Microbe diversity stable in fiber-rich diet
By contrast, none of these 19 inflammatory proteins decreased in participants assigned to a high-fiber diet rich in legumes, seeds, whole grains, nuts, vegetables and fruits. On average, the diversity of their gut microbes also remained stable. “We expected high fiber to have a more universally beneficial effect and increase microbiota diversity,” said Erica Sonnenburg, PhD, a senior research scientist in basic life sciences, microbiology and immunology. “The data suggest that increased fiber intake alone over a short time period is insufficient to increase microbiota diversity.”
The study published online July 12 in Cell. Justin and Erica Sonnenburg and Christopher Gardner are co-senior authors. The lead authors are Hannah Wastyk, a PhD student in bioengineering, and former postdoctoral scholar Gabriela Fragiadakis, PhD, who is now an assistant professor of medicine at UC-San Francisco.
A wide body of evidence has demonstrated that diet shapes the gut microbiome, which can affect the immune system and overall health. According to Gardner, low microbiome diversity has been linked to obesity and diabetes.
“We wanted to conduct a proof-of-concept study that could test whether microbiota-targeted food could be an avenue for combatting the overwhelming rise in chronic inflammatory diseases,” Gardner said.
The researchers focused on fiber and fermented foods due to previous reports of their potential health benefits. While high-fiber diets have been associated with lower rates of mortality, the consumption of fermented foods can help with weight maintenance and may decrease the risk of diabetes, cancer and cardiovascular disease.