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Impact of a Complex Food Microbiota on Energy Metabolism in the Model Organism Caenorhabditis elegans.

Zanni E, Laudenzi C, Schifano E, Palleschi C, Perozzi G, Uccelletti D, Devirgiliis C - Biomed Res Int (2015)

Bottom Line: Little is currently known about the mechanisms underlying the effects exerted by foodborne microbes.Altered expression of nhr-49, pept-1, and tub-1 genes, associated with obesity phenotypes, was demonstrated by RT-qPCR.Since several pathways are evolutionarily conserved in C. elegans, our results highlight the nematode as a valuable model system to investigate the effects of a complex microbial consortium on host energy metabolism.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.

ABSTRACT
The nematode Caenorhabditis elegans is widely used as a model system for research on aging, development, and host-pathogen interactions. Little is currently known about the mechanisms underlying the effects exerted by foodborne microbes. We took advantage of C. elegans to evaluate the impact of foodborne microbiota on well characterized physiological features of the worms. Foodborne lactic acid bacteria (LAB) consortium was used to feed nematodes and its composition was evaluated by 16S rDNA analysis and strain typing before and after colonization of the nematode gut. Lactobacillus delbrueckii, L. fermentum, and Leuconostoc lactis were identified as the main species and shown to display different worm gut colonization capacities. LAB supplementation appeared to decrease nematode lifespan compared to the animals fed with the conventional Escherichia coli nutrient source or a probiotic bacterial strain. Reduced brood size was also observed in microbiota-fed nematodes. Moreover, massive accumulation of lipid droplets was revealed by BODIPY staining. Altered expression of nhr-49, pept-1, and tub-1 genes, associated with obesity phenotypes, was demonstrated by RT-qPCR. Since several pathways are evolutionarily conserved in C. elegans, our results highlight the nematode as a valuable model system to investigate the effects of a complex microbial consortium on host energy metabolism.

No MeSH data available.


Related in: MedlinePlus

Biodiversity of nematode intestinal microbiota. Rep fingerprinting profiles of bacterial colonies randomly chosen after plating MBC homogenates used to feed worms (a) or nematode intestinal lysates at L4 stage (b) and 8 days of adulthood (c) following LAB microbiota supplementation. Arabic numerals indicate each isolate, while roman numerals or letters identify rep groups. M: 1 kb DNA ladder, Promega. Only representative rep groups are shown in panels a and c.
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fig7: Biodiversity of nematode intestinal microbiota. Rep fingerprinting profiles of bacterial colonies randomly chosen after plating MBC homogenates used to feed worms (a) or nematode intestinal lysates at L4 stage (b) and 8 days of adulthood (c) following LAB microbiota supplementation. Arabic numerals indicate each isolate, while roman numerals or letters identify rep groups. M: 1 kb DNA ladder, Promega. Only representative rep groups are shown in panels a and c.

Mentions: A more in-depth analysis concerned strain typing of a representative number of isolates, ranging from 20 to 40 colonies, performed at time point 0 (representing the initial microbial LAB consortium used to feed the worms), as well as at different nematode stages (representing the intestinal microbial community of C. elegans fed MBC microbiota). In this latter case, worms supplemented until L4 stage or 8 days of adulthood with cheese microbiota were washed and lysed, and the resulting lysates were plated on MRS in order to isolate bacterial colonies. Strain typing was carried out by rep fingerprinting (see Section 2) and the results are shown in Figure 7. Isolates displaying the same fingerprinting profile were assigned to a single rep group. Rep-PCR amplification identified 8 distinct rep groups, out of 28 isolates analyzed, at time point 0 h (Figure 7(a)), while at L4 stage (Figure 7(b)) and at 8 d (Figure 7(c)) 8 rep groups, out of 40 isolates analyzed, and 3 rep groups, out of 34, were identified, respectively. Only representative rep groups are shown in Figures 7(b) and 7(c). Species assignments were defined on the basis of sequencing results (see Section 2) or restriction digestion (data not shown) of 16S rDNA amplified from representative isolates. Correlations between the species and rep groups, as well as their distribution in the worm gut at different stages or at time point 0, are summarized in Table 2. Overall, we observed an equal distribution of L. delbrueckii, L. fermentum, and Leuc. lactis in the initial microbial consortium, while a progressive decreasing of Leuc. lactis was observed in the worm gut microbial community at the observed time points. In particular, only L. fermentum and L. delbrueckii were recovered from nematode lysates at 8 days of adulthood, with a prevalence of the L. delbrueckii species (28 isolates out of 34) (Table 2).


