The effect of gestational weight gain on serum total oxidative stress, total antioxidant capacity and gut microbiota.

This study aimed to investigate the effect of gestational weight gain on total oxidative stress (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), dietary antioxidant intake, and the gut microbiome. The study was carried out on 40 pregnant women divided as follows: a) normal prepregnancy weight and gestational weight gain of 11.5-16.0 kg (n=10) b) normal prepregnancy weight and gestational weight gain of >16.0 kg (n=10) c) obese before pregnancy and gestational weight gain of 5-9 kg (n=10) and d) obese before pregnancy and gestational weight gain of >9.0 kg (n=10). Serum TOS and TAC levels, dietary antioxidant intake, and microbiome diversity of the gut microbiome were evaluated during the third trimester of pregnancy. A positive correlation was found between body mass index (BMI) in the third trimester and serum TOS levels and OSI. In women with normal prepregnancy weight, an increase in the Firmicutes and Bacteroidetes phyla was observed when gestational weight gain was above the recommended values (p<0.05). In women who were obese before pregnancy, an increase only in the Bacteroidetes phylum was observed when gestational weight gain was above the recommended values (p<0.05). A positive correlation was found between Firmicutes/Bacteroidetes and OSI, and a negative correlation was found between Firmicutes/Bacteroidetes and dietary antioxidant intake (p<0.05). Prepregnancy body weight, high serum TOS level, and dietary antioxidant intake are determinant factors for microbial diversity, with increased serum TOS levels caused by increased gestational weight gain.