Đồ án kỹ thuật sấy probiotics

CHAPTER 1: OVERVIEW OF PROBIOTICS I History and definition of probiotics: History of probiotics: Probiotics was first conceptualized by the Russian Nobel Prize winner and father of modern immunology, Elie Metchnikoff, at the beginning of the 20th century He believed that the fermenting bacteria in milk products consumed by Bulgarian peasants were responsible for their longevity and good health Recent research is now catching up with what he already knew The actual word was first used by Lilly and Stillwell in 1965 as a contrast to the word “antibiotics” By the 1970s, “probiotics” was being used in the sense that we know it today The use of live microorganisms in the diet has a long history and is one of the oldest methods for producing and preserving food Soured milks and such cultured dairy products as kefir, koumiss, leben, and dahi were often used therapeutically before the existence of microorganisms was recognized Such dairy products are mentioned in the Bible and the sacred books of Hinduism Definition of probiotic: Probiotics are live microorganisms which, when they are administered in adequate quantities, have beneficial effects on the health of the host Probiotics are products designed to deliver potentially beneficial bacterial cells to the microbiotic ecosystem of humans and other animals II Microbes used as probiotics: Strains of lactic acid bacteria are the most common microbes employed as probiotics, especially Lactobacillus and Bifidobacterium species, but lactococci, some enterococci and some streptococci are also included as probiotics Table 1.1: Species of bacteria the most common and considered as potential probiotic Bacteria of the family of the lactobacillus Bacteria of the family of the bifidobacteria Other bacteria Lactobacillus acidophillus Bifidobacterium adolescentis Enterococcus faecalis Lactobacillus casei Bifidobacterium animalis ssp animalis Enterococcus faecium Lactobacillus johnsonii Bifidobacterium animalis ssp lactis Lactococcus lactis Lactobacillus lactis Bifidobacterium bifidum Pediococcus acidilactici Lactobacillus paracasei Bifidobacterium breve Propionibacterium freudenreichii Lactobacillus plantarum Bifidobacterium infantis Lactobacillus reuteri Bifidobacterium lactis Lactobacillus rhamnosus Bifidobacterium longum Lactobacillus salivarius Bifidobacterium thermophilum A strain probiotic is classified by genus, species, with a designation alphanumeric In the scientific community, there is a nomenclature recognized and accepted for micro-organisms — for example, Lactobacillus casei DN-114 001 or Lactobacillus rhamnosus GG (Fig 1.1) Fig 1.1 : Nomenclator for the micro-organisms Genus species Genus species designation of the strain designation of the strain Lactobacillus rhamnosus GG Lactobacillus casei DN-114 001 Table 1.2 : Examples of probiotics in different products Strains (alternative designation) Commercial Manufacturer name Bifidobacterium animalis DN 173 010 Activia Danone/Dannon Bifidobacterium animalis subsp lactis Bb-12 Chr Hansen Bifidobacterium breve Yakult Bifiene Yakult Bifidobacterium infantis 35624 Align Procter & Gamble Bifidobacterium lactis HN019 (DR10) Howaru™ Bifido Danisco Bifidobacterium longum BB536 Morinaga Milk Industry Cerbios-Pharma Enterococcus LAB SF 68 Bioflorin Escherichia coli Nissle 1917 Ardeypharm Mutaflor Lactobacillus acidophilus LA-5 Chr Hansen Lactobacillus acidophilus NCFM Danisco Actimel, Danone/Dannon Lactobacillus casei DN-114 001 DanActive Lactobacillus casei CRL431 Chr Hansen Lactobacillus casei F19 Cultura Arla Foods Lactobacillus casei Shirota Yakult Yakult Lactobacillus johnsonii La1 (Lj1) LC1 Nestlé Norrmejerier Lactococcus lactis L1A Lactobacillus plantarum 299V GoodBelly, NextFoods Probi ProViva Lactobacillus reuteri ATTC 55730 Retueri BioGaia Biologics Lactobacillus rhamnosus ATCC 53013 Vifit et autress Valio (LGG) Lactobacillus rhamnosus LB21 Verum Norrmejerier Lactobacillus salivarius UCC118 Saccharomyces cerevisiae (boulardii) lyo DiarSafe, Wren Laboratories, Ultralevure et Biocodex, autres and others Testé comme mélange: Bio K+ Bio K+ Lactobacillus acidophilus CL1285 & International Lactobacillus casei Lbc80r Testé comme mélange: Lactobacillus FemDophilus Chr Hansen rhamnosus GR-1 & Lactobacillus reuteri RC-14 VSL#3 Sigma-Tau Testé comme mélange: VSL#3 (mélange Pharmaceuticals,Inc d’une souche de Streptococcus thermophilus, quatre de Lactobacillus spp & trois de Bifidobacterium spp Testé comme mélange: Lactobacillus acidophilus CUL60 & Bifidobacterium bifidum CUL 20 Testé comme mélange: Lactobacillus A'Biotica et Institut Rosell helveticus R0052& Lactobacillus autres rhamnosus R0011 Testé comme mélange: Enterogermina Sanofi-Aventis Bacillus clausii strains O/C, NR, SIN, et T III.Charateristics of probiotics: Properties of trains of probiotics: Line Villeneuve, microbiologist among Abiasa, describes the conditions of growth of probiotics They are sensitive to great heat, the ideal temperature is around 37°C, that is to say the same as the human bod y Precisely, several