Probiotics, prebiotics and the gastrointestinal tract in health and disease

Abstract

The microbiome located in the human gastrointestinal tract (GIT) comprises the largest community (diverse and dense) of bacteria, and in conjunction with a conducive internal milieu, promotes the development of regulated pro- and anti-inflammatory signals within the GIT that promotes immunological and metabolic tolerance. In addition, host-microbial interactions govern GIT inflammation and provide cues for upholding metabolic regulation in both the host and microbes. Failure to regulate inflammatory responses can increase the risk of developing inflammatory conditions in the GIT. Here, we review clinical studies regarding the efficacy of probiotics/prebiotics and the role they may have in restoring host metabolic homeostasis by rescuing the inflammatory response. The clinical studies reviewed included functional constipation, antibiotic-associated diarrhoea, Clostridium difficile diarrhoea, infectious diarrhoea/gastroenteritis, irritable bowel syndrome, inflammatory bowel diseases and necrotizing enterocolitis. We have demonstrated that there was an overall reduction in risk when probiotics were administered over placebo in the majority of GIT inflammatory conditions. The effect size of a cumulative reduction in relative risk for the GIT conditions/diseases investigated was 0.65 (0.61-0.70) (z = 13.3); p < 0.0001 that is an average reduction in risk of 35 % in favour of probiotics. We also progress a hypothesis that the GIT comprises numerous micro-axes (e.g. mucus secretion, Th1/Th2 balance) that are in operational homeostasis; hence probiotics and prebiotics may have a significant pharmacobiotic regulatory role in maintaining host GIT homeostasis in disease states partially through reactive oxygen species signalling.

Influence of Drinking a Probiotic Fermented Milk Beverage Containing Bifidobacterium Animalis on the Symptoms of Constipation

“…According to Vitetta and colleagues, the consumption of yoghurt may be beneficial for facilitating the action of digestive enzymes and proteins. Dairy products are similarly recommended for consumption for their probiotic and nutritional characteristics (19) . One of the beneficial effects observed in the present study concerned the type and consistency of feces, which became less fragmented, segmented and hardened.…”

Microbiota Manipulation With Prebiotics and Probiotics in Patients Undergoing Stem Cell Transplantation

“…Probiotics have proven efficacious in treating a wide variety of diarrheal illnesses, including antibiotic-associated diarrhea [55–57], infectious diarrhea or gastroenteritis [58, 59], irritable bowel syndrome [60–64], ulcerative colitis [65, 66], necrotizing enterocolitis [67–69], constipation [70], and pouchitis [71–73], although they have not yet shown significant efficacy in the treatment of Crohn’s disease [74]. Proposed mechanisms for probiotic efficacy include the microorganism-based remodeling of microbial communities and suppression of pathogens through direct antimicrobial effects, stimulation of immune responses that lead to upregulation of anti-inflammatory cytokines and IgA, and promotion of intestinal barrier function [75, 76]. …”

A prospective study to evaluate the safety and efficacy of symbiotic supplementation (probiotic and prebiotic combination) in stage 5D chronic kidney disease patients

“…16 In contrast, Prebiotic have been defined as those nutritional supplements (like inulin) that favors the growth and increasing survival of probiotic bacteria. 17 A symbiotic preparation is one that combines multi strain probiotic micro-organism with prebiotic compounds.…”