Colitic scid mice fed Lactobacillus spp. show an ameliorated gut histopathology and an altered cytokine profile by local T cells.

BACKGROUND: Scid mice transplanted with CD4 T blast cells develop colitis. We investigated if the disease was influenced in colitic mice treated with antibiotic and fed Lactobacillus spp. METHODS: Colitic scid mice were treated for 1 week with antibiotics (vancomycin/meropenem) followed or not followed by a 3-week administration of Lactobacillus reuteri DSM-12246 and Lactobacillus rhamnosus 19070-2 at 2x10 live bacteria/mouse/24 hours. After 12 weeks, the rectums were removed for histology, and CD4 T cells from the mesenteric lymph nodes (MLN) were polyclonally activated for cytokine measurements. RESULTS: Irrespective of no treatment or treatments with antibiotics and probiotics, all mice transplanted with T cell blasts lost 10% of their body weight during the 12-week experimental period, whereas the nontransplanted mice had a 10% weight increase (P<0.001). All mice treated with antibiotics but not fed probiotics showed severe gut inflammation, whereas only 2 of the 7 mice fed probiotics showed signs of severe colitis (P<0.05). MLN-derived CD4 T cells from this latter group of mice showed lower levels of interleukin-4 secretion (P<0.05) and a tendency to higher interferon-gamma production than mice not fed probiotics. CONCLUSIONS: Our data suggest that probiotics added to the drinking water may ameliorate local histopathological changes and influence local cytokine levels in colitic mice but not alter the colitis-associated weight loss.

Genotyping of starter cultures of Bacillus subtilis and Bacillus pumilus for fermentation of African locust bean (Parkia biglobosa) to produce Soumbala.

Bacillus spp. are the predominant microorganisms in fermented African locust bean called Soumbala in Burkina Faso. Ten strains selected as potential starter cultures were characterised by PCR amplification of the16S-23S rDNA intergenic transcribed spacer (ITS-PCR), restriction fragment length polymorphism of the ITS-PCR (ITS-PCR RFLP), pulsed field gel electrophoresis (PFGE) and sequencing of the 968-1401 region of the 16S rDNA. In previous studies, the isolates were identified by phenotyping as Bacillus subtilis and Bacillus pumilus. The phenotyping was repeated as a reference in the present study. The ITS-PCR and ITS-PCR RLFP allowed a typing at species level. The PFGE was more discriminative and allowed a typing at strain level. Full agreement with the phenotyping was observed in all cases. The sequencing of the 16S rDNA allowed the identification at species level with an identity from 97% to 100% comparing the sequences to those from the GenBank databases. The desired cultures of B. subtilis and B. pumilus from African locust bean fermentation were distinguished by ITS-PCR and ITS-PCR RLFP from Bacillus cereus and Bacillus sphaericus which sometimes occur in the beginning of the fermentation.

Effect of probiotic Lactobacillus strains in young children hospitalized with acute diarrhea.

BACKGROUND: Oral bacteriotherapy promotes recovery from acute childhood diarrhea, but few strains have been shown to have therapeutic potentials. We examined the effect of two newly identified probiotic Lactobacillus strains in acute childhood diarrhea. METHODS: Sixty-nine children were randomized during hospitalization for acute diarrhea to receive a mixture of Lactobacillus rhamnosus 19070-2 and Lactobacillus reuteri DSM 12246, 10(10) colony-forming units of each strain or placebo twice daily for 5 days. Before selection of these stains their potential probiotic characteristics were demonstrated in vitro and in healthy volunteers. RESULTS: In patients receiving probiotics, the diarrheal phase was reduced by 20%. The duration of diarrhea was 82 h in the treatment group vs. 101 h in the control group (not significant, P = 0.07). However, 3 of 30 patients from the treatment group vs. 13 of 39 from the control group still had loose stools at the end of the study period (P = 0.03). In patients with diarrhea for <60 h before start of treatment (early intervention), a clear effect of the probiotics was demonstrated (80 h in the treatment group vs. 130 h in the control group, P = 0.003). After early intervention, the length of hospitalization was reduced by 48% (3.5 vs. 1.7 days, P = 0.03). At the end of the intervention, rotavirus antigen was found in 12% of patients from the treatment group vs. 46% from the control group (P = 0.02). CONCLUSIONS: The two probiotics, L. rhamnosus 19070-2 and L. reuteri DSM 12246, ameliorated acute diarrhea in hospitalized children and reduced the period of rotavirus excretion. Oral bacteriotherapy was associated with a reduced length of hospital stay. The beneficial effects were most prominent in children treated early in the diarrheal phase.

Effect of probiotic Lactobacillus strains on acute diarrhea in a cohort of nonhospitalized children attending day-care centers.

BACKGROUND: Certain strains of lactobacilli have been shown to promote recovery from rotavirus enteritis in hospitalized children. Few studies have examined the effect of probiotics in nonhospitalized children with mild diarrhea. METHODS: We studied in a randomized placebo-controlled trial the effect of lyophilized Lactobacillus rhamnosus 19070-2 and Lactobacillus reuteri DSM 12246, 10(10) colony-forming units of each strain twice daily for 5 days, on acute diarrhea in children in a cohort of children recruited from local day-care centers. The duration of diarrhea and assessment of stool consistency were recorded by the parents. RESULTS: In patients treated with the selected Lactobacillus strains, the mean duration of diarrhea after intervention was reduced (76 h in patients treated with probiotics vs. 116 h in the placebo group; P = 0.05). In patients with diarrhea for <60 h before start of treatment (early intervention), a more pronounced effect of probiotics was found. The time to recovery after early treatment was 79 h vs. 139 h in the placebo group (P = 0.02); 1 of 17 patients treated early vs. 6 of 13 in the control group still had loose stools 120 h after start of treatment (P = 0.03). CONCLUSIONS: In children from day-care centers with mild gastroenteritis, the combination of L. rhamnosus 19070-2 and L. reuteri DSM 12246 was effective in reducing the duration of diarrhea.

Fermentation and microflora of plaa-som, a thai fermented fish product prepared with different salt concentrations.

Plaa-som is a Thai fermented fish product prepared from snakehead fish, salt, palm syrup and sometimes roasted rice. We studied the effects of different salt concentrations on decrease in pH and on microflora composition during fermentation. Two low-salt batches were prepared, containing 6% and 7% salt (w/w) as well as two high-salt batches, containing 9% and 11% salt. pH decreased rapidly from 6 to 4.5 in low-salt batches, whereas in high-salt batches, a slow or no decrease in pH was found. Lactic acid bacteria (LAB) and yeasts were isolated as the dominant microorganisms during fermentation. LAB counts increased to 10(8)-10(9) cfu g(-1) and yeast counts to 10(7)-5 x 10(7) cfu g(-1) in all batches, except in the 11% salt batch, where counts were 1-2 log lower. Phenotypic tests, ITS-PCR, carbohydrate fermentations and 16S rRNA gene sequencing identified LAB isolates as Pediococcus pentosaceus, Lactobacillus alimentarius/farciminis, Weisella confusa, L. plantarum and Lactococcus garviae. The latter species was only isolated from high-salt batches. Phenotypic characteristics, ITS-PCR and carbohydrate assimilation identified 95% of the yeasts as Zygosaccharomyces rouxii. It is concluded that the fermentation of plaa-som is delayed by a salt-level of 9% due to an inhibition of LAB growth. The growth of Z. rouxii has no influence on the fermentation rate, but may contribute positively to the flavour development of the product.