Modification of the Normal Microbiota by Diet, Stress, Antimicrobial Agents, and Probiotics

Effect of benzoic acid and combination of benzoic acid with a probiotic containing Bacillus Cereus var. toyoi in weaned pig nutrition

“…Administration of probiotics to re-establish the ideal relationship between beneficial and pathogenic microorganisms is preferred during periods of stress whereas this balance can be altered (Fox 1988). Probiotics act as growth promoters for use after weaning to slaughter, nutritional bioregulators competing with harmful gut flora, stimulators of immune system of the animal (Fuller 1989) and increase the body's resistance to infectious diseases (Tannock 1997(Tannock , 2001). The use of a probiotic containing Bacillus cereus var.…”

Glucocorticoids and the Intestinal Environment

“…They are mediated by stressrelated neuropeptides such as CRF, neural mechanisms and mast cells [18,20,65]. Various stress factors including heat, nutritional alterations, overcrowding, physical restraints and transporting also destroy the microbial balance and their microenvironment in the gut [66,67]. When the stressful events cause a decrease in beneficial bacteria, they generally increase the pathogenic species within the gut microenvironment [67][68][69].…”

“…Various stress factors including heat, nutritional alterations, overcrowding, physical restraints and transporting also destroy the microbial balance and their microenvironment in the gut [66,67]. When the stressful events cause a decrease in beneficial bacteria, they generally increase the pathogenic species within the gut microenvironment [67][68][69]. In following sections, the effects of stress mediators on each component of barrier were discussed in details.…”

“…However, various stress factors such as heat, cold, nutritional alterations, overcrowding, physical restraints and transporting or fouled or contaminated foods can destroy the microbial balance in the gastrointestinal system [66,67,[191][192][193][194][195] and alter their relationships with each other and with their hosts. Stressful stimuli can affect gastrointestinal microbiota directly, for example via limited availability of food ingredients or direct actions of stress mediators such as adrenaline or noradrenaline on microbiota [27,196], and indirectly via altering the intestinal environment of bacteria such as intestinal secretion, motility, permeability and immune functions as reviewed above.…”

“…They are essential not only in colonization, growth and survival of the microbiota in intestinal system but also in maintaining the balance among different species and their localization within its lumina [67,192,227,228]. Nutrition plays an important role as stressor for host organisms and their gastrointestinal tract via three mechanisms.…”