Facilitating the gut brain axis by probiotic bacteria to modulate neuroimmune response on lead exposed zebra fish models

Unravelling the efficacy of gut biome has a major impact on health. An unbalanced microbiome composition is linked to many common illnesses such as gut dysbiosis, mental deformities and immunological imbalance. An optimistic influence on the gut biome can be made by consumingprobiotics. This would stimulate neuroprotection and immunomodulation intended by heavy metals pollution. Lead is a major source of neurotoxin that can induce neural deformities. Lactobacillusspecies isolated from curd were characterized to confirm its specificity. Zebra fish was reared at standard conditions and preclinical assessment on the intensity of induced neurotoxin lead was performed. The embryo toxic assay, immunomodulation effects and animal behavioural models endorsed the consequence of neurotoxicity. Different concentrations of bacterial isolate with standard antidepressant was considered for analysing the vigour of toxicity and its influence on cognitive behaviour by novel tank diving method. The restrain in the animal behaviour was also conferred by all the test samples with a decreased bottom dwelling time which was authenticated with haematology and histopathological studies. The alterations in morphology of the lymphocytes were balanced by the treated test samples. This study paves a twofold potential of probiotic as neuroprotectant and immune modulator against heavy metal toxicity.

Validade e confiabilidade de kits para detecção dos níveis de estreptococos do grupo mutans e lactobacilos na saliva de crianças e adultos / Validity and reliability of kits for salivary detection of mutans streptococci and lactobacilli in infants and adults

Objetivo: Avaliar a validade e a confiabilidade dos resultados obtidos por meio de kits pré-fabricados disponíveis no mercado brasileiro para a detecção e quantificação dos níveis de estreptococos do grupo mutans e lactobacilos na saliva de crianças e adultos. Método: Amostras salivares de 15 crianças (12-24meses) e 14 adultos (17-35 anos) foram coletadas e analisadas quanto aos níveis salivares de estreptococos do grupo mutans e lactobacilos pelo uso dos kits Dentacult I e II (Laborclin) e por método microbiológico convencional, baseado em cultura em meios seletivos. Os resultados de ambos os métodos foram comparados pelo uso dos coeficientes Kappa ponderado (Kp) e de correlação de Spearman. Para a determinação da concordância inter e intraexaminador da leitura dos resultados obtidos com o uso dos kits, os dados foram comparados por meio do Kp. As análises estatísticas foram realizadas utilizando o software Minitab 15 (versão 15.1.0.0.). Foi adotado o nível de significância de 5%. Resultados: Os resultados apresentados pelo kit Dentalcult I apresentaram concordância regular e correlação não-significante com os obtidos com o método microbiológico convencional (rs=0,53; p maior que 0,05). Por outro lado, os resultados obtidos com o kit Dentalcult II apresentaram boa concordância e correlação estatisticamente significante com os do método convencional (rs=0,77; p menor que 0,05). Os kits Dentalcult I e II tiveram confiabilidade de leitura perfeita (Kp=1) em momentos distintos, independentes do examinador. A concordância interexaminadores foi perfeita para o kit Dentalcult II (Kp=1) e ótima para o Dentalcult I (Kp=0,94). Conclusão: O kit Dentalcult II pode ser indicado para a estimativa dos níveis salivares de estreptococos do grupo mutans em substituição aos métodos convencionais.

