A recent study published in Nature by a group of researchers from the University of Groningen in the Netherlands investigated bacterial composition, function, antibiotic resistance, and virulence factors in the gut microbiomes of more than 8,000 people from 2,756 Dutch families. They correlated these microbiome features with 241 social and environmental factors including among others physical and mental health, use of medication, and diet. The authors concluded that the main factors shaping the human gut microbiome are the environment and cohabitation, whereas only a relatively small portion of the gut microbiome is heritable.
Graphical summary of the samples and available metadata
GACESA ET AL., 2022
The authors also observed that a healthy diet, exposure to pets and rural environments are positively correlated with beneficial commensal bacteria and negatively correlated with potential pathogens. On the other hand, smoking, a high-carbohydrate diet, and exposure to NO2 and small particulate matter (particles or droplets in the air that are smaller than 2.5 microns) are positively correlated with disease-linked microorganisms. The results also suggest that exposure to air pollutants has a negative effect on the gut microbiome and increases the risk of gastrointestinal infections.
...cohabitation and environment play a more important role in shaping the gut microbiome than genetic relatedness.
Furthermore, the authors found that the results of childhood exposures to various environmental factors may still be observed in adulthood. This implies that the early stages of the microbiome development have long-term effects on its composition and function throughout the individual’s life. For example, former smokers shared some microbiome signals with current smokers, although at lower levels. This means that a negative microbiome impact (e.g., smoking, exposure to pollutants) that an individual experienced in their childhood may follow them later in life which emphasizes the importance of forming a healthy microbiome in the first few years of life.
...a healthy diet, exposure to pets and rural environments are positively correlated with beneficial bacteria and negatively correlated with potential pathogens.
The authors conclude that despite a large amount of sequencing data analyzed in this study, they could explain only 15% of the variation in microbiome composition and function. Such a low explanatory power implies that the gut microbiome is highly individual and that it contains many rare microbial taxa that cannot be identified due to the use of database-centered classification approaches. The authors also suggest that application of database-independent methods will play an important role in disentangling the complex interconnections between the structure and function of the gut microbiome and various environmental and genetic factors.
Reference:
Humpenöder, F., Bodirsky, B.L., Weindl, I. et al. Projected environmental benefits of replacing beef with microbial protein. Nature 605, 90–96 (2022). https://doi.org/10.1038/s41586-022-04629-w
Comments