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Gut microbiome derived metabolites modulate intestinal epithelial cell damage and mitigate Graft-versus-Host Disease

View Article: PubMed Central - PubMed

ABSTRACT

The impact of alterations in intestinal microbiota on microbial metabolites and on disease processes, such as graft-versus-host disease (GVHD), is not known. Here we performed unbiased analysis to identify novel alterations in gastrointestinal microbiota-derived short chain fatty acids (SCFA) after allogeneic bone marrow transplant (allo-BMT). Alterations in the amounts of only one SCFA, butyrate, were observed only within the intestinal tissue. The reduced butyrate in CD326+ intestinal epithelial cells (IECs) after allo-BMT resulted in decreased histone acetylation, which was restored upon local administration of exogenous butyrate. Butyrate restoration improved IEC junctional integrity, decreased apoptosis, and mitigated GVHD. Furthermore, alteration of the indigenous microbiota with 17 rationally selected strains of high butyrate producing Clostridia also decreased GVHD. These data demonstrate a heretofore unrecognized role of microbial metabolites and suggest that local and specific alteration of microbial metabolites has direct salutary effects on GVHD target tissues and can mitigate its severity.

No MeSH data available.


Allogeneic BMT reduces IEC intracellular butyrate(a) Fatty acid levels (short and long chain) on day 7 in the intestinal luminal contents (stool) and (b) in the intestinal tissue of recipients of syngeneic BMT (BALB/c → BALB/c), allogeneic BMT (C57BL/6J → BALB/c), or no BMT (N - naive). Graphical results of all animals combined are shown below heatmaps for SCFAs butyrate, propionate, and acetate. Representative heatmaps are shown of n = 10 animals in naive and syngeneic groups and n = 9 in allogeneic group. *P < .05; **P < .01 of ANOVA test. Bars and error bars represent the means and standard errors of the mean, respectively.
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Figure 1: Allogeneic BMT reduces IEC intracellular butyrate(a) Fatty acid levels (short and long chain) on day 7 in the intestinal luminal contents (stool) and (b) in the intestinal tissue of recipients of syngeneic BMT (BALB/c → BALB/c), allogeneic BMT (C57BL/6J → BALB/c), or no BMT (N - naive). Graphical results of all animals combined are shown below heatmaps for SCFAs butyrate, propionate, and acetate. Representative heatmaps are shown of n = 10 animals in naive and syngeneic groups and n = 9 in allogeneic group. *P < .05; **P < .01 of ANOVA test. Bars and error bars represent the means and standard errors of the mean, respectively.

Mentions: We hypothesized that alterations in the composition of the microbiota in the GI lumen would result in an altered microbial metabolome after GVHD4,18. We determined the concentration of microbial FA metabolites, both short-chain FAs and long-chain FAs up to 18 carbons in length, from several sites seven days (day +7) after BMT. We analyzed the serum, spleen, liver, intestines, and luminal contents (stool) of the intestines with gas chromatography mass spectrometry (GC/MS) (Supplementary Fig. 1a). We utilized a well-established, clinically relevant model of MHC-mismatched BMT with C57BL/6J (H-2b) cells transferred to lethally irradiated Balb/c (H-2d) mice and compared it to syngeneic transplant and naive animals. The animal cages were exchanged on day 3 to take any alterations in the microbial environment into account, and analysis following GC/MS was performed in a blinded manner. The concentrations of the FAs were not significantly different in the luminal contents of the intestines between any of the groups (Fig. 1a and Supplementary Fig. 1b). They were also not significantly different in the serum or the tissues such as the spleen and liver of allogeneic animals (Supplementary Fig. 1c and Supplementary Table 1) compared with syngeneic animals and naive controls. However, the greatest and the only statistically significant difference was observed in just one SCFA, butyrate, which was significantly decreased only in the intestinal tissue at day 7 (Fig. 1b and Supplementary Fig. 1d). We once again observed similar results on day 21 as on day 7 (Supplementary Fig. 2). Collectively these data demonstrate that butyrate levels are consistently reduced only in the intestinal tissue after allo-BMT.


