher parasitaemia than nonpregnant-infected mice. Most notably, levels of malondialdehyde (MDA), a measure of lipid peroxidation, reduced glutathione (GSH) and superoxide dismutase (SOD) levels were significantly higher in the liver, spleen, kidney and brain of pregnant-infected mice compared with pregnant mice. Although MDA levels were significantly higher, GSH and SOD levels remained unaltered in the placenta of pregnant-infected mice compared with pregnant mice. Furthermore, catalase activity was significantly lower in all the organs of pregnant-infected mice compared with pregnant mice. Histopathological observations in the organs clearly show the cellular and morphological alterations that may be occurring due to increased lipid peroxidation. Taken together, the data suggest that the increased severity of malarial infection during pregnancy may be due to accentuated oxidative stress.

The present study describes the in vivo ameliorating effect of Lactobacillus casei supplementation in renourished Giardia intestinalis infected BALB/c mice. It was observed that daily administration of probiotic 7 days prior to Giardia-infection to renourished mice, efficiently reduced the excretion of Giardia cysts and trophozoite counts, along with significant increased fecal lactobacilli counts compared with Giardia-infected mice. It was also observed that oral feeding of probiotic to renourished-Giardia-infected mice abrogated all the anthropometric and biochemical anomalies. Histologically, morphological and cellular alteration of microvillus membrane integrity revealed that probiotic administration further ameliorated the mucosal damage in renourished-probiotic-Giardia-infected mice compared to severe microvillus atrophy, oedematous, vacuolated epithelial cells and ileitis in renourished-Giardia and Giardia-infected mice. Thus, it is suggested that probiotic used as the functional food helps in restoration of anthropometric, biochemical alterations and atrophied gut by enhancing the goblet cells and reducing the giardiasis.

The study describes the in vivo activity of Lactobacillus casei in malnourished Giardia lamblia -infected BALB/c mice. By experimentation, it was found that daily administration of the probiotic 7 days before inoculation with Giardia trophozoites in malnourished mice efficiently reduced both the severity and duration of giardiasis. More specifically, excretion of Giardia cysts and trophozoites counts were reduced, while faecal lactobacilli counts increased significantly in probiotic-fed malnourished mice, compared with control mice. Interestingly, it was also observed that oral feeding of the probiotic to malnourished mice abrogated all the anthropometric and biochemical anomalies. Histologically, morphological and cellular alteration of microvillus membrane integrity revealed that probiotic administration ameliorated the mucosal damage in malnourished, probiotic-inoculated, Giardia-infected mice compared with the severe microvillus atrophy, œdematous and vacuolated epithelial cells, and ileitis in malnourished Giardia-infected mice. The results clearly show the antigiardial effect of the probiotic in vivo by modulating the gut cells to inhibit the colonization and multiplication of Giardia trophozoites, thus reducing the severity and duration of murine giardiasis.

Objective To assess the role of heat shock proteins (hsps) in the placental pathology of Plasmodium berghei infected mice. Methods Female BALB/c mice were infected with Plasmodium berghei infected RBC intraperitoneally on 10th gestational day. The expression of hsps in the placenta were monitored by reverse transcriptase real time PCR. Results There was increased expression of hsps 90, 70, 60 and 25 genes on day 2, 4 and 6 post infection in the infected placenta. However, the expression of hsps 70, 60 and 25 genes decreased with the progression of malaria infection. Conclusions Decreased expression of hsps 70, 60 and 25 genes in the malaria infected placenta might be one of the many other factors responsible for apoptosis in the placenta and may be responsible for associated altered placental pathology and fetal abnormalities.

