Page 12 - Introduction to FMT

FMT Introduction

POTENTIAL THERAPEUTIC ROLE IN EXTRA-INTESTINAL TUMORSOTENTIAL THERAPEUTIC ROLE IN EXTRA-INTESTINAL TUMORS
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A strong association has now been illustrated between the intestinal microbiota (e.g., Streptococcus
bovis, Enterococcus spp, enterotoxigenic Bacteroides fragilis, pathogenic Escherichia coli, and
Fusobacterium nucleatum) and colorectal cancer[108-110]. Recently, incremental data has suggested
that the gut flora (namely Streptococcus bovis and Helicobacter hepaticus) might be involved in extra-
intestinal tumors. Gold et al[15] reviewed 8 extraintestinal malignancies [3 pancreatic adenocarcinomas, 1
lung cancer, 1 ovarian cancer, 1 endometrial cancer, 2 non-solid-organ malignancies (1 chronic
myelogenous leukemia with blast crisis and 1 chronic lymphocytic leukemia with end-stage liver disease)]
in 45 cases with Streptococcus bovis bacteremia in a retrospective study, which suggested that
extraintestinal malignancy might be warranted in patients with Streptococcus bovis. In addition, prior
work has shown the gut microbiota is also involved in mammary tumors[111,112]. The authors infected
recombination-activating gene 2-deficient multiple intestinal neoplasia (Apc ) mice with Helicobacter
hepaticus and found the gut flora modulated the carcinogenesis of both mammary carcinoma and
intestinal adenocarcinoma in females by triggering inflammatory responses. On a similar note, Rao et
al[113] emphasized the question as to whether the gut bacteria should be examined in terms of prevention
and treatment for mammary cancer.

In addition, Fox et al[114] used a mouse model to examine the hypothesis that specific intestinal bacteria
were associated with hepatocarcinogenesis. The progress of hepatocellular carcinoma induced by
aflatoxin and hepatitis C transgene was promoted by Helicobacter hepaticus colonization in the intestine
through activation of the nuclear factor-κB pathway, which was associated with immunity in the intestine
and liver. Surprisingly, neither hepatitis nor bacterial translocation to the liver was essential during this
course. These results lead us to think of intestinal bacteria as an attractive therapeutic target.

More recently, Yamamoto et al[115] investigated the relationship between the gut microbiota and
lymphoma. Using an Atm mouse model (mice with ataxia-telangiectasia, which can eventually developed
into lymphoma), the authors compared the incidence of lymphoma in isogenic mice reared in 2 distinct
housing conditions, and found that the gut microbiota acted as a potential contributor to lymphoma
onset. Meanwhile, Lactobacillus johnsonii was identified to be abundant in more cancer- resistant mice
and was further tested for its ability to confer reduced systemic inflammation and genotoxicity when re-
established by oral transfer. Given that gut microbiota impact lymphoma incidence and latency, FMT
holds promise for reducing lymphoma risk in susceptible individuals.

CONCLUSION

FMT is proven to be a well-established procedure and the most effective therapy for recurrent CDI to
date. Case studies suggest that FMT also has potential clinical applications in treating a wide spectrum
of other conditions associated with intestinal dysbiosis. However, additional high quality data are urgently
needed to further establish the efficacy of FMT. It is expected that the standardization of FMT will be
established in the coming years and its indications expanded. For this reason, besides conventional
approaches, FMT is promising as an alternative therapy for many extra-intestinal disorders associated
with gut microbiota.

P- Reviewer: Blanco LP, Krishnan T S- Editor: Gou SX L- Editor: Rutherford A E- Editor: Wang CH

FMT Introduction