دانلود ترجمه مقاله استفاده از پریبیوتیک و پروبیوتیک ها در عمل آوری طیور

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میکروبهای روده ای – اپی تلیوم وسیستم ایمنی در برابر عوامل بیماری زای روده مقاومت می کنند. اطلاعات اخیر نشان می دهد که پایداری ومقاومت سیستم ایمنی تنها به علت مجموع اجزاء نمی باشد، اما باید یاد آوری کنیم که این مولفه ها عواملی هستند که پایداری سیستم ایمنی رادر حد تعدیل نگه می دارند. باید از ابتلا به بیماریهایی که بوسیله سیستم ایمنی ایجاد می شوند جلوگیری کنیم . این جانداران کوچک جانداران میکروبی ناسازگارگفته می شوند که بوسیله تداخل میکروبی که دربرابر عوامل بیماری زا نوعی مانع ایجاد می کنند . باکتریهای روده ای که بطور طبیعی در سیستم ایمنی وجود دارند از ایجاد بعضی ازبیماریها جلوگیری می کنند واین جلوگیری بوسیله همکاری ورقابت وجایگزینی وحرکت در تولید مواد غذایی – توید ترکیبات سمی وایجاد تحریک در سیستم ایمنی است.
این مکانیسم ها برای مقابله با بیماری به تنهایی عمل نمی کنند بلکه ممکن است این مکانیسم ها جلوگیری کنند ویا با هم یا با مکانیسم های دیگر ترکیب شوند . غذاهای تخمیری اگر با هم مورد استفاده قرار گیرند موجب بهبود وسلامتی می شوند وهمچنین باکتری های اسید لاکتیک وعوامل دیگری سبب پیشرفت بهبودی می شوند . تحققات اخیر نشان می دهد که باکتری های اسید لاکتیک وجانوران کوچک ومیکروسکوپی ریز دیگری هستند که مقاومت در برابر بیماری ها را افزایش می دهند .باکتری اسید لاکتیک می تواند غنی شود . اثر میکروبهای روده ای که با تغذیه مواد کربوهیدراتی ایجاد می شود این است که مقاومت باکتریایی در انسان نسبت به آنتی بیوتیک ها افزایش داده می شود . به این دلیل علاقه به عدم استفاده از آنتی بیوتیک ها برای درمان دامها دربین مردم وحکومت ها کم شده است .
راه حل دسترسی به درمانهای فرعی آنتی بیوتیکی در دامها استفاده از میکروارگانیسم های ریز (پروبیوتیک ) است . پروبیوتیک ها جاندارانی هستند که قبلا در لایه های زیرین بودند که توسعه یافته وبصورت گروههای باکتریایی ویا بصورت ترکیباتی از پروبیوتیک ها وپری بیوتیک ها (ساین بیوتیک ها ) در آمده اند . تحقیقات تاکیید دارند که فایده ی تغییر شکل یابنده این است که باکتری های لایه های زیرین را مشخص می کنند زیرا به نظر می رسد که آنها به نهوی برسلامتی تاثیر دارند.
مقدمه
بیماری روده ای یک نگرانی مهم در صنعت طیور است زیرا با این بیماری بازدهی کم شده و مرگ ومیر طیورافزایش می یابد وبه این طریق آلودگی های انسانی از مصرف محصولات طیور افزایش می یابد .با افزایش مقاومت آنتی بیوتیکی استفاده از آنتی بیوتیک های درمانی دراروپا ممنوع شده است ودرادامه درخود امریکا نیز ممنوع خواهد شد .علاقه برای پیدا کردن جایگزینی دیگر برای استفاده در صنعت طیور بیشتر شده است که این خود راهی برای افزایش بیشتر تولیدات است .