This study describes the in vivo activity of Lactobacillus acidophilus in Giardia lamblia infected BALB/c mice. Experimentally, it was observed that daily administration of lactobacilli 7 days before or in simultaneous inoculation with Giardia trophozoites efficiently reduced G. lamblia infection in mice. More specifically, excretion of Giardia cysts were reduced significantly in probiotic-treated groups, and resolution of infection was observed by day 21 post-inoculation. It was also observed that the lactobacillus count increased tremendously and continuously in faeces of all probiotic-fed mice, and was significantly higher as compared with that in control mice. Histological analysis of microvilli membrane integrity revealed that probiotic administration also protected mice against parasite-induced mucosal damage, whereas Giardia-infected mice had severe villous atrophy, oedema, vacuolation and ileitis. Immunologically, the anti-Giardia serum IgG level was not stimulated significantly by probiotic treatment administered both prior to and simultaneous with Giardia infection, but remained high after the infection peak. Taken together, the data demonstrates the anti-giardial effect of the probiotic in vivo by modulation of the intestinal epithelial cells, inhibiting the colonization of Giardia trophozoites and thereby reducing the severity of Giardia infection.

In the present study, an attempt has been made to assess the probiotic characteristics of lactobacilli and yeast strains isolated from whey beverage under conditions simulating the in vivo stresses encountered in the gastrointestinal tract i.e. acid, alkaline, proteolytic enzymes and bile stress. The therapeutic potential of probiotics Lactobacillus casei or Lactobacillus yoghurt was assessed in Giardia infected mice. All the isolated strains well tolerated the gastrointestinal stresses. It was found that probiotic supplementation of either L. casei or L. yoghurt, one day after Giardia infection, reduced the severity of infection compared to Giardia infected mice. Pathophysiologically, the morphological and cellular changes in the small intestine were least in probiotic treated mice compared to severely inflamed, oedematous, vacuolated epithelial cells in Giardia infected mice. It can be concluded that L. yoghurt possessed better probiotic properties and has the potential to reduce the severity of Giardia infection in mice.

The aim of this work was to investigate the effect of live Staphylococcus aureus commonly present in the cervix of females on sperm motility and agglutination in vitro. Highly motile samples of spermatozoa (40 x 10 6 /ml) from normozoospermic males were co-incubated for 4h with 10 7 cells/ml of live S. aureus. After 30 minutes, 1, 2 and 4h of incubation, sperm motility and agglutination was checked by light microscopic examination (X 400). From the onset, it was apparent that the live bacteria reduced the motility of spermatozoa. The promptness with which the decreased motility was observed to occur in the live S. aureus group was striking. After 30 minutes of mixing the ejaculate with the live bacteria, decrease in motility and clumping of the spermatozoa was noted. Interestingly, no agglutination and immobilization was observed in other experiments in which the bacteria were killed by heat, lysozyme or antibiotics and mixed with the ejaculate. Certainly, it seems evident that live S. aureus can significantly depress the motility and agglutinate human spermatozoa in vitro. The mechanism by which this alteration takes place is not obvious, however, detrimental effect on sperm motility by live staphylococci may be an as yet unrecognized component of fertility problems.

The present study was designed to evaluate the effect of Plasmodium and Salmonella co-infection in LACA mice. The parasitaemic level, bacterial load, histological alterations and levels of oxidants/antioxidant activity were measured. Co-infected mice had a high parasitaemic level, increased bacterial load, and died earlier than Plasmodium-infected mice. Histologically, co-infected mice had more architectural damage in the liver, spleen, kidney, and brain than the control groups. The level of lipid peroxidation was significantly increased and the activities of antioxidative enzymes (superoxide dismutase and catalase) were decreased in all organs of co-infected mice compared to the control groups, indicating depression of the antioxidant defense system. The present study demonstrates more severe histological and biochemical alterations in co-infected mice, highlighting the importance of early diagnosis for selection of appropriate treatments and reducing the likelihood of further complications.

