Screening of probiotic candidates in a simulated piglet small intestine in vitro model.

The CoMiniGut in vitro model mimicking the small intestine of piglets was used to evaluate four probiotic strains for their potential as a preventive measure against development of diarrhea in weaned pigs. In the in vitro system, piglet digesta was inoculated with pathogenic enterotoxigenic Escherichia coli F4 (ETEC F4), and the short-chain fatty acid profile and the gut microbiota composition were assessed. A total of four probiotic strains were evaluated: Enterococcus faecium (CHCC 10669), Lactobacillus rhamnosus (CHCC 11994), Bifidobacterium breve (CHCC 15268) and Faecalibacterium prausnitzii (CHCC 28556). The significant differences observed in metabolite concetration and bacterial enumeration were attributed to variation in inoculating material or pathogen challenge rather than probiotic treatment. Probiotic administration influenced the microbiota composition to a small extend. Learnings from the present study indicate that the experimental setup, including incubation time and choice of inoculating material, should be chosen with care.

The Smallest Intestine (TSI)-a low volume in vitro model of the small intestine with increased throughput.

There is a growing interest in understanding the fate and behaviour of probiotic microorganisms and bioactive compounds during passage of the human gastrointestinal tract (GIT). Here, we report the development of a small volume in vitro model called The smallest Intestine (TSI) with increased throughput focusing on simulating passage through the stomach and small intestine (SI). The basic TSI module consists of five reactors, with a working volume of 12 ml each. During the simulated passage through the SI, bile is absorbed and pH is adjusted to physiologically relevant values for duodenum, jejunum and ileum. A consortium of seven representative bacterial members of the ileum microbiota is included in the ileal stage of the model. The behaviour of three putative probiotic Lactobacillus strains during in vitro simulated upper GIT passage was tested in the model and results were compared to previous studies describing probiotic survival. It was found, that probiotic persistence is strongly related to whether food was ingested, but also to presence of the ileal microbiota, which significantly impacted probiotic survival. In conclusion, TSI allows testing a substantial number of samples, at low cost and short time, and is thus suitable as an in vitro screening platform.