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ABSTRACT The intestinal microbiota, epithelium, and immune system provide resistance to enteric pathogens. Recent data suggest that resistance is not solely due to the sum of the components, but that cross-talk between these components is also involved in modulating this resistance. Inhibition of pathogens by the intestinal microbiota has been called bacterial antagonism, bacterial interference, barrier effect, colonization resistance, and competitive exclusion. Mechanisms by which the indigenous intestinal bacteria inhibit pathogens include competition for colonization sites, competition for nutrients, production of toxic compounds, or stimulation of the immune system. These mechanisms are not mutually exclusive, and inhibition may comprise one, several, or all of these mechanisms. Consumption of fermented foods has been associated with improved health, and lactic acid (Key words: intestinal microbiota, poultry, prebiotic, probiotic) 2003 Poultry Science 82:627–631 INTRODUCTION Enteric diseases are an important concern to the poultry industry because of lost productivity, increased mortality, and the associated contamination of poultry products for human consumption (human food safety). With increasing concerns about antibiotic resistance, the ban on subtherapeutic antibiotic usage in Europe and the potential for a ban in the United States, there is increasing interest in finding alternatives to antibiotics for poultry production. Prebiotics and probiotics are two of several approaches that have potential to reduce enteric disease in poultry and subsequent contamination of poultry products. Probiotic, which means “for life” in Greek (Gibson and Fuller, 2000), has been defined as “a live microbial feed supplement which beneficially affects the host animal by improving its intestinal balance” (Fuller, 1989). Prebiotics are defined as “a nondigestible food ingredient that bene- ficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of 2003 Poultry Science Association, Inc. Received for publication September 8, 2002. Accepted for publication January 27, 2003. 1 Paper 16972 of the Purdue University Agricultural Programs. 2 To whom correspondence should be addressed: jpatters@ purdue.edu. 627 bacteria (lactobacilli and bifidobacteria) have been implicated as the causative agents for this improved health. Research over the last century has shown that lactic acid bacteria and certain other microorganisms can increase resistance to disease and that lactic acid bacteria can be enriched in the intestinal tract by feeding specific carbohydrates. Increased bacterial resistance to antibiotics in humans has caused an increase in public and governmental interest in eliminating sub-therapeutic use of antibiotics in livestock. An alternative approach to sub-therapeutic antibiotics in livestock is the use of probiotic microorganisms, prebiotic substrates that enrich certain bacterial populations, or synbiotic combinations of prebiotics and probiotics. Research is focused on identifying beneficial bacterial strains and substrates along with the conditions under which they are effective. bacteria in the colon” (Gibson and Roberfroid, 1995). Combinations of prebiotics and probiotics are known as synbiotics. Probiotic and prebiotic foods have been consumed for centuries, either as natural components of food, or as fermented foods. Interest in intestinal microbiology and the dietary use of prebiotics and probiotics blossomed in the late 1800s and early 1900. The growing enthusiasm was motivated Escherich’s isolation of Escherichia coli in the late 1800s, as well as active research on the benefits of feeding lactic acid bacteria and lactose near the turn of the 20th century (Rettger and Cheplin, 1921). Metchnikoff noticed the longevity of Bulgarians who consumed yogurt, and in 1907, he proposed that the indigenous bacteria were harmful and that ingestion of lactic acid bacteria in yogurt had a positive influence on health (Stavric and Kornegay, 1995; Rolfe, 2000). Numerous in vivo and in vitro studies since then have shown that the commensal intestinal microbiota inhibit pathogens, that disturbances of the intestinal microbiota can increase susceptibility to infection, and that addition of prebiotics and probiotics increase resistance to infection (Stavric and Kornegay, 1995; Rolfe, 2000). Intestinal pathogens encounter a multifaceted defense system composed of low gastric pH, rapid transit through sections of the intestinal tract, as well as the intestinal microbiota, epithelium, and immune systems. Although 628 PATTERSON AND BURKHOLDER not reviewed here, there is extensive information on the mucosal