In view of the increasing interest in the bioecological and nutritional control of diseases, use of probiotics alone or in combination with prebiotics (synbiotics) appears as a therapeutic option for various diseases. In this study, an attempt was made to explore the protective potential of Lactobacillus acidophilus as a probiotic, inulin as a prebiotic and both L. acidophilus and inulin as synbiotic against Salmonella-induced liver damage in a murine model. The probiotic, prebiotic and synbiotic supplementation resulted in decreased bacterial translocation in the liver of mice challenged with Salmonella typhimurium and decreased levels of serum aminotransferases, suggesting their protective role against Salmonella infection. Mice supplemented with these preparations before Salmonella challenge also revealed decreased levels of lipid peroxidation, increased levels of superoxide dismutase and glutathione, along with reduced levels of nitric oxide. Thus, bacteriological and biochemical alterations correlated well with the histological evidence. Protection afforded by supplementation with the probiotic alone was found to be more effective. None of the observations was suggestive of the synergistic effect in the synbiotic-supplemented animals. Thus, it is indicated that the probiotic and the prebiotic used in the present study may act by different mechanisms involved in affording protection against Salmonella-induced liver damage.

The present study was designed with the aim to study the modulation of giardiasis with natural intervention, i.e., Lactobacillus casei--a probiotic, in a murine model. Probiotics are viable microorganisms having a beneficial effect on the prevention and treatment of specific pathological conditions. Various dairy products such as curd, lassi, and kulfi were employed particularly to isolate live organisms (probiotics). Out of five isolated strains only one was found to be similar to a standard strain--Lactobacillus delbrueckii. Experimentally, it was observed that oral feeding of isolated strain A, 7 days prior to inoculation with Giardia lamblia trophozoites, was not as efficient as L. casei in eliminating Giardia infection from BALB/c mice. Interestingly, it was observed that L. casei fed 7 days prior to Giardia infection was more effective and efficient in eliminating the infection from mice. On histological examination, it was observed that probiotic-fed mice had less atrophied villi and infiltrating cells in the small intestine compared to the control. Ultrastructural studies by scanning electron microscopy further confirmed the protection of the mice dosed with L. casei 7 days prior to Giardia infection and also when simultaneously infected with Giardia. It is felt that probiotics, particularly L. casei, modulate Giardia infection by minimizing or preventing the adherence of Giardia trophozoites to the mucosal surface, suggesting that probiotics offer a safe and effective mode to prevent and treat Giardia infection.

Zinc (Zn) has been reported to influence the susceptibility of the host to a diverse range of infectious pathogens, including viruses, bacteria, fungi and protozoa. We report here an evaluation of the effects of Zn supplementation on Salmonella enterica serovar Typhimurium (S. typhimurium)-induced hepatic injury in the murine model. Zinc levels in the plasma and liver tissues were measured by atomic absorption spectroscopy. The effect of Zn supplementation was evaluated by assessing the bacterial load and levels of lipid peroxidation (LPO), antioxidants and monokines present in the hepatic tissue as well as by histopathological studies. Zinc supplementation reduced the bacterial load in the liver and reversed hepatic microscopic abnormalities. It also decreased the levels of LPO but increased the levels of reduced glutathione (GSH) as well as the activities of superoxide-dismutase (SOD) and catalase in the livers of infected mice supplemented with Zn compared to the livers of infected mice not supplemented with Zn. Zinc supplementation was also able to modulate the levels of monokines such as tumour necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6). Our results indicate a role for Zn in downregulating oxidative stress and upregulating antioxidant defense enzymes through the action of monokines, suggesting that supplementation with Zn has a protective function in Salmonella-induced liver injury.

Malnutrition reduces the host immunity and enhances the host susceptibility to various diseases. The present study describes the effect of oral administration of probiotic Lactobacillus casei to malnourished-Giardia-infected BALB/c mice with respect to surface alterations and brush border membrane enzyme activity of the small intestine. It was observed that probiotic feeding either prior to or simultaneously with Giardia infection to malnourished mice led to significantly enhanced activity of disaccharidases compared with malnourished and Giardia-infected mice. Scanning electron microscopy also revealed less mucosal damage in the villi of small intestine of probiotic-fed malnourished-Giardia-infected mice compared with completely damaged, mummified, or blunted villi of malnourished-Giardia-infected mice. The findings indicate that probiotics can be used as the prophylactic candidate in abrogating the gut and intestinal dissacharidases anamolies in malnourished hosts suffering from the intestinal diseases.

