Review article: bifidobacteria as probiotic agents – physiological effects and clinical benefits

Abstract

Summary Bifidobacteria, naturally present in the dominant colonic microbiota, represent up to 25% of the cultivable faecal bacteria in adults and 80% in infants. As probiotic agents, bifidobacteria have been studied for their efficacy in the prevention and treatment of a broad spectrum of animal and/or human gastrointestinal disorders, such as colonic transit disorders, intestinal infections, and colonic adenomas and cancer. The aim of this review is to focus on the gastrointestinal effects of bifidobacteria as probiotic agents in animal models and man. The traditional use of bifidobacteria in fermented dairy products and the GRAS (‘Generally Recognised As Safe’) status of certain strains attest to their safety. Some strains, especially Bifidobacterium animalis strain DN‐173 010 which has long been used in fermented dairy products, show high gastrointestinal survival capacity and exhibit probiotic properties in the colon. Bifidobacteria are able to prevent or alleviate infectious diarrhoea through their effects on the immune system and resistance to colonization by pathogens. There is some experimental evidence that certain bifidobacteria may actually protect the host from carcinogenic activity of intestinal flora. Bifidobacteria may exert protective intestinal actions through various mechanisms, and represent promising advances in the fields of prophylaxis and therapy.

Inter-species transplantation of gut microbiota from human to pigs

“…Bifidobacteria is the third most common genus in the human intestine, constituting about 3% of the adult fecal flora and more than 75% of the infant fecal flora (Langendijk et al, 1995;Franks et al, 1998;Harmsen et al, 2000). Moreover, some strains of bifidobacteria have been used as probiotics to modulate the human intestinal ecosystem due to the many health-promoting properties of these bacteria (Picard et al, 2005). Bacteroides spp is the most dominant group of the normal indigenous flora in the human gut comprising more than 25% of the total bacteria in human feces (Wilson et al, 1997;Suau et al, 1999;Sghir et al, 2000).…”

Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: A pilot study

“…The colonic transit assessment also showed that kefir is associated with the acceleration of colonic transit in patients with slow transit (ST group). Several studies have shown that probiotics can improve colonic transit times in a healthy population (28) and in constipated patients (29,30). Cardosa et al (31) reported that kefir could enhance intestinal transit in Wistar rats.…”

“…Although the exact mechanisms of how probiotics accelerate intestinal transit are still unclear, it has been proposed that probiotics lower the pH in the colon by producing lactic acid, acetic acid, and other acids. These effects result in enhanced peristalsis and, subsequently, in decreased colonic transit time (28,32).…”

Preparation of Selenium-enriched Bifidobacterium Longum and its Effect on Tumor Growth and Immune Function of Tumor-Bearing Mice

“…Bifidobacterium longum (B. longum) is a lactic acidproducing bacterium that grows naturally in the human gastrointestinal tract and defends the host against viral infection (Otles et al, 2003;Picard et al, 2005). As an anaerobe, B. longum can selectively germinate and proliferate in the hypoxic regions of solid tumors (Yazawa et al, 2000).…”