Long-Term Microbiome Studies Illuminate Gut Bugs’ Roles in Health and Disease
Emerging research continues to show that the microbes inhabiting the gut play pivotal roles in health and disease throughout life. Two recent studies highlight how gut microbiota affect their hosts over the long term.
The first, published today in Nature Communications, charts changes to microbial composition based on life-long caloric restriction. In it, Shanghai Jiao Tong University’s Liping Zhao, Ph.D., and his colleagues show that mice that were calorie-restricted on both high-fat or low-fat diets throughout their lives showed gut microbiota phylotypes that correlated positively with lifespan, such as Lactobacillus, as compared with their non-calorie-restricted counterparts.
“These calorie restriction-induced changes in the gut microbiota are concomitant with signifcantly reduced serum levels of lipopolysaccharide-binding protein, suggesting that animals under calorie restriction can establish a structurally balanced architecture of gut microbiota that may exert a health benefit to the host via reduction of antigen load from the gut,” Dr. Zhao et al. write.
While validation work is needed, the researchers suggest that such structural changes in the gut microbiota could be used biomarkers for the development of dietary anti-aging interventions.
A second study, which appeared online in Science this month, charts the stability of the human gut microbiota and how that changes in response to physiologic changes, like weight loss, over time. For this, Washington University School of Medicine Jeffrey Gordon, Ph.D., and his colleagues used low-error amplicon sequencing (LEA-seq)—an approach based on redundant sequencing of bacterial 16S rRNA genes—on fecal samples from 37 healthy adults, sampled two to 13 times up to 296 weeks apart. In doing this, the scientists took stock of the diversity of species present, finding that, on average, the volunteers’ “individual microbiota was remarkably stable, with 60% of strains remaining over the course of five years,” they write.
Dr. Gordon et al. also performed LEA-seq on four individuals samples during an eight- to 32-week calorie-restricted dietary study. They found weight stability to be a “significantly better predictor of microbiota stability than the time interval between samples,” suggesting that gut populations are more or less stable despite changes in diet and weight.
“Early gut colonizers, such as those acquired from our parents and siblings, have the potential to exert their physiologic, metabolic, and immunologic effects for most, and perhaps all, of our lives,” the authors concluded.
“Structural modulation of gut microbiota in life-long calorie-restricted mice” appeared online in Nature Communications July 16. “The long term stability of the human gut microbiota” was published July 5 in Science.