This week in Biofilms and Microbiomes: Monday October 3, 2016

A round-up of what we read last week in the media's coverage of biofilms and microbiomes research.

Like Comment

Honey may be a natural remedy to curb bacterial growth and inhibit biofilm formation on any surface including plastic, reports a new research published in the Journal of Clinical Pathology. The results hold promise in treating hospital bugs that cause infections via medical devices and tubes. In this study, researchers from the University of Southampton investigated the antibacterial properties of Manuka honey, a special type of honey produced in Australia and New Zealand by bees that pollinate the native manuka tree. It is highly viscous, and there is evidence it has been used in the past to treat wound infections. To assess the influence of honey on early biofilm formation, the researchers cultured strains of E. coli and Proteus mirabilis bacteria on vinyl plates in the laboratory. These two strains of bacteria are known to cause most of the urinary tract infections associated with long term catheter use in patients. The honey was diluted with distilled water and applied to the plates in 5 different strengths ranging from 16.7% honey down to just 3.3%. The results showed that Manuka honey considerably reduced the stickiness of the bacteria, and therefore the development of biofilm. This was true, even at the lowest dilution of 3.3%, where it curbed stickiness by 35% after 48 hours compared with a medium that did not contain Manuka honey. At 72 hours, all concentrations inhibited maximally, however, the greatest effect was seen at the higher dilution of 16.7%, when stickiness had been reduced by 77%. Bashir Lwaleed, an associate professor from the University of Southampton said: “This really opens a wide kind of usage for honey dilutions to be used as flushing agents for all of these medical devices that are inserted into the body. For example catheters, gastric tubes etc." However, further research is necessary to see if it can be duplicated in a clinical setting. The paper was widely publicized by media, including The Daily Mail, TIME, The Indian Express and The New Zealand Herald.

Another interesting research highlighted by media this week was published in Nature Genetics. The study, led by the University of Groningen Department of Genetics, has associated genetic loci and specific genes in human DNA to bacterial species and their metabolic signatures, suggesting that host genetics influence the makeup of the human gut microbiome. The research team performed metagenomic sequencing on 1,514 subjects and found a number of genetic variants that are linked to the microbial gut composition, including an association with genes involved in innate immunity. A three-stage association analysis was followed by a meta-analysis that drew upon three Dutch cohorts. The team conducted genome-wide analysis to examine associations between common SNPs and microbial taxonomies and functional units that were present in at least a quarter of the individuals. Through this, they linked 58 SNPs at nine loci to microbial taxa and 33 loci with functional units. The strongest taxonomical association the researchers uncovered was for the genus Blautia and the family Methanobacteriaceae and a region upstream of the LINGO2 gene, which is itself linked with body mass index, obesity, and motion sickness. Methanobacteriaceae, they noted, have been linked with BMI and lipid levels. The investigators also uncovered associations in the metabolism-linked genes - PLTP, APOE, and PPARG, thus indicating that the gut microbiome could mediate the link between host genetics and immunological and metabolic phenotypes. "Identifying associations between human genetics and the gut microbiome, and exploring their interactions, can provide insights into the role of the microbiome in complex diseases and drive the development of therapies to modulate the microbiome toward better health," wrote the University of Groningen's Alexandra Zhernakova and her colleagues in their paper.

We’d love to hear what you’ve been reading this week. Please comment below.

Richa Dandona

Partnerships and Operations Manager, Nature Partner Journals, Nature Research