Probiotics efficacy

A number of in vivo studies have been performed which have determined the probiotic capabilities of such strains. While these studies have been important in demonstrating probiotic efficacy against various infectious diseases, few have specifically identified the mechanistic basis behind the observed benefits, and many rely on in vitro data to decipher the possible mechanism of action. However, what has emerged to date is that... 

Epidemiology and properly controlled human intervention studies to confirm probiotic efficacy... 

Numerous studies have proven the probiotic efficacy of the strain E. faecium M-74 in humans and livestock. The strain was isolated from the intestinal tract of a human infant. It is a proprietary strain of probiotic bacteria patented and marketed by Swedish companies. 

In addition to the evidence on the impact on human immunity, evidence has accumulated during the past decade on the capability of the intestinal microbiota to participate in and also influence the metabolism of its human host. The effects of probiotics are still little studied in this area, but considering the global epidemic of obesity and metabolic diseases, this application holds huge possibilities if probiotic efficacy can be scientifically demonstrated and the epidemic of Western diseases ameliorated. 

Existing health targets, as described above, will be further investigated and either confirmed or refuted for probiotic efficacy. New targets will also certainly emerge. Many of these targets will be indicated by the substantial research efforts towards understanding of the intestinal and other microbiota. The influence of the intestinal microbiota on, for instance, the gut-brain axis may hint at possibilities for probiotics and stress or mental awareness. 

Ritchie, M. L., Romanuk, T. N. (2012). A meta-analysis of probiotic efficacy for gastrointestinal diseases. PLoS One, 7. e34938 (11pp.). 

There is a range of therapeutants available to the hatchery manager including vaccines, chemical treatments, antibiotics, immunostimulants and pre-and probiotics. Efficacy of these therapeutants varies depending on a range of factors, such as time of delivery, dose and pathogen. 

The ability of the probiotic strain to persist in the gut has been identified as one important prerequisite of probiotic efficacy. Indeed, a number of probiotic products claim that their strains colonize the human gastrointestinal tract. However, it is more likely that after cessation of probiotic feeding, the vast majority of probiotic strains fall below detection. This is not imexpected since the human gut microflora provides a robust barrier to the establishment of exogenous micro-organisms. 

While the efficacy of probiotics was tested in a wide variety of animals including pets, horses and farm animals, the main potential application will... 

The use of AAAs as feed supplements appears an attractive approach either in itself or in combination with pro-, pre- and synbiotics, but the lack of animal feeding studies in which the efficacy of this approach could be determined makes it difficult to assess to what extent a two-barrier (targeting control at both the stomach and intestinal level) approach is commercially feasible. Also, since the viability of probiotics may also be affected by the use of AAA to increase the disinfection activity of the stomach, probiotics may need to be formulated in a way that protects them during stomach transfer. However, its potential should be determined in future research. 

Besides constipation-related IBS, several studies have also suggested abnormalities of colonic bacterial composition in chronic idiopathic constipation [125]. Here again antibiotic treatment with vancomycin [126, 127], rova-mycin (in combination with diphetarsone, an amebicidal agent) [128,129] or erythromycin [130], which, however, displays a prokinetic activity [131, 132], proved to be capable of reversing long-lasting constipation. Furthermore, the efficacy in both clinical conditions of probiotics [133-135] lends further support to the pathogenic role of bowel flora. 

Lactobacilli used have included a commercial mixture of Lactobacillus acidophilus and Lactobacillus bulgaricus (Lactinex ) and Lactobacillus GG. decreased AAD in adults receiving amoxicillin (3.3%) compared to placebo (21%), but the difference was not statistically significant [69]. A study in children receiving amoxicillin failed to demonstrate a significant decrease in AAD with this probiotic mixture [70], Variability in lots may explain differences in efficacy in many trials [71], Lactobacillus GG may have a better efficacy than this probiotic mixture in... 

More recently, Campieri et al. [51] performed a randomized trial to evaluate the efficacy in the prevention of postoperative recurrence with rifaximin 1.8 g daily for 3 months followed by a probiotic preparation (VSL 3) 6 g daily for 9 months versus mesalazine 4 g daily for 12 months in 40 patients after curative resection for CD. After 3 months of treatment, patients on rifaximin had a significantly lower incidence of severe endoscopic recurrence compared to those on mesalazine [2/20 (10%) vs. 8/20 (40%)]. This difference was maintained since the end of the study using probiotics [4/20 (20%) vs. 8/20 (40%)]. 

