AGA Abstracts
raises a question about possibility that bacteria other than H.pylori may contribute to carcinogenesis of gastric cancer. However, little is known about the effects of other gastric microbiome
on the occurrence of gastric cancer in human. In this study, based on the hypothesis that
certain microbiome may affect the progression of gastric cancer, we intend to observe the
differences in the distribution of microbiomes in gastric cancer patients and normal patients.
Methods: In this study, gastric mucosa collected by biopsy during ensophagogastroduodenoscopy (EGD) from seven patients with advanced gastric cancer (AGC) and from six noncancerous patients(control group). Gastric biopsies were obtained from the margin of cancer
in cancer patients. In control group, biopsies were done from antrum with normal gastric
mucosal morphology. DNA was extracted from the gastric tissues and 16s rRNA genes were
amplified. They were analyazed by using the molecular profiling approach terminal restriction
fragment length polymorphism (T-RFLP) and cloning and sequencing of 16S rRNA genes
was performed.
Results: Higher number of species was detected in control group, average of 102 species,
compared to the cancer group, average of 72 species. The gastric cancer microbiome was
characterized by reduced microbial diversity compared to that of control group. Many
different bacterial species were found in both groups but distribution was quite different
between the two groups. Fusobacteria was more dominant in cancer group and Rhodoacterales
was found more prominent in control group. The gastric H.pylori was detected only in one
patient from each group.
Conclusion: More diverse gastric microbiome was observed in non-cancerous patients and
composition of species was different between the two groups. These results suggest that
microbial dysbiosis may be involved in gastric carcinogenesis, but it is not yet clear that
microbial transition accelerates carcinogenesis. Further studies should include more detailed
analysis of spatial and temporal composition of gastric microbiome. Better understanding
of microbial differences and changes in healthy and gastric cancer patients could verify the
carcinogenesis of gastric cancer.
in LPS-induced inflammation of colon cancer cell line. Methods: L. johnsonii was isolated
from a human fecal sample, and it was cultured under anaerobic conditions. After cultivation,
the EV was separated and concentrated. WST-1, Nitric Oxide concentrations, and ELISA
were used to measure whether the EV effectiveness. Result: The anti-inflammatory effect
of EV isolated from L. johnsonii was confirmed in Caco-2 cell line. All experiments about
EV treatment were under conditions of LPS-stimulation. When the pre-stimulated colon
cancer cells were treated with the EV, the concentration of NO, inflammatory factor, was
significantly reduced than control. The EV (1ug/ml) treatment group (37.2±6.56 mM/L) had
a 34% lower NO value than the positive control group (55.8±4.70 mM/L). Also, EV (1ug/
ml) treatment group showed significantly reduced the TNF (tumor necrosis factor) level
(15%) and IL-8 (interleukin-8) level (24%). In these conditions, cell viability was not different
between EV treatment group and control group. Conclusion: EV isolated from L. johnsonii
had an anti-inflammatory effect in the LPS-induced inflammation of colon cells. These results
suggested the potential that just EV alone without whole live form probiotics could help
suppress the inflammation of colon.
Su535
LACTOBACILLUS REUTERI AND LACTOBACILLUS RHAMNOSUS GG
DIFFERENTIALLY AFFECT GUT MICROBIOTA AND PLASMA
METABOLITES IN MICE WITH TREG-DEFICIENCY
Yuying Liu, Thomas K. Hoang, Christopher M. Taylor, Evelyn S. Park, Jasmin Freeborn,
Meng Luo, Stefan Roos, J. Marc Rhoads
Background: Treg-deficiency causes a lethal, CD4+ T cell-driven autoimmune disease called
IPEX syndrome in humans and called the scurfy (SF) phenotype in a mouse model of the
disease. Feeding Lactobacillus reuteri DSM 17938 (LR) to SF mice reprograms gut microbiota,
markedly reduces disease progression, and prolongs lifespan. However, the efficacy and
mechanism of LR, compared to other probiotics, in producing these effects is unknown.
Probiotic Lactobacillus rhamnosus GG (LGG) is one of the most widely used and welldocumented probiotic strains, often used to prevent or treat gastrointestinal infections,
antibiotic-associated diarrhea, respiratory infections, and allergies. Objective: To further our
understanding of the specificity of probiotics in modulating autoimmunity, gut microbiota
and plasma metabolites in well-characterized model of Treg-deficiency (SF mice). Methods:
We gavage fed 107 CFU/day of LR or LGG to SF mice daily; starting on d13 after the SF
phenotype was identified. Cecal contents and blood were collected on d22 (before weaning)
for microbiota analysis by 16s rRNA gene sequencing and for plasma global metabolomics
by liquid chromatograpny-mass spectrometry which analyzes 696 metabolites (Metabolon).
