Sources, isolation, characterisation and evaluation of probiotics

Abstract

Probiotics are live microorganisms that, when ingested in adequate amounts, provide health benefits to the host. The strains most frequently used as probiotics include lactic acid bacteria and bifidobacteria, which are isolated from traditional fermented products and the gut, faeces and breast milk of human subjects. The identification of microorganisms is the first step in the selection of potential probiotics. The present techniques, including genetic fingerprinting, gene sequencing, oligonucleotide probes and specific primer selection, discriminate closely related bacteria with varying degrees of success. Additional molecular methods, such as denaturing gradient gel electrophoresis/temperature gradient gel electrophoresis and fluorescence in situ hybridisation, are employed to identify and characterise probiotics. The ability to examine fully sequenced genomes has accelerated the application of genetic approaches to elucidate the functional roles of probiotics. One of the best-demonstrated clinical benefits of probiotics is the prevention and treatment of acute and antibioticassociated diarrhoea; however, there is mounting evidence for a potential role for probiotics in the treatment of allergies and intestinal, liver and metabolic diseases. These positive effects are generally attributed to the ability of probiotics to regulate intestinal permeability, normalise host intestinal microbiota, improve gut immune barrier function and equilibrate the balance between pro-inflammatory and antiinflammatory cytokines. However, the positive effects of probiotics are not always substantiated by findings from properly conducted clinical trials. Notably, even when the results from randomised, placebo-controlled trials support the beneficial effects of a particular probiotic for a specific indication, the benefits are generally not translatable to other probiotic formulations.

Effects of Probiotic Intake on Intestinal Bifidobacteria of Celiac Patients

“…Alternative treatments are also available and can be used simultaneously as palliatives, for instance, the use of probiotics, mainly Lactobacillus and Bifidobacterium (7,15,24) .…”

Probiotics - the versatile functional food ingredients

“…Recently, L. johnsonii CRL 1647, isolated from the Apis mellifera L. bee gut, was shown to exhibit a beneficial effect on honeybee colonies. Additionally, probiotic strains have also been obtained from the intestinal tracts of marine and freshwater fish, such as Carassius auratus gibelio, rainbow trout and shrimp (Fontana et al 2013). …”

“…The important criteria which are used for selecting probiotic strains includes that the organism should be: nonpathogenic and non-toxic (Singh et al 2011); isolated from the same species as its intended host (Maurya et al 2014); able to survive during transit through the gastrointestinal tract by being acid and bile resistant (Khan and Naz 2013;Maurya et al 2014); able to adhere and colonize the intestinal epithelium which is an important property for successful immune modulation and competitive exclusion of pathogens (Kechagia et al 2013;Maurya et al 2014); able to stabilize the normal intestinal microflora (Parvez et al 2006); able to produce antimicrobial substances like the bacteriocins against the pathogens (Kral et al 2012); having a demonstrated beneficial effect on the host (Fontana et al 2013); durable enough to withstand the duress of commercial manufacturing, processing and distribution (Khan and Naz 2013); and also having good sensory characteristics by not providing unpleasant flavors or textures (Parracho et al 2007;Mitropoulou et al 2013). The essential criteria for the use of probiotics in humans has been listed in Table 2.…”

“…Treatments with Bacillus spp., Bifidobacterium spp., Lactobacillus spp., Lactococcus spp., Leuconostoc cremoris, Saccharomyces spp., or Streptococcus spp., individually or in combination were shown to have a protective effect in preventing antibioticassociated diarrhea (Fontana et al 2013;Kechagia et al 2013). A meta-analysis consisting of 34 studies which included 4138 patients reported that the pooled relative risk (RR) for antibiotic-associated diarrhea (ADD) in the probiotic group versus placebo was 0.…”

“…Irritable bowel syndrome Irritable bowel syndrome (IBS) is a chronic condition affecting 3-25 % of the population for which no curative treatment is available. Accordingly, therapy is aimed at reducing the symptoms (Fontana et al 2013). A study by Drouault-Holowacz et al (2008) reported an increase in patients with satisfactory relief of overall IBS symptoms after receiving a probiotic mix of Bifidobacterium longum LA101, Lactobacillus acidophilus LA102, Lactococcus lactis LA103, Streptococcus thermophilus LA104.…”