Does yogurt enriched with Bifidobacterium longum affect colonic microbiology and fecal metabolites in healthy subjects?

Abstract

Diet-induced changes in the colonic microflora seem to play a role in colon carcinogenesis. In this study the effects of a yogurt (500 mL/d for 3 wk) enriched with Bifidobacterium longum and 5 g lactulose/L (A) on the fecal bacterial flora and various risk indexes for colon carcinogenesis were tested in 12 healthy volunteers and compared with a conventional yogurt (B). Increased excretion of bifidobacteria (P < 0.017) was found after consumption of both yogurts compared with the prestudy periods, whereas cultural counts of aerobes and anaerobes were not different. Breath-hydrogen exhalation was elevated and mouth-to-cecum transit time was accelerated in the period of yogurt A ingestion (P < 0.05) whereas no differences were found for oral-anal mean transit time, stool weight and pH, and fecal concentrations of short-chain fatty acids, bile acids, and neutral sterols. The results generally indicate great stability of the human fecal flora to this kind of dietary intervention.

Effects of Consumptionof a Milk Fermented by the Probiotic Strain Bifidobacterium animalis DN-173 010 on Colonic Transit Times in Healthy Humans

“…decreased metabolism of primary bile acids. Modulation of the activity (3,7,9,19,29) and composition (6,14,29) of the gut flora by ingestion of large number of living bifidobacteria have already been documented. Similar data have been obtained with the strain Bifidobacterium animalis DN-173 010 on the microbial enzyme activities (1, 11) and on the fecal microflora composition (11,13).…”

Increased probiotic yogurt or resistant starch intake does not affect isoflavone bioavailability in subjects consuming a high soy diet

“…This level of bacterial activity should be sufficient to affect gut microfloral balance as probiotic effects in the gastrointestinal tract have been reported with minimum daily doses of between 10 8 and 10 9 viable cells (13,(23)(24)(25). Oral administration of these probiotic bacteria results in increased populations in the human gastrointestinal tract and faeces (25)(26)(27)(28)(31)(32)(33)(34)(35) and increased fecal β-glucosidase activity (36). Such increases in lactobacilli and bifidobacteria intake and concomitant enhancement in intestinal β-glucosidase activity would be expected to enhance initial hydrolysis and absorption of dietary isoflavone glycosides.…”

Yogurt in the diet of the elderly: a preliminary investigation into its effect on the gut ecosystem and lipid metabolism

“…Other authors have observed an increase in the counts of bifidobacteria in children and young adults [2,8] and of enterococci [17] in children, after yogurt administration. Table V shows the percentage of faecal moisture and the parameters measured on faecal water.…”

“…Previous studies [5][6][7]35] have already demonstrated that yogurt administration positively influences the equilibrium of the intestinal microbiota and the various metabolic activities related to the physiopathology of the host. Various effects have been observed in both man and animals following the ingestion of yogurt bacteria: increased numbers of indigenous lactic acid bacteria and bifidobacteria, alleviation of lactose maldigestion and stimulation of both immunity and antitumoral activity [2,8,22,31].…”

“…The aim of this research was to study the mid-term influence of daily consumption of fruit yogurt on the intestinal ecosystem of the elderly, evaluating the effect on microflora composition and some of the microflora biochemical activities, as already investigated in children and adults [2,8,17]. The investigation concerned the effect of yogurt in modulating colonic microflora and in influencing some metabolic pathways with colonic location (such as the conversion of primary to secondary bile acids, faecal bile acids and cytotoxicity of faecal water), parameters known to affect the health of colonic mucosa [25,32,34].…”