Disturbances in gut microbiota homeostasis may have metabolic
consequences with potentially serious clinical manifestations. Diet
influences the host’s metabolic health in several ways, either directly
or indirectly by modulating the composition and function of gut
microbiota. This study investigated the extent to which dietary quality
is reflected in gut microbiota diversity in overweight and obese
pregnant women at risk for metabolic complications. Dietary quality was
measured by a validated index of diet quality (IDQ) and microbiota
composition was analyzed using 16SrRNA gene sequencing from 84 women
pregnant less than 18 weeks. The alpha diversity, measured as Chao1,
observed operational taxonomic units (OTUs), phylogenetic diversity, and
the Shannon index were calculated. The IDQ score correlated positively
with the Shannon index (rho = 0.319, p =
0.003), but not with the other indexes. The women who had the highest
dietary quality (highest IDQ quartile) had higher gut microbiota
diversity in all the investigated indexes, when compared to the women
with the lowest dietary quality (lowest IDQ quartile; p
< 0.032). Consequently, a higher dietary quality was reflected in a
higher gut microbiota diversity. The presented approach may aid in
devising new tools for dietary counseling aiming at holistic health, as
well as in microbiome studies, to control for dietary variance