In conclusion, the results of this pilot study suggest the efficacy of the sequential combination of rifaximin and the highly concentrated probiotic preparation VSL 3 in the prevention of severe endoscopic recurrence of CD after surgical resection [51],... 

Another recent controlled trial showed a good therapeutic effect of both amoxicillin-clavulanic acid and norfloxacin in SIBO patients [45]. However, a rapid relapse of diarrhea just few days after the withdrawal of antibiotics was evident. In this paper, the efficacy of probiotics in SIBO patients was also evaluated, but no significant effect was described. While on the one hand these results confirm the frequent need of several courses of antibiotic therapy in SIBO patients, on the other they support the idea that rifaximin may represent a good choice on the basis of its excellent tolerability. 

Moxley, R. 2003. Comparison of the efficacy of vaccination and probiotic feeding for reducing the prevalence of E. coli 0157 H7 in feedlot cattle. The second Governor s Conference on Ensuring Meat Safety E. coli 0157 H7 Progress and Challenges. April 7-8, 2003. Lincoln, NE. 

Although progress in probiotic research has been achieved, not all of the available probiotic bacteria on the market have adequate scientific documentation. If nutritional and health benefits are to be derived from products containing probiotic bacteria, the mechanisms by which these benefits are derived should be understood and those strains demonstrating the most promise in this regard should be used. Consequently, it is necessary to establish rational criteria for screening and selection of candidate microorganisms and also to evaluate the efficacy of the selected strains or food products in well-controlled human dietetic or clinical trials. 

If probiotics are to be used to treat and prevent infection, the first studies that must be undertaken are to characterize fully (phenotypical and genotypical traits) the microorganisms that will be used. If they do not demonstrate anti-infective traits in vitro, it seems unlikely that they can be efficacious in humans. Scientific rationale for the selection of the best species or strain for use as probiotics is not possible without more information on the mechanisms by which probiotics exert their beneficial effects in vivo. 

The probiotic strain E. faecium PR88 was studied in clinical trial (Allen et al. 1996). The consumption of this strain led to alleviation of the symptoms of irritable bowel syndrome in humans. The efficacy and safety of live combmedBifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome was also demonstrated (Fan et al. 2006). E. faecium functions as a probiotic strain inhibiting biofilm formation by Streptococcus mutants, which is an etiological agent for dental caries (Kumada et al. 2008). 

Probiotic bacteria differ on the basis of genus, species, and strains. Indeed, strains of the same species vary widely in traits such as expression of enzymes, types of inhibitors produced, carbohydrate fermentation patterns, resistance to acid and bile, ability to colonize the gastrointestinal tract, and clinical efficacy (Berg, 1996 Norat et al., 2002). Furthermore, the active principle has not always been associated with live bacteria, as some immune system modulation activities and macromolecular degradation have been linked to nonviable bacterial components such as enzyme activities or fermentation products (Huttner and Bevins, 1999). 

There are many scientific evidences, supported by clinical studies, on the efficacy of probiotics in the prevention and treatment of gastrointestinal disorders, respiratory, and urogenital diseases. Many microbial strains with probiotic properties are able not only to restore the intestinal microbial balance, but also to impart other beneficial effects on health, associated with the production of acids, bacteriocins and with the competition with pathogenic microorganisms. Among these, the main effects are the reduction of the level of cholesterol in the blood, the reduction of fecal enzymes, with potentially mutagenic activity that can induce the onset of tumors, the reduction of lactose intolerance, the increase of the response of the immune system, the increase of calcium absorption, and synthesis of vitamins. ... 

Probiotics can be included in many different foods, fermented and unfermented. The food matrix is known to have an important role in the stability of probiotics (Forssten et al., 2011). Manufacturers take this into account when developing such foods. However, which role the matrix plays in efficacy is less well understood. For some strains... 

As discussed above, the role that the food matrix plays in the efficacy of probiotics, if any, has been insufficiently investigated. Many studies have been performed with... 

---