Oscar Brunser

Systematic review : are probiotics useful in controlling gastric colonization by Helicobacter pylori?

Helicobacter pylori is a highly prevalent pathogen considered as an aetiological factor for gastroduodenal ulcers, and a risk factor for gastric adenocarcinoma and lymphoma in humans. Most subjects colonized by this micro‐organism are asymptomatic and remain untreated. In symptomatic patients, the antibiotic treatment has a high cost and is not 100% effective because of resistance to antibiotics and to moderate patient compliance. This review discusses the role of probiotics as alternative solutions to assist in the control of H. pylori colonization in at‐risk populations.

Effect of a Milk Formula With Prebiotics on the Intestinal Microbiota of Infants After an Antibiotic Treatment

Antibiotics exert deleterious effects on the intestinal microbiota, favoring the emergence of opportunistic bacteria and diarrhea. Prebiotics are nondigestible food components that stimulate the growth of bifidobacteria. Our aim was to evaluate the effects on the intestinal microbiota of a prebiotic-supplemented milk formula after an antibiotic treatment. A randomized, double-blind, controlled clinical trial was carried out in 140 infants 1–2 y of age distributed into two groups after a 1-wk amoxicillin treatment (50 mg/kg/d) for acute bronchitis. The children received for 3 wk >500 mL/d of a formula with prebiotics (4.5 g/L) or a control without prebiotics. Fecal samples were obtained on d –7 (at the beginning of the antibiotic treatment), on d 0 (end of the treatment and before formula administration), and on d 7 and 21 (during formula administration). Counts of Bifidobacterium, Lactobacillus-Enterococcus, Clostridium lituseburiense cluster, Clostridium histolyticum cluster, Escherichia coli, and Bacteroides-Prevotella were evaluated by fluorescent in situ hybridization (FISH) and flow cytometry. Tolerance and gastrointestinal symptoms were recorded daily. Amoxicillin decreased total fecal bacteria and increased E. coli. The prebiotic significantly increased bifidobacteria from 8.17 ± 1.46 on d 0 to 8.54 ± 1.20 on d 7 compared with the control 8.22 ± 1.24 on d 0 versus 7.95 ± 1.54 on d 7. The Lactobacillus population showed a similar tendency while the other bacteria were unaffected. No gastrointestinal symptoms were detected during the prebiotic administration. Prebiotics in a milk formula increase fecal bifidobacteria early after amoxicillin treatment without inducing gastrointestinal symptoms.

Effect of regular ingestion of Saccharomyces boulardii plus inulin or Lactobacillus acidophilus LB in children colonized by Helicobacter pylori

Aim: To evaluate the effect of a probiotic, Lactobacillus acidophilus LB (LB), or a synbiotic, Saccharomyces boulardii plus inulin (SbI), on Helicobacter pylori (Hp) colonization in children. Subjects and methods: A clinical trial was carried out in a school from a low socio‐economic area of Santiago. Two hundred and fifty‐four asymptomatic children (8.40±1.62 y) were screened for Hp by the 13C‐Urea Breath Test (13C‐UBT). Hp‐positive children were randomly distributed into three groups to receive either antibiotic treatment (lanzoprazole, clarythromycin and amoxicillin) for 8 d, or SbI or LB daily for 8 wk. A second 13C‐UBT was carried out at this time. Spontaneous clearance was evaluated in the same way in 81 infected, untreated children. The differences in the δ13CO2 over baseline values before and after treatments (ΔDOB) were evaluated. Results: 182 subjects (71.7%) were colonized by Hp, and 141 of them completed their treatment (22.5% dropout). Hp was eradicated in 66%, 12% and 6.5% of the children from the Ab, SbI and LB groups, respectively, while no spontaneous clearance was observed in the children without treatment. A moderate but significant difference in ΔDOB was detected in children receiving living SbI (−6.31; 95% CI: −11.84 to −0.79), but not in those receiving LB (+0.70; 95% CI: −5.84 to +7.24).

