Effect of postnatal prebiotic fiber intake on obesity risk and insulin resistance in rat offspring exposed to a maternal obesogenic diet and low-dose aspartame.

Objectives

The objective of this study was to examine whether offspring postnatal prebiotic fiber (Pre) intake could mitigate metabolic risks associated with a maternal obesogenic diet plus aspartame (APM) consumed during pregnancy and lactation.

Methods

Following 11 weeks of obesity induction, female Sprague-Dawley rats (n = 42) were bred and then randomized to a high fat/sucrose (HFS) diet with water (control, CTR) or HFS with APM (7mg/kg/day in drinking water, APM) throughout pregnancy and lactation. From 3 to 12 weeks of age, offspring consumed a HFS or HFS+Pre (10% wt/wt) diet, resulting in the following groups: CTR, APM, CTR+Pre, or APM+Pre. Body composition, glucose tolerance, insulin sensitivity, liver triglycerides, and fecal microbiota were assessed in dams and offspring.

Results

In weanling rats, maternal APM increased hepatic triglyceride levels (P = 0.049), worsened insulin sensitivity, and altered gut microbiota beta diversity (P = 0.029). By 12 weeks of age, maternal APM showed minimal lasting effects on offspring. In contrast, postnatal Pre fiber decreased body weight and body fat percentage and improved glucose tolerance in males (lower glucose AUC during oral glucose tolerance test; P < 0.001). Postnatal Pre intake reduced alpha diversity (P < 0.001), altered beta diversity (P < 0.001), and increased the relative abundance of Bifidobacterium, Blautia, and Streptococcus in female and male adult offspring.

Conclusions

Overall, postnatal prebiotic fiber exerted a beneficial effect on male and female offspring body composition and gut microbiota and male glucose tolerance, whereas maternal APM consumption had modest and largely transient early effects on offspring.