strains of these microoganismes referred to as probiotics are already part of the normal flora of the intestine The ideal pH is near the neutrality Probiotics are also sensitive to the oxygen and in the light Lactobacillus Lactobacillus species are facultative anaerobes They grow in the presence of O2, however, and may convert it to H2 O or H2 O2 Lactobacilli normally predominate in the small intestine, and they are known for their beneficial effects which may antagonize potential pathogens Lactobacilli are sticks gram-positive, often prepared to string More than 56 species of lactobacilli were enumerated, including 21 were found in human Certain strains metabolise sugars by way homofermentaire or hétérofermentaire way Fig.1.2 Electron micrograph of Lactobacillus salivarius 118 adhering to Caco-2 cells (source: Neurogastroenterol Motil 2007;19:166–72) Bifidobacterium Bifidobacterium is not included in the traditional Lactic Acid Bacteria due to its genetic unrelatedness, but the bacterium has a habitat that overlaps with LAB, and it has a metabolism that produces lactic acid as a primary end-product of fermentation Bifidobacteria are strictly anaerobic and normally vie for predominance in the large intestine Bifidobacteria are an obligately anaerobic bacteria, not classified with the lactic acid bacteria, but which occupy similar habitats and produce lactic acid as a sole end-product They are a Gram-positve bacterium in the large intestine (colon) Bifidobacterium infantum is the predominant bacterium in the intestine of breastfed infants because mother's milk contains a specific growth factor that enriches for the growth of the bacterium The bifidobacteria are sticks with varied forms whose most characteristic is in the form of Y Over 30 species are now known, of which 10 were isolated in humans (Table I.3) The bifidobacteria, having effects probiotics and used commercially, are less numerous than lactobacilli The strain that is most studied is Bifidobacterium lactis Bb12.1 Fig.1.3 : Bifidobacterium longum Table 1.3 : Strains of Lactobacillus and Bifidobacterium Streptococcus Streptococcus species are not typically associated with health benefits and some are highly pathogenic However, one facultative anaerobic species, Streptococcus thermophilus, is known to promote health It is one of the two primary species found in yo gurt cultures, the other being L bulgaricus Enterococcus Found in a number of probiotic products, the facultative anaerobe Enterococcus faecium is invariably a component of the normal intestinal microbiota and is considered a beneficial microbe However, E faecium has evolved from a relatively nonpathogenic commensal bacterium to the third most common cause of hospital-acquired infections and now accounts for over 10% of enterococcal clinical isolates Furthermore, it has developed extensive resistance to antibiotics, which it is capable of transferring to other bacteria Lactococcus lactis Lactococcus lactis is a microbe classified informally as a Lactic Acid Bacterium because it ferments milk sugar (lactose) to lactic acid Lactococci are typically spherical or ovoid cells, about 1.2µm by 1.5µm, occurring in pairs and short chains They are Gram-positive, non motile, and not form spores Lactococci are found associated with plant material, mainly grasses, from which they are easily inoculated into milk Hence, they are found normally in milk and may be a natural cause of souring Lactococcus lactis has two subspecies, lactis and cremoris, both of which are essential in manufacture of many varieties of cheese and other fermented milk products Lactococcus lactis is related to other lactic acid bacteria such as Lactobacillus acidophilus in our intestinal tract and Streptococcus salivarius in the mouth However, Lactococcus does not normally colonize human tissues and differs from many other lactic acid bacteria in its pH, salt, and temperature tolerances for growth, which are important characteristics relevant to its use as a starter culture in the cheesemaking industry Fig.1.4 : Lactococcus lactis UW Department of Bacteriology strain LcL325UW Magnification 20000X Scanning electron micrograph by Joseph A Heintz, University of Wisconsin-Madison Technologiacal properties: Important criteria for probiotics - Survive passage through the upper gastrointestinal tract - Resistance to gastric acid and bile, proteolytic enzymes, … - Active during transit from stomach to colon (expression of genes during murine intestinal transit) - Interact with the resident microbiota - Ability to transiently adhere to the intestinal epithelium and colonize the colon - Do not affect the dominant microbiota significantly - Have an effect on the numbers and diversity of the endogenous Lactobacillus and Bifidobacterium species - Affect the function of the host: - Probiotic-host interactions (functional genomics, clinical trials and human intervention studies) - Prevention of (the risk on) disease (meta-analyses) - Resistant towards technological processing and storage - High safety profile and