Pilot study: alterations of intestinal microbiota in obese humans are not associated with colonic inflammation or disturbances of barrier function

Aliment Pharmacol Ther 2010; 32: 1307–1314

Effect of an Acidified Milk on Diarrhoea and the Carrier State in Infants of Low Socio‐Economic Stratum

ABSTRACT. The effect on diarrhoeal disease of an acidified, modified powdered cows milk infant formula (Pelargon®) was evaluated in 82 infants (Group I) for six months; 104 infants who received the same formula but non acidified, served as controls (Group II). Nutritional status remained satisfactory in both groups throughout the observation period. Some children rejected the taste of the acidified milk. The incidence of diarrhoea was lower in Group I (p<0.001). The proportion of days in which the children suffered from acute diarrhoea, and the duration of the episodes were also lower in the children given the acidified milk (p<0.001). The rate of detection of enteropathogens and the species identified were comparable in both groups. Carrier rates for bacterial enteropathogens fell over time in Group I while they rose in Group II (p<0.001). Carrier rates for enteric parasites were comparable to those expected in our setting for this age group. These results suggest that acidified milk exerts a protective effect against diarrhoeal disease.

Field trial of an infant formula containing anti-rotavirus and anti-escherichia coli milk antibodies from hyperimmunized cows

Two groups of 124 and 108 children, respectively, living in urban Santiago, Chile in low socioeconomic conditions were prospectively followed for 6 months for their incidence of diarrhea. Each cohort was divided into two subgroups receiving either a commercial milk formula or the same formula containing 1% (wt/wt) bovine milk immunoglobulin concentrate from cows hyperimmunized with human rotaviruses and the major enteropathogenic Escherichia coli (EPEC) serogroups. Neither group differed with respect to incidence of diarrhea (98 episodes in 117 treated children versus 95 episodes in 115 control children), duration and clinical symptoms of diarrhea, and weight gain. Furthermore, neither group differed with respect to isolation of rotavirus (14 and 13 isolates in treatment and control groups, respectively) and isolation of enteropathogenic E. coli (14 and 15 isolates in treatment and control groups, respectively). The treatment but not the control formula contained neutralizing antibody against all human rotavirus serotypes. Titers were comparable to human breast milk samples. All isolated EPEC serogroups were included in the vaccine used for the immunization of the cows. The treatment, but not the control formula, protected mice against a lethal challenge with an EPEC strain. In conclusion, feeding an antibody-supplemented formula had no positive effect on diarrheal diseases under the conditions of a fairly well-controlled small-scale field trial.

Iron, copper and immunocompetence.

Microminerals including copper and iron are essential to immunity and health in human beings. The development of powerful tools in analytical cell biology and molecular genetics has facilitated efforts to identify specific cellular and molecular functions of trace elements in the maturation, activation and functions of host defence mechanisms. Selected recent reports about the role of copper and iron nutrition on immune functions are critically analysed here. Effects of trace element supplementation on infectious morbidity are also reviewed. While micromineral deficiencies, in general, may have widespread effects on nearly all components of immune response, these effects can be reversed by supplementation. However, the conflicting effects of iron deficiency and iron supplementation in vitro on the defensive systems reveals the urgent need for further additional information on the in vivo situation. In the elderly, vaccination against respiratory infections is likely to protect only 30-70% of the population. However, it may be possible to modulate immune function and ultimately reduce the severity of infections through micronutrient supplementation. Thus, microminerals contribute to the maintenance of the balance between immunity and health in humans.

Amoxicillin treatment modifies the composition of Bifidobacterium species in infant intestinal microbiota.

