Alterations in the Gut Microbiota and Metabolomics of Seafarers after a Six-Month Sea VoyageOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined how a 6-month sea voyage changed the gut microbiome and fecal metabolome of seafarers. It aimed to find risk factors and targets to protect their health. Fecal samples were taken at the voyage start (day 0) and end (day 180). Bacteria were profiled by 16S rRNA gene sequencing on the Illumina MiSeq platform. Untargeted metabolomics used liquid chromatography-mass spectrometry. Spearman analysis then correlated differential microbes with differential metabolites and human metabolic pathways.
Who was studied?
The cohort was 30 seafarers, all healthy males aged 18 to 35 years, sampled before and after one 6-month voyage. This was a preliminary pilot with a small sample size. The voyage ran from June to December 2017, with a uniform food and drink supply and limited fresh vegetables and fruit due to storage constraints. Each participant gave a fresh fecal sample at day 0 and day 180, stored at minus 80 degrees Celsius for sequencing and metabolomics.
What were the most important findings?
Beta diversity shifted significantly by day 180 (p=0.049), though alpha diversity did not change. Predicted folate biosynthesis and biotin metabolism, both B vitamin functions, decreased significantly. Of 880 fecal metabolites, 143 differed. D-glucuronic acid, proline, 2-hydroxycinnamic acid, and citrulline decreased, while acetylcholine increased. The pathogen Plesiomonas rose and correlated positively with acetylcholine, potentially acting on cholinergic synapses. Fourteen differential microbes linked to 6 metabolites across pathways including arginine biosynthesis (p=0.0016) and lysine degradation (p=0.0051).
What are the greatest implications of this study?
The work suggests long voyages induce gut dysbiosis that could affect B vitamin supply and metabolite-driven host pathways. Limited fresh produce may drive folate and biotin declines. Preventive steps such as reducing potential pathobionts, supporting probiotics, and supplementing B vitamins and beneficial metabolites via diet might help seafarer health. The study was a small pilot without blood biochemistry or imaging, and correlations cannot establish that microbes caused the metabolic or health changes.