excellent tolerance (Lb rhamnosus, D-lactic acid)robiotics - Improved food digestion (e.g proteins, dietary polysaccharides) - Reduction of the risk of lactose maldigestion (β-galactosidase) - Supply of nutrients and growth factors (e.g vitamins, bioavailability of minerals) - Maintenance and balancing of the colon microbiota - Reduction of the risk of intestinal disturbances (gastrointestinal infections, constipation) - Reduction of the risk for and duration of diarrhoea (rotavirus diarrhoea, acute infectious diarrhoea, antibiotic-associated difficileassociated diarrhoea, travellers’ diarrhoea) diarrhoea, Clostridium - Inhibition of undesirable and pathogenic bacteria (gastrointestinal infections caused by Streptococcus mutans, Helicobacter pylori, E coli, Salmonella Typhimurium, Clostridium difficile, urinary tract infections, respiratory tract infections) - Beneficial effects on functional bowel disorders: irritable bowel syndrome - Beneficial effects on inflammatory bowel diseases: pouchitis, ulcerative colitis, Crohn’s disease - Modulation/stimulation of the immune system - Reduction of the risk of atopic diseases and allergies (asthma, hay fever, food allergy, eczema, dermatitis) - Anticarcinogenic activities - Lowering of blood serum cholesterol levels IV.Effects probiotics on human health: Disorders associated with the gastrointestinal tract : viruses 1.1 Prevention of diarrhea caused by certain pathogenic bacteria and Infectious diarrhea is a major world health problem, responsible for several million deaths each year While the majority of deaths occur amongst children in developing countries, it is estimated that up to 30% of the population even in developed countries are affected by food-borne diarrhea each year Probiotics can potentially provide an important means to reduce these problems It should be noted that some of the studies referenced below utilize probiotics administered in a non-food form The strongest evidence of a beneficial effect of defined strains of probiotics has been established using Lactobacillus rhamnosus GG and Bifidobacterium lactis BB-12 for prevention (Saavedra et al., 1994; Szajewska et al., 2001) and treatment (Isolauri et al., 1991; Guarino et al., 1997; Majamaa et al., 1995; Shornikova et al., 1997; Perdone et al., 1999; Guandalini et al., 2000) of acute diarrhea mainly caused by rotaviruses in children In addition to rotavirus infections, many bacterial species cause death and morbidity in humans There is good in vitro evidence that certain probiotic strains can inhibit the growth and adhesion of a range of enteropathogens (Coconnier et al., 1993, 1997; Hudault et al., 1997; Gopal et al., 2001; Bernet Camard et al., 1997), and animal studies have indicated beneficial effects against pathogens such as Salmonella (Ogawa et al., 2001; Shu et al., 2000) There is evidence from studies on travellers’ diarrhea, where some of the causative pathogens have been presumed to be bacterial in nature, that benefits can accrue with probiotic administration (Hilton et al., 1997) It is important to note that probiotic therapy of acute diarrhea should be combined with rehydration if available Current WHO recommendations state that clinical management of acute diarrhea should include replacement of fluid and electrolytes losses along with nutritional support (WHO, 1995) Oral rehydration salts (ORS) have been widely used in such disease management, and it is within this context that the combination therapy with probiotics is hereby advocated Effects such as probiotic restoration of the non-pathogen dominated intestinal microflora secondary to infection, maintaining mucosal integrity and improving electrolyte balance could have a significant impact on programs of treatment and prevention of acute diarrhea in developing countries A major problem associated with antibiotic treatment is the appearance of diarrhea, often caused by Clostridium difficile This organism is not uncommon in a healthy intestinal tract, but the disruption of the indigenous microflora by antibiotics leads to an abnormal elevation of their numbers, and subsequent symptoms related to toxin production The rationale therefore to use probiotics is that in such patients, administration of exogenous commensal microorganisms (that is probiotics) is required to restore the microflora to one that more closely reflects the normal flora prior to antibiotic therapy Some open ended studies have indeed shown that this 10 ... SIN, et T III.Charateristics of probiotics: Properties of trains of probiotics: Line Villeneuve, microbiologist among Abiasa, describes the conditions of growth of probiotics They are sensitive... strains of these microoganismes referred to as probiotics are already part of the normal flora of the intestine The ideal pH is near the neutrality Probiotics are also sensitive to the oxygen and... food-borne diarrhea each year Probiotics can potentially provide an important means to reduce these problems It should be noted that some of the studies referenced below utilize probiotics administered