OBJECTIVES Amoxicillin is a beta-lactam antibiotic largely used in childhood. However only few studies described its impact on composition of children gut microbiota, in particular on Bifidobacterium populations considered as beneficial microorganisms. In this study, the impact on faecal Bifidobacterium species of a seven-day amoxicillin treatment was quantitatively and qualitatively assessed in infants during an episode of acute respiratory infection. METHODS Faecal samples from 31 infants were obtained on day 0 (just before amoxicillin therapy) and on day 7 (the end of therapy). Total DNA was extracted and bifidobacteria were quantified using real-time PCR. Predominant Bifidobacterium species were then identified using specific PCR-TTGE. RESULTS Bifidobacteria concentrations were not significantly altered by amoxicillin compared to the healthy group. However, amoxicillin treatment induced a complete disappearance of Bifidobacterium adolescentis species (occurrence rate of 0% versus 36.4% in healthy group, P < 0.001), a significant decrease in the occurrence rate of Bifidobacterium bifidum (23% versus 54.5% in healthy group, P < 0.05), but did not affect Bifidobacterium longum (93.5% versus 100% in healthy group) and Bifidobacterium pseudocatenulatum/B. catenulatum (about 55% in both groups). The number of Bifidobacterium species per microbiota significantly decreased from 2.5 +/- 1 for healthy group to 1.8 +/- 0.9 for treated infants (P < 0.05). CONCLUSIONS This study showed that a 7 day amoxicillin treatment did not alter the counts of Bifidobacterium. However amoxicillin can have an impact by changing the microbiota at the species level and decreased the diversity of this population.

Apple peel polyphenols protect against gastrointestinal mucosa alterations induced by indomethacin in rats.

The stability of an apple peel polyphenol extract (APPE) with powerful antioxidant activity was evaluated under acidic conditions in vitro, and its protective effect against gastrointestinal damage was investigated in rats treated with indomethacin. The antioxidant activity of APPE remained stable at pH 2.0 for 4 h. In rats treated with indomethacin (40 mg/kg ig), the previous administration of APPE protected the gastric, intestinal, and colonic mucosa from oxidative stress by preventing increased malondialdehyde concentrations and decreasing the GSH/GSSG ratio. APPE also displayed anti-inflammatory effects by preventing neutrophil infiltration in the mucosa, as evidenced by the lower myeloperoxidase activity. These protective effects of APPE resulted in the prevention of macro- and microscopic damage and of barrier dysfunction along the gastrointestinal tract of the indomethacin-treated animals. This study supports the concept that apple peel polyphenols may be useful in the prevention and/or treatment of nonsteroidal anti-inflammatory drug-associated side effects.

Local and systemic liberation of proinflammatory cytokines in ulcerative colitis

Determination of plasma and tissue cytokinelevels in inflammatory bowel disease have frequentlyresulted in conflicting data. In the present study wedetermined in patients with ulcerative colitis (UC), the levels of the proinflammatory cytokinesinterleukin (IL)-1β, IL-6, interferon(IFN)-γ, and tumor-necrosis factor (TNF)-αliberated by peripheral blood mononuclear cells (PBMC)and lamina propria mononuclear cells (LPMC) after 48-hrculture with pokeweed mitogen (PWM). IL-1β, IL-6,IFN-γ and TNF-α in the supernatant weredetected by ELISA. Results show low basal levels ofIL-1β secretion by PBMC and LPMC, and a considerableincrease after mitogen stimulation. Basal IL-6production by PBMC was higher in UC patients than incontrols [2029 pg/ml, CI9 (–165 to4223) vs 572 pg/ml (–383 to 1527) respectively, P = 0.05] and also afterPWM activation [14,995 pg/ml (7759 -22230) vs 6598 pg/ml(3240-9956), respectively, P = 0.05]. In LPMC, nodifferences in IL-6 secretion were observed. TNF-α in activated PBMC of patients with UC was notsignificantly increased in relation to control (P =0.09). No constitutive secretion of IFN-γ wasobserved in mononuclear cells. IFN-γ levelssecreted by activated LPMC were lower in patients withUC than in controls [1571 pg/ml (–108 to 3251) vs7953 pg/ml (3851-12,055), respectively, P = 0.03]. Theseresults suggest that IL-6, IL-1β, and TNF-α participate as mediators in the inflammatoryphenomena observed in UC. Further studies are necessaryto evaluate the role of IFN-γ in thiscondition.