Overview
Desulfovibrio piger is a strictly anaerobic, Gram-negative, sulfate-reducing bacterium belonging to the family Desulfovibrionaceae within the phylum Pseudomonadota (formerly Proteobacteria). It produces hydrogen sulfide (H2S) through dissimilatory sulfate reduction and plays a role in hydrogen cross-feeding and sulfur cycling within the gut microbial ecosystem. While it serves useful ecological functions at normal levels, elevated D. piger abundance has been repeatedly associated with neurological diseases, liver disease, and inflammatory conditions, making it a context-dependent organism whose health impact varies with its abundance.
Classification
D. piger belongs to the genus Desulfovibrio within the Desulfovibrionaceae family, order Desulfovibrionales. It shares its family with Bilophila wadsworthensis, though the two organisms use different sulfur compounds as electron acceptors — D. piger reduces sulfate directly while B. wadsworthensis cannot. The genus Desulfovibrio contains multiple species found in various anaerobic environments, with D. piger being the most commonly detected species in the human gut microbiome. The strain GOR1 is the most extensively studied gut isolate with a fully sequenced genome.
Key Characteristics
D. piger performs dissimilatory sulfate reduction, using sulfate as a terminal electron acceptor and producing H2S as a metabolic end product. At physiological concentrations, H2S serves as a signaling molecule involved in vasodilation, cytoprotection, and anti-inflammatory responses. However, at elevated concentrations, H2S disrupts colonic mucus disulfide bonds, impairs butyrate oxidation by colonocytes, and compromises tight junction integrity — particularly the ZO-1 protein. The bacterium also participates in hydrogen cross-feeding, consuming hydrogen gas produced by other gut microbes, which can influence the overall fermentation efficiency and gas composition of the gut ecosystem.
Health Significance
The clinical significance of D. piger is increasingly recognized in neurological disease research. Elevated Desulfovibrio abundance has been repeatedly reported in patients with Parkinson's disease, multiple sclerosis, autism spectrum disorder, and colorectal cancer. In multiple sclerosis patients, elevated D. piger was accompanied by reduced microbial diversity and significant alterations in sulfur metabolism pathways. Preclinical studies have also demonstrated that D. piger increases hepatic steatosis and fibrosis in high-fat-diet mice while disrupting intestinal tight junction integrity. It is important to recognize that at normal physiological levels, D. piger likely contributes to healthy gut function through hydrogen cross-feeding and sulfur cycling. The transition from commensal to pathobiont may depend on factors including diet, host genetics, overall microbial community composition, and abundance thresholds. Monitoring D. piger levels may be useful as a dysbiosis marker, though interventional strategies for managing its abundance are still under investigation.