Lactobacillus casei Shirota for influencing the microbiome of patients with Barrett's esophagus.

Barrett*s esophagus (BE) is a premalignant condition, in which the normal
squamous epithelium is replaced by intestinal epithelium. BE is the most
important risk factor for the development of esophageal adenocarcinoma (EAC).
EAC has very low survival rates; a 5-year survival of 25% for non-metastatic
disease and a 2-year survival of 9% for metastatic disease.
The most important risk factor for developing BE is gastro-esophageal reflux
disease (GERD). It is believed that the abberrant chronic immune response in BE
leads to the induction of dysplasia and finally EAC. Comparison of the
microbiome of healty individuals, GERD patients and BE patients has resulted in
the finding that BE was associated with a microbiome containing more Gr-
bacteria compared to healthy individuals and GERD patients. In contrast to Gr+
bacteria, Gr- bacteria carry large numbers of lipopolysacharides (LPS) in their
cell wall, and LPS molecules are strong stimulators of the Th2 immune response.
The observation of an increased load of Gr- in previous studies has led to the
hypothesis that there is a potential contribution of these Gr- bacteria to the
chronic inflammatory response in BE by activating the LPS/TLR4/NF-kB pathway.
Restoring the Gr+/Gr- bacterial ratio with Lactobacillus casei Shirota (LcS)
may revert the activation of the pro-inflammatory pathway and reduces the risk
of neoplastic progression. Earlier studies with LcS have suggested that the LcS
bacterium may be capable of influencing the environment in the esophagus.

Primary objectives
To study if LcS can colonize the esophagus of BE patients.
To study the effect of LcS colonization on the Gr+ (except for LcS)/ Gr-
bacterial ratio of the esophagus.

Secondary objectives
To quantify the number of specific pathogenic bacteria
To explore the effect of restoration of the Gr+/Gr- bacterial ratio on the
Th1/Th2 response and the associated cytokines
To explore a change in the clinical endpoint inflammation as seen during
endoscopy

The study is a single-arm, interventional pilot study to investigate the
possibility of changing the esophageal microbiome by ingestion of a fermented
milk drink containing LcS in patients who undergo Barrett surveillance at het
Radboud University Medical Center, Nijmegen.
The study will be introduces to the patients by the treating physician. The
actial inclusion will be performed by the research physician who will further
inform the patients. Informed consent is signed in the presence of the research
physician.

At baseline (day 0) patients will undergo an endoscopy with biopsy sampling.
Besides from the biopsies needed for histological evaluation as standard care,
biopsies for study purposes will be taken.
Subsequently the intervention period of 4 week starts (day 1-28). Patients will
be drinking two 65ml bottles per day of Yakult, a fermented milk drink
containing at least 6.5*10^9 LcS bacteria. During the intervention period,
patients will not take any (other) probiotics. If a patient needs antibiotic
therapy, they will be excluded from the study. The intervention period will be
continued until the last evening prior to the endoscopy.
After the intervention (day 29), all patients will again undergo an endoscopy
for the collection of biopsies (6 from BE, 6 from squamous epithelium).

Patients will be drinking 2 bottles per day of a LcS containing drink (Yakult),
for a period of 4 weeks.

The risks associated with participation are considered to be negligible.

Patients who will participate in the study will undergo two endoscopies with
biopsy sampling.The first endoscopy is part of the routine surveillance
programme (standard care). Additional biopsies will be collected for study
purposes, this will extend the procedure for 5 minutes.Taking biopsies is
associated with a very low risk of secondary bleeding or perforation.
Therefore, the risk of taking additional biopsies is considered to be minimally
increased.
The second endoscopy is not standard care. However, the risk of an endoscopy is
considered extremely low. Complications are rare during and after upper
ensdoscopy (1-2 : 1000 patients). The most common complain after the procedure
is a sore throat. Major complications such as an upper gastrointestinal
bleeding and perforation are rare (0.1% and 0.0001%, respectively).

During the intervention period, Yakult will be supplemented to the diet of the
patients. Yakult is commercially available since 1994 in the Netherlands and no
adverse events have been reported with the consumption of this product by
healthy volunteers. Furthermore, there is no report on complications of the
consumption of Yakult by BE patients. Given the fact that both Yakult
consumption and BE are common in the Western countries, it is safe to assume
that if such an adverse effect existed, it would probably have been noticed
already.