Safety and protective effectiveness of two strains of Lactobacillus with probiotic features in an experimental model of salmonellosis.

Two strains of Lactobacillus, previously isolated from bovine faeces and tested in vitro for properties desired in probiotics, were evaluated for their in vivo effectiveness in protecting against experimental salmonellosis. L. salivarius L38 and L. acidophilus L36 previously demonstrated the ability to successfully colonize the gastrointestinal tract of germ-free mice and stimulate the immune system associated with the intestinal mucosa. L38- or L36-feeding showed no detrimental effect on the general health indicators and did not induce changes in normal architecture of liver and small intestine, indicating that the use of these strains is apparently safe. In control animals fed L38 strain, several cytokines had augmented mRNA levels that can be associated with a homeostatic state of intestinal mucosa, while L36 had less diverse regulation. IgA production and secretion in the intestinal lumen induced by infection was abrogated by pretreating with both lactobacilli. In addition, liver and small intestine histological scores and, translocation of Salmonella cells to liver and spleen, indicated that these strains did not confer protection against the infection. So, the IL-12:IL-18àIFN-g axis, essential for an effective immune response against Salmonella, was not favored with L38 or L36 strains. However, increased expression of IL-10 in different portions of the gastrointestinal tract of L38-fed animals is indicative of anti-inflammatory effect to be explored furthermore.

Pediatric functional constipation treatment with Bifidobacterium-containing yogurt: a crossover, double-blind, controlled trial.

AIM: To evaluate the treatment of pediatric functional chronic intestinal constipation (FCIC) with a probiotic goat yogurt. METHODS: A crossover double-blind formula-controlled trial was carried out on 59 students (age range: 5-15 years) of a public school in Belo Horizonte, MG, Brazil, presenting a FCIC diagnostic, according to Roma III criteria. The students were randomized in two groups to receive a goat yogurt supplemented with 10(9) colony forming unit/mL Bifidobacterium longum (B. longum) (probiotic) daily or only the yogurt for a period of 5 wk (formula). Afterwards, the groups were intercrossed for another 5 wk. Defecation frequency, stool consistency and abdominal and defecation pain were assessed. RESULTS: Both treatment groups demonstrated improvement in defecation frequency compared to baseline. However, the group treated with probiotic showed most significant improvement in the first phase of the study. An inversion was observed after crossing over, resulting in a reduction in stool frequency when this group was treated by formula. Probiotic and formula improved stool consistency in the first phase of treatment, but the improvement obtained with probiotic was significantly higher (P = 0.03). In the second phase of treatment, the group initially treated with probiotic showed worsening stool consistency when using formula. However, the difference was not significant. A significant improvement in abdominal pain and defecation pain was observed with both probiotic and formula in the first phase of treatment, but again the improvement was more significant for the group treated with B. longum during phase I (P < 0.05). When all data of the crossover study were analyzed, significant differences were observed between probiotic yogurt and yogurt only for defecation frequency (P = 0.012), defecation pain (P = 0.046) and abdominal pain (P = 0.015). CONCLUSION: An improvement in defecation frequency and abdominal pain was observed using both supplemented and non-supplemented yogurt, but an additional improvement with B. longum supplementation was obtained.