Results: LR was more effective than LGG in prolonging survival. Both probiotics increased
the percentage of tolerogenic dendritic cells in the intestinal mucosa, while only LR reduced
inflammatory CD44+ T cells in the mesenteric lymph nodes and circulating blood. Both
probiotics restored the fecal microbial alpha diversity, but they produced distinct fecal
bacterial clusters and differentially modulated microbial relative abundance (RA). LR
increased the RA of Firmicutes, g_Oscillospira while reducing Bacteroidetes, g_Bacteroides
and g_Parabacteroides, reversing changes attributed to the SF phenotype. LGG reduced
primarily the RA of g_Bacteroides. Both LR and LGG reduced the potentially pathogenic
taxon c_Gammaproteobacteria. Plasma metabolomics revealed similar changes of many clusters
of metabolites in SF mice associated with treatment with either LR or LGG. However, some
unique effects of LR included increased inosine metabolites, central energy metabolismglycolysis-tricarboxylic acid (TCA) cycle intermediates, as well as alterations in redox homeostasis, while LGG heavily affected bile acid metabolism. Conclusions: 1) Different probiotics
produce distinct signatures in the fecal microbial community in mice with Treg deficiency.
2) There are many similarities of LR compared to LGG in global plasma metabolites. However,
there are strain-specific microbial products with different anti-inflammatory properties,
reinforcing the concept that “one size does not fit all” in the treatment of autoimmune disease.
Su536
MIXTURES OF LACTOBACILLUS ACIDOPHILUS, LACTOBACILLUS
PLANTARUM, AND BIFIDOBACTERIUM LACTIS MITIGATE a-AMYLASE
INHIBITION BY EXTRACTS OF NON-GLUTEN WHEAT PROTEINS
Tom Fairlie, Anh Do, Ayesha Shah, Mark Morrison, Gerald J. Holtmann
Background:Gluten is associated with food hypersensitivity in adults, however non-gluten
components such as a-Amylase Trypsin Inhibitors (ATI) are known to induce an immune
response, and various bacteria can degrade these ATI’s and reduce inflammatory activity[1].
We explored the interaction between bacterial and non-gluten wheat proteins in pursuit of
development of therapeutic options such as probiotic-containing functional foods. Methods:Non-gluten soluble proteins of plain wheat flour (WE) were extracted with salt solution
following described methods[2]. Saliva from a single volunteer was collected and processed
according to standard protocols[3]. A commercial mixture containing Lactobacillus acidophilus,
Lactobacillus plantarum, and Bifidobacterium lactis was used. For the assays, saliva was diluted
(1/1500.PBS), and then 0.025ml transferred to individual wells of a microtitre plate. Then
0.025ml of either PBS (control, saliva); WE alone (8μg/ml final concentration, WE); or the
probiotic mixture from one capsule resuspended in 2ml PBS (ProB). In parallel, volumes
of WE and the probiotic mixture were mixed and incubated for 12h at 37oC, then 0.025
ml of this mixture was added to 0.025ml saliva (Saliva+ProB+WE). The a-amylase activity
in these preparations was measured immediately via coupled enzymatic assay using commercially available kits. Two biological replicates using the same source of saliva were performed.
Results:Figure 1 shows the a-amylase activity of different mixtures (% of controls). The
added WE reduced a-amylase activity to 8.1%±8.0. Coincubation with the probiotic mixture
mitigated the effect, as the a-amylase activity was 83.3%±2.1. Saliva a-amylase activity was
not altered by the probiotic mixture alone (88.3%±2.7). As such, neither the WE nor the
probiotic mixture has detectable a-amylase activity. Conclusions:Soluble non-gluten proteins
from wheat inhibit saliva a-amylase activity, but the coincubation of this extract with a
commercial probiotic mixture for 12h appears to mitigate these inhibitory effects. Our
findings suggest the ATI in WE were inactivated on exposure to specific probiotic bacterial
Su534
ANTI-INFLAMMATORY EFFECT OF EV (EXTRACELLULAR VESICLES)
ISOLATED FROM LACTOBACILLUS JOHNSONII IN COLON CELL
Dong Ho Lee, Jung-Hyun Kim, Ki Sung Kang, wonsuk Lee, Young Soo Park, Cheol Min
Shin, Hyuk Yoon, Nayoung Kim, Eun Ji Lee, Yoo Jin Kim
Aim: Lactobacillus johnsonii along with other bacterial and mammalian cells releases extracellular membrane vesicles (EV). EV is involved in cell-cell communications in various biological
systems. Cell-cell interactions, especially microbiota-host cell crosstalk are multifunctional
that implicate complex interactions between cells and cellular factors; many of these cellular
factors such as lipids, proteins, nucleic acids, polysaccharides, and various soluble factors
are associated with EVs. It was also reported EVs from Lactobacillus sp. can stimulate the
host immune and nervous systems, enhance the host immune responses against other bacteria.
In this study, we tested whether EV isolated from L. johnsonii has an anti-inflammatory effect
AGA Abstracts
S-730