Probiotics

Patient Education

Definition

Probiotic has been defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host" as determined by an expert panel convened by the FAO¹.

Actions of probiotics

Probiotic bacteria benefit the host by adhering to the gut epithelium, stimulating host immune response, inhibiting epithelial and mucosal adherence of pathogens and producing antimicrobial substances². Probiotics have the potential to impact physiologic and metabolic parameters which are influenced by normal indigenous microbes, such as immune system maturation, gut barrier function, levels of metabolic end-products available to alter luminal conditions or serve as substrates to epithelial cells, binding or degradation of potential carcinogens, enzymatic alteration of bile acids and competitive exclusion.³

Uses of probiotics

There has been increasing evidence in the last decade for the efficacy of probiotic agents in the treatment of acute diarrhea², persistent diarrhea⁴, and prevention of antibiotic-associated diarrhea⁵. Other benefits that have been documented are regulation of immune function,⁶ prevention of infection,⁷ prolongation of remission in patients with inflammatory bowel conditions,⁸ reduction of incidence of atopic dermatitis in high-risk infants,⁹ control of symptoms associated with lactose intolerance,¹⁰ decreasing symptoms for irritable bowel syndrome,¹¹ prevention of Helicobacter pylori colonization,¹² vaginal microbiota restoration,¹³ improve growth parameters in undernourished children,¹⁴ decrease incidence of dental caries,¹⁵ and respiratory infections.¹⁶

It should be remembered that these effects have been observed for only one or a limited number of strains and other strains of even the same species cannot be presumed to demonstrate the same effects.³

Common probiotics used

Members of the genera Lactobacillus and Bifidobacterium are mainly used as probiotics in food supplements, but not exclusively, as probiotic microorganisms and a growing number of probiotic foods are available to the consumer.¹

Bifidobacterium

Bifidobacterium species have a long history of safe use when consumed as part of food and supplement products.¹⁷ No cases of clinical infection have been reported from such use. The species generally used for such applications are longnum, infantis, breve, bifidum, adolescents, and animals (both subspecies lactis and animals).³

Lactobacillus

Lactobacillus converts lactose and other sugars to lactic acid. The genus Lactobacillus currently consists of over 125 species and encompasses a wide variety of organisms. According to metabolism, the commonly used lactobacilli as probiotics are lactobacillus acidophilus, lactobacilli casei.

Safety

Probiotics should not be given to children who are seriously or chronically ill until the safety of administration has been established. With the exception of one strain belonging to the L. rhamnosus species, lactobacilli and bifidobacteria used for food production are "generally recognized as safe" (GRAS) by the Food and Drug Administration of the USA. The two strains of lactobacilli and bifidobacteria are classified as absolutely safe.¹⁸