Population level evidence for seasonality of the human microbiome

Abstract

The objective of this study is to determine whether human body odors undergo seasonal modulation. We utilized google trends search volume from the United States of America from January 1, 2010 to June 24, 2017 for a number of predetermined body odors. Regression modeling of time series data was completed. Our primary outcome was to determine the proportion of the variability in Internet searches for each unpleasant odor (about the mean) that is explained by a seasonal model. We determined that the seasonal (sinusoidal) model provided a significantly better fit than the null model (best straight line fit) for all searches relating to human body odors (P <.0001 for each). This effect was easily visible to the naked eye in the raw time series data. Seasonality explained 88% of the variability in search volume for flatulence (i.e. R2 = 0.88), 65% of the variability in search volume for axillary odor, 60% of the variability in search volume for foot odor, and 58% of the variability in search volume for bad breath. Flatulence and bad breath tended to peak in January, foot odor in February, and Axillary odor in July. We conclude that searching by the general public for information on unpleasant body odors undergoes substantial seasonal variation, with the timing of peaks and troughs varying with the body part involved. The symptom burden of such smells may have a similar seasonal variation, as might the composition of the commensal bacterial microflora that play a role in creating them.

A global metagenomic map of urban microbiomes and antimicrobial resistance

“…Seasonal variation also remains open to study as the majority of the samples collected here were from two global city sampling days (June 21, 2016, and June 21, 2017). Further studies, some generating novel data, will need to explore whether the core microbiome shifts over the course of the year, with a particular interest in the role of the microbiome in flu transmission ( Cáliz et al., 2018 ; Korownyk et al., 2018 ).…”

Global Genetic Cartography of Urban Metagenomes and Anti-Microbial Resistance

“…Seasonal variation also remains open to study as the majority of the samples collected here were from two global City Sampling Days (June 21, 2016 and 2017). Further studies, some generating novel data, will need to explore whether the core microbiome shifts over the course of the year, with particular interest in the role of the microbiome in flu transmission (Cáliz et al, 2018;Korownyk et al, 2018).…”

Challenges in Human Skin Microbial Profiling for Forensic Science: A Review

“…This is due to human-associated microbiota existing on, within and around the body in a complex state of cooperation/competition with each other and their environments. Additionally, these microbial interactions are linked to many intrinsic and extrinsic factors, including nutrient availability [ 71 ], season [ 72 ], oral antibiotic use [ 73 ] and host diet [ 5 ], to name a few. When studied, microbiomes should be considered as ecosystems that require careful consideration from researchers regarding experimental design to limit confounding variables and enable the analysis of nuanced differences or associations within microbial community structures, or changes over time.…”