E. Garello

Probiotics: from research to consumer

Intestinal microflora has metabolic, trophic and protective functions, and can be modified in pathological conditions and by the exogenous administration of probiotics. Probiotics are defined as living microorganisms which resist gastric, bile, and pancreatic secretions, attach to epithelial cells and colonize the human intestine. In the last twenty years research has been focused on the identification of the role of planktonic flora and adhesive bacteria in health and disease, and on the requisite of bacterial strains to become probiotic product which can be marketed. Probiotics can be commercialized either as nutritional supplements, pharmaceuticals or foods, but the marketing as a pharmaceutical product requires significant time, complex and costly research, and the demonstration of a well-defined therapeutic target. This review examines the sequential steps of research which, from the identification of a possible probiotic strain, lead to its production and marketing, summarizing the whole process existing behind its development, through its growth in laboratory, the studies performed to test its resistance to human secretions and stability, microencapsulation technologies, and safety tests.

Endoscopy or surgery for malignant GI outlet obstruction

BACKGROUND The treatment of gastroduodenal outflow obstruction (GOO) caused by malignant diseases represents a significant challenge. Open surgical gastrojejunostomy (GJ) has been the treatment of choice, but it has high morbidity and mortality rates. More recently, endoscopic placement of self-expanding metallic stents (SEMS) has been proposed and the results of small, preliminary studies are encouraging. This study compared technical and clinical success, morbidity, mortality, and hospital stay in patients undergoing endoscopic and surgical treatment of GOO. METHODS Medical records of 60 consecutive patients with GOO seen between April 1997 and November 2002 were retrospectively reviewed. Because of extremely short life expectancy, 13 patients were treated by insertion of a double-lumen nasogastric-jejunal tube. The remaining 47 patients (28 men, 19 women; mean age 73.5 years, range 48-92 years) with unresectable pancreatic (33), gastric (7), metastatic lymph nodal (4), papillary (2), and biliary (1) tumors were treated by placement of a SEMS (24) or open surgical GJ (23). RESULTS The technical success rates were similar, but clinical success was lower in the GJ group (92% vs. 56%, p = 0.0067). The SEMS group had a shorter length of hospital stay (3.0 [1.4] days vs. 24.1 [10.3], p < 0.001). Thirty-day mortality was 30% in the GJ group, and 0% in the SEMS group ( p = 0.004). Morbidity was higher in the GJ compared with the SEMS group (61% vs. 17%, p = 0.0021). Mean survival was longer in the SEMS group (96.1 [9.6] days vs. 70.2 [36.2] days, p = 0.0165 for a single test of hypothesis; Bonferroni correction for a multiple testing removes this significance), consequently, out-of-hospital survival was longer for the SEMS group (93.2 [9.3] days vs. 46.0 [31.5] days, p < 0.001). None of the endoscopic procedures required the assistance of an anesthesiologist or the use of an operating room. CONCLUSIONS The results of this retrospective study suggest that SEMS insertion is better than surgical GJ for palliation of patients with GOO in terms of clinical success, morbidity, and mortality. Technical success rates were similar. SEMS placement should be proposed as the first-line treatment for relief of GOO. However, a randomized, comparative, prospective study of SEMS vs. laparoscopic GJ is needed.

In vitro sensitivity of probiotics to human pancreatic juice.

Background The resistance of gut flora with probiotic activity to pancreatic juice is usually tested with artificial pancreatic fluid. Previous studies evaluated the sensitivity of diverse probiotics to human gastric and biliary secretion; none tested the resistance of probiotics to human pancreatic juice. As most bacteria sensitive to artificial pancreatic fluid in vitro have a high rate of isolation from feces, the resistance to human pancreatic juice could be higher. Aim The aim of this study was to compare the sensitivity of different strains of probiotics to artificial and human pancreatic juice. Materials and Methods The viability of 8 strains of Lactobacillus and 4 strains of Bifidobacterium was tested with standard artificial and human pancreatic juice withdrawn from 16 patients during endoscopic retrograde cholangiopancreatography procedure. The mortality rate (%) of various bacteria was measured after 5, 30, and 60 minutes contact time. The results were normalized for mortality rate induced by hypotonic condition and time exposure to 37°C. Results When incubated with artificial and human pancreatic juice, the mortality rate of all strains of Lactobacillus at 5, 30, and 60 minutes was 10.1 versus 7.6, 20.5 versus 19.7, and 28.6 versus 29.8, respectively; whereas the mortality rate of all strains of Bifidobacterium was 8.0 versus 9.2, 33.3 versus 28.9, and 42.2 versus 44.4, respectively. Conclusions All the tested strains were sensitive to artificial and human pancreatic juice depending on time contact. Bifidobacterium strains seem to be more sensitive than Lactobacillus strains in particular at higher time contact. There is no significant difference between sensitivity to simulated and human pancreatic juice. For this reason, probiotics activity may be tested with artificial pancreatic fluid using a standardized, easier, and less costly procedure.

Clinical experience with probiotics in the elderly on total enteral nutrition.

Background: Recent data support that after 2 years of age, intestinal microflora remains relatively constant over time, except in elderly people, who harbor fewer bifidobacteria and a higher population of fungi and enterobacteria than young adults. Diet supplementation with probiotics may improve the nutritional status and reduce the impaired immunity associated with aging. The goal of this study was to establish the effect on bifidobacteria fecal counts, and some clinical parameters, of bifidobacteria supplementation to elderly patients in total parenteral nutrition. Methods: Thirteen patients (6 men and 7 women; mean age, 69 years; range, 65–76 years) affected by permanent vegetative status (PVS) and fed by total enteral nutrition (TEN) were studied. Bifidobacteria and clostridia were investigated by microbiologic and molecular biology methods in stool specimens collected twice at basal time (T–2 and T0) and after 12 and 15 days (T12 and T15, respectively). Seven patients with basal bifidobacteria counts less than 10−7 were supplemented with Bifidobacterium longum W 11 for 12 days. The remaining 6 patients were used as control subjects. For 1 month diarrhea and fever episodes, use of antibiotics, and nutritional status (BMI) were assessed. Results: In the 7 patients with bifidobacteria counts less than 107, the administration of B. longum W 11 resulted in a 1 log increase in 6 of 7 patients at T12. No statistically significant difference in episodes of fever or diarrhea, use of antibiotics, or BMI was observed between the treatment and control groups. Conclusion: The administration of B. longum W11 in PVS patients fed by TEN is effective in increasing the population of bifidobacteria. Larger studies with longer follow-up could demonstrate the influence of these microbiologic changes in a clinical setting.