Gut homeostasis can be altered by the oral administration of health-promoting microorganisms, namely probiotics that are known to reinforce the host immune response. The aim of this study was to elucidate the immunomodulatory effect of orally administered probiotic Lactobacillus rhamnosus GG (LGG) in Giardia-infected mice. BALB/c mice were fed orally with probiotic LGG either 7 days prior to or simultaneously with the challenge dose of Giardia trophozoites. The administration of the probiotic was continued for 25 days, and immunomodulatory potentials in terms of secretory immunoglobulin A (IgA) levels, CD8+ and CD4+ T lymphocytes, and expression of pro-inflammatory [tumor necrosis factor-alpha, interferon-gamma (INF-γ)] and anti-inflammatory cytokines [interleukin (IL)-4, IL-6, IL-10] were studied. Oral feeding of LGG prior to or simultaneously with the test dose of Giardia seems to have modulated both arms (humoral and cellular) of the mucosal immune system since a significant increase in the levels of specific secretory IgA antibody, IgA+ cells, and CD4+ T lymphocytes were observed in contrast with the decreased percentage of cytotoxic CD8+ T lymphocytes. The stimulated mucosal immune response in probiotic fed Giardia-infected mice was further correlated with the enhanced levels of anti-inflammatory cytokines IL-6 and IL-10 and reduced levels of pro-inflammatory cytokine INF-γ. This is the first study to show that oral administration of the effective probiotic LGG to Giardia infected mice could be used as a bacterio-therapy that restores the normal gut microflora and modulates the mucosal immune response.

Background: Food borne infections caused by Salmonella enterica species are increasing globally and pregnancy poses a significant threat in developing countries, where sanitation facilities are inadequate. Thus, the present study was designed to delineate the effect of Salmonella infection during pregnancy. Methods: Pregnant, BALB/c mice were challenged orally with Salmonella enterica serovar Typhimurium on gestational day 10 and were monitored for bacterial load, hepatic injury, histopathological alterations vis-a-vis oxidant and antioxidant levels. Results: Pregnant-Salmonella-infected mice had higher bacterial translocation in the liver, spleen as well as liver enzymes mainly aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase compared with Salmonella-infected mice. The levels of lipid peroxidation were significantly higher in all the organs of both pregnant-Salmonella-infected and Salmonella-infected mice compared with control mice. However, the activities of antioxidant enzymes (reduced glutathione, superoxide dismutase and catalase) were lower in the liver, spleen and placenta of pregnant, pregnantSalmonella-infected and Salmonella-infected mice compared with control mice, but the decrease was more in pregnant-Salmonellainfected mice indicating depression of antioxidant defense system. Histopathologically, pregnant-Salmonella-infected mice had more architectural damage in the liver, spleen and placenta compared with other groups.

