Simulating colonic survival of probiotics in single-strain products compared to multi-strain products

Abstract

Background: Probiotic formulations can be single- or multi-strain. Commercially, multi-strain preparations have been suggested to have improved functionality over single-strain cultures. Probiotics are often tested as single-strain preparations but may subsequently be commercially formulated as multi-strain products. Objective: The aim of this study was to determine what happens at the site of action, the intestine, with probiotics as single- compared to multi-strain preparations. The human gastrointestinal tract contains a broad mixture of different microbes which may affect the survival of different probiotics in different ways. Design: The current study was performed to evaluate, in an in vitro colon simulation, whether probiotics influence each other’s survival when they are taken as a combination of several strains (HOWARU Restore; Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bl-04 and B. lactis Bi-07) compared to the strains as single preparations. Results: All strains could be detected after the colon simulations and there were no substantial differences in levels of the same strain when comparing single- and multi-strain products. Conclusions: It can be concluded that probiotics do not have an antagonistic effect on each other’s survival when used in a multi-strain product compared to a single-strain product, at least within a microbiota in a simulated colonic environment.

Dose-Response Recovery of Probiotic Strains in Simulated Gastro-Intestinal Passage

“…The simulations had a relatively high background level of endogenous L. acidophilus. They were nevertheless within the range of 10 4 -10 7 gene copies per gram, as we have observed before [3,17]. This explains why the low dose did not increase the levels of L. acidophilus as compared to the control and the placebo.…”

“…There are indications that in some cases multi-strain formulations may be more beneficial than single-strain products, but the evidence is, again, limited [2]. We have shown earlier, in simulated digestion experiments, that in multi-strain formulations strains do not negatively impact each other as compared to the single strains [3]. The aim of the current study was to determine to what extent strains in a multi-strain probiotic formulation at two different doses survive simulated digestion.…”

“…The simulations were continued for 48 h, after which the fecal slurry samples from all vessels were collected. At this point, the volumes in the vessels were 6, 8, 10, and 12 mL [3].…”

“…The quantity of extracted DNA was determined by a Qubit ® dsDNA HS Assay Kit (Thermo Fisher Scientific, Vantaa, Finland). Strain and/or species-specific qPCR were performed for the probiotics from all vessels (V1-V4) of all simulations on 7500FAST real-time PCR instruments (Applied Biosystems, Waltham, MA, USA), using FAST protocols and SYBR or Taqman chemistries [3]. Primer sequences and annealing temperatures are presented in Table 1.…”

“…The assumption is that a combination of strains leads to improved efficacy, although this is not always clear from the literature [2]. However, we have recently shown that negative interactions should not be expected between strains in a product [3]. What is less documented is whether there is a benefit from using higher doses.…”