Gut microbiome derived metabolites modulate intestinal epithelial cell damage and mitigate Graft-versus-Host Disease
Allogeneic BMT reduces IEC intracellular butyrate(a) Fatty acid levels (short and long chain) on day 7 in the intestinal luminal contents (stool) and (b) in the intestinal tissue of recipients of syngeneic BMT (BALB/c → BALB/c), allogeneic BMT (C57BL/6J → BALB/c), or no BMT (N - naive). Graphical results of all animals combined are shown below heatmaps for SCFAs butyrate, propionate, and acetate. Representative heatmaps are shown of n = 10 animals in naive and syngeneic groups and n = 9 in allogeneic group. *P < .05; **P < .01 of ANOVA test. Bars and error bars represent the means and standard errors of the mean, respectively.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4836986&req=5

Figure 1: Allogeneic BMT reduces IEC intracellular butyrate(a) Fatty acid levels (short and long chain) on day 7 in the intestinal luminal contents (stool) and (b) in the intestinal tissue of recipients of syngeneic BMT (BALB/c → BALB/c), allogeneic BMT (C57BL/6J → BALB/c), or no BMT (N - naive). Graphical results of all animals combined are shown below heatmaps for SCFAs butyrate, propionate, and acetate. Representative heatmaps are shown of n = 10 animals in naive and syngeneic groups and n = 9 in allogeneic group. *P < .05; **P < .01 of ANOVA test. Bars and error bars represent the means and standard errors of the mean, respectively.
Mentions: We hypothesized that alterations in the composition of the microbiota in the GI lumen would result in an altered microbial metabolome after GVHD4,18. We determined the concentration of microbial FA metabolites, both short-chain FAs and long-chain FAs up to 18 carbons in length, from several sites seven days (day +7) after BMT. We analyzed the serum, spleen, liver, intestines, and luminal contents (stool) of the intestines with gas chromatography mass spectrometry (GC/MS) (Supplementary Fig. 1a). We utilized a well-established, clinically relevant model of MHC-mismatched BMT with C57BL/6J (H-2b) cells transferred to lethally irradiated Balb/c (H-2d) mice and compared it to syngeneic transplant and naive animals. The animal cages were exchanged on day 3 to take any alterations in the microbial environment into account, and analysis following GC/MS was performed in a blinded manner. The concentrations of the FAs were not significantly different in the luminal contents of the intestines between any of the groups (Fig. 1a and Supplementary Fig. 1b). They were also not significantly different in the serum or the tissues such as the spleen and liver of allogeneic animals (Supplementary Fig. 1c and Supplementary Table 1) compared with syngeneic animals and naive controls. However, the greatest and the only statistically significant difference was observed in just one SCFA, butyrate, which was significantly decreased only in the intestinal tissue at day 7 (Fig. 1b and Supplementary Fig. 1d). We once again observed similar results on day 21 as on day 7 (Supplementary Fig. 2). Collectively these data demonstrate that butyrate levels are consistently reduced only in the intestinal tissue after allo-BMT.

View Article: PubMed Central - PubMed

ABSTRACT

The impact of alterations in intestinal microbiota on microbial metabolites and on disease processes, such as graft-versus-host disease (GVHD), is not known. Here we performed unbiased analysis to identify novel alterations in gastrointestinal microbiota-derived short chain fatty acids (SCFA) after allogeneic bone marrow transplant (allo-BMT). Alterations in the amounts of only one SCFA, butyrate, were observed only within the intestinal tissue. The reduced butyrate in CD326+ intestinal epithelial cells (IECs) after allo-BMT resulted in decreased histone acetylation, which was restored upon local administration of exogenous butyrate. Butyrate restoration improved IEC junctional integrity, decreased apoptosis, and mitigated GVHD. Furthermore, alteration of the indigenous microbiota with 17 rationally selected strains of high butyrate producing Clostridia also decreased GVHD. These data demonstrate a heretofore unrecognized role of microbial metabolites and suggest that local and specific alteration of microbial metabolites has direct salutary effects on GVHD target tissues and can mitigate its severity.

No MeSH data available.