Article

Lactobacillus plantarum Promotes Drosophila Systemic Growth by Modulating Hormonal Signals through TOR-Dependent Nutrient Sensing

Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR 6216/Aix-Marseille Universités, 13288 Marseille, France.
Cell metabolism (Impact Factor: 17.57). 09/2011; 14(3):403-14. DOI: 10.1016/j.cmet.2011.07.012
Source: PubMed

ABSTRACT

There is growing evidence that intestinal bacteria are important beneficial partners of their metazoan hosts. Recent observations suggest a strong link between commensal bacteria, host energy metabolism, and metabolic diseases such as diabetes and obesity. As a consequence, the gut microbiota is now considered a "host" factor that influences energy uptake. However, the impact of intestinal bacteria on other systemic physiological parameters still remains unclear. Here, we demonstrate that Drosophila microbiota promotes larval growth upon nutrient scarcity. We reveal that Lactobacillus plantarum, a commensal bacterium of the Drosophila intestine, is sufficient on its own to recapitulate the natural microbiota growth-promoting effect. L. plantarum exerts its benefit by acting genetically upstream of the TOR-dependent host nutrient sensing system controlling hormonal growth signaling. Our results indicate that the intestinal microbiota should also be envisaged as a factor that influences the systemic growth of its host.

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    • "Since wild flies develop in and consume decomposed fruit, ethanol is likely a common constituent of their environment. As ethanol is a fuel source for Acetobacter, a prominent fly commensal that modifies insulin and TOR signals in the midgut (Shin et al., 2011;Storelli et al., 2011), it remains possible that the lifespan extension we see from ethanol depends on the microbiota.Since we observed benefits from glucose independent of the microbiota, we were interested in the host response to glucose that extends lifespan. High dietary glucose lowers insulin sensitivity in flies (Musselman et al., 2011), and decreased insulin activity in the gut increases lifespan in the fly (Biteau et al., 2010). "
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    • "Using the FlyAtlas tool, we identified that most of these peptidases have a basal expression level enriched in both the adult and larval midguts of the conventional individuals (CONV; i.e, carrying commensal microbes), a signature confirmed in adult midguts by RT-qPCR (Erkosar et al., 2014). Since we hypothesized that Lp WJL may exert its growth-promoting activity during juvenile development by enhancing protein assimilation in the host (Storelli et al., 2011), this observation prompted us to investigate the expression of these peptidase genes by time course RT-qPCR in larval midguts of GF or Lp WJL -associated individuals on a low-nutrition diet (see Figure 1A for detailed experimental scheme). We found the expression profile of 7 peptidases (Jon66Cii, Jon66Ci, Jon44E, Jon65Ai, Jon99Ci, CG18179, and CG18180) presents a robust and detectable transcriptional signature during larval development (Figures 1B–1I). "
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    • "Similarly, Storelli et al. (2011) showed that infection by Lactobacillus plantarum correlates with upregulated IIS pathway when comparing to GF flies. L. plantarum exhibits growth-promoting effect in L. plantarum-monoassosiated D. melanogaster (Storelli et al. 2011). This indicates that L. plantarum may be required for normal body size in D. melanogaster. "
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