In Vivo Study of the Survival of Lactobacillus delbruecki subsp. bulgaricus CECT 4005T and Streptococcus thermophilus CECT 801 by DVC‐FISH after Consumption of Fermented Milk

Abstract

Direct Viable Count (DVC) method has been recently combined with fluorescent in situ hybridization (FISH) for the specific detection of viable cells of Lactobacillus delbrueckii subsp. bulgaricus CECT 4005T and Streptococcus thermophilus CECT 801. This method has been used to determine their in vitro viability to gastrointestinal juices, being the resistance of L. delbrueckii subsp. bulgaricus and S. thermophilus 26.2% and 9.2%, respectively. On the other hand, an in vivo study has been carried out with the application of this technique for their detection in human feces, after consuming fermented milk. Cells of L. delbrueckii subsp. bulgaricus CECT 4005T were not detected, whereas viable cells of S. thermophilus CECT 801 were detected in a number higher than 10(3) cells per gram in a 30% of the samples after 4 wk of consumption. DVC-FISH is a quick and culture-independent useful method, which has been applied for the 1st time in an in vivo survival study of LAB.

Influence of Different Sterilization Conditions on the Growth and Exopolysaccharide of <i>Streptococcus thermophilus</i> and Co-Cultivation with <i>Lactobacillus delbrueckii</i> subsp. <i>bulgaricus</i> OLL1073R-1

“…Previous reports indicated that the viable cell numbers of S. thermophilus in yogurt were higher than those of L. bulgaricus [15] [16] [24], and bacterial cell numbers of L. bulgaricus in yogurt were increased by stirring during fermentation [25]. Based on these findings, we hypothesize that bacterial cell numbers of L. bulgaricus and S. thermophilus in yogurt depend on cultivation time and environmental conditions.…”

Improving antioxidant properties and probiotic effect of clementine juice inoculated with Lactobacillus salivarius spp. salivarius (CECT 4063) by trehalose addition and/or sublethal homogenisation

“…Values obtained after the whole gastrointestinal simulation were of the same order as those reported for other lactic‐acid bacteria, such as L. delbrueckii spp. bulgaricus and Streptococcus thermophilus inoculated in a lactic substrate, with mean cumulative viabilities around 26.2% and 9.2%, respectively (García‐Hernández et al ., ), or Lactobacillus reuteri inoculated in raw and fried tomato, with mean cumulative viabilities around 24% and 26.3%, respectively (García‐Hernández et al ., ).…”

“…salivarius after both the gastric step (%VIAB ST1 ) and the intestinal step (%VIAB ST2 ) were calculated as the ratio in percentage between the number of living cells leaving and entering each step. In accordance with this, the probiotic resistance to the entire simulated gastrointestinal digestion (%VIAB TOTAL ) was calculated from the product of probiotic viabilities obtained for each of the two steps making up the process (García‐Hernández et al ., ).…”

Tomato-antioxidants enhance viability of L. reuteri under gastrointestinal conditions while the probiotic negatively affects bioaccessibility of lycopene and phenols

“…The in vitro method that simulates the gastrointestinal tract is of great interest to find out whether microorganisms can survive through it (García-Hernández et al, 2012). Before subjecting the bacteria to the effects of the gastrointestinal juices, plate counts from the initial dilution were performed in triplicate, being the result 2.80 x 10 9 (5.84 x 10 8 ) cfu / ml of L. reuteri.…”