Background Amoebiasis is a major public health problem in tropical and subtropical countries. Currently, metronidazole is the gold choice medication for the treatment of this disease. However, reports have indicated towards the possibility of development of metronidazole-resistance in Entamoeba strains in near future. In view of the emergence of this possibility, in addition to the associated side effects and mutagenic ability of the currently available anti-amoebic drugs, there is a need to explore newer therapeutics against this disease. In this context, the present study evaluated the amoebicidal potential of cryptdin-2 against E. histolytica. Methods/Principal Findings In the present study, cryptdin-2 exhibited potent in-vitro amoebicidal activity against E. histolytica in a concentration dependent manner at a minimum amoebicidal concentration (MAC) of 4 mg/L. Scanning electron microscopy as well as phase contrast microscopic investigations of cryptdin-2 treated trophozoites revealed that the peptide was able to induce significant morphological alterations in terms of membrane wrinkling, leakage of the cytoplasmic contents and damaged plasma membrane suggesting a possible membrane dependent amoebicidal activity. N-phenyl napthylamine (NPN) uptake assay in presence of sulethal, lethal as well as twice the lethal concentrations further confirmed the membrane-dependent mode of action of cryptdin-2 and suggested that the peptide could permeabilize the plasma membrane of E. histolytica. It was also found that cryptdin-2 interfered with DNA, RNA as well as protein synthesis of E. histolytica exerting the highest effect against DNA synthesis. Thus, the macromolecular synthesis studies correlated well with the observations of membrane permeabilization studies. Significance/Conclusions The amoebicidal efficacy of cryptdin-2 suggests that it may be exploited as a promising option to combat amoebiasis or, at least, may act as an adjunct to metronidazole and/or other available anti-amoebic drugs., Author Summary Intestinal amoebiasis, caused by Enatmoeba histolytica continues to be a major public health problem in tropical and subtropical countries and is considered to be the third principal parasitic disease responsible for mortality in the world. In addition to the mutagenic ability and known toxicity of conventional anti-amoebic drugs, there are reports indicating the emergence of treatment failures to these drugs. Therefore, there has been a considerable interest in exploring the potential of various antimicrobial peptides having higher efficacy and lower toxicity to combat such parasitic infections. Herein, we present the amoebicidal efficacy of cryptdin-2, a Paneth cell alpha-defensin against E. histolytica. Cryptdin-2 was found to decrease the number of trophozoites of E. histolytica in a concentration dependent manner. By and large, cryptdin-2 could retain its amoebicidal activity in the presence of cations, bile salts and at various pH values. Microscopic analysis and N-phenyl napthylamine (NPN) uptake assay revealed membrane dependent amoebicidal action of the peptide. It was also demonstrated that cryptdin-2 has the potential to target the intracellular macromolecular synthesis machinery of Entamoeba. Based on these results, cryptdin-2 seems to be a promising agent for the development of novel therapeutics against amoebiasis or at least may act as an adjunct to conventional antibiotics against E. histolytica.

The gut microflora is an important constituent in the intestinal mucosal barrier and has been introduced as the concept of probiotic therapy that beneficially affects the host by improving its intestinal microbial balance. Therefore, the main objective of the study was to explore the protective potential of various lactobacilli strains for murine giardiasis. By experimentation, it was found that the probiotic supplementation of eitherLactobacillus casei,L. acidophilus,L. plantarum, orL. rhamnosusGG, 7 days prior to inoculation withG. lambliatrophozoites, reduced the rate of cyst excretion compared withGiardia-infected mice. Interestingly,L.GG was found to be the most effective probiotic in reducing the duration of giardia cycle and acts as an effective prophylactic probiotic for murine giardiasis but needs to be clinically correlated due to entirely different human microflora.

Placental malaria is a common clinical complication during pregnancy and is associated with abortion, premature delivery, intrauterine growth retardation and low birth weight. The present study was designed to delineate the underlying mechanism of placental pathology during malarial infection with special reference to oxidative stress and apoptosis. Experimentally, pregnant BALB/c mice were infected with Plasmodium berghei infected red blood cells on gestation day 10. The presence of malarial infection in placenta was confirmed by histopathological studies. It was observation that infected placenta had plugged placental sinusoids with parasitized red blood cells and malarial pigments. Interestingly, we found significant increase in the level of malondialdehyde, the index of oxidative stress and decreased activity of catalase, the antioxidant in infected placenta. Furthermore, in infected placenta the oxidative stress mediated apoptosis was determined by DNA fragmentation assay, ethidium bromide/acridine orange staining and caspase activity. It was observed that oxidative stress begin after second day of malarial infection. Interestingly, it was observed that there was down regulation of anti-apoptotic protein Bcl-2 and up regulation of pro-apoptotic protein Bax in infected placenta, suggesting the involvement of mitochondrial pathway of apoptosis which was further confirmed by activation of caspase 9. However, no change in the expression of Fas gene and caspase 8 activity, indicated the absence of death receptor pathway. Thus, it can be concluded that the placental pathology during malarial infection is mediated by mitochondrial pathway of apoptosis occurring due to augmented lipid peroxidation which may in turn jeopardise the materno-fetal relationship.