Objective: To compare the results of commercially available kits for determination of mutans streptococci (MS) and lactobacilli (LB) salivary levels in infants and adults. Method: Salivary samples of 15 children (aged 12-24 months-old) and 14 adults (aged 17-35 years-old) were collected and evaluated for salivary levels of MS and LB by using the Dentacult I and II kits, respectively (Laborclin) and conventional methods based on culture in selective media. The results of both methods were compared to those obtained by the weighted kappa coefficients (Kp) and Spearman's correlation. Statistical analysis was performed using Minitab software 15 (version 15.1.0.0). It was adopted a significance level of 5%. Results: The data obtained with the Dentalcult I kit showed regular agreement and no significant correlation with the conventional microbiological method (rs=0.53, p greater than 0.05). On the other hand, results provided by the Dentalcult II kit produced good agreement and were statistical significant correlated with those of the conventional method (rs=0.77, p less than 0.05). The kits Dentalcult I and II presented perfect reading reliability (Kp=1) in distinct moments, not -dependent on the examiner. The inter-examiner agreement was considered perfect for the kit Dentalcult II (Kp=1) and satisfactory for Dentalcult I (Kp=0.94). Conclusion: The kit Dentalcult II proved validity and reliability for detecting salivary MS.

Effects of enteropathogenic bacteria & lactobacilli on chemokine secretion & Toll like receptor gene expression in two human colonic epithelial cell lines.

Background & objectives: The intestinal epithelium is part of the innate immune system responding to contact with pathogenic or commensal bacteria. The objective of this study was to compare innate responses of intestinal epithelial cell lines to pathogenic bacteria and to lactobacilli. Methods: Two human intestinal epithelial cell lines, HT29 (enterocyte-like) and T84 (crypt-like), were exposed to pathogenic bacteria representative of non invasive (Vibrio cholerae O1 and O139), adherent (enterohaemorrhagic Escherichia coli, EHEC) or invasive (Salmonella Typhimurium and Shigella flexneri) phenotypes and to non pathogenic Lactobacillus rhamnosus GG or Lactobacillus plantarum. Interleukin-8 (IL-8) was measured in culture supernatant by ELISA, while mRNA from cells was subjected to quantitative reverse transcriptase PCR for several other chemokines (CXCL1, CCL5 and CXCL5) and for Toll-like receptors (TLR) 2, 4, 5 and 9. Results: V. cholerae, S. Typhimurium, S. flexneri and EHEC induced IL-8 secretion from epithelial cells into the medium. Salmonella, Shigella and EHEC, but not V. cholerae, significantly increased mRNA expression of CXCL1. None of the pathogens induced CCL5 or CXCL5. Salmonella and Vibrio significantly increased TLR4 expression, while Vibrio and EHEC decreased TLR5 expression. EHEC also decreased TLR9 expression. Lactobacilli attenuated the IL-8 response of the cell lines to V. cholerae, Salmonella, and EHEC but did not significantly change the IL-8 response to Shigella. Interpretation & conclusions: Distinct patterns of epithelial cell chemokine responses were induced by the bacterial pathogens studied and these were modulated by commensal lactobacilli. Alterations in TLR expression by these pathogens are likely to be important in pathogenesis.

Actividad adyuvante de bacterias lácticas: perspectivas para su uso en vacunas orales / Adjuvant activity of lactic bacteria: perspectives for its use in oral vaccines

Se estudió el efecto de la administración oral y subcutánea de Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus bulgaricus y Streptococcus thermophilus, sobre la respuesta inmune humoral e hipersensibilidad retardada para el antígeno glóbulo rojo de carnero (GRC). Las especies del género Lactobacillus fueron más efectivas en ambas respuestas, siendo mayor el efecto cuando las bacterias eran viables. La dosis óptima efectiva fue de 6 x 10**9 células. El número de células formadoras de placas (PFC) el título de anticuerpo circulante para el antígeno GRC fue de 2 a 3 veces mayor que los obtenidos en el grupo control. En los ratones alimentados con bacterias lácticas no se detectaron anticuerpos contra sus propios epitopes, pero sí se obtuvieron altos niveles de anticuerpos anti-bacterias lácticas en aquellos animales que habían sido inoculados subcutáneamente con estas bacterias. S. thermophilu no incrementó la respuesta inmune. Los resultados indican que los lactobacilos administrados por vía oral, ejercen una fuerte actividad adyuvante, responsable del aumento de la respuesta imune del húsped. Dichos organismso podrían ser candidatos a ser empleados como adyuvante en vacunas orales