Impact of a Complex Food Microbiota on Energy Metabolism in the Model Organism Caenorhabditis elegans.

Zanni E, Laudenzi C, Schifano E, Palleschi C, Perozzi G, Uccelletti D, Devirgiliis C - Biomed Res Int (2015)

Biodiversity of nematode intestinal microbiota. Rep fingerprinting profiles of bacterial colonies randomly chosen after plating MBC homogenates used to feed worms (a) or nematode intestinal lysates at L4 stage (b) and 8 days of adulthood (c) following LAB microbiota supplementation. Arabic numerals indicate each isolate, while roman numerals or letters identify rep groups. M: 1 kb DNA ladder, Promega. Only representative rep groups are shown in panels a and c.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4417589&req=5

fig7: Biodiversity of nematode intestinal microbiota. Rep fingerprinting profiles of bacterial colonies randomly chosen after plating MBC homogenates used to feed worms (a) or nematode intestinal lysates at L4 stage (b) and 8 days of adulthood (c) following LAB microbiota supplementation. Arabic numerals indicate each isolate, while roman numerals or letters identify rep groups. M: 1 kb DNA ladder, Promega. Only representative rep groups are shown in panels a and c.
Mentions: A more in-depth analysis concerned strain typing of a representative number of isolates, ranging from 20 to 40 colonies, performed at time point 0 (representing the initial microbial LAB consortium used to feed the worms), as well as at different nematode stages (representing the intestinal microbial community of C. elegans fed MBC microbiota). In this latter case, worms supplemented until L4 stage or 8 days of adulthood with cheese microbiota were washed and lysed, and the resulting lysates were plated on MRS in order to isolate bacterial colonies. Strain typing was carried out by rep fingerprinting (see Section 2) and the results are shown in Figure 7. Isolates displaying the same fingerprinting profile were assigned to a single rep group. Rep-PCR amplification identified 8 distinct rep groups, out of 28 isolates analyzed, at time point 0 h (Figure 7(a)), while at L4 stage (Figure 7(b)) and at 8 d (Figure 7(c)) 8 rep groups, out of 40 isolates analyzed, and 3 rep groups, out of 34, were identified, respectively. Only representative rep groups are shown in Figures 7(b) and 7(c). Species assignments were defined on the basis of sequencing results (see Section 2) or restriction digestion (data not shown) of 16S rDNA amplified from representative isolates. Correlations between the species and rep groups, as well as their distribution in the worm gut at different stages or at time point 0, are summarized in Table 2. Overall, we observed an equal distribution of L. delbrueckii, L. fermentum, and Leuc. lactis in the initial microbial consortium, while a progressive decreasing of Leuc. lactis was observed in the worm gut microbial community at the observed time points. In particular, only L. fermentum and L. delbrueckii were recovered from nematode lysates at 8 days of adulthood, with a prevalence of the L. delbrueckii species (28 isolates out of 34) (Table 2).

Bottom Line: Little is currently known about the mechanisms underlying the effects exerted by foodborne microbes.Altered expression of nhr-49, pept-1, and tub-1 genes, associated with obesity phenotypes, was demonstrated by RT-qPCR.Since several pathways are evolutionarily conserved in C. elegans, our results highlight the nematode as a valuable model system to investigate the effects of a complex microbial consortium on host energy metabolism.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.

ABSTRACT
The nematode Caenorhabditis elegans is widely used as a model system for research on aging, development, and host-pathogen interactions. Little is currently known about the mechanisms underlying the effects exerted by foodborne microbes. We took advantage of C. elegans to evaluate the impact of foodborne microbiota on well characterized physiological features of the worms. Foodborne lactic acid bacteria (LAB) consortium was used to feed nematodes and its composition was evaluated by 16S rDNA analysis and strain typing before and after colonization of the nematode gut. Lactobacillus delbrueckii, L. fermentum, and Leuconostoc lactis were identified as the main species and shown to display different worm gut colonization capacities. LAB supplementation appeared to decrease nematode lifespan compared to the animals fed with the conventional Escherichia coli nutrient source or a probiotic bacterial strain. Reduced brood size was also observed in microbiota-fed nematodes. Moreover, massive accumulation of lipid droplets was revealed by BODIPY staining. Altered expression of nhr-49, pept-1, and tub-1 genes, associated with obesity phenotypes, was demonstrated by RT-qPCR. Since several pathways are evolutionarily conserved in C. elegans, our results highlight the nematode as a valuable model system to investigate the effects of a complex microbial consortium on host energy metabolism.

No MeSH data available.


Related in: MedlinePlus