Life Under Stress: The Probiotic Stress Response and How it may be Manipulated

Abstract

The continuing expansion of interest in probiotic bacteria has led to an increase in manufactured Functional Foods and medicines containing these bacteria. Given the intestinal origin of these microorganisms, the challenges these sensitive bacteria face in order to be in a highly viable state throughout processing, storage and gastrointestinal transit to the site of action in the human gut are enormous. These bacteria encounter stresses including temperature, acid, bile, exposure and osmotic and oxidative stress in both product matrices and during gastrointestinal transit. However, like all bacteria, probiotic bacteria retain a broad arsenal of molecular mechanisms to combat the often lethal environmental stresses encountered during processing and following ingestion. A comprehensive appreciation of these mechanisms should inevitably lead to the design and manufacture of probiotic cultures, which retain greater viability through to the target site in the intestine. This review attempts to catalogue the cellular processes available to probiotic bacteria to facilitate survival in stressful conditions, and to speculate on how manipulation of these cellular systems can lead to production of designer strains with enhanced viability in food systems and efficacy following ingestion.

Proteomic and transcriptomic analysis of the response to bile stress of Lactobacillus casei BL23

“…Probiotic micro-organisms are currently the focus of an intense research effort that aims to determine their possible health benefits and to identify the mechanisms through which they exert them (Oelschlaeger, 2010;Sánchez et al, 2010). Although there is evidence showing that dead probiotic cells can also confer some beneficial effects upon the host (Adams, 2010), it is generally agreed that probiotic micro-organisms must survive the transit through the gastrointestinal tract, where they will encounter a very acid environment in the stomach and a high concentration of bile salts in the upper small intestine (Corcoran et al, 2008).…”

Viability of Probiotics in Frozen Yogurt with different levels of Overrun and Glycerol

“…Oxygen tolerance is different in different strains of probiotics (Kawasaki et al, 2006). Probiotics are gut origin where the environment is anaerobic, The oxygen as such does not harm the bacteria but when it is converted into different reactive compounds like superoxide (O 2 -) and hydroxyl anion (OH -) in the cell and leads to bacterial death (Talwalkar and Kailasapathy, 2003;Corcoran et al, 2008). These toxic compounds upon reacting with the major components of the cell like nucleic acid, lipids and proteins cause death of the cell (Ferraz et al, 2012).…”

Probiotics in Aquaculture - Benefits to the Health, Technological Applications and Safety

“…Environmental stresses such as temperature, acid, exposure and osmotic pressure, oxygen have important effects on probiotics survival and activity both in product and animal gut. However, like all bacteria, probiotic bacteria retain a broad arsenal of molecular mechanisms to combat the often lethal environmental stresses encountered during processing and following ingestion and therefore the comprehensive appreciation of these mechanisms should inevitably lead to the design and manufacture of probiotic cultures, which retain greater viability through to the target site in the intestine (Corcoran et al, 2008). Environmental stress responses in Lactobacillus, which have been investigated mainly by proteomics approaches, are reviewed by De Angelis and Gobbetti (2004) and the physiological and molecular mechanisms of responses to heat, cold, acid, osmotic, oxygen, high pressure and starvation stresses are described.…”