immune system (Schat and Myers, 1991; Kitagaw et al., 1998; Mayer, 1998; Muir, 1998; Hershberg and Mayer, 2000; Shanahan, 2000; Erickson and Hubbard, 2000; Jeurissen et al., 2000; Spellberg and Edwards, 2001; Toms and Prowrie, 2001), the intestinal epithelium (Glick, 1995; Fontaine et al, 1996; Dai, et al., 2000; Freitas and Cayuela, 2000; Deplancke and Gaskins, 2001; McCracken and Lorenz, 2001) and their interactions. Stress also has detrimental effects on the immune system and intestinal epithelium (Blecha, 2000; Matteri et al., 2000; Maunder, 2000; Soderholm and Perdue, 2001; Tache et al., 2001) and the neuro-endocrine system is intimately involved in the response of immune and epithelial systems to stress (Cook, 1994; Kohm and Sanders, 2000; Levite, 2001; Petrovsky, 2001). Additionally, there is information on cross-talk between pathogens and epithelial tissues, resulting in extensive rearrangement of epithelial cells upon colonization by pathogens (Goosney et al., 2000; Sansonetti, 2001). Recently, Hooper et al. (2001) have shown that cross-talk between Bacteroides thetaiotaomicron and the epithelium results in epithelial secretion of specific glycans, which are utilized by the bacterium. It is probable that other intestinal bacteria, including probiotic bacteria, may interact with the epithelium in a similar manner to enhance the ability of these microorganisms to colonize the mucosal lining. Intestinal microbial populations have been characterized using classical plating techniques (Savage, 1987; Vahjen et al., 1998; Van der Wielen et al., 2000). Although Bacteroides and Bifidobacterium predominate in the human intestine, Ruminococcus and Streptococcustend to predominate in the chicken intestinal tract (Apajalahti et al., 1998; Van der Wielen et al., 2000). However, recent molecular techniques indicate that only 20 to 50% of the bacterial species present in the intestinal tract have been cultured. Molecular approaches identifying changes in specific bacterial populations or general changes in microbial community structure should enhance our understanding of intestinal microbial ecology, including the influence of probiotics and prebiotics (Apajalahti et al., 1998; Netherwood et al., 1999; Gong et al., 2002; Zhu et al., 2002). The concept of a balanced intestinal microbiota enhancing resistance to infection and reduction in resistance when the intestinal microbiota is disturbed is important in understanding the microbe-host relationship. What constitutes the balanced and disturbed populations is not clear; however, lactobacilli and bifidobacterial species seem to be sensitive to stress, and these populations tend to decrease when a bird is under stress. Proposed mechanisms of pathogen inhibition by the intestinal microbiota include competition for nutrients, production of toxic conditions and compounds (volatile fatty acids, low pH, and bacteroicins), competition for binding sites on the intestinal epithelium, and stimulation of the immune system (Fuller, 1989; Gibson and Fuller, 2000; Rolfe, 2000). These are not mutually exclusive mechanisms, and some microorganisms may effect change with a single mechanism, whereas others may use several mechanisms. TABLE 1. Characteristics of ideal probiotics and prebiotics1 Probiotics Be of host origin Non-pathogenic Withstand processing and storage Resist gastric acid and bile Adhere to epithelium or mucus Persist in the intestinal tract Produce inhibitory compounds Modulate immune response Alter microbial activities Prebiotics Be neither hydrolyzed or absorbed by mammalian enzymes or tissues Selectively enrich for one or a limited number of beneficial bacteria Beneficially alter the intestinal microbiota and their activities Beneficially alter luminal or systemic aspects of the host defense system 1 Adapted from Simmering and Blaut, 2001. PROBIOTICS AND PREBIOTICS Characteristics and effects of ideal probiotics and prebiotics are shown in Tables 1 and 2. Proposed mechanisms by which probiotics and prebiotics act include competition for substrates, production of toxic compounds that inhibit pathogens, and competition for attachment sites. Extensive research conducted with humans and rodent models has shown a reduction in pathogen colonization, alteration of microbial populations, alteration of the immune system, prevention of cancer, and reduction of triglycerides, cholesterol, and odor compounds (ammonia, skatole, indole, p-cresol, and phenol) associated with probiotic and prebiotic use (Walker and Duffy, 1998; Gibson and Fuller, 2000, Simmering and Blaut, 2001). More research and commercial application of probiotics and prebiotics has occurred in Japan and Europe than in the United States.