Tools
Tools
Crost, Emmanuelle H., Le Gall, Gwenaelle 
ORCID: https://orcid.org/0000-0002-1379-2196, Laverde-Gomez, Jenny A., Mukhopadhya, Indrani, Flint, Harry J. and Juge, Nathalie
(2018)
Mechanistic insights into the cross-feeding of Ruminococcus gnavus and Ruminococcus bromii on host and dietary carbohydrates.
Frontiers in Microbiology, 9.
ISSN 1664-302X
Preview |
PDF (Published manuscript)
- Published Version
Available under License Creative Commons Attribution. Download (8MB) | Preview |
Abstract
Dietary and host glycans shape the composition of the human gut microbiota with keystone carbohydrate-degrading species playing a critical role in maintaining the structure and function of gut microbial communities. Here, we focused on two major human gut symbionts, the mucin-degrader Ruminococcus gnavus ATCC 29149, and R. bromii L2-63, a keystone species for the degradation of resistant starch (RS) in human colon. Using anaerobic individual and co-cultures of R. bromii and R. gnavus grown on mucin or starch as sole carbon source, we showed that starch degradation by R. bromii supported the growth of R. gnavus whereas R. bromii did not benefit from mucin degradation by R. gnavus. Further we analyzed the growth (quantitative PCR), metabolite production (1H NMR analysis), and bacterial transcriptional response (RNA-Seq) of R. bromii cultured with RS or soluble starch (SS) in the presence or absence of R. gnavus. In co-culture fermentations on starch, 1H NMR analysis showed that R. gnavus benefits from transient glucose and malto-oligosaccharides released by R. bromii upon starch degradation, producing acetate, formate, and lactate as main fermentation end-products. Differential expression analysis (DESeq 2) on starch (SS and RS) showed that the presence of R. bromii induced changes in R. gnavus transcriptional response of genes encoding several maltose transporters and enzymes involved in its metabolism such as maltose phosphorylase, in line with the ability of R. gnavus to utilize R. bromii starch degradation products. In the RS co-culture, R. bromii showed a significant increase in the induction of tryptophan (Trp) biosynthesis genes and a decrease of vitamin B12 (VitB12)-dependent methionine biosynthesis as compared to the mono-culture, suggesting that Trp and VitB12 availability become limited in the presence of R. gnavus. Together this study showed a direct competition between R. bromii and R. gnavus on RS, suggesting that in vivo, the R. gnavus population inhabiting the mucus niche may be modulated by the supply of non-digestible carbohydrates reaching the colon such as RS
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | cross-feeding,gut bacteria,ruminococcus,mucin,resistant starch |
| Faculty \ School: | Faculty of Science > School of Biological Sciences Faculty of Science > School of Pharmacy Faculty of Medicine and Health Sciences > Norwich Medical School |
| UEA Research Groups: | Faculty of Medicine and Health Sciences > Research Centres > Lifespan Health |
| Depositing User: | LivePure Connector |
| Date Deposited: | 07 Nov 2018 11:30 |
| Last Modified: | 14 Dec 2023 02:56 |
| URI: | https://ueaeprints.uea.ac.uk/id/eprint/68793 |
| DOI: | 10.3389/fmicb.2018.02558 |
Downloads
Downloads per month over past year
Actions (login required)
 |
View Item |